ACCURATE SPEED IN A CAN
Watch Out Speedsters!
And Don't Leave Your 101 Sidestand Down!
INTRODUCTION
Get accurate speed indication in a historic-looking Corbin speedometer can. No actual, authentic Corbin parts are required. Looks just like (well, almost) an original Corbin speedometer, but it is entirely electronic.And its dead-on accurate.
Don't have a Corbin speedometer for your 101 or other Indian? Try this instead. Its easy to build and its dead-on accurate Did I already mention that? At least the digital LED display is.
This GPS speedometer can be configured to work with either 6 volt or 12 volt systems, or built for both voltages as instructed here. Great for 101's lacking a speedometer, or for any Indians with inaccurate speedometers. Great for both tank and dash mounting.
But before you get too excited, check if this thing is right for you. Jump to the section at the end of these instructions; see: "ADDITIONAL IMPORTANT INFORMATION" before you decide to build.
FORWARDING REMARKS
These instructions simply present and direct what was a first prototype build. There are things I would do differently on a second attempt. Please, take over now and further this with your own discoveries of component selections and build methods. I must say, though, that I avoided the use of many tools I have (lathe, mill, welders), and purposely built this with the least sophisticated tools to make it possible for as many as possible to follow and build one.
I identify the products I selected from U.S. retail sources and what I actually used in this prototype. You may find better selections searching on your own. Please share your discoveries! Builders outside the United States will probably have to do more extensive searching for substitutes, as well as deal with "inches" and "MPH."
During the build of this prototype I discovered problems and I thought of some better construction, all ideas I mention along the way, highlighting these with a bold "BETTER." Remember, this is a first build prototype, the purpose of which is find "issues." I found "issues."
I need to actually go to work in the morning tomorrow (Monday) to earn money so I can play with Indians. Thus, rather than let this blog post sit for another week, I'm releasing it now. Anything I think of later I'll post at the end section: "UPDATES." So check back if this thing interests you. I may have updates within a few hours or days. Its a work in progress!'
I WOULD LIKE TO PRESENT ...
This is the Indian that will receive my final Corbin GPS speedometer build as a tank mount. I would like to blog this build, and will in time, which has taken me over 2 years. My 101 Scout already has a mechanical speedometer. Hopefully I'll be riding it this "new" 101 this spring (2018). Its a custom build starting with a 741 frame (and engine), scaled up in length and height too, to be comfortable for a 6 ft. 3 in. rider like me. These old Indians feel so small! Indian probably did not envision such giant riders as me. With its extra frame/seat height increase and a 62 in. WB, it should be right for me. And its rake and trail increase hopefully will make it perform like a "bigger" 101. Details later. Its a 57 ci. BTW thanks to Jim Solberg and its been taking a lot of my time finishing and fitting. Lot's of nickle on this one. Note how I like to build on what are commonly called "gang boxes." These are tradesmens' rolling tool boxes. We use them at work. I stole one. While I have a lift. its great to start a build with a frame straddled over one of these. When its done, I pick up the MC with a forklift and slings.
TERMINOLOGY USED
"Indicator" = the needle or arrow pointing to the speed.
"Dial" = what some call the "face" plate.
THE FINISHED PROTOTYPE
Estimated parts budget: $600.00
No original Corbin Speedometer Parts Used.
100% electronic.
100% accurate.
_______________________________________________________
THE STEP-BY-STEP INSTRUCTIONS
PART A. Get the Guts and Make the Interface:
1. Buy an Autometer GPS speedometer. Be sure its a stated "GPS" model Autometer. It should cost over $200.00 and list price is $349.95. Beware, they offer the same looks in non-GPS models. Get either the black Model 1749 (maybe best because the indicator is already white for a black Corbin dial), or the beige Model 1849 (because you may like its looks as I do and want to use it mounted on a handlebar as-is).
Model 1849 GPS speedometer mounted on my TROG #15 racer, ridden in 2016 by my nephew Bryan Ames. Its a modified (45 ci) Indian 741. The Autometer is mounted to its handlebar in Autometer's 3-3/8 in. black cup No. 5204. Stop now and reflect: will this here do? Or do you want to proceed along the directions below which shall lead you into a more costly enterprise. Mirror and phone mount added for street use. Racers don't need mirrors because what you leave behind should be history.
Model 1849 GPS speedometer mounted (to the "Hollywood bar") on my 1946 84 ci, 4 speed Chief - a very special ride (the Kansas Chief - see earlier blog). Why a GPS speedometer? Because the original Corbin is a bit off at the higher speeds. Maybe just needs re-magnetization. For this ride, I want precision. And it comes cheap in an auxiliary Autometer (subject to motorcycle ignition modifications noted elsewhere).
The Dream Catcher was a gift from a daughter. Its important.
Best prices for the Autometers seem to be from Summit Racing in Talmadge Ohio where a model 1849 is currently selling for $287.97 and the less popular model 1749 for $309.97 (summitracing.com). If you use the beige model 1849 you will need to paint the indicator white. Use ONLY white artist's"gouache" for this because gouache is the most opaque paint with the least volume and has little weight. Use a fine, flat artist's (so-called "camel hair") brush and brush out long strokes. Repeat to build a thin, opaque and even overall film. Spray painting may work too, has to be matte, but the weight of the spray paint could be too much for the analog motor's torque. Notice how lightweight this indicator is. In this blog I illustrate with a Model 1849 ("antique beige") because its what I have in surplus. I use several Model 1849 Autometers on my Indians, each mounted to a handlebar in an Autometer cup, such as Autometer's 3-3/8 in. black cup No. 5204.
