# Curtis 1238 Weak Brake at high speed



## AmpEater (Mar 10, 2008)

You might try switching the proportional brake regen off entirely and turning the neutral regen up to your desired range.

This is how regen works on the Tesla, and I like it. It avoids the need to switch pedals nearly so often, and with some finesse you don't loose your ability to idle, you just modulate the pedal so you're neither accelerating or decelerating. 

It also speeds up your reaction time because braking starts as soon as you let off the accelerator. 

Efficiency should go up a little too because you're not splitting the energy between electricity and heat.


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## evmetro (Apr 9, 2012)

When you put a meter on the brake pot, does the brake pot look smooth all the way from 0 to 5k?


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## fgcity (Mar 5, 2016)

Using the neutral braking as a main brake is not really a solution. Don't see how that would be efficient as you would always have to apply some throttle just to coast and would have no control over the braking at all.

The Pot on the brake is fine. I mean i calibrated everything to the point where the car is driving fine but i feel as if there is not enough braking on high speeds. I feel some braking but not something as powerful as when the car comes to a stop. 

The High Speed and Low Speed RPM's are defined properly and it seems that everything else is within reason. Maybe i am just being paranoid since if i do press the pedal a bit harder i do feel some power to the brake (probably the max regen power) just where the hydraulic brakes are about to touch the drum.

Perhaps the controller simply cannot brake that hard on high speed due to too much power going from the motor?


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## piotrsko (Dec 9, 2007)

My experiences on a forklift with Curtis controller: Regeneration can be set such that the bloody thing will throw you off the moment you get off the go pedal.


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## fgcity (Mar 5, 2016)

Don't know if the forklift can go up to 40 miles per hour but if it is possible then what can be the problem? Anyone?


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## mizlplix (May 1, 2011)

I am far from an expert on anything, but I have used the 1238 on 5 different motors and I have noticed one thing about regen....it is better on motors that use less field weakening.

So, that makes me guess that it might be related to back EMF.

Do you have a high or low field weakening setting?

Miz


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## fgcity (Mar 5, 2016)

I think i found the problem but will have to confirm.

Essentially i have the 1238 controller but the software i use is the 1314 which is floating on the web. I found that it will not have the settings i need to change the parameters.

I can sort of confirm this since i have the service manual for the car and the parameters listed there are nowhere to be found on the software. So i shall be purchasing the OEM handheld unit to do the tests as there are parameters for Low and High Deadband for the Regen which are not seen on the software i have for windows.


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## fgcity (Mar 5, 2016)

Does anyone by any chance have the latest software V4 which i can use? I have the USB cable and everything so just the software is needed.


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## mizlplix (May 1, 2011)

Please note: The VCL sets what is in the controller, not the hand held or computer software. If one version of the software could not read something, the newer one will not either, as it is not in your VCL. The hand held, new or old will not read what the OEM is hiding from you.

ALSO: The new version of the software uses and requires the new dongle to permit it to work. Your present hook up will not work with the new software.

I had to reflash my VCL to open up all parameters for adjustment. The OEM vehicle manufacturer writes their own VCL so they can lock you out of certain settings. My reflash utility was written by a third party and cuts off all of the non essentual settings as well as the communication to the spy glass. 

So, to get complete adjustability in your controller, you need a new VCL flash. (Which is written by a coder.) Just be careful having anyone play around and loading their own written VCL. You lose the old one and can not save it.

Certain Curtis dealers used to reflash open VCL for a couple of hundred USD. no idea who still does it now times.

Miz


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## mizlplix (May 1, 2011)

Please note: The VCL sets what is in the controller, not the hand held or computer software. If one version of the software could not read something, the newer one will not either. The hand held, new or old will not read what the OEM is hiding from you.

The old 1314 software does everything the newer one does, the newer one just has USB support and not serial like the old one.

ALSO: The new version of the software uses and requires the new dongle to permit it to work. Your present hook up (dongle) will not work with the new software. The newer software needs the chip set in the dongle in order to permit commumication to hand shake.

I had to have my VCL reflashed to open up all parameters for adjustment. The OEM vehicle manufacturer writes their own VCL so they can lock you out of certain settings. My reflash utility was from a past Curtis dealeer and cuts off all of the non essentual settings as well as the communication to the spy glass. 

So, to get complete adjustability in your controller, you need a new VCL flash. Just be careful having anyone play around and loading their own written VCL. You lose the old one and can not save it.

Certain Curtis dealers used to reflash open VCL for a couple of hundred USD. no idea who still does it now times. Call around.

Miz


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## fgcity (Mar 5, 2016)

Thank you for the reply. 

Seems odd that i would need to reflash VCL. I have the Service manual of the car and the parameters listed there are simply not present but they specifically state that you can change them and give the correct ones. 

Also things like Negative Field is in those parameters but i cannot find it even in my own settings. Not sure what to do at this point.


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## mizlplix (May 1, 2011)

Hmmm...Negative field is sonething I have never seen in Curtis parameters....
Cant really explain that, except to say that your OEM might have some things special to them. 

Not saying that you need to reflash VCL, just saying that a lot of things are readable but not changeable, that is the way I did it.

Like I needed to be able to adjust motor slip and it would change but when I exited the parameter, it would default back to the original setting. To make it actually changable, It needed reflashed.

If you do a search with my name, mizlplix, you will find a thread where I use the old Internet software and make my own dongle. my biggest problem was forcing the newer windows (XP and up) to find the port with the curtis communication active. It just connected one day and worked ever since.

I finally found that the hand held was faster to use and bought one. 

My good friend has the new factory software. That is why I know my homemade dongle fails to work. I emailed Curtis and got a factory engineer to talk to me. We talked over the course of several years. 
He was a source of good information as he was the teacher who taught their customers to write their own VCL variant and built his own EV.

If you ask, someone on the DIY site might rent you a handheld to try before you bought. Just a thought. Miz


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## fgcity (Mar 5, 2016)

Tnx for the reply. I already ordered the programmer so will have to see if something new will appear there when i connect it. 

I suppose if it doesn't then i will just have to live with it.


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