home made cruise control

[quixotic]

Made from UHMW plastic (ultra high molecular weight) from Lee Valley.  I think it's just teflon.  Works sort of like a guillotine.  The rough edges from the coping saw on the white bit work well, since a smooth edge would defeat the purpose (teflon is very slippery).  Seems to work fairly well.  Can be applied and de-applied with just the thumb of the throttle hand.   And for emergency stops, the throttle reverse is no problem.   Even for starting a cold engine, I like it a lot better than the tiny screw.  I put a small carabiner on it to attach to the mirror stalk, just in case I de-apply it a bit too enthusiastically on the highway.  

I may cut another white piece with the lower prongs sticking down another 1/4 of an inch (a little bit more friction).  

[Rob Valdez 79 R65]

I think this is one case where video is needed!

[quixotic]

I think this is one case where video is needed!  

Sounds like a plan.  GoPro on the helmet should work.  It may take a week or so, since I think I'll re-do the white portion with slighly longer prongs.  

[montmil]

I just snug up the screw on the twist grip housing that BMW fitted to hold a specific rpm for tuning and carb synch work.

Still, a nice little project. [smiley=thumbup.gif]

[marcmax]

My homemade cruise control is a bar end mirror and a slightly too long grip. Slight bump in on the mirror turns it on. Slight tug out on the mirror turns it off.  For me it has to be idiot proof.  
[smiley=ROTFLMAO.gif]

[montmil]

But Mark... Can you remember which way is "in" and which way is "out"?

With the throttle set screw, I have to attempt to remember which way to turn the twist grip

[Barry]

I heard some use a large O ring to produce friction in the narrow gap between the handle bar rubber and the switch housing. Never tried it though.

Did US bikes have the BMW throttle set screw fitted from the factory ?
Mine doesn't have one. I'd make one but the thread is not a common metric pitch.

[georgesgiralt]

Barry,
This screw is available new for quite cheap. I buy one now and then (i tend to loose them because I unscrew them too much, often).
The threaded hole is normally sealed with a white plastic cap. So the installation is easy : §Buy a screw, remove the cap, screw, enjoy.

[montmil]

The throttle screw is specific to the twist grip design in that there is a nylon tip on the threaded end of the throttle screw which will prevent damage to the twist grip tube.

That may be why BMW used an odd ball thread pitch.

[Rob Valdez 79 R65]

And you got to remember to remove the screw before you try to remove the throttle grip...  

(the screw will keep it in place!)

[quixotic]

Well it seem the GoPro works about as well as the Boyer ignition did (ie, like crap).  So here's a camera video of the unit controlling the idle speed:

http://www.youtube.com/watch?v=NfnP_tn6o_M&feature=youtu.be

[quixotic]

Gee, I finally found a computer fast enough to process the files from my GoPro

http://www.youtube.com/watch?v=szdCR8Zx_CY&feature=youtu.be

[Luca]

Looks to work quite nicely!  Cool stuff  [smiley=thumbup.gif]

What exhaust do you have on that bike?  I like the tone!

[quixotic]

What exhaust do you have on that bike?I like the tone!

I'm not too sure.  But the guy at Anderwerks who sold me the bike did say that it was aftermarket and stainless steel.  

[georgesgiralt]

I think that regulations mandate that maker's name and number to be stamped on the exhausts. You may check there for information...