Topic: Home brew speedo/tacho in one housing *UPDATE on page 2*

[davis96]

**UPDATE ON PAGE 2**

I've always had this idea and wondered if it would work logistically... The mechanism inside the speedo or tachometer is so small compared to the housing, I thought why not squeeze both into the same housing. It is similar to older cb350s etc etc, except it doesn't have a ginormous weird oval shaped housing. Its not done yet, but here are pics of the mechs put together and inside the housing, along with my design for the future face of the gauge.

started with the guts from the speedo and the tach:


made a couple stainless brackets to hold em together, and checked to make sure they'll fit in the housing:






and finally the soon-to-be face:

[Dimitri13]

Looks nice so far. Can't wait to see it running.

[Lars]

Liked it, too, keep us updated

[Chachi]

Yeah - looking forward to see how this works out.

[iron_worker]

Very unique and cool.

IW

[flybox1]

schweet! 

[RFogelsong]

Awesome idea.  Would you consider selling me a face like the one above when you get yours built? Also, what're you doing for needles? Cutting the old ones down?

[WhyNot2]

can wait for pics.....................definitely gonna be kewl.

[toytuff]

Subscribed!

tt

[Roach Carver]

Cool. be nice if the tach was the more prominent one as I am more concerned with my revs than my mph. Small issue and not a critique. Nice work and carry on!

[jackseattle]

sweet concept, nice execution, keep us posted

[Vinhead1957]

That is cool!

[lwahples]

Like it! Can't wait to see the end results.

[davis96]

Cool. be nice if the tach was the more prominent one as I am more concerned with my revs than my mph. Small issue and not a critique. Nice work and carry on!

I agree 100% I haven't run a speedo at all in years. I tried every way imaginable to have the tach on bottom and more prominent, but it didn't work. Its hard to explain, but the mechanisms only fit together this way. Oh well, at least Ill be able to see both. Still trying to work out a way to incorporate the innards of my oil pressure gauge inside.

[wowbagger]

+1 

[Ace2cool]

Just an idea, but what about reversing it vertically, like the 944 Turbo. Only problem I'd see with that is the odometer would be in the middle of the tach, but if that doesn't bother you (it wouldn't me) then it would be pretty cool.

[worlddrum13]

I LOVE IT. i have been interested in something like this as well.  this might be a silly question because i know nothing about the inner workings of a speedo and tach, but how would you calibrate the speedo mech to work with the new face?

[brewsky]

There are a couple different ways to calibrate the speedo, but any "new" face should have the same incremental degree measurements as the old, so the calibration holds true at differing speeds.

Here is one way to calibrate I have used with success:

Steps:

1. Ride bike at constant speed (I used 50MPH) and check actual speed vs GPS or other known correctly calibrated speedo riding with you.
(I used a hand held GPS zip tied to the steering damper

2. Note the difference. (When my speedo said 40MPH, my GPS indicated 50 MPH actual)..10 MPH off!

3. Dissamble the speedo.

4. Connect the bottom end of the speedo cable to a reversable drill, run the drill wide open (in reverse) and note the indicated speed on the speedo. (my speedo indicated 38 MPH with the drill running wide open)

5. Rotate the tab on the needle spring stop to either increase or decrease the tension on the spring.
(since mine was reading low, I needed to decrease the spring tension)

6. Re-run the drill and see if the new max reading on the speedo is increased (or decreased) by the same amount as the original error. (My error was 10 MPH, so the new drill max reading should be 48MPH on the speedo instead of 38MPH.) This is a trial and error process.

7. Repeat 5 and 6 if necessary.

8. Reassemble and reinstall the speedo.

When I rechecked the bike on the road against the GPS, it was dead on the money.

Note that when choosing a "correct" speedometer to check against to begin with, the speedometer on most cars and motorcycles are at least 5 to 7 MPH off at 60 MPH even when new, so GPS is best to use.

(I now check with "Speed View", a free app for android phones, which gives accurate speed info)


Another method is to just re-position the needle on the shaft to make up the difference between actual GPS and indicated speed.

[HondanutRider]

Sounds like some great tips for the mechanical style of speedo gauges.  A lot of newer machines use electronic pickups to drive the gauge instead of the cables.  This is the case on my regular ride, a 2003 Goldwing.  On it the speed indicated is always optimistic; something deliberately done by the manufacturer on most new machines.  An indicated road speed of 100kph is only 94kph on the GPS.  (Try telling that to the other half on the pillion, banging me on the back. )

I wonder if disassembling the gauge and tweaking the spring similarly would be a solution.  Otherwise, there are electronic black boxes that are sold to alter the pulses and "fool" the gauge into reading something else.

