Demon Pro-King speedo

[stegger]

Demon pro king can't remember or find the specs for this and would love to run this in a re-issue RC10. Would a Lipo be ok powering it ?
Anybody got a copy of the manual ? Cheers

[racingdwarf]

I wouldn't get a lipo anywhere near it

[minimini]

if you want to run Lipo with brushed motor..... Tekin FX Pro would be more safe......

[dodgydiy]

never had a manual with mine when i bought it, still have one of these working. i doubt the bec will take lipo as it was quite weak anyway, often blew the bec transistor on mine until i started using 4 wire servo's. so unless you want to modify the bec by changing components i wouldnt try it. novak international works though! (probably still not a good idea!)

[bluewormx]

Originally Posted by stegger

Demon pro king can't remember or find the specs for this and would love to run this in a re-issue RC10. Would a Lipo be ok powering it ?
Anybody got a copy of the manual ? Cheers

Hi, I might be able to answer this question. In mind I had two of these back in the 80's and I was 15 at the time.

The Pro-king went through a few upgrade in its lifetime. It came in a sealed plastic bag with a small photocopy instructions. One pot was neutral the other was Gain. similar to what Novak had also.
Bare in Mind Nick Adams (Mr Demon) was one of the fathers of the electronic speed control whose designs are prior to all of the American designs by Tekin (Kevin Orton) and Novak (Bob Novak).

It originally, as far as I know, had eight BUZ11 fet's rated at 30Amps each for a total of 240Amps continuous current. 720Amps peak.
With a total resistance of about 0.005 Ohms.
The dynamic braking was handled by a power transistor TIP 36A, 25Amps continous, 40A peak.

The King was the same except that it had 6 fets instead of 8. rated at 180A continuous, 540A peak.

All these values are theoretical since all the power went across the NC (normally closed) contact of the reverse relay which I doubt was rated as high as the FETS.
There was therefore a large performance boost on forward only versions which simply removed the relay and hard wired the contacts on the PCB.

The first thing to receive an upgrade was the weak brake transistor, the nasty little clip on heatsink was removed and another TIP 36A was shoe horned in parallel to the first doubling its power, up to 50A continous, 80A peak.

I believe that later versions received upgraded FET's perhaps IRFZ40 which would have boosted the spec to 400A continous.

Basically this speed control was in line with the Novak 1 (not T1) slightly superior because of extra 2 fet's but crippled by reverse relay and brake transistor, and larger size.

Nevertheless Jamie Booth used one (FWO) to great effect in 1986 Euros and in 1987 worlds. If I recall I saw him still using it in his RC10 at an event at Eden park in 1989 or perhaps 1990.

Please take everything I have said with a pinch of salt since I am no expert and I am basing this on very hazy memories.

As far as I know the BEC was fine with the servos of the time: Futaba S131-s; S131-SH; S132-H (1/12th).
Newer servos are still new to me, since I have just started to race again after almost 27 years away.
It is rumored that Savox servos draw a lot of current, I have the equipment to measure this but not the servo. So oh well!

Anyhow If anyone is willing to part with a Demon proking or king, working or not I am looking for one. Add in WANTED section.
http://www.oople.com/forums/showthread.php?t=185941

I am trying to make a replica of my own car from 1988.

http://www.rc10talk.com/viewtopic.php?f=35&t=40779

Here is a Demon 2C from 1981 that I am restoring. This is from a time that fet's were not available and the only racing class was 1/12th
This speedo probably spawned the later 2DH which was a more robust buggy version prior to the proking.
http://www.rc10talk.com/viewtopic.php?f=78&t=41162

[daz75]

Oh my God I remember those