Rough drive == overheating

[10bulls]

I was having some problems with my setup over the weekend...missing steps and motors sounding rough.

I had recently adjusted my machine so everything was aligned and rigid.
I naturally presumed something was binding. After stripping down the machine, I ended up getting the same behaviour with a motor not attached to the machine.

I opened up the controller box and the heatsinks on the LMDs were very hot.
I guess the LMDs thermal protection was kicking in (clever LMD).
I'm using old P2 cpu heatsinks plus fans, 1 between 2 picsteps (4 LMDS).
However, the fans are pretty puny and it's been very warm here over the weekend. Leaving the controller cover off and blowing a desk fan over it
completely cured the problem.

In light of this, I intend to try a couple of things

1) Add a couple more fans to the inside of the box.
2) Lower the current limit (currently set to 2.9A)

[santiniuk]

Been here and bought the T-shirt mate

I had quite decent heatsinks on my LMD's but at 3.0A they could still kick out some heat.

It seems that the LMD's go through an erratic pulsing / stepper drive period before the thermal shutdown kicks in. (I presume it shut's off but not got that far myself)

Solution for me was to fit a 120mm fan to the top of the enclosure. Some form of active cooling seems to be required when at the top limit's of the ratings.

On a sidenote let's see what you have been upto and update your thread.

Cheers

[Garfield2]

Originally Posted by 10bulls I opened up the controller box and the heatsinks on the LMDs were very hot. I guess the LMDs thermal protection was kicking in (clever LMD).

I must admit I like drivers that have thermal and overload protection built-in. It really makes for a bullet-proof system. It also stops you from accidently blowing the magic smoke out of some poor unsuspecting expensive-to-replace device. I mean look at Terry and his board short! He had drive voltage pumping into the DAC lines!

So anyway how have you people been? I've not seen any updates in a while?

In other news, I've bought some things with a bit of my donated PayPal money, I got three 150oz/in triple stack steppers from Singapore. They're 2.9A 8 wire steppers that when driven at 2.9A bipolar parallel I cannot stop them or turn the shaft with anything but vice grips! I think they'll be adequate for my table router.

Cheers,
Alan.

[zoltan]

Hi Alan,

Could you please, tell me the source of your steppers and the price? I am planning to buy some "real" steppers as far now I got only from old stuff. Until now the shipping fees killed my plan due to the budget limitation, but also, the steppers have not been cheap so I am hoping to get a source from the total cost to be in the budget.

Thank you.

Zoltan

[abasir]

It from here http://www.pro.com.sg/
(I'm in no way affiliated with them except as buyer )

[10bulls]

Originally Posted by Garfield2 I must admit I like drivers that have thermal and overload protection built-in....

I couldn't agree more...I'd much rather scrap a few pieces of stock material if my controller overheats, than scrap my controller.
Apart from my own sillies of over-driving my motors and under-cooling my driver, all 4 X PICSteps are working brilliantly. Nice one Alan!

Originally Posted by Garfield2 In other news, I've bought some things with a bit of my donated PayPal... money, I got three 150oz/in triple stack steppers

Only 150oz!...what a stingy bunch of bar-stewards we are!

Finish V1.1 firmware, first release of pic servo AND get Santini's opto board sorted (...no I don't know what he's playing at either! ), then maybe,... just maybe, you may accrue enough donations to buy some shaft couplers to go with those motors...nothing fancy mind you...PVC tube and jubilee clips are quite adequate