My Senior design project - a "Swamp Thing" tracked vehicle clone

FrankTailor · Feb 17, 2021

Oh man! I'm jealeous! You are working on a great project. I have been currently working on my work project. Once I finish it, I will do something creative and post it here. I will work days and nights I promise.

Garauld · Feb 17, 2021

Yes, it has been a fun project. Yesterday, I installed the new grab rail for the passenger per the suggestion of my wife. Have a looky at the attached photo. I've been thinking more about adding gauges so I ordered new oil pressure and water temp gauges. I should have those in hand shortly. Now, what to do about a speedometer? I ruled out GPS-sensing speedos as they do not work well in the woods. I could mount a pickup and sense the driveshaft rpm to power a display. I took apart the old toyota dash display to investigate their speedo drive mechanism. Toyota used an air-core motor to drive the speedo pointer. This motor uses a pair of windings wound at 90° to each other. When a voltage is sent to each winding, the magnetic force generated by each coil turns the pointer relative to the voltage applied to each coil. There is a special IC chip used to drive these; CS8190 to be specific. It could take in a frequency signal from my driveshaft sensor and output the two voltages to a speedometer based on the pulse frequency. This could be one option if I wanted to reuse my Toyota speedometer. There are other options out there as well such as sending the driveshaft pulse train to a digital bicycle speedometer - I have one of those on order as well. I'll be in touch...

Kernopelli · Feb 18, 2021

Garauld said:
..... There are other options out there as well such as sending the driveshaft pulse train to a digital bicycle speedometer - I have one of those on order as well. I'll be in touch...

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There are some nice featured and attractive digital units available for offroad motorcycles also. Search digital motorcycle speedometer on Amazon and a number of brands and models are available

pmsmechanic · Feb 18, 2021

Kernopelli said:
There are some nice featured and attractive digital units available for offroad motorcycles also. Search digital motorcycle speedometer on Amazon and a number of brands and models are available

I ordered a wireless one to use on my tractor as a speedometer. It wouldn't send the signal through my fiberglass fender so I ended up getting one with a wire. It was easy to calibrate and now I know how fast I'm going. It doesn't work going very slow so an extra magnet or two is in order.

FrankTailor · Feb 21, 2021

Oh man! I'm jealeous! You are working on a great project. I have been currently working on my work project with TheWordPoint. Once I finish it, I will do something creative and post it here. I will work days and nights I promise.

ArlyA · Feb 21, 2021

FrankTailor said:
Oh man! I'm jealeous! You are working on a great project. I have been currently working on my work project with TheWordPoint. Once I finish it, I will do something creative and post it here. I will work days and nights I promise.

Is this a spam post??

jmc · Feb 21, 2021

ArlyA said:
Is this a spam post??

Good chance of it. Almost the same comment as a few days ago, but with a link to some irrelevant site this time.

jsaw · Feb 22, 2021

i used a bicycle speedometer on my homebuilt motorcycle . cheap and it works good

Garauld · Apr 13, 2021

Happy spring everyone. Now that the weather is getting nicer in upstate NY, I can get back to tweaking Snowzer. Over the past few weeks, I have been working on the dashboard gauges as well as the new LED speedometer display. Here's a photo of the dash prior to mounting the speedometer display. The digits will actually be mounted behind the dash metal and a cover plate with a colored plastic panel will hide the digits. I'll post another image once it is all powered up. Are the digits readable?

Left-to-right I have oil pressure, water temp, fuel level, and the speedometer. The dial is the auto transmission gear over-ride. The rocker switches the transfer case between high and normal speed ranges. The three leds above it show the high, neutral or normal position the transfer case was moved to. Finally, there is the rpm gauge. I left room on the left for another gauge which is undecided at this time. Any suggestion what to put there? Maybe manifold vacuum.