Let's Get The Show On The Road......

[BobLWeiss]

Originally Posted by santiniuk Can you comment on how easy / successful it is ? From the images you posted it looks great.

To me it can't be any easier, after printing it out (I use Staples Picture Paper and haven't tried anything else), I press a hot iron on it for about 7 minutes and move it around to make sure I get every inch. After that I let it cool for about 5 minutes then place it in warm water with some dish soap in it. I let it sit for about 15 minutes and peel the first layer of paper off. Then soak some more and do this until you get 90% of the paper off (total of 30-45 minutes). I then use an eraser on a number 2 lead pencil and rub off the remaining bits (make sure you do this in the water and not dry).

Sometimes it rubs off a little piece of toner so you will need to look at it with a magnifying glass and touch up the spot(s) with a fine pointed Sharpie. Now your ready to etch away. I can get as small as 10mil traces with 10mil spacing between them. I haven't tried any smaller yet but I'm sure if your careful it can be done.

Bob

[Garfield2]

Originally Posted by BobLWeiss Andy, what kind of speed (rpm's) are you getting with your design? I built one as a test and I cannot get it to move fast at all. I changed the source to make it run continuoulsy so I can test my hardware and I had to put a delay loop in between each step (40ms). With this delay its painfully slow. It could be something on my end that is wrong but I just wanted to see what speed you were able to get by using the computer to generate steps (TurboCNC, etc). Thanks!

Andy or Alan?

Umm I have a video on my website of the PICStep running a motor via TurboCNC on a crappy Celeron 300. I guess the motor was turning at about 1000 - 2000 rpm.

That's if you're talking about PICStep that is..

I'm confused.

[BobLWeiss]

I ment Alen, sorry. Yeah I saw that video..so it must be my mistake somewhere. I am anxious to get one of them completely built and try it out using TurboCNC.

[Garfield2]

Originally Posted by BobLWeiss I ment Alen, sorry.

Closer! It's Alan.

Originally Posted by BobLWeiss Yeah I saw that video..so it must be my mistake somewhere. I am anxious to get one of them completely built and try it out using TurboCNC.

Silly question, you using a 20MHz resonator/crystal setup? I ask as you mentioned you've modified the design a bit and I'm wondering if your clock is one hundred percent.

Cheers,
Alan.

[BobLWeiss]

Originally Posted by Garfield2 Closer! It's Alan.

Ignore my stupidity...sorry again. I am bad with names, both in person and in type.

Originally Posted by Garfield2 Silly question, you using a 20MHz resonator/crystal setup? I ask as you mentioned you've modified the design a bit and I'm wondering if your clock is one hundred percent.

Yes, I am using a 20Mhz crystal and its running 100%. I checked it with a frequency meter. I tried to speed it up by making the loop 30ms and it won't run at that interval. It starts to work at 40ms and slower. I am not going to worry too much about it unless it does the same thing on the new boards (which I didn't modify at all as you can see from the pictures I posted.) I am waiting on the resonators and drill bits so I can put those together then I can fully test it using the computer to drive it.

[MrBean]

Here's some piccys of my freshly CNC milled board. No holes yet, as it was just a test to see how the modified track layout would work. Looks like it should be usable.

Regards Terry.....

[Garfield2]

Originally Posted by BobLWeiss Yes, I am using a 20Mhz crystal and its running 100%. I checked it with a frequency meter. I tried to speed it up by making the loop 30ms and it won't run at that interval. It starts to work at 40ms and slower. I am not going to worry too much about it unless it does the same thing on the new boards (which I didn't modify at all as you can see from the pictures I posted.) I am waiting on the resonators and drill bits so I can put those together then I can fully test it using the computer to drive it.

Hmm weird, by my ruff calculations with a 16KHz pulse you'd get around 600rpm with a 1.8degree motor at 1/8th step.

16000 steps per second
1600 steps per 360 (360 / (1.8 / 8))

16000 / 1600 = 10 revs per second
10 * 60 seconds = 600rpm

I've had my motors up to at least that high.

Also by my calculations using the 200ns instruction time would mean one step per 0.0135 milliseconds with the current firmware. This could theoretically be achievable by the 20MHz PIC.

