Black/Red in PA... New build notes

[pete7919 (Pete)]

Thanks for looking in! “New Build in PA” was already taken so I should come up with a name… For now it’ “Black and Red in PA”. Beware, this is a bit lengthy. I couldn’t find any of my local friends to get interested in this so I figure this would be a good outlet to show what I’ve done and ask questions.

I’m going to detail as much of my new build as possible. I’ve printed all parts and I’m starting to assemble. I hope to put the machine together mostly this weekend, but I’m really enjoying it so I’m going to try and take my time. I find when I get excited I like to just get to the end of a project and I start to take shortcuts to get there. Not this time… I hope.

I’m using my Monoprice Maker Select V2 with home-built enclosure to print all the parts. I have Octoprint installed on a Pi3 with a camera and remote power relay. (Side note - OctoPi with Telegram plugin is awesome!) It took me awhile to dial it in but the parts I’ve made seem to be up to par and they’re very strong.

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I used the infill and shell recommendations and printed the red parts in Robo3d strawberry “smellament” PLA that I got on sale. I know it’s a novelty but it smells like strawberry while printing and seems to be just as strong once printed. Sadly, no smell after printing. The black parts are printed in eSun ABS+ which printed really easy as it has less warp than normal ABS. I really like it.

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I’ve gathered the other parts, some from the shop here (Steppers, LCD, wiring), some from Amazon (pulleys, belts, drivers, Dewalt), and the bearings came from Aliexpress ($17.51 for 60 bearings - long lead time but they seem good). All the hardware was sourced from the local hardware store except for a few bolts and EMT tubing picked up at the local Home Depot.

I started assembly with the middle section and was stymied when I thought I didn’t have the right long bolt. The one I had was fully threaded and wouldn’t fit. I got a partially threaded bolt and it turns out that either would probably work but I needed to run a 5/16" drill bit through the assembly as it was a little undersized. It’s interesting because all the other holes are just right.

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I had a brief panic when I thought I had printed 4x Roller and not 2x Roller and 2x RollerM, but then I looked closer and finally figured out that I had two of them upside down on my desk. I did have the right parts after all. Another help was the Octoprint history plugin so I could look at what I printed.

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Late last night I got all the EMT cut to the right lengths. Initially, I had a major problem getting it cut straight and also in the right spot. I used sawhorses and 3 clamps but I couldn’t get it held down with the vibration. I imagine it’d be much easier with a metal chop saw, but I don’t have one. First, I tried to use a sawzall. That didn’t work AT ALL and ended up creating a mess. Next, I tried a hacksaw, and that gave me a cleaner cut but it was still crooked no matter what I tried. It may have been easier if I had made a mitre box, but I moved on. I finally found the finest blade that I could put on my circular saw and that got me the precision I needed to get a flat, straight cut. I know it’s not the best way but it worked.

After that I was able to get the Z axis finished, the legs assembled and I started with the frame. I have to build a table in order to proceed.

Here’s where I have some questions and need to do some more searching for info. Listing these here if anyone wants to comment. Please realize that some of these questions I haven’t needed to tackle yet so I haven’t done full research:

1. Is there any place that has good plans for a table? The table instructions in the assembly area are very basic. I’ve seen a few in the forums that I could reproduce but nothing I’ve found that is well documented. I think I’d like to start with a basic table and over time build a nice drop table. I realize that making a square table isn’t too complicated but if anyone has tips please do share.

2. Also looking for guidance on a control box. I really like this design - http://www.thingiverse.com/thing:1716182. I think I’m going that route or something similar. Is there any downside to using ethernet cables? Can they handle the current? Could you terminate the wiring kit into a cat 5 plug or is the wiring too thick?

3. What’s the recommended software? I’ve looked at ESTL Cam. I will be doing more on this but if you’d like to share your software please do.

4. Along those lines, is there a good repository of pre-made projects anywhere online? I use Thingiverse (and others) in the FDM world, but if there are other websites in the CNC world feel free to let me know. Again, I’m going to look into this more and I think some of this stuff is on Thingiverse, but interested in other places, even if the plans/files need to be purchased.

5. Another for the “not quite there yet” but I’d like to get more info on what bits/mills are “must have”? Which bits do I need more than 1 of? Will I be breaking them? Also, what tools are complementary that I should make sure I have on hand? Should I start with dust collection from the beginning or add that later?

6. Is there a good source for materials that I can use to make that wouldn’t be found at Home Depot? I’m thinking of sheets of foam or plastic that might be fun to use.

I’m very impressed (very) with the design and assembly of every part of this so far. The parts have printed great, fit great and assembled pretty easy. Everything seems to have a purpose and was really well designed. I’m excited to continue and get to making some stuff.

