Anomie
Posts: 3364
Joined: 4/15/2005
From: Liverwurst, CA, USA
Status: offline
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quote:
ORIGINAL: AS-EE
You know this roll back issue with nitro is not an issue. If you think about it then you will realize that the servo controlling the throttle of the nitro engine's carb can also be used to control a drive shaft disk brake.When you let off the throttle the servo is actually returning to its normal position. By using this fact you can connect a rod to the servo horn that will engage a break shoe each time the throttle is let off of hence this will prevent the crawler from rolling back. Also it is completely unnecessary to have a generator to power the components. Simply use a lithium polymer battery which is light weight. Now the question may arise: How do I get 5 volts then? Well the answer is use a 5-volt regulator module. It can either be built or you can use this one here: http://www.robotmarketplace.com/marketplace_elect_other.html
Get the top one that costs $46.99.
I did think about the servo braking mixed with the throttle for a time, but while the truck is stopped, the worm will not allow any reverse motion. I also eventually decided to incorporate a mechanical coupling that can physically disconnect the driveline after the worm. A one-way bearing will keep the model stopped after it is decoupled. This would also allow for a separate reverse motor that can propel the model without interfering with the nitro engine's operation.
Where the electrical is concerned, I will still need to use some batteries, and I am working on a 3-output regulator for powering the microcontroller, stepper controller, and receiver. The stepper motor itself will be too high a current draw to use the gen, but everything else running off the regulator can be powered by it. There was a discussion of the Sullivan Genesys system in this thread some time ago, and it appears that system is capable of approaching 1 amp while still maintaining around 4v. If I were to use 2 such gens, the output should be satisfactory for operating everything short of the stepper and reverse system.
quote:
ORIGINAL: RC-Archer
Reiko, I agree that that Saito would be an excellent choice for an engine and would nicely complement your handiwork. You may have already discussed using an hydralic clutch (or torgue converter) and you probably would want to reconsider. I would try it using various shock oil weights to adjust the stall speed.
If you want to go ahead and use a centrifical clutch, then I'd would seal the clutch and make a wet clutch like high performance motorcycles use. The oil would keep the linings from burning and glazing.
The torque converter idea would solve a number of issues inherent in making this type of setup reliable. I have a couple of coworkers that have tried to help in working out a good starting point from which to experiment with different oil weights and blade pitches, but as of now I have not attempted to make one. If this coupling turns out to be a pain, I may go in that direction, and then use a one-way bearing to allow for electric reverse.
Also, making the clutch wet is a great idea. There would be no cooling issue, it seems to me, and the resulting life would be extended greatly. Thanks for the tip!
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~Reiko~ RCU Car Forums Moderator
http://www.rcuniverse.com/forum/m_377662/tm.htm
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All Forums >> RC Cars, Buggies, Trucks, Tanks and more >> RC Rock Crawlers >> RE: Nitro Rock Crawlers Only 
RE: Nitro Rock Crawlers Only - 
