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ERC TimSav - Cheap DIY CNC Foamboard Cutter

luvmy40

Elite member
I put the ERC TimSav together last weekend. I am having a problem with the stepper connections. At least I think that is the problem.

When I fired it up and ran the 100 mm/200 mm calibration test, the servo worked correctly, but the steppers only stuttered. I know the pairs at the stepper, but cannot find anything, any where that tells me the pin out at the CNC shield.

I tried switching the pairs at the board and somehow smoked the Arduino. My 15 year old laptop also decided to give up the ghost at the same time. Possibly coincidental, but find that unlikely.

I currently have the CNC Shield powerd through the UNO with the jumper soldered in per ERC's instructions. I will remove the jumper and power the Shield seperately when I get the replacement.

Can anyone help me with the proper pin out of the CNC Shield?

Thanks!
 
if you haven't ordered your uno yet then I would try and get one with the amtel 16u2 chip rather than the ch340 as they are closer copies of the real uno. They do cost a bit more but I think they are worth it. The one you want will have a square chip next to the usb port rather than a rectangular chip.
 

Attachments

Quick question for anyone:

Can this design be easily scaled up?

I can get 1/8” foam board in a 32” x 40” size.
I can also get 3/16” foam board in a 40” x 60” size (or 48” x 96” if I want, but it’s a little more difficult & expensive).

I’m interested in a light machine that can cut the 40” x 60” foam on a large table.

Lane
 

luvmy40

Elite member
I would guess, and it is just a guess, that you could make your X, and Y axis any length you want. Limited by the structural integrity/rigidity of the aluminum channel. At some size, I would bet you need to make the Y axis frame four sided or there will perceivable tail lash on the x axis gantry. You can make your plans any size in Ink Scape.
 

rkozak

Junior Member
Hi!
My version of a needle cutter. Went for two y-axis and the motor holder Matthew Gladfelter constructed (files on Facebook group "ERC Timsav...). Only cut some test bits so far but it looks promising :) Using a 0.5mm wire to cut with and connected it to a Raspberry pi zero w running CNCjs.
Would you be able to share the STL's for Matthew's motor holder? I do not have a facebook account.
 
I've got a couple of machines set up with diode lasers right now... yes. Actually started testing several Neje lasers to see how they compare with the Banggood/Eleksmaker lasers I've used in the past. There are things to like about them and a couple of things not to. Still playing... ;)

This is my latest machine... basically two opposing modified TimSav machines with a common gantry and sporting a new, fully-implemented Z-axis. This one mounts a Neje laser I'm currently playing with...

View attachment 191901

Rolling-gantry miniFoamRipper with 2.5W Banggood laser, cutting two-piece tabbed boxes for the grandkids Christmas money...

View attachment 191902

What'cha got going?

-- Davdi
Hello! interesting your new Z axis, but question? can you dock the dremel too? wouldn't you have the stl file? please thank you
 
Hello! interesting your new Z axis, but question? can you dock the dremel too? wouldn't you have the stl file? please thank you
Like TimSav itself, my machines and Z-mechanisms nowadays are designed for very light tools and cutting forces... i.e. laser, pen, marker, needle-cutter, etc. You might possibly get away with drag-knife and dremel depending on materials you are cutting and how heavy-handed you get... but I've not set them up for that; i.e. no STLs.

If you want to get into light milling/engraving, you should probably be looking at MPCNC (if you're a DIY guy)... lots of 3d-printing, lots of STLs, and lots of versatility and fun.


-- David
 
Like TimSav itself, my machines and Z-mechanisms nowadays are designed for very light tools and cutting forces... i.e. laser, pen, marker, needle-cutter, etc. You might possibly get away with drag-knife and dremel depending on materials you are cutting and how heavy-handed you get... but I've not set them up for that; i.e. no STLs.

If you want to get into light milling/engraving, you should probably be looking at MPCNC (if you're a DIY guy)... lots of 3d-printing, lots of STLs, and lots of versatility and fun.


-- David
yes I had already seen the NPCNC but I only cut light materials, depron or balsa .. your Z axis was interesting
Thanks for the reply
 
yes I had already seen the NPCNC but I only cut light materials, depron or balsa .. your Z axis was interesting
Thanks for the reply
Maybe a bit more info will help. I have a whole progression of Z-machanisms that range from motorized to manual... and all are later versions than the one you were referencing in my post in this thread. Possibly this one could be altered to mount on your machine and suit your need for cutting "light materials, depron or balsa" with a small rotary tool... but needle-cutter and/or laser can also be used to cut those materials. The Neje A40640 laser module is what I use mostly and fits directly on this Z-mechanism... as do almost all the Neje laser modules. I also have a version of Edward Chew's needle cutter that could easily be adapted to mount on it.

Since you asked about STL files, I assume you can 3d-print... and all I mentioned above is easily manipulated to come up with something that will cut light materials such as depron or balsa. Personally I'd prefer a laser and needle cutter to "Dremel"... far less noise and debris. I'll work with you if you're interested and willing to provide info regarding your machine and use case.