[vicious1 (Ryan)]

Looking good so far.

Depends on what you want to do with it, if you have a look at the gallery page you will see why these are not easy questions to answer these machines are build very different and used for very different things. Other cnc kits end up with almost identical builds, not so much with the MPCNC, like snowflakes no two builds are the same, and almost no one uses them for the same thing. Your questions are a little too broad to answer very specifically.

1-Depends on your use you can even use a pre existing table if you have one.
2-I attach mine to the edge of the table, a recent build has it in the table.
3-Learn ESTlcam first, you won’t regret it, everything else is much more complicated.
4-Not to sure about this one.
5-Depends but probably a regular endmill, ball end for sculpture, or a v bit for carving.
6-For practice? HD foam, so awesome.

[niget2002 (David Walling)]

1. Is there any place that has good plans for a table?

I built a torsion box table. Do a search for that on youtube and there’s a couple of examples. I made my top and bottom just large enough for the printer to fit on. Then I used 3" wide boards for the grid section. My 24"x24" MPCNC used 1 4’x8’ sheet of particle board to make the table with some left over.

2. Also looking for guidance on a control box.

I’m still trying to design one. I used Ryan’s LCD box, but for now my RAMPs board is sitting naked. I may be the one Ryan is referring to, as I left one section of the torsion box open and I slid all the electronics into that open section. I may not put the RAMPs into a box as it sits far enough in the slot that it doesn’t get much dust on it. The stepper drivers don’t run hot enough to need much air flow on my build.

3. What’s the recommended software?

A lot of people are using ESTLcam. Another one to look at is Fusion360, but it is more difficult. There’s a post file on this forum for the Fusion360 HSM for outputting the CAM to gcode for the MPCNC

4. Along those lines, is there a good repository of pre-made projects anywhere online? I use Thingiverse (and others) in the FDM world, but if there are other websites in the CNC world feel free to let me know. Again, I’m going to look into this more and I think some of this stuff is on Thingiverse, but interested in other places, even if the plans/files need to be purchased.

Google for CNC designs. There’s a few sites out there that have things to download. A lot are for lazer cutters, but you can always reprocess them for the thickness of a mill.

5. Another for the “not quite there yet” but I’d like to get more info on what bits/mills are “must have”?

I started with a 1/8" End Mill and I’ve since added a 1/16" end mill. I haven’t made it beyond that. If you keep your feeds and speeds good, you shouldn’t break any, but it can happen.

6. Is there a good source for materials that I can use to make that wouldn’t be found at Home Depot? I’m thinking of sheets of foam or plastic that might be fun to use.

My first few moves were using a Pen holder and paper. I found this to be great for testing. Ryan has a pen holder that has some flex that makes it great for holding pens. Once I was comfortable that I knew which way the CNC machine would move when I sent it a file, I moved on to cutting stuff from my leftover MDF. My first cuts were just simple shapes… circle, square, triangle. Eventually I’ll be cutting acrylic, PVC flat sheet, and maybe aluminum, carbon, g10. I might even be milling PCBs at some point

[idesignstuff (christian ritchie)]

David, I Was telling a friend at work about your torsion box. I think it’s begging for the work envelope spoil board to have lots of holes, and a vacuum hose attachment on the back or bottom. Then, caulk the joints on all sides, screw down your spoil board with a foam gasket, and boom, vacuum holding your workpiece, or vacuum forming sheet plastic over cnc’d patterns.

[jeffeb3]

6. look around locally for plastic and lumber stores. There must be a ton in PA. There is a plastic place here that has remnants for sale once per month. I don’t want a full sheet of acrylic, that’s for sure. And lumber yards have interesting sheet goods, like the highest quality Baltic Birch plywood (that stuff is like sugar cookie dough in an MPCNC but I paid $78 for a 5’x5’ of 3/4") and odd varieties of outdoor approved ply, different MDF sizes, hardboards, etc. I also found a local metal place for my pipes, and they had some aluminum scraps in a bin for sale by the front desk. I didn’t buy any, but I made a note. If you want foam sheets for planes and stuff, skip the expensive stuff. The dollar store has them for a dollar, and it’s 10x better than the $6 stuff at Staples.

7. If you find some cool CNC designs please share here, there are a few places I’ve linked but I haven’t found a great collection that has available dxfs.

[pete7919 (Pete)]

Thanks All. I forgot to check the box for notifications so I didn’t see any responses until just now. I’ll post some pictures tomorrow, but I’ve got my table made (with drawers for storage!) and got the machine mounted and aligned. I think it’s aligned anyway.

