I finally built an enclosure for my MPCNC. I still need to put doors on it, but there’s at least a little reduction in sound when you’re standing behind it. I might need to add some foam to the inside of the top.
All the side panels are removable if I need to cut a larger board or service the machine.
Had the day off from work thanks to a very long overnight deployment Saturday night…
So I got to spend some time cutting some parts for a friend out of MDF. These parts are for a faceplate for a woodworking lathe.
Part way through the second part I started smelling wood burning. I took a look inside the enclosure and the bit was burning instead of cutting. I bumped up the cut speed of the machine and the burning went away and it started cutting again. I also sucked up a lot of sawdust that was sitting on the board.
I started playing around with the cut speed and was able to find a better total cut speed from what it was originally set to.
After the parts finished, I put another board on and ran it at the faster speed to check. It does seem to like to cut a little better at the faster speed.
This was with a single flute 1/4" end mill. DOC .15" Feed rate: 7IPM (bumped up to 140% on the LCD). I’m assuming this means that I should be running the machine at 9IPM instead of 7.
The parts are 12" across and took about 2 hours each to cut at my original cut speeds.
In general you increase the depth of cut rather than moving the carriage around faster. Faster moves mean the inertia becomes more of a factor when you start or stop movement. Cutting deeper gives the same end result, more chips out of the bit so less heat generated by recutting the same chips. You’ll still get the same speed advantage since it’ll now take fewer passes to finish. 0.150" (about 4mm I think) is still fairly shallow in MDF. Also, unless you are primarily pocketing a 1/8 end mill will move faster than a 1/4, since there is less wood to remove.
Yeah. I understand all that, but I can’t adjust the DOC once the cut starts, whereas I can adjust the speed from the LCD.
The 1/8" single-fluted end mill I have only has a .5" DOC so it won’t do a full-depth finishing pass on a 3/4" piece of MDF.
I’ll play around some more with the speeds and the DOC. Maybe there’s a happy medium where I can get a bit more speed out of it and increase the DOC some. I still think the 7IPM I was running the machine was just too slow. That comes out to ~3 mm/sec, which seems to be really slow. My reason for cutting the speed back so much is that I was getting some pretty bad flex in the machine and a lot of chatter at the speed I was trying to run it.
I ruined a board right at the end of a cut. I decided I would go back to square one and start over. I somehow lost my tool database in estlcam that I had originally setup. I think it happened when I had a project that was using foam, so I had adjusted a lot of the feeds/speeds for running faster in the foam. Now I’m having to re-find all of the speeds that I had figured out.
This did get me into a better habit of having more than one tool-file. Each file has a ‘-material’ at the end of the name. This will make it easier to load up the tool speeds for the different materials I use.
The next design I’m cutting has a 3" circle pocketed 3/8" deep. That alone would take forever with a 1/8" end mill.
This will probably all be a moot point as my new spindle comes in tonight, so I’ll have to figure out new feeds/speeds with the new spindle’s power and RPMs.
“stupid” just cost me $40 
The new 500watt spindle came in. I’m working from home, but thought I’d take a minute to wire it up and make sure it spins… Guess which dumb@$$ screwed up and hooked the AC cable up to the wrong pins on the power supply…
It’s ok, though. The power supply that came with the spindle didn’t offer a DC speed control, just the potentiometer. If everything worked well, it was going to be an eventual upgrade path.
It’s not a very good quality video, but the gentleman I cut the face plates for made a little video so I could see how the parts performed.
Enjoy:
I had a small 12V PSU I was going to leave attached to my tool wall, and I wired up the AC to the DC output… It toasted the PSU, and a power strip I plugged it into. I decided to use one of the laptop power supplies instead.
AC is unforgiving, for sure.
Made some progress on the MPCNC lately.
I got the spindle installed and up and running. I then decided to attach a shop vac again. As usual, I tested with zip ties and when it looked like it would work, I designed a part to finalize it. I ended up modifying an existing 52mm spindle mount off of thingiverse and added a 1" PVC pipe down one side of it. It looks like I’ll lose just a tad bit of my X axis… maybe 1/2" or so?
The red part sticking off the bottom of the PVC pipe is just slip fit. That way I can slide it on/off when I need to switch end mills. The part doesn’t stick out past the bottom of the spindle collet, so I don’t have to worry about it hitting the board I’m milling.
