Paul & Sabrina's cheap DIY 144v motor controller

[Daox]

Nice work! I'm very jelous of the mill. I've been wanting one of those for ages.

[brihoo2k]

Nice work Paul also thats a sweet mill. I also have a mill but it is a speedway series mini mill that I got from homier for considerably less but is perfectly capable of doing everything I need it to. I also have a speedway series 7"x12" mini lathe. These mini machine tools sold by homier, harbor frieght, commings, grizzly were all made by the same company in china. There are tons of upgrades that can be done to these machines like turning them into cnc or making a dro out of a set of cheap digital calipers. Also I would sugest getting a set of collets for your mill as that jacobs chuck is better suited for drilling action than side force put on it from milling. Im looking forward to seeing your progress in the pwm controller.

[MPaulHolmes]

Originally Posted by brihoo2k

Nice work Paul also thats a sweet mill. I also have a mill but it is a speedway series mini mill that I got from homier for considerably less but is perfectly capable of doing everything I need it to. I also have a speedway series 7"x12" mini lathe. These mini machine tools sold by homier, harbor frieght, commings, grizzly were all made by the same company in china. There are tons of upgrades that can be done to these machines like turning them into cnc or making a dro out of a set of cheap digital calipers. Also I would sugest getting a set of collets for your mill as that jacobs chuck is better suited for drilling action than side force put on it from milling. Im looking forward to seeing your progress in the pwm controller.

Thanks! I looked up collets on Ebay.

Collets!

Do those look OK? I have an R8 spindle. Also, what else do I need? It seems like those go inside something that clamps them around the mill bits. All my mill came with was that "jacobs chuck" (I didn't know it had a special name). Thank you for your help! I'm definitely making this thing a CNC later. Holy cow it's a lot of work keeping track of how many 0.1" turns I'm doing. hehe.

-Paul

[motor_control]

You can use more thick copper sheet glueded to spear side of common pcb by epoxy for more current compabelity.

[MPaulHolmes]

That's a good idea, motor_control! I've had a terrible time finding 4 or 5 ounce copper PCB, but copper sheet is pretty cheap. What sort of epoxy do you use?

[motor_control]

Originally Posted by MPaulHolmes

What sort of epoxy do you use?

I don't do that. It's just idea that sparks me while wieving your art work.

I think in shop of auto spare parts (in Russia, Moscow it is that) you can find high temp adgesives. The best will be glue for braking pads.

Something like "ABRO Epoxy Steel" "Qualco Epoxy Fast Setting" or
Done Deal Adhesives on line - Home

Or

"Aremco-Bond 805" epoxy till 300°С - is a two component, 100% solids, aluminum-filled, epoxy ideal for bonding, potting and tooling applications to 300 C (572 F).

http://www.globalspec.com/FeaturedPr..._EPOXY/52258/0

[brihoo2k]

Those look like an excellent find in fact I may have paid more for the exact same set from LittleMachineShop.com - Search but that was like 3 years ago so it now its water under the bridge ive been working with pulse width modulation since about 95 but never considered doing one until lately and noticing your thread upon further research I find lots of people doing different designs but all with the same concept making a dc motor controller. Heck I even seen one design where the guy was using the fets in a circular configuration for a more even heat distribution. Some guy was doing one where it was all soldered in componets no programming what so ever. I myself have a warp13 pic programmer and have owned it since about 2000 or 2001. Too bad the guy that made them Jim Robertson just stopped making them because they would also work in mplab as a picstart plus as well as its own software and he would come up with improvements to his own design.

[zgendron]

Paul,

Absolute great work so far. Keep it up! Can't wait to see the finished product!

Took me 3 days just to read all 20 pages!

- Zack

[MPaulHolmes]

Thanks zgendron!

This is draft #100 of the schematic. haha. I simplified the 2 wire throttle input. I haven't checked it for mistakes yet. I just finished it. I need to go through each part to make sure everything is right, and then I need to build each part as a black box and make sure they work. Then I need to build the whole thing and test it all.

Features in this schematic:

144v battery pack.
hardware current limiting.
temperature monitoring
current monitoring.
2 wire throttle monitoring.

The throttle is drastically simplified. It's not perfectly linear, but pretty close. I looked at the graph in Excel. The throttle range into the A/D is only like 2v, but that will be plenty resolution, because I'm going to change all the inputs to 10 bit. I don't have to monitor current as fast anymore because of the hardware current limiting.


Is there a place like photobucket that allows higher resolution large pictures? This schematic is a bit hard to read.

I just found an error! The NAND chip pin 7 needs to be attached to ground. I'll upload the modified version later, after more checking.
Another Error: IN4148 diode is actually 1n4148.


I never tried PNG before! ya! Thank you!

[motor_control]

Originally Posted by MPaulHolmes

This schematic is a bit hard to read.

Try free EAGLE 5.40 - it's simple and awersome !
CadSoft Online: Download
Free for any schematic size, but pcb till 80x100 mm

or DipTrace - it's fully free for till 250 pins design (by e-mail they send key for 1000 pins free) for pcb NO restriction at all !
Screen Examples :: DipTrace

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I've added to your schematic some common hardware for robust design for noisey envieroment. I think it is right.