Re: (ET) Curtis controller mod

[Kim Petty <kim coveside net>]

        This winter I was able to divert an E20 and an I-5 from the scrap 
pile . Both have been fitted with Roberts basic design and coaching. I 
bought a used curtis 1204 on ebay for $170. and had a PB6 potbox  for the 
foot throttle on the E20 . For the I-5 I used a  Taylor Dunn(curtis) 
controller with an electronic foot throttle from a fork lift that I had on 
hand . The biggest head scratcher on that one was figuring out the 
connection between the controller and the throttle unit. That controller 
has only one throttle spade( instead of the two with a potbox)and a KSI 
spade . The throttle has four wires. Anyway, I did find a fork lift wiring 
diagram with the right color codes and it is working as it should. If 
anyone else gets into that situation I may be able to shorten your 
learning curve. 
        The addition that I made to this system was a DPDT switch operated 
field weakening Hyperdrive. I used a stock field card and since I didn’t 
know which combination of resistors would be the most useful I wired a 
rotary s/w to put 1,2,or 3 resistors in line on the field circuit.  I am 
about to start the mowing season today with the I-5. I am not sure yet but 
I think I will end up mostly using the tractor in fieldweakened mode with 
2 resistors in line and switching to full field voltage if I need it. I 
will certainly know more after a few months of use. It is nice to have the 
faster speed available and with the curtis creeping is always an option . 
Kimball
> On Apr 28, 2016, at 9:27 AM, jlantonucci comcast net wrote:
> 
> I agree completely.  If you are going to buy a new controller - buy an 
> Alltrax made for our tractors.  I was one of those guys who got a free 
> replacement after it was long out of warranty.  My E-20 with an Alltrax 
> was a beast.  I also agree you should rewire your tractor.  I never 
> understood why people live with 40 yr old relays and mouse chewed wires 
> and expect their machines to be reliable.
> 
> T-Mobile. America's First Nationwide 4G Network.
> 
> ------ Original message------
> From: Robert Troll
> Date: Thu, Apr 28, 2016 8:37 AM
> To: elec-trak cosmos phy tufts edu;
> Subject:Re: (ET) Curtis controller mod
> 
> > I think Robert Troll made a wiki on Curtis controllers, but again my> 
> > memory is not notably reliable.>> --CharlieIndeed I did. The full 
> > detailed plans list should be out there, shoot me an email if you want 
> > to know more. The Curtis 1204 with high pedal disable works just fine 
> > with the ET motors, and was made for permanent magnet motors. It has 
> > not even gotten remotely warm in the few years of use that i have 
> > gotten out of it. I was not the first to use this setup, i just came 
> > up with a simple analog safety ckt to control the field and make sure 
> > that the field always has power before the armature. No need to use 
> > any relay for reverse, you simply reverse the field using a switch. 
> > Varistor prevents back voltage, and 4a fuse prevents over current.  I 
> > did this because when i went looking for info how to install a 
> > controller i got lots of "Yeah no problem, or at least it should 
> > work." type of answers. One of two people had working designs, but did 
> > not have automatic safety's or were using home brew control boards. I 
> > also had a few hucksters try to sell me controllers with "special 
> > programming" for only $900. It was a good exercise and learning 
> > experience that i am very satisfied with and i learned a lot about 
> > controllers and the ET's.The Alltrax DCX-300 is a replacement for the 
> > Curtis with the addition of a field controlling ckt. 4QD controller 
> > will also work (must add field control ckt) and give you the benefit 
> > of regen. A few people have complained that the Alltrax cannot be 
> > rebuilt. This is BC the alltrax encases their ckts in epoxy for 
> > durability (think golf carts). The curtis is rebuild-able by most golf 
> > cart shops for a few hundred. On the other hand i hear that the 
> > alltrax warranty is fantastic and they often do courtesy replacements 
> > long after the warranty is up.Here is what it comes down to for me. Do 
> > you have a curtis lying around that is not being used? If so you are 
> > looking at around $50 in parts to build the field ckt. The cost of the 
> > ET specific alltrax is $450. I would not go out any buy a new curtis, 
> > or used one, unless it could be had for under $200. If not then give 
> > Jim or Harold a call and buy the Alltrax. The ET specific alltrax 
> > controls the field natively, and will reducing the wiring down to 
> > almost nothing. I would also gut and rewire the tractor, rather than 
> > retrofitting the controller. I never saw the point of putting a new 
> > controller in with original wiring all over.  I have heard from 6 or 
> > so people who have installed the curtis using the ckt i put out and 
> > they are all happy. These are just my thoughts, your mileage may 
> > vary._______________________________________________Elec-trak mailing 
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