@plengo

what does the 500/550 ms pulse duration at ~960 rpm do with/in the circuit?

seems kind of high if it's for the on time for your drive coils.

take care.

nap

Quote from: 4Tesla on June 06, 2011, 03:21:25 PM
I was wondering what to use to drill large holes in acrylic.. would this hole saw work?..
http://www.sears.com/shc/s/p_10153_12605_00966287000P?sid=IDx20070921x00003a&ci_src=14110944&ci_sku=00966287000P

Thanks!

I tried that and it was a disaster for plexiglass. It is too brittle and will be very difficult to cut without a drill press.

If you have drill press I would buy a set of better drills. If you will use a hand drill definitely forget about those ones.

Fausto.

Quote from: 4Tesla on June 06, 2011, 03:21:25 PM
I was wondering what to use to drill large holes in acrylic.. would this hole saw work?..
http://www.sears.com/shc/s/p_10153_12605_00966287000P?sid=IDx20070921x00003a&ci_src=14110944&ci_sku=00966287000P

Thanks!

I wouldn't try it unless you have a drill press that can run at a very slow speed.  Hole saws are hard to keep stable also and will tend to grab if they get off angle in the least.  If you were close to the edge like when cutting a hole in the rotor you might easily break out the side if it grabbed.  However there are not many other affordable options.  Water jet and laser cutting will probably cost a lot.  I haven't worked much with acrylic but I believe it will easily melt if cutting too fast with any type of blades.  Slow speed and a rigid setup will be important. 
P.S.  I see now you got a number of replies.  I think Magluvin and some others probably know plastic better than I do so don't let my advice override what they are suggesting.  Good luck. 

Quote from: slapper on June 06, 2011, 09:59:12 PM
@plengo

what does the 500/550 ms pulse duration at ~960 rpm do with/in the circuit?

seems kind of high if it's for the on time for your drive coils.

take care.

nap

good question. I don't know. I have not spent too much time thinking about this yet. This was just my second run quick test to see if it would even spin. My first run test with relay was a total disaster and was running at less than 20rpm.

Those little coils made a gigantic difference. Now, the timing was a error and trial until I found a good spot. What was interesting to me is that longer pulses were worse and shorter were better. Resonance plays a big role where once you achieve it you can proportionality decrease the ON time duration (which is my case) and still improve things.

My setup is not taking the speed of the rotor into consideration so as faster it goes I am still at a constant ON time. I will eventually fix that on the code.

BTW, I think it is not 500 ms but 0.5 ms ON time or may be even 0.05ms. I have to check the code.

Fausto.

Quote from: plengo on June 06, 2011, 10:41:04 PM
BTW, I think it is not 500 ms but 0.5 ms ON time or may be even 0.05ms. I have to check the code.
Fausto.

that makes more sense.

thanks.

nap