Re: (ET) Elec-Trak E20 fixing up and modifications (including Curtis conversion)

[Ben Carter <ibekoolman yahoo com>]

 David,
Thank you for the feedback! Thoughts/responses to some topics below.

>One thing I didn't see you mention is a main breaker or fuse between the 
>battery and the controller.  Do you have one?  If not, you really should. 
> 
>A good DC rated breaker could replace the original disconnect, though not 
>in the same location, I don't think.

A good question. I do have separate 250A fuses for both the motor 
controller and the PTO outlet, and these are called out in the circuit 
diagram. I suppose this is a good time to say that I never intended my 
previous message to be a complete "how to" for the DCMC conversion; I 
suspect very few people will be willing to completely gut their tractors 
and so my clean sheet wiring design may be of limited use.

>I looked at a couple of Happ controls, intended for arcade games.  They 
>aren't cheap, but 
>they seem pretty darn sturdy, even more so than the Curtis potboxes.

Very interesting! This never occurred to me, but it makes perfect sense 
that real arcade gear is sturdy because it's commercial moneymaking 
equipment. For fun and games, yes, but nobody makes money if it breaks 
down. I bet that stuff IS built tough!

>In the end, I decided I wanted to stay with a hand control
This seems like personal preference, though there are many times I need 
both hands to wrestle the steering wheel as steering at low speed can get 
quite difficult with a load in the bucket. That's a problem I've brought 
upon myself, though, and not really something that's an issue without a 
loader.

>I think of high pedal disable as requiring a return to zero after 
>powering 
>up the controller with the accelerator potentiometer set high, but that's 
>a 
>good use for it too.
I think we are saying the same thing - the armature cannot be powered up 
without the throttle starting out fully closed. This applies at initial 
turning on of the tractor, and thereafter at any time the motor is shut 
off due to a safety switch opening (e.g. seat switch) or the tractor's F/R 
directional switch being flipped, the throttle has to be closed (returned 
to zero/rest position) before the motor controller can be powered up.  

>The Curtis controllers don't have HPD built in?  It seems like basic 
>safety.  A couple of on-road EV Curtis-precursor series motor controllers 
>I 
>had 30-35 years ago (PMC DCC-96 and PMC-25) certainly had it.
Not my 1205, and I don't think the 1204 does either, though I could be 
wrong as it's been years since I researched the controllers. It's fairly 
easy to add one, though, as it just requires a single relay as long as the 
throttle potbox has the appropriate microswitch built in.


> FRONT LIFT TO WINCH CONVERSION
>I'll be keen to hear how this works out with the mower deck and other 
>front 
>accessories.  We've discussed replacements for the front lift many times 
>on 
>this list.
I've used it with the stock dozer blade and it was OK. I don't currently 
have any provision to prevent me from breaking something due to excessive 
pulling force; when using front attachments perhaps it would be smart of 
me to put in a length of decorative chain or something else that would 
break with too much force.
Unfortunately I don't have an OEM mowing deck - to mow with the ET, I 
adapted a spare E15 drive motor to an Allis Chalmers 42" mowing deck and 
it cuts quite well, though the blade tip speed is a bit low. I set it up 
in a hurry and pulled it behind the tractor for a season, using an 
Anderson battery connector I rigged up as the PTO outlet in the rear. I 
found that I don't like pulling the deck and I've been meaning for a long 
while now to convert it to front mount.


>One thing to watch out for with modular charging - before starting the 
>tractor, make sure all the battery blocks are actually charged! 
>If one charger bank fails and you don't notice, you'll be left with a 
>pair 
>of battery blocks that didn't charge fully, it at all.
This is a great point and not something I had really considered. I've long 
been kicking around ideas for battery and power usage monitoring - there 
are all kinds of smart devices these days which attempt to track actual 
power usage and other things. It has not been a priority, though, as my 
property is not big enough to go through a complete charge for pretty much 
any job, and so it doesn't seem worth the time and money to fit one of 
these devices.
That said, I did get a gaggle of cheap, tiny 8-segment LED type voltage 
meters/displays and have been meaning to mount 6 of them all together 
somewhere on the dash. Each display would be measuring one battery and so 
imbalances would be quickly known.

>Sounds like a huge improvement over the dim stock incandescent lights. 
They are super bright! And in my opinion the front headlights look great 
cosmetically as well. No more yellowed or cracked diffusers, now they are 
modern looking LEDs.

>A couple of years ago I looked at small LED light bars for mounting on 
>top 
>of the hood, or maybe on the grille, but I never followed through.  
>Fitting 
>them to the stock headlight buckets is much more elegant.

I realized I didn't have any pictures showing how they are mounted, so I 
added two pictures to the album. They were taken March 31, 2020 and are 
about two-thirds of the way down. Everything is in chronological order 
with the oldest pictures first at the top. I used silicone to "glue" them 
in to the stock locations. The little rubber pieces shown in one of the 
pictures were holding them level until the silicone dried. I had to remove 
both endcaps to make them fit, which also included removing the stock 
power leads. It was a bit ugly due to limited access but I managed to 
solder on new power leads without too much trouble.


>Those [bolt on battery connectors] work, but they're actually meant for 
>temporary use.  Crimp on 
>connectors are a better choice for the long term, especially with flooded 
>batteries.

Another good point I had not thought of - I found the bolt on connectors 
and moved on to the next engineering problem, without giving it a second 
thought. I will research these and see what makes sense of the various 
paths (hydraulic, hammer, bolt cutter, etc.). I would look forward to 
getting rid of these bolt on connectors as periodically some of them seem 
to loosen, probably due to heating cycles or jostling of the tractor 
moving.

Regards,Ben


  
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