Darren's CNC - Rebuild

Darren Wright

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Springfield, Missouri
My DIY "JGRO" cnc router has been in storage for about 3 years. When I was running it before, I used a program called KCam on windows 98 to control the machine. Being windows based, it was choppy and would pause the cnc when other tasks kicked off on the pc and had to minimize the screen to get the best performance. I also found I could only cut about 5 inches per minute with it...yes it was slow.

Today I loaded up EMC2, which is a linux based cnc control software. After a lot of tweaking to the settings I finally got it where each axis was moving the right direction and finally got a program to load up for running. For my first test I ran the machine at 11 inches per minute, which is twice as fast as I have ever gotten it to go...yes it's still slow.

http://www.youtube.com/watch?v=KdcHbQ6Z9tA

The final result. The right side of this piece is a little choppy, I had some play in the rails I've now worked out, and still have some additional adjustments to make.
IMAG0776.jpg
 
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After some adjustments and playing around with the speed. I got it up to about 18 inches per minute, 23 travel speed between passes. I'll bump the travel back down to 18 or so as the steppers start to lose steps as they get warmer. For this file updated the code to turn on/off the spindle while traveling vs. cutting. I've also found I can adjust the spindle speed with emc2 using solid state relay, so will play around with that more.

http://www.youtube.com/watch?v=wk3EHDfRCKA

The final piece:
IMAG0777.jpg

One thing I still need to do is figure out how to get things drawn for EMC2. Going to test out some sketchup plugins later, but if anyone has any suggestions, I'd appreciate them...Thanks. :wave:
 
@ Jay. If you are not already spending too much time on Joe's, then go to CNCZone. I had to go cold turkey to get off of them. When I became interested in another that was basically a CNC kit ready to assemble, plug and play for about the same money, I had to fish or cut bait. The long term picture doesn't have space or time for a CNC. If I were 20 years younger and with a permanent shop, then maybe. I am looking at my seventh decade before the end of this year and there is another move coming up in about 15 months. Likely all the toys will be looking for a new home, and Larry will have to swim to come to visit. Nothing concrete yet, but planning is in the beginning stages.
 
This is really cool, Darren!

I'm in the middle of building my own CNC router, inspired by Joe's 2006 design. I modified it pretty severely, though. I don't wanna hijack your thread, but I've got a handful of videos of both the design and my build process up to this point. I'm currently awaiting lead screws to continue building. Once I have the screws, I'll have a feel for how much torque I'll need from my steppers. That's the plan anyway.

I love that you're using EMC - I just setup a VM on my laptop to play with EMC and Axis as well. I've been watching the Mach3 videos the last few days and I'm very tempted to pick it up but there's too much yankee in me to just buy something - I gotta do it the hard way first. What kinda catches did you encounter with EMC?

I've been toying with the DXF and STL export plugins for SketchUp a bit - but not having a clue what I'm doing I don't know if they're good or bad. There are about a half dozen that I've downloaded - the Phatscript one seems to be the most mature (ironically enough). I haven't tried anything in 3D yet. I've also gotten quite tempted by the Vectric forum and their product offerings - talk about spendy!

I'm looking forward to watching your progress on your machine!
 
Awesome. That looks like it could really be a lot of fun.

What limits the speed? The motors?

I'm still experimenting, guys with this same machine use 1/2"-13 all thread with a 30 volt power supply and claim 100 inches per minute, but I think in my case it's my power supply. I've got a 24 volt linear supply, but I think my amperage is a little low. Second, I'm using 1/4-20 threaded rod, if I updated to acme rod I could probably add speed without losing torque and reach those speeds.

I also have some binding issues due to my rail alignment I'm working out, the added resistance causes the steppers to lose steps, just think of the torque on your drill moved from the drill selector to a lower setting and you hear that sound of it not moving the bit, same sound.
 
EMC2 allows for python scripts, think plug-ins, that allow you to do complex layouts really easy, such as text for signs (as already shown) or drill holes for vents in cabinets. Here is a test of it, I have some small speakers that I may mount behind something like this and cover the front with fabric.

IMAG0782.jpg IMAG0780.jpg IMAG0781.jpg

Some other variations.
IMAG0783.jpg IMAG0784.jpg

I have the site bookmarked on the cnc...will post it later.
 