I had a little bit of concern that the center assembly was not square. All the parts went together great with the exception of the 5" bolt that was a bit tight. Since it went together easy and all bearings were making contact I was surprised it was so far out of square. I tried to bend it and I started to hear some cracking noises. I don’t think I broke anything but I stopped quickly! It looks like most of it was taken care of when I tightened everything up. We’ll see when I power up whether I can draw squares or rectangles.

I also installed the steppers and got the pulleys on. Next step is to get the wiring and belts on. Almost time to power it up.

I did print the pen holder. Thanks for that advice. At some point I’ll probably build a better table, so I’ll keep looking into that.

Am I right in thinking as long as everything is flat, level is not really too important? Seems as long as the tool is in plane with the bed surface it would be OK as long as it’s not so far off to be a strain on belts and motors.

Also, I found a video for worktable clamps that I plan on making: https://youtu.be/O-rqf4uSXRE

[pete7919 (Pete)]

Photo of current progress. The drawers were salvaged from a neighbor that put them out on the curb for free.

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[niget2002 (David Walling)]

That’s looking really good. I like the drawers. I still need to build a dedicated stand, but floor space in my garage is a premium. I’m part way thinking of hanging my CNC from the ceiling so I can lift it up when not in use.

[vicious1 (Ryan)]

I wish I had the foresight to put all of my builds on wheels! The drawers are just icing on the cake, looks great and you have some rolling storage.

[pete7919 (Pete)]

Thanks. You can see that I had to make some room in the garage to make it fit. I just piled everything a little higher everywhere else. A good reason to clean up the garage. While in use I’m allowed to pull it out but it needs to be tucked away to fit my wife’s car in at night.

I’m curious how the wheels might affect performance or make the table wobble. I cheaped out and bought castors at Harbor freight. Just after installing I tried to set the brake on one and the whole brake assembly snapped right off. I guess I learned my lesson there.

[jeffeb3]

@pete7919

Just after installing I tried to set the brake on one and the whole brake assembly snapped right off.

Ha! I hope it broke in the loose position.

[jeffeb3]

Maybe you could just make some wooden feet to put under it when cutting.

[niget2002 (David Walling)]

I use the same castors under my table saw. I haven’t had a problem with them snapping off yet.

Take it back and get another one. Then try to be less ‘godzilla’ when you flip the brake on

[pete7919 (Pete)]

Well… I had a bit of setback tonight. Here’s where I’m at:

I put belts on and tightened them.
I flashed Marlin onto my Mega2560 + Ramps 1.4 - I was missing the power connector so I removed it and soldered the wires with a DC barrel connector.
I installed the stepper drivers.
I wired the stepper motors and attached them to the board.
I installed ESTLcam and Repetier Host. I followed the setups (2x to make sure) and input settings.
I created a test file, then loaded it into Repetier.
I connected the board. All jog movements work fine and the machine moves nicely in every direction.
I click Print. The machine proceeds to go haywire.

I tried for about an hour and a half. It would only move in the X direction. The software showed it moving in Y but it wouldn’t go. Motors didn’t seem to be working as I checked for the belt slipping. It was also spastic. Sometimes it would just tremble and the motors wouldn’t go anywhere.

I also have confusion about “homing”. My 3d printer has end stops so it goes to home until the end stop is tripped. This machine doesn’t have any. I hit home and it just flew left and clicked unti l I killed it. What is the “Set Home Offset” on the LCD?

The only thing I need to go back through is the stepper motor voltage. I’ll admit that I didn’t understand what was needed so I skipped setting it so it’s set to whatever they put it on at the factory. Could this be the culprit? I’m thinking it’s not since it manually jogs really nice.

I tried to control using ESTLcam and that worked but produced the same result. Then I had to reflash Marlin to get it back working with Repetier. I also tried the test file provided and couldn’t get that to work, either.

One other piece that confuses me is that it says not to plug/unplug while powered. The USB powers the Mega board so I can’t power it down without unplugging that. I pull the power to the Ramps and the LCD and Mega are still powered through USB. As I’m typing this sounds like a really dumb question, but am I missing something here? Is there a jumper that I missed to not have it power through USB?

Any thoughts on what is going on are greatly appreciated!

[pete7919 (Pete)]

@niget2002

I use the same castors under my table saw. I haven’t had a problem with them snapping off yet.

Take it back and get another one. Then try to be less ‘godzilla’ when you flip the brake on ?

It actually fell off without any help from me. I think the UPC sticker is really all that holds the brake on. 15 reviews on Harbor Freight’s website mention the same thing. Maybe there’s a bad batch or something.

[nailhead409 (Johnny)]

The Home function will not work without end stops. The thing you have to remember about CNCs that run gcode is the machine has no idea where the tool head is located. All it knows is from whereever it is located it goes where the next line of code tells it to. Big industrial cncs are the same way. You can crash a machine if you don’t bring it back to “zero”, the set location in which the program is supposed to start. Technically Home is as far in any given direction the machine can go until it hits an end stop.