[davis96]

Just an idea, but what about reversing it vertically, like the 944 Turbo. Only problem I'd see with that is the odometer would be in the middle of the tach, but if that doesn't bother you (it wouldn't me) then it would be pretty cool.

Well the odometer is attached to the speedo so it always has to be on top of the speedo needle. If I flipped the whole assembly the numbers on the odometer would be upside down. The only way it world work would be to run the tach upside down which technically would work but the OCD in me can't stand to see a needle move right to left or up to down. I'm still working on it but I believe I have come up with a way to integrate a mechanical oil pressure gauge in the housing so this could get good

[davis96]

So here's a bit of an update on where I'm at for the double gauge I'm building. I thought I could integrate my oil pressure gauge into the assembly but after much consideration I decided against it.

I became sidetracked when I relocated the oil psi gauge down near the points cover... I decided to combine the oil pressure gauge mount with a little point cover window because I've always liked being able to see the points moving and watching them spark at night.









The ring I used is some sort of wheel spacer I found at the local Napa parts depot. Obviously I cut a hole in the points cover. Sandwiched between the ring and the chrome cover is a circle cut from acrylic. I soon learned keeping the acrylic flat it would contact the shaft on which the spark advance mechanism mounts. So I heated up the entire assembly in the oven and molded the acrylic over a convex form (a glass headlight projector).
*When judging my craftsmanship, do note that I was limited by the fact that my angle grinder #$%* the bed a week ago, so I wasn't able to clean up my welds or make precise cuts in thick steel of the gauge bracket. 
I haven't decided whether I like it or not, but I'll keep it for a while and see how it suits me..

Back to the task at hand.
I have the housing almost complete and the acrylic for the face cut and fitted.




I finalized the design for the gauge face, and grabbed two little white LED strips from Wal-Mart which should light this bad boy up nice and bright.


Still left to do:
- Final paint/fit/finish work on the housing
- Make a decision on how to print the graphics for the gauge face... My inkjet printer isn't going to cut it, but finding a capable printer locally is tough because I'm not quite sure what exactly I need.
- If I ever plan to actually use the speedometer function of the gauge (and since I haven't run a speedo in quite some time) I'll need to source a cheap speedo cable as well as:
The wheel-side speedometer drive

AND the helical gear from inside the speedo drive housing

I can't remember why I ditched my old stuff or where it is now... Anybody out there got these bits laying around and want to donate?

I'll keep youse guys posted
-Davis

[davis96]

Awesome idea.  Would you consider selling me a face like the one above when you get yours built? Also, what're you doing for needles? Cutting the old ones down?

Well it has taken a hell of a lot more work than just the gauge face, so you'd have to figure out all the inner working stuff and get it all to fit. If you get all that stuff sorted I'd be happy to send you the Adobe Illustrator or PDF file of the face design if you want it, but who knows if it would actually fit your setup.

As for the needles, I reckon I can run an unmodified needle on the speedometer portion, but for the tach I'll have to shorten the needle a bit

[seanbarney41]

Davis...I usually only care about stuff that improves performance...but that is some ingenious #$%*...nice job

[mrrch]

Some nice at home engineering, I like it.
True meaning of hand crafted.

[RFogelsong]

Awesome idea.  Would you consider selling me a face like the one above when you get yours built? Also, what're you doing for needles? Cutting the old ones down?

Well it has taken a hell of a lot more work than just the gauge face, so you'd have to figure out all the inner working stuff and get it all to fit. If you get all that stuff sorted I'd be happy to send you the Adobe Illustrator or PDF file of the face design if you want it, but who knows if it would actually fit your setup.

As for the needles, I reckon I can run an unmodified needle on the speedometer portion, but for the tach I'll have to shorten the needle a bit

Yeah, based on your pictures I think I can probably reverse engineer or copy the vast majority of the innards, but taking the time to draw up a face plate from scratch when someone else has already done the same setup seemed a bit redundant to me, so yeah, I'd definitely be interested in the PDF and Illustrator files for that. 

Also, on your points cover, there's a guy making some very similar to what you've fabricated if you decide against your design...frankenbike is the name I think, he's around here somewhere.  His cover has a bit more standoff so that the plexiglass can be flat.  It's made of some type of plastic or resin based stuff though so fabbing a mount for your oil gauge could be problematic.