Model 1849 ("Antique Beige")
Model 1749
2. Remove the Autometer's bezel (there goes any warranty!). To do this, which is difficult, just slightly soften the plastic shell ("housing") with a hot air gun and then press a wide screwdriver into the housing directly under the bezel at the bottom of the speedometer (or top, depending on where you want the damage to appear in case you need to back out of this procedure) and start prying the bezel off the housing's widely flanged upper end. This will likely permanently damage the housing, but with extra care (= time + perception) some damage can be avoided. I tried overall compression with a hose clamp, socket wrench on the clamp and hot air gun and this did not offer any advantage. It seems you just need to start by pressing in at one point to reduce this diameter of the huge flange. Its a mystery to me how in manufacturing and in service repair they get this bezel on, and also off.
3. Remove the Autometer's indicator by pinching your fingers (thumb and index finger) tightly on its center and with determination of controlled strength pull upward. Then remove the electronic device along with its dial from its plastic housing by unscrewing the two black screws in back (save these for some potential later use). Now, remove the dial by unscrewing two screws on the face of the dial (save these screws for later use). Set aside these parts. Go to the craft section of Walmart and buy yourself some plastic bin organizers hobby jewelers use and save those fine screws there. Remove and safely save (!) the two LED display control rods with their springs. You will later have to drill new glass to accommodate these. Twist to take out the lamp. It can't be used because it will be in the way of some things and removing it reduces speed-depriving weight (
Two-Lane Blacktop, a Monte Hellman Film).
The Autometer's Dial Removed.
4. Buy a reproduction Corbin 120 mph speedometer dial. It
MUST be a 120 mph reproduction dial. I got mine from eBay seller "gordonwobert." If he has none currently being offered for sale, "message" him on eBay via "gordonwobert" and ask. But also check with Terry Marsh and other Corbin speedometer experts (such as J. Napielera) on availability. One thing seems important to me: you will be cutting a rectangular opening into the reproduction dial so such a cut into an "Indian" script logo may look really bad. Observe my dial example with no "Indian" script logo. Note how closely aligned the speed markings of this Corbin 120 mph dial are with the Autometer's dial. 60 mph aligns perfectly at their tops. I'll explain later how to deal with the small radial (bandwidth) discrepancy between the two dials at their start and end position markings.
5. Both dials are exactly the same diameter! Align the Corbin dial behind the Autometer's dial by aligning the Corbin's lighting arched cut into the Autometer's rectangular LED screen opening, as shown below. The far right and left ends of the LED opening should show identical positioning of the ends of the cut arc in the Corbin dial. Get this perfect! Now tape them together with paper masking tape in this position at the edges to hold this alignment.
Above: Perfect end-to-end alignment of the Corbin dial's arc lighting cut
into the LED opening of the Autometer's dial.
6. Tape the sandwiched dials down on a wood board for drilling and cutting. I illustrate with a cut-off scrap of black painted wooden shelving. Drill through
all the Autometer's holes into the aluminum Corbin's face using bits that exactly match the Autometer holes' diameters. You will next be cutting a rectangular opening in the Corbin face with a woodworker's chisel. If you do not have a woodworker's chisel narrow enough to fit the narrow left and right ends of the Autometer's rectangular LED display opening, then drill the corners using a drill bit of a diameter so the holes touch or almost touch at the narrow sides. Be very careful these bits do not cut beyond the rectangular perimeter due to drift. You do not want to enlarge the corners. Err on the inside as you can dress outward in time with a fine file.
7. Now cut a rectangular opening in the Corbin's face exactly matching the LED display opening of the Autometer. To do this neatly, use a very expertly sharpened woodworker's chisel. I used a British Marples chisel. Very carefully align the flat, non-bevel, side of the chisel with the Autometer's opening edge. Go around and around, aligning and tapping the chisel with a light mallet (a "mallet" is not a "hammer") to gradually cut through the Corbin's aluminum face. Too much at once in one area may distort the Corbin's aluminum. Take your time to achieve a precision result. Or fabricate a stamping die.
8. If you drilled the corners, and you should have used drill bits that make holes nearly touching, the small remnant of aluminum can easily be cut through with a utility knife.
9. Un-tape the sandwiched faces. Dress the edges of the rectangular opening with a very fine flat file taking care not to enlarge or round the corners. Any deviations from sharp 90 degree corners will be very apparent.
10. Paint the inner edges of the rectangle and the holes to eliminate the glint of light on bright aluminum. Use black artist's gouache because this is the most opaque paint with the least volume. Use a fine brush and avoided getting any on the Corbin's face as it is dead matte and will show. Take pains to be neat here.
11. You are now ready to install fake odometer and trip numerals in the round openings.You can buy and use pre-existing odometer numerals meant for restoring, like "1955 and later G.M. Passenger/Corvette Odometer Restoration Decals" from Southern Classic Chevy selling on eBay. But they are just very slightly too large for the Corbin's openings, though work well enough in a pinch. Perhaps you will be able to obtain better matching numerals. And you can print your own using fonts on a computer, printing with a laser printer on good paper as I explain further below. The same method illustrated below applies as well to any custom printed numerals you endeavor to make, and as I suggest you do. Immediately below I illustrate using the "1955 and later G.M. Passenger/Corvette Odometer Restoration Decals."