-- David
 
Maybe a bit more info will help. I have a whole progression of Z-machanisms that range from motorized to manual... and all are later versions than the one you were referencing in my post in this thread. Possibly this one could be altered to mount on your machine and suit your need for cutting "light materials, depron or balsa" with a small rotary tool... but needle-cutter and/or laser can also be used to cut those materials. The Neje A40640 laser module is what I use mostly and fits directly on this Z-mechanism... as do almost all the Neje laser modules. I also have a version of Edward Chew's needle cutter that could easily be adapted to mount on it.

Since you asked about STL files, I assume you can 3d-print... and all I mentioned above is easily manipulated to come up with something that will cut light materials such as depron or balsa. Personally I'd prefer a laser and needle cutter to "Dremel"... far less noise and debris. I'll work with you if you're interested and willing to provide info regarding your machine and use case.

-- David
thanks for help!
 

luvmy40

Elite member
OK, I'm here to beg for help!

I cannot get my TimSav to work. When I run the 10 cm/20 cm test the only thing that happens is the cutter head servo raises and lowers the cutter assembly. No motion at all from the steppers. I've tried different motors, different stepper cables, different stepper control chips, etc.

The first go round had the steppers stuttering and the servo working correctly. I was putzing around with the servo connections and fragged the UNO. This latest attempt was with all new boards, UNO, Shield and stepper chips.

I've watched the build videos a dozen times and I don't see anything I've done wrong. I even got rid of the power jumper and wired a separate power plug to the shield.

Is there any chance my issues could be caused by trying to run this from a Windows Vista machine?

Please, somebody save me from my self!!! I'm sure it's something stupid that I overlooked/.
 

luvmy40

Elite member
I finally figured out the steppers, got running right and melted the fly wheel on the 30 minute run test. I had to turn down the small washers for the bearing manually with a drill and belt sander. I maybe should have gone a little smaller...
 
I finally figured out the steppers, got running right and melted the fly wheel on the 30 minute run test. I had to turn down the small washers for the bearing manually with a drill and belt sander. I maybe should have gone a little smaller...
Just wondering what was wrong? how did you get it running?
 

luvmy40

Elite member
Just wondering what was wrong? how did you get it running?
I started this project with parts salvaged from a 3D printer that had issues unrelated to the steppers. Rollers, T nuts, stepper motors came from the printer. I googled the stepper model # and they came up as NEMA 17 steppers. Those are the motors that stuttered the first time around. I still have no idea what I did to fry the UNO, but I did.

When I replaced the UNO, CNC Shield and stepper drivers with all new, I got rid of the power jumper on the shield and just wired in a power plug for the shield. When I tried to run this one, the steppers did nothing. The servo still worked, so I assumed the robitini firmware loaded successfully. After finally getting someone from the ERC TimSav FB page to go through the wiring and set up with me, we determined there were no physical errors or mistakes. That left firmware. It took three tries to get the robitini loaded and verified. After that, the steppers started stuttering again. I tried 4 different motors and several cables. I then ordered new steppers from Amazon, and they worked perfectly.

Of course, the fly wheel melted down on the 30 minute test run! I'll print a new flywheel and go with the printed needle holder this weekend.
 
I started this project with parts salvaged from a 3D printer that had issues unrelated to the steppers. Rollers, T nuts, stepper motors came from the printer. I googled the stepper model # and they came up as NEMA 17 steppers. Those are the motors that stuttered the first time around. I still have no idea what I did to fry the UNO, but I did.

When I replaced the UNO, CNC Shield and stepper drivers with all new, I got rid of the power jumper on the shield and just wired in a power plug for the shield. When I tried to run this one, the steppers did nothing. The servo still worked, so I assumed the robitini firmware loaded successfully. After finally getting someone from the ERC TimSav FB page to go through the wiring and set up with me, we determined there were no physical errors or mistakes. That left firmware. It took three tries to get the robitini loaded and verified. After that, the steppers started stuttering again. I tried 4 different motors and several cables. I then ordered new steppers from Amazon, and they worked perfectly.

Of course, the fly wheel melted down on the 30 minute test run! I'll print a new flywheel and go with the printed needle holder this weekend.

Thanks for the reply. I am getting ready to try mine for the first time and am a little leery myself.
 

luvmy40

Elite member
So, I got everything working again and ran some simple cut tests. Nerdnic's glider x 3, an F18 glider x 2 and a couple swappable power pods. I edited the PDFs for the power pod and F18 and generated the Gcode in Inksacpe. I used Nerdnic's Gcode for his gliders. All turned out nice.
Then I got uppity and tried to run Sheet 1 for the FT Edge 540 from the FB group library. It went well at first but about 3/4 through the cut the Y Axis was suddenly offset by about 1/4". I chalked it up to the X axis cable dragging and catching on one of the foam board clamps. I saw it about to happen and guided the cable by hand once, but thought I might have missed it at another spot.

I removed one clamp taped some poster board ramps on the other that might come into play and ran the cut again. This time I watched everything very closely and there were no incidents of the cable catching up on anything. There was, however one spot where the cutter head just went up and down 3-4 times in the same spot with out moving otherwise and then the Y axis was offset again. It looks like(camparing the two sheets) it happened at exactly the same point in the cut both times.

Am I correct in assuming this a bug in the Gcode? Or, is it still possiblly a mechanical issue with the cutter?