1000 ms / 0.0135 = 74074 steps per sec
1600 steps per 360 (360 / (1.8 / 8))

74074 / 1600 = 46 rev per second
46 * 60 seconds = 2760 rpm

So what does it do with a 40ms delay that's different from the 30ms? Are the motors singing like the current limiting is working? Also what drive current do you have set? Can you email me your source code for your driver so I can see if there isn't something else going on.

Cheers,
Alan.

[BobLWeiss]

I just emailed you the code. As far as the motors singing, all it did was step, step, step, step...sort of like 4 steps per second if that. I know something is not right as it should got alot faster than that. I used a 10K resistor for 2amps per phase and I used a 24vdc powersupply. If I changed it to 30ms it does absolutly nothing. No noise, nothing.

[Garfield2]

Originally Posted by BobLWeiss I just emailed you the code. As far as the motors singing, all it did was step, step, step, step...sort of like 4 steps per second if that. I know something is not right as it should got alot faster than that. I used a 10K resistor for 2amps per phase and I used a 24vdc powersupply. If I changed it to 30ms it does absolutly nothing. No noise, nothing.

Hmm the fact the motors aren't singing leads me to believe that something isn't right with the oscillators the LMD's use (R1,R3, C1,C3). These set the switching frequency for the current limiting of the LMD's. Normally when the motor is just sitting without any stepping and the coils engergised the motors will sing a little (more so when they're in a 1/8 step quadrant).

Do you have a CRO or a frequency meter?

If so, check the RC pins on the LMD's to see they're oscillating at about 19KHz, also check the LSB (RA0, RB2) pins (and the others if you want) of the PIC while running the step pulses, you should see quite a bit of action there with a CRO. If not, something is not right with the firmware you're using. I'll have a look at the code when I get some spare time.

Cheers,
Alan.

[BobLWeiss]

I think I see one problem, your schematic calls for a 2.2nf cap and I used a 2.2uf. I just noticed that so that could be it since it messed up the timing circuit. I do have a meter and will check it out. Don't worry about the code part since it was only for testing the hardware. I will have the "real' boards built by this weekend and it should be good. I am also using your original code from the website too. Thanks for taking the time to check it out for me though. Back to the original intent of this post...sorry for "hijacking" it. Hopefully it helps someone out.

Here is a picture of my Z axis with motor. I got it off ebay, custom built to my specs...nice guy and great deal:

[santiniuk]

Finally received my pcb drill's today and amazingly managed to drill all four boards without snapping a bit ! That's got to be a first maybe things are looking up

I have all the components now to build the boards except the damn resonator !

If anyone can recommend a source for a 20MHz 3 pin resonators in the U.K I would be very grateful. R.S and Farnell don't have them (Or I cannot find them).

I need to sit back now and see what Stepping motor's I require.

What else...

I upgraded the firmware of my Microchip Picstart programmer. This required a new I.C in the past but they released a small module that replaces this. This module is flash upgradable via the release of MPLAB IDE. So hopefully this will meet my needs for a while.

I downloaded Alan's firmware v1.01 code for the micro's as well.

That Z axis looks top quality Bob, very professional.

Mr Bean, good to see the progress on your milled boards. I'm interested how you create the cutter path from pcb artwork. I can imagine this being a very useful tool.

Cheer's

[Garfield2]

Originally Posted by santiniuk I have all the components now to build the boards except the damn resonator ! If anyone can recommend a source for a 20MHz 3 pin resonators in the U.K I would be very grateful. R.S and Farnell don't have them (Or I cannot find them).

http://www.dontronics.com/

He's a really nice guy and ships to anywhere in the world. Plus for 20MHz resonators they're pretty cheap to buy and ship from anywhere in the world really.

Originally Posted by santiniuk I downloaded Alan's firmware v1.01 code for the micro's as well.

Cool, it's only minor. But you might as well upgrade to it.

Originally Posted by santiniuk Mr Bean, good to see the progress on your milled boards. I'm interested how you create the cutter path from pcb artwork. I can imagine this being a very useful tool.

I believe he did it very skillfully by hand in photoshop. I'd be very interested to see if it works. Perhaps I should start using polygons for traces rather than tracks and pads..

Alan.