12. Select the numerals you want. Here, I chose 2,3,5,7,9 for the odometer and 000 for the trip meter. Use an Xacto knife (I used a surgeon's scalpel with a No. 11 blade) and cut the
numerals you want with a little extra paper from the adjacent numerals to
facilitate handling. Peel each from the backing and set aside ready to pick each up.
13. Mask an area for spray adhesive to adhere the odometer numerals. Use masking tape to hold the dial on cardboard for positioning vertically for spraying. And use the same tape to mask you adhesive area. Spray a couple light passes of 3M Scotch Photo Mount. This makes a powerful bond so only a light application is recommended in case you have to undo and redo your work.
14. Attach the odometer numerals. Hold each one, one-by-one, on a moistened finger tip face out or face up (the moistened finger holds the paper back to your finger without its backing adhesive sticking to your finger. While viewing the front of the Corbin face plate. bring your finger and the paper to the back of a hole and get it aligned as you slowly press it in place against the spray adhesive you just applied. This is a temporary sticking of the numbers at this stage.
15. Repeat the above masking, spray adhesive and numeral placements for the trip meter, only use paper, not tape, across the back of the odometer numerals you just applied as a means of masking them from additional spray adhesive. When all numerals are in place, the reverse should look like this:
16. Now apply strips of a thin and opaque backing to better fix the little numeral papers in place and prevent the speedometer lamp from illuminating them . While illuminating them may be considered to be nice by some, the Autometer's dial plate plastic support that surrounds the stepper motor's shaft obscures the odometer's center holes. If you look in there, you can see that probably the arc of plastic around the shaft that obscures the center hole may be cut away (after its removal) and the remaining ends may still adequately support the dial. So, you probably could make illuminated odometer numerals. However, below we will be installing a very low amperage DC-to-DC step-up converter to input 6 volts and output 12 volts. I am not certain this DC-to-DC step-up converter is robust enough to handle over a long term the amperage of an incandescent bulb. Another thing, this can will be crammed full with wiring and the bulb may need to be removed to get everything to fit. Strips of heavy duty aluminum foil sprayed with the photo mounting adhesive work well for this support and light-masking task. When finally backed with foil, if you press the numerals into their holes some from the reverse, you make make them appear less flat, and even appear like they were on an odometer drum - though this style Corbin speedometer used overlapping discs. Pressed in, the reverse should look like this:
17. Now the front should look like the below image. However, do not attach the analog indicator (the pointer) just yet! Keep in mind that attaching, removing, and re-attaching this plastic indicator will quickly wear out its grip on the speedometer's spindle. So do this very sparingly.
18. Much better is to print your own numerals if you can. Print a sheet or more of various colors as bars and numerals upon them. The colors should be a silvery gray with a yellowish tint - just like aged Corbin odometer disc colors. It will be surprising how dark a color you must print to come close to the color of those aged metallic discs. Of course, we can not print metallic silver. For color permanence and best appearance, print on Epson Ultra Premium Luster paper and use an Epson photo printer using Epson Ultrachrome K3 colorfast inks.
19. Use in Microsoft Word the font Bodoni MT at size 17 and space the numerals at 5 spaces. Then, some numeral sequences will match the odometer openings perfectly and you can simply cut a single strip, as I did (above) selecting numerals 92347. If you printed multiple random numeral sequences, you can slide the reproduction Corbin dial around to find a string of numerals that are aa good fit.This font has some characteristics that make many of the numerals appear to be the Corbin originals.
20. Finalizing the interface, you may consider now or later snipping the tail of the Autometer's indicator (which you must use as it fits the Autometer's fine spindle) to better approximate a 1928 year 80 MPH Corbin speedometer by snipping off its tail entirely, or to approximate somewhat the later "dovetail" Corbin indicators by snipping off just the Autometer's moon and leaving a stub. Autometer's indicator moon does block the LED display at high speeds. I'm holding of on this surgery until I firmly decide which way I want it.
21. You may install the Corbin dial now onto the GPS unit. However, the drilled reproduction Corbin dial will be needed again as a template. You could now use it where it is required as a template for drilling the glass for the two LED display control rods. Drilling the glass is explained way below but you can jump ahead of that step if you want.
PART B. Modify the Electronics:
22. The Autometer has a coaxial antenna wire. The stiffening of the coaxial wire at the connector exceeds the depth of a Corbin can. So install a 90 degree SMA (
Sub
Miniature version
A) adapter from DigiKey. Specifically, install a CONN ADAPT PLUG TO JACK SMA (Part ACX1249-ND, Location KF2213 (www.digikey.com). Turn it in the direction illustrated below, in the direction of the greatest distance from the inside of the can, or 90 degrees from where the antenna wire will enter the can via the drive coupling.