I have crashed a commercial cnc 3 times during my time as a machinist. Twice because I stopped the program instead of pausing it and forgot to zero it before hitting the go button again. The last time I had the rapids cranked up on this little cnc and went to send it home forgetting to lower the rapid first. And then I sent it home the wrong direction causing the X axis to go as fast as it could until it hit the end of the rails going towards the chuck. I got lucky the tools were indexed in a way that nothing actually collided. Could have been an expensive oops.

So take your time and don’t rush yourself with the machine. Keep the rapids slow until you get it all figured out. When you rush or get impatient is when you will break something.

[jeffeb3]

From what I am reading:

• it jogs fine, but gcode goes haywire
• you need help understanding home coordinates.
• your y axis wasn’t moving at least once.

So let’s start with coordinates. Wherever you power the machine on is 0,0,0 in X,y,z. When you jog the X positive 50mm, it will be at 50,0,0. If you start your gcode there, it will drive back to 0,0,0 right away. You need to make sure you are controlling where 0,0,0 is on your machine before starting. The gcode you are making in your CAM is going to have a 0,0,0. In EstlCAM, there is an origin crosshair. If you set up EstlCAM from the tutorials, then the 0 Z coordinate is just touching the top of your workpiece.

So if you manually jog the machine into place, then you can either reset the home offsets to 0,0,0 in the LCD screen, or you can power cycle the Arduino to reset it’s counters.

As for the voltage on the drivers, did you buy them from vicious1? If not, then you definitely have to set them. This might be why your y axis failed. Also, if the limits are set too high, you could start toasting motors and drivers.

For the hot swap. Just don’t unplug the motors or the driver boards while anything is powered. You can plug USB and the 12V separately whenever.

The other thing that bothered me is that you connected power to the barrel jack. You don’t have anything connected to the green power input? I’m not sure the barrel jack is capable of supplying the current for the motors.

[pete7919 (Pete)]

@jeffeb3

The other thing that bothered me is that you connected power to the barrel jack. You don’t have anything connected to the green power input? I’m not sure the barrel jack is capable of supplying the current for the motors.

What I meant was that I soldered a barrel jack onto the power connector for the ramps board. I was missing the green plug for the power connector so I had to unsolder that and solder the wires direct. I just put on the barrel connector so I didn’t have to cut the end off the power supply.

Thanks for all the great advice. I’ll work on setting the voltage next chance I get.

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[niget2002 (David Walling)]

I usually power my machine on (but not spindle), then manually pull the xy to where I want 0 to be. Then I use the pineapple to lower the cutting tool until it just touches the material top. This is now my 0,0,0. I leave the ‘Home’ buttons alone in the Marlin firmware and make sure I never touch them as I don’t have electric end-stops.

Once I hit ‘go’ on the gcode, it then makes all moves in relation to that point.

I’ve even used clamps on the x and y axis to set a ‘zero’ point. This allows me to pull the x and y back to where the gantry just touches the clamps so that I can switch tools and re-zero the z axis for using the next mill on the same project. At some point I plan on designing some type of plastic end stop that I can move along the axis to do this instead of the clamps.

You ‘can’ swap drivers and steppers with the 12V removed and USB still plugged in, but I usually go ahead and unplug the USB too. It doesn’t hurt anything to disconnect it from the laptop multiple times. It sounds like you lost the green connector, so you put a bullet where the green power connector used to be… make sure your 12V is in the outer two holes. I believe the inner two on the green connector are for powering a heated bed, which we don’t have.

It’s possible you burned up your drivers by not setting their voltage first. You can test this by swapping the drivers for x and y. If y now moves but x doesn’t, then you know it’s the driver.

Do you have a SD reader for your RAMPs board? If so, you could try using ESTLCAM to produce some gcode and just run the job direct from the SD Card. This helps eliminate any computer<->RAMPS issues. I only run my CNC off of the SD Card. It’s one extra step, but I don’t really want my nice laptop in the garage with all that sawdust anyway.

[jeffeb3]

@niget2002

Once I hit ‘go’ on the gcode, it then makes all moves in relation to that point.

This depends on your gcode. You are either sending the ‘set zero here’ command at the beginning of your gcode (G92 X0 Y0 Z0, maybe), or you’re using relative coordinates in your CAM (G91, plus relative coordinates). In my gcode, if you don’t set the 0,0,0 then it will cut based on where the machine was turned on. The first coordinate in my gcode is usually on the clearance plane above the origin, so it will drive to 0,0,3.0 from wherever it was when I started the gcode.