I’m planning a build of a burly MPCNC. I have a project in mind for it that’s going to require a 16x18x1/2” machinable working area and here’s the kicker, it’s mostly going to be cutting steel or aluminum. I understand the larger area and harder materials might be problematic but that’s what I need from it. Doable?
Tube length calculations
I’ll probably round up the numbers for wiggle room.
I’ll probably need a little more more machining area in a future project so 18x18, and I want a decent amount of height but I also want stability and accuracy. I do understand lever effects. So I’ll put in adjustable height legs and 6” of z, but then only use what I need in height only extending the z as much as needed for the piece. I got this idea from the build thread “My MPCNC made in China”. I really like the bed auto leveling feature too, Great Idea. I’ll need the stoutness of “Red, Black and on wheels” awesome machine Ryan.
Whatever other mods that will help with machining steel & aluminum.
I’m still in the process of sourcing SS tubing/conduit the only stuff I’ve found around here is 1.05” OD. Which I think would be great because it would have a wall thickness of .15 (1.05-.75)/2 unless I’m off on the ID. That would be really stout, and I’d trade the speed for machining abilities. I do have a hictop 3dp-12, I built and that I have recently flashed with Marlin RC8. I’ve only printed PLA and ABS so far. I’m thinking of getting some PETG for any parts that may need it though. Thanks for all the design and hard work from Vicious1, and everyone else that has contributed.
Do me a favor and just have a look around for a machine that is capable of these dimensions that can mill steel. I see the least expensive by far a tormach 1100M at $15k-$25K gets you 11"x18" (198in2). Unfortunately you are not even in the ballpark with these requirements (you asked for 324in2).
Plasma, sure. Not milling.
1.05" is 26.67mm, and that will not work with the 25.4mm set.
I did know about 1.04” not working, I am looking to order 1” true OD SS tube. I didn’t know about pla being more rigid. And I could use some guideence in the rest of these areas. Are you suggesting I bring the z down to 1.5”?
There are so many little thing I suggest poking around all/every the pages for the machine you want, and the FAQ’s. Half hour of catching up will come in handy.
Steel…That is not something I will ever promise anyone, it is not easy. So if you are coming at this with steel as your goal you should just start with a much larger machine. I did not even think it was possible until a few months ago.
I managed to find some 1” outside diameter tube from a supplier here in town. They had 1” OD 304SS 0.065 wall. I bought all they had left in stock which was one 3’10”, one 7’7”, and one 8’ piece. So I’m one step closer to being able to build this. Last night I ran a 20mm test cube on my printer. It came out 20.1mm in x at the middle, but 20.2 at the top and bottom of the cube. 20.25 in Y middle of cube and a little wider 20.29 top and bottom of the cube. z is closer but 20.05 on the sides and 19.9 front and back. I know I’ll need to adjust x & y steps per mm but to how much? should I Just average my results and then divide by what I want (20) and then multiply that by my steps per millimeter to get my total steps per millimeter. What’s throwing me off is the variances in each X,Y,Z measurements.
How accurate does my printer need to be for these parts. BYW, I’m not great at figuring out code and this was my first flash of Marlin RC7, since I’ve flashed a few more times with different z offsets trying to get it to print the first layer right. I wrote some measurements into the bed leveling of Marlin that I may have gotten the wrong.
Overall dimensions are close, just a little off. One way or another, not consistently larger or smaller. So I think my mm per steps are on. Microsteping seems to me to be inaccurate. Anyway I started printing mpcnc parts. I seem to have some problems with overhangs curling up. Only on the right side though. I added more cooling fan, that seemed to make it worse. If anybody has a good easy to follow guide on how to calibrate your printer I’d be interested. Now that I am ready to start putting it together, the kit has gone oos. I searched for when it would be back in stock, and saw your replies that. Shipments were held up with no definitive date. I was thinking of going with the achiem board, am I correct that it will do the Dual Endstop/firmware? I’ll want to go to that later. And are you just oos on the steppers for the kits. If so what would it cost me for a Archim board in a kit with dual and series wiring, without the steppers and anything else oos?
But last time I was printing with 220°C, I had the fan on. I was still having the curling a problem in fact it was worse. Last night I was printing a pair of the rollers and I was watching and I thought it looked like it printed significantly better this time. I also have a enclosure around it this time to increase the ambient temperature.
This is the techniques I use for ABS, seems to be working.
I’ll also profread a little more before posting, speech to text, that typo is embarrassing.
I’d stop trying with ABS (I hope you weren’t trying that at 220C). At this point, that’s an advanced filament (because you need to really dial everything in. feed rate, nozzle temp, ambient temperature). PLA is much, much easier. Get those right first.
And then 220C is really a bit too hot for PLA, try 210 with some cooling after the first couple layers and keep your heat bed around 60C and. If your printer is in a cold place… you need room temperature for PLA to print nicely. I’m running my Prusa mk3 in a semi enclosure, ambient temperature in the enclosure is about 35-40C. This yields strong, good looking parts.
This print curled too, I just can’t see that kind of detail in the enclosure. I’ll probably be lowering the print temp next to see if that works. I am using PLA here. It is the first time I’ve been running this filament, it is supposed to be a better filiment. I do run it hot. My old filament would have layer adhesion issues running below 210°C , I’m just used to running hot. I’ll run a test at 210.
Thank you for the picture. Keep posting them. Because that looks over-extruded (using too much plastic). 210C and start by lowering the amount of plastic you’re using. Either by lowering the extrusion multiplier (try 0.95 for 95%) or measuring your filament diameter and adjusting that in the slicer or adjusting the extruder mm per step.
What printer do you have?
I know you just want to build, but do yourself the favour of getting your 3D prints really nice. Print benchy http://www.3dbenchy.com until you get it to look nice and clean. Measure it until the dimensions are spot on. That way, there will be very, very little to adjust to square your MPCNC. Without adjustment, my 70x90 cm frame was square to within 1.5 mm, my middle assembly XY came out at about 1 or 2 degrees of perpendicular. I had trouble measuring them. My prints are very clean.
“I do have a hictop 3dp-12, I built and that I have recently flashed with Marlin RC7, (I had to check). I’ve only printed PLA and ABS so far.” I have checked my filiment and it was 1.75 in enough spots, I just left that alone, I’ll check again at lunch. This is new filiment.
I got 1.74, 1.74,1.73 & 1.74 E steps per mm are at 94.4, I run 55*C bed temp. It’s some kind of Prusa clone, I’m not sure which, ramps 1.4, 24v PS, modified w 10mm y rods and 50 mm of z lift for that much more z height.
I’ve got some questions about the Archiem board vs Rambo. I’ve read somewhere here that along with 1/32 microsteping the drivers have less current capabilities? How much less? And does it come pre flashed with ready firmware. Somewhere I read that it was still experimental, Ryan hadn’t made a cut yet (may have been an outdated article) and firmware was still being developed. I also think I read that all of them get your firmware flashed. I just wanted to know where the firmware development sits right now? Archiem can run 24v? For future mod, I saw that “Big O” got it running without too many problems on a ramps board, I know Archiem’s specs said it can handle 24v but has anyone done it? I like 24v on my printer.