23. To convert the Autometer to 6 volt power operation, purchase an eBoot Module XL6009 DC to DC 3.0-30 V to 5-35 V Output Voltage Adjustable
Step-up Circuit Board (available from sellers on Amazon.com). You can find them on eBay too but note if they are shipping from China. Why wait? These are in stock in the U.S. Get two or more just in case. Maybe even get the 5-pack. Now adjust the eBoot Module XL6009 DC to DC to output 12 volts. Go get that big 6 volt lead acid battery from your Harley Panhead and, using alligator clip leads, supply the 6 volt power to the input spots at the corners of the eBoot Module XL6009 circuit board. Attach your voltmeter to the circuit board's output corners with two more alligator clips leads. Turn the tiny brass screw on top of the rectangular component on the tiny circuit board inwards (potentially up to 20 turns) until your measured output is 12.0 volts or more. I reached 12.05 volts and stopped. Once thus adjusted, it will tend to stay as adjusted.
6 volts in, 12.05 volts out. Simple. Tiny screwdriver required.
24. Now wire up with your alligator clips and give the 6 volt input a test. If the LED's light up, all is well. If the antenna is not connected, nothing more will happen and the LED display will inform you "NO ANTENNA."
25. Trial wire this Output Voltage Adjustable
Step-up Circuit Board, off of the Autometer for now, providing it with the soldered-on leads it needs (input and output) at its corners. Requirements are low amperage so use as fine a wire as you can get, such as 22 AWG (American Wire Gauge). Use stranded wire, not solid copper, for flexibility as you will have to cram some wire spaghetti into the small can. Stranded wire is also the preferred choice for crimped connectors as well as for the flexibility. But in a pinch you can use small gauge solid copper "bell wire" you may find in an old hardware store. We can't just make a quick run to Radio Shack anymore, like we did in the past, unfortunately, so the spontaneity of prototype building is gone. Here I have to hope you have the knowledge, skills and tools for fine circuit board wiring. Don't forget to floss!; oh, I mean flux! The Autometer's inputs are, from left-to-right, 12 v + / Ground - / 12 v + for lamp. We can ignore the lamp connection. In fact, that right lamp tab will need to be bent backwards to allow room for incoming motorcycle electrical system wiring. The + and - inputs require 16-14 AWG flat female disconnects, 16-14 AWG because each of these you will supply with three (3) wire inputs (+ and - accordingly). Three twisted 22 AWG wires make up a thick bundle (and should be fluxed and "tinned" with solder), hence you will need the larger 16-14 AWG disconnects. Be aware when buying these in store bubble packs the wire gauge indicated on the package. One input wire is the 12 volt converted from the eBoot Module XL6009 DC to DC 3.0-30 V to 5-35 V Output Voltage Adjustable
Step-up Circuit Board. The second input is direct 12 volts from what you will make as screw post terminals for connections direct from 12 volt motorcycle electrical systems. The third input wire is from a 12 volt test jack you will install in the can for temporarily powering the GPS speedometer from a lithium power pack for calibrations. Its also useful if you just want to run your GPS speedometer from an independent lithium power pack - which is OK - as they power for many hours. The ends of all these leads soldered to the eBoot Module or plugged in with female flat connectors will need terminal rings for screw post connections or soldered directly to the test jack. I'll tell you now, get tiny ring connectors for the upcoming
recommended Mar Vac Electronics. SKU 25788 TRW Cinch 3-140, 3 Position Terminal Block Barrier Strip (sales@marvac.com) or just snip the edges of the terminals to fit.
A Uxcell 5.5mm x 2.1mm DC Power Jack Socket Female
Panel Mounting Connector
shown with a 5.5 mm plug inserted from a lithium power pack.
26. Solder the + and - 12 volt input leads as one of the three leads bundled into the female flat connectors with terminations at an Uxcell 5.5mm x 2.1mm DC Power Jack Socket Female
Panel Mounting Connector. Now, 5.5 mm plugs from lithium battery packs are quite common. And if not provided with your lithium power pack a variety of conversion plugs are often provided to meet this standard. This jack you will put into the bottom plate of the can for connection of a lithium power pack during off-motorcycle testing and calibrations. The center pin is + and there is a soldering strap clearly connected to this center pin. One of the two ground soldering straps should be found with a connectivity meter. But it is essential that a 5.5 mm plug is inserted to cause a connection of the ground strap to the threaded base. Is that clear? Otherwise, the ground strap does not connect to the threaded base and to chassis ground.
27. When soldering the wires to the + and - straps of the Uxcell 5.5mm x 2.1mm DC Power Jack Socket Female
Panel Mounting Connector (yep, that mouthful was a copy/paste) insert the wires' twisted strands from the inside to the outside of the solder straps so ends do not touch and conflict. Give it a test for electrical functionality with your lithium power pack and volt meter or, better, plug in the flat female connections to the Autometer inputs and check that the Autometer powers up from the 12 volt lithium power pack. and jack.
28. Now adhere the eBoot Module XL6009 DC to DC 3.0-30 V to 5-35 V Output Voltage Adjustable
Step-up Circuit Board to the Autometer bottom circuit board. To do this I used a 100% silicone multi-purpose adhesive/sealant, and a weight. Many other adhesives may work as well. However, hot glue could be risky due to heat on the integrated circuit components. Place the circuit board so that the soldered corners are accessible in case of a need for re-soldering a wire as shown below.
Above: The connection tab for power to the lamp has been bent back because it interferes with wiring and the antenna cable coming into the can.
