PICStep experience

[MrBean]

I've been using Alan's PICStep drivers for around 18 months now, and not had any major issues with them. In fact, they've been really good.

I recently changed to the new V2.0 firmware (1/16 stepping), when a glitch started to appear. One of the motors (Z) was behaving erratically. I'm pretty sure I've tracked this down to a heat issue concerning the LMD's.

Is it logical, that running 1/16 microsteping would cause the LMD's to generate more heat than they did at 1/8 microstepping?

I tried to switch back to 1/8 mode for my Z axis, but found that the jumpers on the interface board no longer seem to alter the step mode??

My Setup.......

I'm running the old, non opto interface board from Alan's site (V2.0).
The V 2.0 PICStep driver hardware.
The new V2 firmware (1/16 microstepping)

Has anyone else tried the new firmware with the older interface board and not been able to use the jumpers to change stepping modes?

It looks like I'll have to make up a heatsink and fan assembly to keep them LMD's cooler.

The 1/16 mode does generally seem to make my machine run smoother. Cheers Alan....

Regards
MrBean.

[Garfield2]

Is it logical, that running 1/16 microsteping would cause the LMD's to generate more heat than they did at 1/8 microstepping?

I tried to switch back to 1/8 mode for my Z axis, but found that the jumpers on the interface board no longer seem to alter the step mode??

Ooo really? The pins are the same on both versions, the firmware is universal. Perhaps something else is broken..

Heat is generated with switching so I'd assume with the higher switching rates needed for 1/16 mode the MOSFETs would generate more heat. The LMDs need a fair amount of heatsinking.

Glad the 1/16 mode makes you machine smoother. I'll have a look at that bug shortly.

Alan.

[MrBean]

Hi Alan. I've now got some CPU heat sinks on the LMD pairs. All of the motor glitching is now gone. 1/16 mode is running like a champ. Thanks.

The jumper problem on the interface board for mode switching is odd. After all it just sets the PIC pins high/low, what can be broken? If I get time later I'll flash the old hex file back into one of the pics and see if the mode jumpers work for that axis.

It's no biggie. Now 1/16 mode is running well, I'd like to stick with that anyway.

Right now I'm milling a PCB for my wind turbine. I'll post a picture once it's done.

BTW. The thread with RadekCX and the LMD bug, was quite entertaining. Glad you got it sorted in the end.

Regards Terry.

[MrBean]

Well... I haven't had time to re-program the PICs, but I did get my PCB done. I guess PCB, should really be MCB? (Milled Circuit Board).

I know it's not that interesting, but machine was "Powered by PICStep", so I thought you might like to see the results.
I just need a sticker now saying....... "PICStep Inside"

I'll try using the old firmware regarding the mode jumpers tomorrow.

Regards Terry.

[HayTay]

...but I did get my PCB done. I guess PCB, should really be MCB? (Milled Circuit Board).

I know it's not that interesting, but machine was "Powered by PICStep", so I thought you might like to see the results.

Fantastic result on your MCB!!!

Give us some more details, please (what bit(s), feed rate, DOC, mill time, etc.).

Very, very, nice work. Can't wait to see PICS of the PICStep populated with some components.

[gmfoster]

Man that board does look first class....

Thanks for posting..
Garry

[santiniuk]

Totally awesome board result.

Interesting find on the jumper settings. I haven't had chance to investigate this yet but will be interested to see what Alan finds.

Great work.

[MrBean]

Fantastic result on your MCB!!!

Give us some more details, please (what bit(s), feed rate, DOC, mill time, etc.).

Thanks for the kind comments. I was pretty chuffed at how well the board came out.
Okay........ A few details for those the want them.
I used a 30 degree, single fluted, conical cutter.
Feedrate while cutting was ~300mm/min. These small cutters require low feedrates and high spindle speeds. At over £10 a go, I don't want to break any.
Depth of cut was just enough to get through the copper layer. I'm not sure exactly what the numbers were. It took a couple of false starts to get the depth just right.
Mill time.....Hmmm. The actual isolation traces were finished in around 7 mins, but I chose to run an off-set stepover to remove some of the excess copper around each trace. This step is not neccesary, but I like the look it gives. The more you remove the longer it takes. Figures really!
Drilling cycle was about 15 mins with 5 tool changes. I cheated and used the same size bit for all the holes, but it still lifted the Z and paused each time a new size was required. I just hit cycle start and carried on.

This is only my second attempt at this type of milled board. I still have some stuff to figure out, but it's looking promising so far.

Right.... I'm off to flash me chips, see if I can pin down this PICStep mode select weirdness.

Cheers guys.
Regards Terry.

[PsyKotyk]

The results are very impressive. What kind of spindle speeds are we talking? Like 3000-5000, 10,000-15,000 or higher? What's the size of the mill bit, or since it's conical, is it just as pointy as it can be?

I would be quite happy to get those results everytime.

Thanks for the kind comments. I was pretty chuffed at how well the board came out.
Okay........ A few details for those the want them.
I used a 30 degree, single fluted, conical cutter.
Feedrate while cutting was ~300mm/min. These small cutters require low feedrates and high spindle speeds. At over £10 a go, I don't want to break any.
Depth of cut was just enough to get through the copper layer. I'm not sure exactly what the numbers were. It took a couple of false starts to get the depth just right.
Mill time.....Hmmm. The actual isolation traces were finished in around 7 mins, but I chose to run an off-set stepover to remove some of the excess copper around each trace. This step is not neccesary, but I like the look it gives. The more you remove the longer it takes. Figures really!
Drilling cycle was about 15 mins with 5 tool changes. I cheated and used the same size bit for all the holes, but it still lifted the Z and paused each time a new size was required. I just hit cycle start and carried on.

This is only my second attempt at this type of milled board. I still have some stuff to figure out, but it's looking promising so far.

Right.... I'm off to flash me chips, see if I can pin down this PICStep mode select weirdness.

Cheers guys.
Regards Terry.

[MrBean]

The results are very impressive. What kind of spindle speeds are we talking? Like 3000-5000, 10,000-15,000 or higher? What's the size of the mill bit, or since it's conical, is it just as pointy as it can be?

Hi. I would say the spindle was running in the region of 25,000 rpm
And, yes the cutter is pretty much as pointy as you could make it.
The widest part you can see of the shaft is 3mm, the thinner part is 2mm.

Picture attached below...

[HayTay]

Okay........ A few details for those the want them.
I used a 30 degree, single fluted, conical cutter.
Feedrate while cutting was ~300mm/min. These small cutters require low feedrates and high spindle speeds. At over £10 a go, I don't want to break any.
Depth of cut was just enough to get through the copper layer.

Thanks for the updated info and the photo of the cutter!

I was pretty chuffed at how well the board came out.

Had to consult "The English-to-American Dictionary" to make sure of the meaning of "chuffed".
Yo, dawg, dat board b look'n right nice, yous gots ev'ry right ta b chuffed! Word!

[smarbaga]

what would the machine movement resolution distance be on your finest pass ?
is this a home made machine ?
do u drill at 25k rpm's as well?
a sugestion, if i may, if you drilled first there may not be as much traring.
the board looks great, and you can have one anytime, in your own home.
thanks for sharing , MrBean.