It does a fairly good job at pulling up all the free-floating dust, but my shop vac is old and doesn’t work as well as it used to, so it doesn’t clear all the dust out of the grooves. It might be time for me to invest in a new shop vac.
Maybe I should be taking a closer look at my MPCNC more often.
I was almost to the end of a 2.5 hour program and the z-motor clamp busted and dropped the spindle into the top of the workpiece. Luckily, it was with the 1/4" bit and the machine didn’t have the torque to cut at full depth, so I was able to kill the machine. The part will be salvageable, I’ll just have to finish it by hand on the bandsaw. It’s just a circle at this point, so no big deal.
I downloaded the new Burly Z-motor clamp and printed it out. Went outside to install it on the machine and discovered the lower z-bracket was cracked in the same place that the upper one let loose. Now I’ll be printing a new one of those too.
I will admit that I’m still running the original parts from when I built the machine April 1st 2017. I just had to look that up. I didn’t realize my machine is almost 2 years old!
Maybe when we get into the new house this summer, I can take some time to print all new Burly parts and upgrade the machine. I’m also still running the original threaded rod on the Z axis. I guess that’s a pretty good testament to the design of the parts and to how well PLA holds up even when setting in a North Texas garage all summer and winter.
Oh man, lucky catch and glad you were nearby.
2 years old, it deserves a Burly update for it’s birthday! I am really starting to got extra light on all the clamps. I have not had one crack in a while. It really does not take much to keep the parts from moving in the orientation they are in …and the Burly parts are, well, more burly to resist cracking.
Made a quick video of all the fun I had this weekend. Including some fun ‘fixes’ to try to finish a long running part.
It’s been a bazillion minutes since I’ve updated my build thread.
In that time I’ve made a lot of changes.
I’ve gone back to the dewalt from the spindle. I’ve upgraded to the leadscrew, and I’ve replaced the Ramps board with a mini-rambo. I’ve recently added one of the V1 touchplates on the Z axis.
This weekend I plan on doing some serious wiring renovations on the machine. I have all the materials I need to add some better cable management. I also plan on replacing all of the stepper motor wiring with better multi-stranded cables than the crappy single-strand stuff I originally used. I plan on wiring up the aircraft connectors on the control box and using the tape-measure trick on the X,Y, and Z axis.
I also plan on re-arranging the wiring so that the stepper motors run out the back of the machine instead of the front. This should open up the front of the machine to make it easier to slide new boards in to be cut.
I’ll get some before and after pictures posted.
No pictures, but I made ‘some’ progress on the wiring upgrades.
I did get a tape measure trick tested out on the Z axis for both the stepper and the spindle. It seems to be working pretty good.
I also spent a little time wiring in an emergency stop that I bought over a year ago. It doesn’t kill the spindle, but it should shutdown the Rambo and the Raspberry Pi. I’ll still need to manually kill the spindle. It’s pretty much the same setup I had already, just with a paddle on the ‘off’ instead of just a switch.
I still haven’t wired up any of the aircraft connectors for the XY or Z axis. I guess that’ll have to wait for another weekend. I try to stay out of the shop during the week. I don’t want to be an absent parent too much.
Ok. Picture…
Next up on the list of things to change… The Y axis cable is currently coming out of the front of the machine. I want to re-route that out the back and around the edge. Then I want to do the tape measure trick on the X and Y axis. I bought all the materials to sleeve everything.
And I want to mount the Controller to the inside wall on the left hand side.
Finally, I want to 3d mount a bracket for the LCD and the touch plate to hang from when not in use.
All that requires me pulling the machine away from the wall and taking the back and side panel off. Luckily those are just screwed on.
Eventually I want to build doors for the front with plexi panels for viewing.
It doesn’t look like much, but it took me an hour or so to fully rewire the Z axis. I also took the time to cut the spindle’s power cable and run it through a connector. I can now undo two connectors and pull the entire Z assembly off.
BTW: make sure you unplug the spindle before cutting the cable… got a nice spark out of that one.
That looks great.
Oh. And you can see the new air duct I added to the right side. The fans draw air from holes on the bottom and the exhaust blows out the front.
What are those 4-pin adapters called that you have affixed to the case? Are those GX16-4?
Those are aircraft connectors. They have them with many different pin count. I have both 2-pin and 4 pin ones.