29. Now adhere a
screw terminal block for the wiring connections. I recommend the one
illustrated below, from Mar Vac Electronics SKU 25788 TRW Cinch 3-140, 3
Position Terminal Block Barrier Strip (sales@marvac.com). Adhere this to the eBoot Module XL6009 DC to DC 3.0-30 V to 5-35 V Output Voltage Adjustable
Step-up Circuit Board by bonding to the tops of the two BEC aluminum electrolytic capacitors. Initially do this with some thick, fast setting epoxy (shown below as black - 6 min. JB Weld). Epoxy does not bond well to plastic and this terminal block will be subject to leverage when attaching wires, so follow up by "potting" its underside and the top components of the XL6009 DC to DC using 100% silicone adhesive/sealant. Silicone bonds well to plastic.
(Above) Get yourself (or a pack of) Mar Vac Electronics SKU 25788 TRW Cinch 3-140,
3
Position Terminal Block Barrier Strip. Adding this fills a 2-1/4 in. can to the limit (well. build with some extra) and its isolation strips prevent contact with the back of the can bottom.
PART C: Fabricating a Reproduction Can:
30. Buy a DOM exhaust pipe adapter with ID: 03.0 in. and OD: 03.125-03.15 in. Keep in mind that the OD could be ground or sanded down or painted as thickly as needed to make small adjustments for a tight but removable bezel. A perfect piece of steel to use is product WLK-41973 from Summit Racing Company in Ohio. That is what I used and illustrate here.
31. Remove the huge and very well adhered label by first torching it to carbon, then taking off the remnant adhesive with toluene and a rag or paper towels.
32. I made my first cut at the top of the wide end, creating a cutting line about 3/8 inch down with split filament packing tape, split at the approx. 3/8 inch point. Trying to cut the pipe on a bandsaw did not work well. I did not have a big enough clamp and it was difficult to see the cut being made. Instead, clamp a right angle grinder in a vice and install a cut-off disc. Make sure its oriented to throw sparks downward. If your face hurts and hair is burning, turning it the other way in the vice. Slowly and with great care bring the work piece to the tool, turning and gradually wearing a groove around the circumference. Obviously, getting a neat cut depends entirely on the skill in keeping from tilting the pipe when cutting.
BETTER: Cut first at the start of the reduction curve, then measure up and cut at the top.
33. A Corbin cup is 2-1/4 inches deep. I measured this down from my first cut and marked the 2-1/4 area with dots from a Sharpie marker. I then used stretchable plastic black electrical tape to make a cutting guide edge a bit further down. This is to allow some extra metal because both cut ends will need some truing up by grinding. I cut at the tape edge. It is very critical that this speedometer can not be any less than 2-1/4 in. tall or the electronic components will not fit. It would be a good idea to err a bit over 2-1/4 in. tall. Read elsewhere and you will see. The prototype componets make for a very tight pack in a 2-1/4 in. can. If I were to do it again I'd make my can 2-5/16 in. in depth. No one will probably note you have a "tallboy" can.
34. Deburr and true each of your cuts on a stationary belt grinder, here the great Burr-King is used, removing excess metal to reach 2-1/4 inches tall. It is very critical that this can not be any less than 2-1/4 in. tall or
the electronic components will not fit. It would be a good idea to err a
bit over 2-1/4 in. tall. Did I already state that? If you don't have a belt grinder like this, you can deburr the inside with a fluted carbide bit on a Dremel tool and true the ends against a spinning sanding disc on an electric drill held stationary in a vise.
35. Now fill the slots with JB Weld SteelStik epoxy putty or a "plumbers" putty. But to keep your hardened fills from falling out, use a fluted carbide bit to cut bevels on the slots, both inside and outside surfaces, so that the putty "mushrooms" to help it stay in place. Pinch with thumb and index finger the putty firmly into place. It hardens quickly so maybe you will need to fill two slots, then mix again and fill the other two. When first firmly set, grind off the excess hardened putty from the outside using the stationary belt grinder and by final sanding, and reduce the excess on the interior, just enough to allow the Autometer to be inserted, using a fluted carbide bit on a Dremel tool.
36. Now make the drive cable connection. You can buy a reproduction threaded adapter. Or you can do what I did: fabricate one up. First thread together the following (left-to-right in the image below):
7/8-24 Permanent Bushing (Texas Pneumatic Tools Part TX-01008, Fulfilled by
Crowder Supply Co., Inc., Commerce City, CO. Shipped by Texas Pneumatic Tools,
Michigan (810-695-5733).
3/8 in. MIP Hex Nipple (Everbilt Brass Pipe product LFA-783, from Home Depot).
5/8 in. common lamp nipple nut.
37. Now, using the stationary belt grinder (a lathe would be better) round off the hex points on the 7/8-24 Permanent Bushing to achieve a perfect 1 in. diameter circle that fits snugly into a 1 in. diameter cardboard tube you obtained by buying a roll of Rustoleum LeakSeal Self-Fusing Silicone Tape, unrolling all 10 feet of the tape and throwing it out, retaining the valuable tube.
38. Slide the cardboard tube down over the 7/8-24 Permanent Bushing until one end reaches the outer edge of the brass hex (near the lamp nipple nut) on the 3/8 in. MIP Hex Nipple, remove the lamp nut, and cover all threads with tape because we are going to fill that tube with epoxy. Stand the assembly up with the 7/8-24 Permanent Bushing down on a level surface, and fill the tube with epoxy to the top of the tube. Use a slow cure epoxy of a fluid kind. You just can't pour this stuff. Instead, after mixing in a small cup, use a stick to deliver epoxy to the tape-protected threads of the 3/8 in. MIP Hex Nipple sticking above the open end of the cardboard tube. Each delivery of some epoxy will run down the tape and into the tube. Repeat until filled. Let it cure. Remove the cardboard with water and scraping. Finish with the stationary belt grinder and sanding to achieve a perfect transition to the rounded steel of the 7/8-24 Permanent Bushing. Be careful - the epoxy portion will be far more quickly affected by the belt grinder than the steel. Endeavor to retain an even cylinder and not make a cone!
