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Trev-Dawg
02-11-2005, 06:35 AM
I know this sounds stupid but playing around with some old resistors and a ohm meter I found that I can make a Turbo have get this(Adj. Sensitivity) from what I found for falcon racing you put a 25ohm in the handle and a 4 ohm for the sensitivity pod. If any of you guys want to see this in action you can see me racing in the midwest in most if the series.

Intimidator#3
02-11-2005, 06:53 AM
can you post a pic,?
thanks
Kevin

Trev-Dawg
02-11-2005, 10:51 AM
Yea I am still working on the actual controller but I have a skematic that I will post shortly I am at school waiting for the scanner to open up. I thought of this at 10:30 last night so I hope to have it done by tonight.

Intimidator#3
02-12-2005, 07:02 AM
any pics yet :p

team burrito
02-16-2005, 12:32 PM
...it's two resistors running in parallel. The formula is (R1 x R2) / (R1 + R2); R1 is the base resistor & R2 is the adjustable pot. So, if R1 is 4 ohms & R2 is 25 ohms, the result is 3.45. Solder one wire to the full power band & one to the last power band before the brake band. Mount the adjustable pot somewhere on your controller (I prefer to bend the flap over the resistor straight up & drill a hole) & solder the two wires to the pot. You have a choice of clockwise or counter-clockwise adjustment, so check this with an ohm meter. Itís not rocket science, just stupid toy cars. :D

Foamy
02-18-2005, 12:55 PM
Originally posted by team burrito
...it's two resistors running in parallel. The formula is (R1 x R2) / (R1 + R2); R1 is the base resistor & R2 is the adjustable pot. So, if R1 is 4 ohms & R2 is 25 ohms, the result is 3.45. Solder one wire to the full power band & one to the last power band before the brake band. Mount the adjustable pot somewhere on your controller (I prefer to bend the flap over the resistor straight up & drill a hole) & solder the two wires to the pot. You have a choice of clockwise or counter-clockwise adjustment, so check this with an ohm meter. Itís not rocket science, just stupid toy cars. :D

Weren't we doing this in H.O. like 30 years ago???

Monty@B.O.W.
02-18-2005, 01:25 PM
This was the principle behind the MRC controllers with adjustable resistance in '67-68.

Caution: the variable resistor will take up a serious fraction of the total current draw, so use the highest wattage you can find! A 10 watt, for instance, will be toast with anything hotter than a homeset motor. For even a mere 2 amps, you'll need 25 watts! That can be one BIG pot... thats why the MRC used a slide contact on a second resistor the same size as the primary.

team burrito
02-18-2005, 05:04 PM
...yes, Foamy. I did it to Gary Beedle's controller, except he wanted double wires (what a pain).

to Monty: that's why I used the aluminum frame & 12.5W rehostat (same size as the brake pot). The frame acts as a nice heatsink; as for the rehostat getting hot, I never noticed (but I didn't put my hand on it either).

Trev-Dawg
02-22-2005, 11:50 AM
I have Pics!!! The design works well and it survived an endourance race too. ooh I know this isnt in the right post but did you guys hear that wayne bramble is going back to aussie land?

MikeWho?
03-02-2005, 01:12 PM
Originally posted by Monty @ B.O.W.
This was the principle behind the MRC controllers with adjustable resistance in '67-68.

Caution: the variable resistor will take up a serious fraction of the total current draw, so use the highest wattage you can find! A 10 watt, for instance, will be toast with anything hotter than a homeset motor. For even a mere 2 amps, you'll need 25 watts! That can be one BIG pot... thats why the MRC used a slide contact on a second resistor the same size as the primary.

I still have one of these(it is a red handle) and a non-adjustable(lime green)!!!!!

Trev-Dawg
03-03-2005, 06:25 AM
I was messing around with some resistors I had laying around I think they were a 7ohm and a 45 ohm and realize this the curve is not linear it looks like a hill. It will be down then go up to full resistance then back down to zero. Does anyone have any ideas to this delimea :D

Monty@B.O.W.
03-03-2005, 07:05 PM
Use two resistors of the same value, and approx. twice the resistance of the least sensitive setting you want. Anotherwords, if you want a controller that goes from 0 to 3 ohms, use two 6 ohm resistors. Just remember, that as the variable resistor approaches zero, it takes ALL the current - and you're using almost none of the resistance wire at that point, meaning less than rated wattage. Poof. Best, in this example, to limit the downside on the variable.

The limits aren't linear, but its the best you're going to get.

Remember, R1xR2 / R1+R2. Plot the curve.

If the variable, again in my example, is limited on the low side to 1 ohm, the total range will be 3 down to .84 ohms. Of course, in actual use, BOTH resistors are variable. The throttle response isn't linear either.

Bartx7000
03-08-2005, 10:01 PM
I belive that you need to put one leed of the pot on the wipper of the controller and the other on the full throtal tap of the resistor.
If you have it wire up with the pot on both ends of the parma resistor the car will be the slowes when it reaches the middle bands depending on the Pot resistance setting.

Trev-Dawg
03-09-2005, 10:18 AM
I dont think it would work i think the car would move at what ever ohm rating the pot was it it was 3 ohms the car would move at 3 ohms even when you are on the brake band I think unless you use a diode which I might do

Bartx7000
03-09-2005, 01:10 PM
Correct You would need to have some sort of switching device for the pot also.

Trev-Dawg
03-10-2005, 10:42 AM
ok I wil run a small micro switch or diode in the handle. If this works It will be good but then again who the hell cares when we have our difalcos.?? I still use my omni stick and continue to love it. But if anyone has a difalco that they want to sell could you get a hold of me.