Hey guys! It’s been a while since I’ve been on these forums. And unfortunately my MPCNC has been in a defunct state for a while. Anyways, I got it up and running again and I’ve actually made some stuff with it.
We have a large picture wall with all of our family pictures. I CNC’d the lettering and then sanded and painted. It turned out ok for my first “real” project on the MPCNC.
All said and done with these projects, I’ve got quite a bit of flexing going on with my conduit. I really wish I would have gone stainless maybe a rebuild is in order.
I was only asking because you can make it smaller, see how that works for you, and then maybe consider building a LR later, instead of rebuilding the mpcnc with SS. You’ll need all new printed parts for SS.
The Z also causes flex. If it’s more than 2", then that’s another easy thing to add rigidity. The rigidity will increase exponentially with smaller length. So if you made it 1/2 the length, it would be 4x more rigid.
It’s not a bad idea to just cut it down. I think I only have 2.5” of z movement. I really like the idea of being able to make large signs, but if I can’t make large signs that meet my expectations, then it’s just an idea that I like that I can’t actually do. In which case reducing the size to gain rigidity would at least give me the ability to make things half the size and with good tolerances.
Either way, I’m getting better at manipulating my gcode with Fusion 360 to make things I want.
On a different note, I have a few questions.
Do you happen to know how to limit the amount of gcode that repetier host sends to marlin? I’ve found that sometimes I want to change my feed rate “live”, but repetier has sent out so many commands that it might take 2-3 minutes before my change actually occurs. Surely there is a buffer or something that can be adjusted?
Is there anyway to get a view of the tool paths with repetier host? Our CNC at work uses pathpilot which gives a really nice view of the gcode toolpaths and lets you see exactly where you are at. I know that’s another class of tool, but it would be a really nice addition.
I completely agree with cutting it down but at the same time you can just make more conservative cuts and make you giant build work.
1-No, the buffer hold 8-12 commands I believe. so long straight cuts can be a huge bugger, and curves are basically instant.
2-yes, show moves. I should have this on the software page.
2- show moves only shows you a preview, not a live position. CNC.js gives you a live preview. You can install it as a standalone app or, attach a pi with the v1pi image and use a web browser.
The size thing is a personal choice. I had a similar sized MPCNC and I got some great projects, but I like to tinker with that stuff. Making it smaller will also give you sone perspective, which might be helpful. Someone needs to make a quick size changing MPCNC.
@scrounge79 Thanks for noticing, it took a very long time. There is no final clear coat. It was a lot of persistence. Paint, sand, paint, sand, etc, etc. I thought it was never going to end. I also used a very nice paint brush with a paint leveler to make super smooth coats. There is definitely an art to making it look nice, I’m not all the way there yet. Some people can make it look like that in a single coat. I had to do 3-4.
@jeffeb3 & @vicious1 ok I will enable show moves. I did notice that the “lag” was on long straight cuts, that makes sense. When doing helical moves, it was “instant”. I forgot about cncjs, I think I might give that a try. I have a laptop on a cart I move from my laser to the CNC. I’ll put it on there.
I’ve got this enabled to try to keep repetier from queuing commands after an M00 and that is working, but an @pause after the M00 may achieve the same results (in my use case).
I’m not sure what kind of performance hit you may see with ping-mode enabled though…
I also had the same problem with the lag, and I suppose because my laptop is old af, repetier wasn’t quite snappy enough for me. I picked up a couple cnc shield hats and a couple uno’s to run GRBL. For my gcode sender/cnc controller I use the OPENBUILDS cnc controller. It’s free, super easy to work with, and it only cost a few bucks to try. You will lose out on the SD, LCD, and you will have to run with a laptop or PC all the time, but IMO for the few bucks it costs, its definitely worth a try. I still keep the ramps handy for laser projects, as I feel I have it dialed in pretty well. I dont run end stops, so all I have to do is pull 3 motor leads, swap board, reconnect and go. Best of both worlds.
It’s interesting you bring up the CNC shield and the Arduino. It was only recently that I began to regret the ramps board purchase. I reconfigured my K40 laser with a CNC shield and an UNO with Grbl. Cost me about $16 with 1/32 microstep drivers (drastically cheaper than the RAMBo board) and I’ll never go back. In combination with LightBurn, it has completely changed my K40 workflow into something that is truly usable. K40 Whisperer is great with the stock M2 Nano board, but pales in comparison to Grbl and LightBurn. I’m fairly sure I can get Grbl to run on that expensive RAMBo board, and it would probably kick ass. My long term plan is to build a Core XY 3D printer and use the RAMBo board in that, and then use the cheaper Arduino solution on the MPCNC. I really wish I had at least purchased the Archim board, at least it has a 32 bit architecture and has 1/32 stepper drivers.
I wasn’t aware that it was possible to run a laser off the shield, I will have to look more into this. Also, what would be the advantage of the RAMBO board vs the ramps? I’ve built 2 core XY printers already, and I haven’t personally been able to justify the cost difference between the 2 boards. My first core XY printer was Spaulding’s D-Bot from Thingiverse. Once I came up with a way to keep the bed solid, it was set. I havent had to adjust the bed since I got ot dialed it, and it works off regular limit switches.
It’s really hard to backfeed power and fry your stepper drivers on a rambo. I’ve seen one boot a 3d printer when the hot end was moved around quickly. If you get them from the shop, or directly from ultimachine they’re pretty bombproof. The clones are flakey. The ramps/arduino combo started to give us fits, bad qa on the parts.
Off the top of my head, the only thing I can think of is that the RAMBo board has 5 stepper drivers, so you can have dual extruders. I have only seen CNC shields for ramps boards with 4 stepper drivers.
Yep, Grbl has a laser mode. Just set $32=1 and you are ready to run as a laser. Grbl uses the “spindle speed” pin as the “laser power” output. So far so good for me.
I’ve considered the D-Bot, what quality of prints are you getting from it? How do you like it?
maybe a rebuild is in order.