BETTER: Install with epoxy a 1 in. OD metal tube over the 3/8 in. MIP Hex Nipple to match the ground 1 in. OD of the 7/8-24 Permanent Bushing and sand to achieve a flawless transition across the joint.
39. Drill the hole for inserting the end of 3/8 in. MIP Hex Nipple. Place the center of the hole 7/8 in. from the bottom of the cup. Deburr the inside edge of the hole with a fluted carbide bit on a Dremel tool.
40. Insert the end of the 3/8 in. MIP Hex Nipple into the hole using a circle of rolled JB Weld SteelStik epoxy putty or some "plumbers" putty to fill the gap between the flat side of the brass hex of the 3/8 in. MIP Hex Nipple and the curved surface of the cup. Draw it up tight with the lamp nut and trim the excess epoxy putty with a sharp knife. Sand the transition when cured.
VOILA!
The reproduction Corbin can with a fabricated drive cable threaded adapter next to a real (later) Corbin speedometer.
PART D. Preparing the Bottom Plate:
41. Procure or prepare a 3 in. diameter 1/4 in. thick bottom plate. The 1/4 in. thickness is for needed depth of threaded metal for the speedometer's mounting screws. You can obtain stamped 1/4 in. thick steel circles of different diameters, including 3 in., on eBay. However, I just cut my own using a bandsaw, cutting a little outside my marked circle, then adjusting down the diameter on the magnificent Burr-King until I got a nice fit into the can. For this prototype, though, I actually used some scrap rolled 100% zinc plate, 1/4 in. thick, that I had in the shop. Zinc plate, even aluminum plate, works fine and both are so much easier to machine than steel. Zinc plate of 1/4 in. thickness is very hard to find though. Its principally custom cast for use as dividing strips in the design of terrazzo floors.
42. Use an end mill (illustrated below) and recess the bottom surface for a flush or sunken mounting of the
Uxcell 5.5mm x 2.1mm DC Power Jack Socket Female
Panel Mounting Connector. The largest mill I had in the shop at the time was 1/2 in. A little larger would be better so you can get a socket in there to tighten the 3/8 in. nut on the connector. But a suitable socket is so close to fitting that a little grind/thinning of the socket's wall will make it fit. Drill and tap holes for the mounting screws for two different mounts: one pair 1-1/2 in. apart and the other pair 2-1/4 in. apart. Drill with a #21 bit ( 0.1590 in.) and tap for #10-32 brass mounting screws.
BETTER: Crap! The Uxcell 5.5mm x 2.1mm DC Power Jack Socket Female
Panel Mounting Connector did not fit when I tried to close the can by inserting the bottom plate. I now see it needs to be placed in the open space shown available in the photos below. OK, I had to remake the bottom plate anyhow. Keep in mind that if you use the 3-in. ID ring idea I mention later as a support of the bottom plate, that you cut out of the ring a space for this vertical connector. See: 43 below for more information.
43. Prepare a removable bottom plate. You will need to access the bottom of the electronics to attach the incoming positive & negative wires and the coaxial antenna cable. To attach the removable disc bottom plate I simply drilled and tapped the prototype for #6-32 brass screws into the can sides.
BETTER: install a 3 in. OD steel ring (many are available online) as an internal supporting edge for the bottom plate and drill/tap for bottom perimeter counter-sunk screws. The internal ring can be fixed into place by tack welds on the other (upper) side or by pinning with fine brass or steel wire nails hammered into drilled interference fit holes, snipped of excess and ground/sanded smooth. A cut will need to be made in this ring to accommodate the jack pictures above.
PART E. Drilling the Glass:
44.
BETTER: Learning curve here! STOP. See eventual Updates for the problems and possible solutions. The LED display has two control rods. These need to pass through holes in the glass. You will be drilling holes in the glass with a diamond core bit of a diameter 0.1225-0.1245 in. The holes this makes end up being a little larger and will tightly fit the diameter of the black plastic rods which are 0.1250 in. Here's how to locate those holes on the glass for drilling. Lay a strip of clear tape on the glass in the vicinity of the holes. With greatest precision you can manage, center the speedometer dial on the glass with the two rod holes over the tape. Hold the position by taping the dial to the glass with masking tape. This precision positioning is best done over a light box. Then dip the actual diamond core bit you will use on a stamp inking pad, center the bit in a hole and press to mark the drill position with this ink onto the tape. Repeat for the other hole.
45. Now drill the glass.You will need the glass in a shallow plastic container to hold water and so it will not slip around. Fill the container until water covers the glass by about 1/8 in. Water must also be touching under the glass. The water is there to draw heat away from the glass at the drilling areas and also helps to carry away particles from the holes being drilled. Lower the bit (not spinning) and precisely position the bit on your mark and try to maintain that position of the glass. Then, with the bit spinning, gently press the bit against the glass. Let the diamonds do the work. Do not press hard. Your hand advance is not to do work, but rather to follow work done. Repeat for the other hole.