Oh boy I feel just like Carol and now both you and Carol have started me down the road again. I want to play with cnc so so badly but i dont want to fuss with all the building etc. I saw a link which led to another etc on Joes site that mentions http://www.mechmate.com/ this looks more like my cup of tea. Metal. :D Darren you amaze me. In a very motivating and positive manner. I am inspired by your willingness to work through all the issues and your patience in working with a unit at that speed. 30 years ago i would have too but today i feel time and what one wants to accomplish in this time is the important thing to me. I dont mean this in a time is money kind of way, my concern is two fold. How much time i have before i cannot do these kind of things due to health, (i am in good health but we cannot fight the inevitable aging process) and second before we aint around anymore and that is not in our hands. With how fast i seen the last 10 years go by i am now trying to prioritise where i would like to place my time. I would like to have a total kit. Not just certain parts that one can machine but the whole schebang. By the time one is finished buying bits and pieces and having them shipped one might as well get a complete kit from one source. Then get stuck in on the building and not look back. I have had a hunkering for just buying a shop bot but they just getting that wee bit too up there in cost to justify for playing around on the what if basis and trully if i want to make something i am going to sell repeatedly then i would sooner contract that kind of thing out to a guy that has a set up geared for production. So to me this area of shop tools fits the category of trying out ones ideas and seeing if they have merit if they were machined on cnc and then saying ok i got the prototype now on to the next thing. There is enough to learn in Cnc with the program and operating side on its own so i would rather spend valuable time doing that than sourcing bits and pieces.One thing i am cured of seeing you working on your own home grown version is i have no desire now to diy without a kit. The issue is which kit and what the kit manufacture offers in the way of support.On first look this mechmate looks like a good approach. Some guy is offering laser cut parts herehttp://www.cvsupply.com/servlet/the-MechMate/s/10/CategoriesThis makes more sense to me than trying to make it from mdf but i have seen many from mdf.


Thanks for stiring the pot for me on this topic. Stay with it with your talents i dont see you being long before its knocking out Photobooth parts and accessories. :)
 
I am looking at my seventh decade before the end of this year and there is another move coming up in about 15 months. Likely all the toys will be looking for a new home, and Larry will have to swim to come to visit. Nothing concrete yet, but planning is in the beginning stages.

thats to bad carol,, i tend to shy away from water i would melt if i were to jump in it:)
 
This is really cool, Darren!

I'm in the middle of building my own CNC router, inspired by Joe's 2006 design. I modified it pretty severely, though. I don't wanna hijack your thread, but I've got a handful of videos of both the design and my build process up to this point. I'm currently awaiting lead screws to continue building. Once I have the screws, I'll have a feel for how much torque I'll need from my steppers. That's the plan anyway.

I love that you're using EMC - I just setup a VM on my laptop to play with EMC and Axis as well. I've been watching the Mach3 videos the last few days and I'm very tempted to pick it up but there's too much yankee in me to just buy something - I gotta do it the hard way first. What kinda catches did you encounter with EMC?

I've been toying with the DXF and STL export plugins for SketchUp a bit - but not having a clue what I'm doing I don't know if they're good or bad. There are about a half dozen that I've downloaded - the Phatscript one seems to be the most mature (ironically enough). I haven't tried anything in 3D yet. I've also gotten quite tempted by the Vectric forum and their product offerings - talk about spendy!

I'm looking forward to watching your progress on your machine!

What size of steppers and which controller are you using?

EMC has been easy to use, and I'm not much of a linux guy, but ubuntu has been easy to use as well. Like I mentioned, I've got to figure out how to get files created for EMC, which require NGC format (gcode). I've been trying the Phatscript plugin, but haven't generated any gcode from it yet to test, but will post results here. I've also got several apps on an old computer that died, need to pull the hard drive and see if I can salvage them to use.

As for catches, I haven't found a good way to tweak the machine settings other than manually. There is a built in wizard that lets you modify your settings, but seems if you do any manual updates to the files, it sees this and you can't just modify it again through the wizard.:doh: So I need to go though a new setup again and figure see if it will allow modification to existing files. Seems like a lot of entries you have to calculate for your machine setup too, just isn't plug and play. Like instead of just entering what you want to run inches per minute on each axis, instead it is entered as inches per second. :huh: Easy enough to calculate, but seems they could have made this easier. It does do it's best to calculate speed based on available resources. I've notice when it's doing more complex cuts, it slows down the inches per minute.