Breakouts at the bottom of the glass! "Ka-Ching." But maybe not so serious. Correction ideas coming in this blog's "Updates." Like I said, a "protoype" is an opportunity for discovery.
PART F: Assembly:
46. See eventual updates. Its a really tight fit.
PART G. Exterior Finishing:
47. Spray paint. Maybe more advice later.
PART H: Calibration:
48. The 120 mph Corbin (original and reproduction) speed dial has its speed markings almost matching the placement of the Autometer's 120 mph dial. But not exactly. Like a broken clock that still is correct twice a day, your Corbin GPS speedometer's analog indicator will only be perfectly correct at one speed (the digital LED display of speed will always be perfectly correct). However, it can be fairly accurate to 10 mph over and to 10 under that correct speed indication. Thus you can enjoy fairly good accuracy of analog speed indication over a 20 mph range. You set your Corbin GPS speedometer for your desired 20 mph range of accuracy by installing the indicator at the midpoint of that range when the speedometer is operating. I personally want the best accuracy between 25 and 45 mph. So I installed the indicator on my GPS speedometer at 35 mph when the speedometer's LED display showed that I was actually traveling at 35 mph. Don't attempt this on a motorcycle. Do it in an automobile. And do it in an automobile with a driver to do the driving for you and an automobile with cruise control would be best. When the driver has reached the midpoint of the desired 20 mph speed range and the LED display confirms this, install the indicator on its spindle pointing at the same speed displayed in the LED bar. See the illustrations of accuracy of the analog indicator below where the indicator was installed at 35 mph. Note the accurate digital LED display of GPS speed and the deviations of the analog indicator. This "Corbin" speedometer does display 100% accurate speed (checked against several other GPS devices) but the analog indicator will require your memory adjustments.
25 MPH (Indicating 24 MPH)
35 MPH (Right On - Indicating 35 MPH)
45 MPH (Indicating 46.5 MPH)
55 MPH (Indicating 59 MPH)
65 MPH (Indicating 71MPH)
PART I: Installation:
49. Use needle-nose pliars to tightly route the coaxial antenna cable to its destination and use a 5/16 in. wrench to tighten it up. For an empty 5/8 in. Corbin speedometer drive housing for a tank mount check with Terry Marsh (eBay:
marsh1915hd). The electrical wires and the antenna coaxial cable could run through this. It is recommended that the wire crimp connectors be open ended so that you do not have to remove screws from the screw post connection block. If you have trouble with electromagnetic RF interference (EMI) blocking the GPS signal even though you have installed suppression ignition wiring (see note #2 below), you may need to cover the antenna with tinned copper braided.
ADDITIONAL IMPORTANT INFORMATION
1. My GPS speedometers based on the Autometer products work fine on several of my motorcycles on which they are installed and their accuracy is a pleasure to observe. Get one and your fellow riders with vintage speedometers will be constantly asking you "how fast am I going now?"
2. This GPS speedometer will NOT work on a motorcycle with solid copper ignition wires. Just don't even waste your time trying it. Solid copper ignition wiring will block out the GPS signal reception with its powerful electromagnetic RF (EMI). You must use suppression ignition wiring to avoid interfering with the GPS
signal. Get and install 8mm lacquered cloth covered vintage-style ignition
(but suppression) wiring sets from LowBrow Customs. Currently available in
"oak" with red and black tracers or black with red tracers (just
$39.95).
3. Next, antenna placement is critical. This is try-and-try. Placement as far from the coil and distributor would be best.
4. The GPS device's antenna consists of 16 feet of fine coaxial lead wire and a small block antenna with a very strong magnet. This magnet is so strong that it is hard to get around a room without it sticking to steel somewhere. On one bike it stays put sitting on top of the round, steel speedometer cup mounted on the handlebar. Don't cut to shorten this 16 feet which was provided for car routing. Instead, coiling is up has no adverse affects. Hide the coil somewhere. If using with saddle tanks, placement between the tanks is a good place.
5. There are three circumstances you will not receive a GPS signal (LED displays "NO SIGNAL"): (1) ignition electromagnetic interference; (2) under canopies, trees or other obstructions to direct access to the sky; (3) in some very rural areas or other areas with a weak GPS communication. Brief interruptions from trees and overpasses as you ride will not cause a noticeable interruption on signal acquisition. However, should you experience a long blockage and the speedometer LED display "No Signal," you may just have to turn off the power (shut the engine down) and start again. This has happened to me many times, especially when fueling at stations under canopies. I have learned to duck-walk my bike out from under a canopy after refueling before starting.
6. It can take the GPS sensor from 30 seconds to 120 seconds or more to establish a signal. Be sure you are not sitting under a tree. Therefore, its best to wire the GPS to ignition power rather than to "lights" so that you get a quick start on the signal acquisition process and use the engine warm-up time to get that signal connection. That way, you accurately take off in odometer recording mode. If you have to use an independent 12v lithium power pack for some reason, get in the habit of turning on your GPS speedometer as the first step in the start-up procedure.
7. Altering the Autometer product as we are suggesting here that you do will totally void its warranty. Worse, Autometer told me they will not even offer any services for repairs for your altered device. Even worse, Autometer told me they will not provide any technical information related to desired user alterations, hacking, or even provide an electrical schematic of the circuit design. I would like to see this hacked to adjust its motor to fit reproduction Corbin speedometer dials. I suspect it can be done. No fear! The Autometer GPS speedometer consists of three durable market-available components that are user-replaceable (if suitably skilled - if you have mastered de-soldering, have incredible eyesight or own a stereo-binocular microscope). All else in there are proprietary circuit boards for interfacing and controlling these components and would be expected to be durable. And the whole "shebang" is relatively cheap enough to toss and replace if needed. The Autometer uses a Condor family of GPS sensors, specifically the Trimble Model C1919C, Part No. 67650-20. The analog motor operating the speedometer's indicator ("needle" or "arrow") is the highly durable and common VID29 Series Stepper Motor. This motor has just four soldered connections. It is incredibly robust. It is fast and accurate with micro steps up to a twelfth of a degree! Finally, the LED display is a durable OSRAM SCE5782 (Super Red) 8-charachter 5x7 dot matrix intelligent display.
8. You can mark your dial with tiny dots for the true speed indications, such as at the common speed limits of 25, 35, 45, 55, 65 and 70 mph. Or mark a mph dial at kph speeds. To do this neatly, it is suggested you use Testors model enamel in silver and apply tiny dots of the paint with great care using the famous Winsor & Newton Series 7 Kolinsky sable brush in size 3/0 (or 000) available from online art art suppliers (such as www.dickblick.com).
9. One use for the Autometer lamp is for illuminating the dial for visibility when riding in the dark. One can drill tiny holes in the dial at, for example, the common speed limits noted in #8 above, or at common kph speeds. These will then light up like stars. However, for those using 6 volts, it is uncertain if the tiny eBoot Module XL6009 DC to DC 3.0-30 V to 5-35 V Output Voltage Adjustable
Step-up Circuit Board can handle the amperage draw of an incandescent bulb.
UPDATES
1. DISPLAY MODES: The LED display modes. Push the left control button (or "rod) to cycle through the following modes (the right one sets to zero or makes selections as pushed):
- Speed (current)
- Trip (miles)
- Trip (time)
- Odometer (accumulates)
- Location (Longitude and Latitiude)
- Hours ("engine hours")
- Display (briefly available choide of brightness 1-6).
- Time (current clock time)
- Heading (compass degrees) - this one got me out of confused country roads trouble once.
- Peak Speed (not sure if its current or since started or available peak speed).
Defaults to current GPS speed when restarted.
2. DRILLING THE GLASS: The "Scotch" tape on which was marked the two hole drilling positions did not last long under water. But it lasted just long enough for me to get the second hole started. Experiment with a longer lasting tape so you can take more time drilling. I may have drilled too fast as some glass broke out where the bit exited its drilled holes. This may not happen if the speedometer glass is resting on another piece of glass and one drills right though into this other glass - as we do when drilling wood and we want a clean exit. The diamond core bit measured to be 0.1225-0.1245 in. (nominally a 1/8 in. bit) made two holes which just fit tightly the two plastic LED display rods - too tightly. However, it was simple to shave these rods down by scraping with a utility knife blade (removed from its handle) until they would easily go up and down in the holes (these are spring-supported "push" controls and must be able to spring back up. My two marks were right-on and the two rods ended up operating well in holes tight enough to prevent dust and maybe some rainwater from entering. The two rubber buttons touch the glass when installed on the tops of the rods providing further sealing of the openings in the glass and are rubbery enough to compress when pushing on one to operate a rod.
3. PLACEMENT: For a tank mount (101 etc.) the fine coaxial antenna cable and the +/- current wires are to be run out of the can and through an empty drive housing (maybe Terry Marsh will supply these). The coaxial cable is 16 ft. long! Just coil up the excess and maybe hide that under the seas and place the magnetic block antenna on the rear fender behind the seat. It does need sky access but can be tilted. And it can be painted the color of your fender!
4. REPEAT: Important Repeat of No. 2 above under heading ADDITIONAL IMPORTANT INFORMATION:
This GPS speedometer will NOT work on a motorcycle with solid copper
ignition wires. Just don't even waste your time trying it. Solid copper
ignition wiring will block out the GPS signal reception with its
powerful electromagnetic RF (EMI). You must use suppression ignition
wiring to avoid interfering with the GPS
signal. Get and install 8mm lacquered cloth covered vintage-style
ignition
(but suppression) wiring sets from LowBrow Customs. Currently available
in
"oak" with red and black tracers or black with red tracers (just
$39.95).
5. WATERPROOF: For a tank mount, if you ride in the rain, have a quart size clear plastic bag in your pocket + a rubber band. However, I repeat from #2 above: "My two marks were right-on and the two rods ended up operating well
in holes tight enough to prevent dust and maybe some rainwater from
entering. The two rubber buttons touch the glass when installed on the
tops of the rods providing further sealing of the openings in the glass
and are rubbery enough to compress when pushing on one to operate a
rod."
5. HACKER WANTED: It would be great if someone could hack the Autometer's circuit to adjust the VID29 stepper motor so that it operates in the range matching that of the Corbin 120 mph speed dial. (https://guy.carpenter.id.au/gaugette/resources/vid/20091026113525_VID29_manual_EN-080606.pdf).
6. THE CAN NEEDS TO BE DEEPER! : I find that I need to mill the 1/4 in. closing base plate to recess some electronics so that the dial and speedometer indicator do not bulge up into the glass. So build you can (speedometer head) deeper.