I have a buddy that runs his mills using Mach3 and swears by it. It uses a driver, similar to a print driver, to communicate with the machine to get past latency issues, which I had with my first software (Kcam). I may have gone with it as well, but not in the budget right now.

I did a trial of Vectric years ago and it seemed to work well, need to look at it again, was easy to use and could set it up for bit changes and such. Speaking of, EMC does have a tool table to manage, which you can assign in gcode. It will pause and park for you to change the bit and re-home the machine, then do that bits work.
 
What size of steppers and which controller are you using?

EMC has been easy to use, and I'm not much of a linux guy, but ubuntu has been easy to use as well. Like I mentioned, I've got to figure out how to get files created for EMC, which require NGC format (gcode). I've been trying the Phatscript plugin, but haven't generated any gcode from it yet to test, but will post results here. I've also got several apps on an old computer that died, need to pull the hard drive and see if I can salvage them to use.

As for catches, I haven't found a good way to tweak the machine settings other than manually. There is a built in wizard that lets you modify your settings, but seems if you do any manual updates to the files, it sees this and you can't just modify it again through the wizard.:doh: So I need to go though a new setup again and figure see if it will allow modification to existing files. Seems like a lot of entries you have to calculate for your machine setup too, just isn't plug and play. Like instead of just entering what you want to run inches per minute on each axis, instead it is entered as inches per second. :huh: Easy enough to calculate, but seems they could have made this easier. It does do it's best to calculate speed based on available resources. I've notice when it's doing more complex cuts, it slows down the inches per minute.

I have a buddy that runs his mills using Mach3 and swears by it. It uses a driver, similar to a print driver, to communicate with the machine to get past latency issues, which I had with my first software (Kcam). I may have gone with it as well, but not in the budget right now.

I did a trial of Vectric years ago and it seemed to work well, need to look at it again, was easy to use and could set it up for bit changes and such. Speaking of, EMC does have a tool table to manage, which you can assign in gcode. It will pause and park for you to change the bit and re-home the machine, then do that bits work.

I haven't gotten any of the electronics yet. I"ve been eying the Probotix kits or the Keling kits - I'm not sure I can justify springing for gecko drives yet. So far, I've got about $1300 into my machine using an MDF torsion box, welded base and a lot of scrap aluminum from a local store (Cheap!). I picked up linear rails on ebay - some nice 16mm fully supported steel rods on aluminum bases with bearing blocks - they're pretty much the basis of the whole machine's design. Once I get my screws (should be shipping this week.

Btw - your lead screws - give cjamasterworks.com a look - Chris Jones has been emailing (at length) with me for the last year to get me the right kits together for the size machine I'm building. He deserves every ounce of business I can send his way. A real stand up guy, for sure.

Going from CAD to gcode is one area that seems to be the trickiest. I've heard good things about CamBam but I haven't used it. I wonder if LazyCAM (comes with mach3) can be used in the trial form. I've been watching their videos quite a lot and it's very intriguing. I have to try EMC first, though. I thought I read something about a program called Axis that comes with EMC. I'm not 100% sure what that does (might not even be a CAM package).

This stuff sure is fun to tinker with for sure! I'm on day 21 of my build and have a rolling gantry at this point but I've captured everything with numerous pics and youtube videos for another forum so it wouldn't be too hard to do a catch up thread here. Maybe I'll start a build thread here if folks are interested? :)
 
Well twist my arm ... Alright - i'll throw together a thread here just so that this community can have it without fear of it falling off into the internet abyss. Stay tuned, i'll get started on it tonight :)
 
Well, I found my old pc's hard drive that used to control the CNC last night. Loaded it up as a slave in another computer and retrieved all the installs for my old CAM and Controller software as well as a few other utilities.

As mentioned before, I was having a hard time finding a way to get drawings converted to run on EMC2. I found I can open the autocad files in my old controller software and export the gcode for EMC2. I also have a copy of BobCad-Cam, which worked well for design, but can generate the gcode from it as well, also optimizing tool paths. The software will generate multiple pass paths for deep recesses based on how much material you wanted to remove per pass with a given bit.

I was happy to find all of my old drawings on there too, found the templates for the engine/sides of my motorcycle rockers, so may make a few to sell to help pay for some shop upgrades.

I'm sure I've got some things that others might find useful. I know I had a program that would generate Celtic knots and save them to autocad files. I'll go through some of it tonight and see if there's anything I can share or find links to.
 
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