MPCNC in WI

Hey everybody. This is my second attempt at a MPCNC build. The first one I did used the first iteration of the system and when the next iteration came out I began to print it and dismantled the old one. (Also when I tried running in the neighbors in my apartment would complain of the noise… they sucked.) Anyways I’m back and attempting to do it again and this time following the steps as closely as possibly. I recently ordered a MK3 that will be delivered in May and when that arrives I’ll be upgrading to 1" SS tubing.

Anyways here a few pics of my setup. I’m really excited to get going on this. I have the plotter ready to go, the cutter (but will need to find a place to operate not in an apartment setting), and the laser coming soon.

I’m also using the dual-end stop firmware. When I first built it I could the X-axis very square but the Y-Axis was off a lot. I’d retension the bolts and try again and yet no luck so I’m hoping that a high quality printer will produce great parts for my next upgraded build. But with that said for the plotting that I have been doing the dual-end stop is working awesome!

 

Also! If you see anything off on the pics and have suggestions for improvement hit me!

Looks great!

The plots are as flawless as they can get on a wood surface so you are on the right track this time. The laser and drag knife are silent so that could get you going without using a router.

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Cabin and Hobbs is a very good use of the MPCNC plotter. I approve. :slight_smile:

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Thanks! So two questions. I’ve been watching CNC videos all night and came across this guy:

His projects are awesome and have me super inspired. But has anybody on here used double sided tape (Permacell) for their hold downs? It looks like a very intruiging concept. I understand that the tape is expensive but could help reduce the chance of hitting the cutter on a clamp.

Also, Ryan, what do you propose for smoothing out the plotting? I need to get a mirror for the drag knife that I ordered from you so I would assume that using something like that would improve greatly.

I also was looking at the X-Carve and I really like how they use extrusion as the frame on the bottom and then the spoil board and then the CNC on top of it. I might look into that as an option for future upgradeability.

When I do metal I use blue painter’s tape and superglue as a hold down. I’ve got some quarter inch plywood strips I use, and some 3d printed hold downs as well. Just depends on what I’m doing at the time. I’ve hit a sheet rock screw before, it’s the end of the end mill and screw when that happens.

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It really is best to use a larger piece of stock. Trying to squeeze a part in is when we hit screws (we all do it). A ruined $7 endmill is always more expensive then some more material. Plastic or wood hold downs are a great idea as well as putting a box around your cut and testing the path before cutting with it.

Anything flat works for plotting, even drawing on the notepad instead of taking teh paper out first. Make sure to use as light of pressure as possible, most times I can get away with 0.5mm depth.

 

Thanks for the suggestions! I will definitely be trying these.

I made a thing. The Dewalt 660 is insanely loud and in order to ensure that I stay a good neighbor in my apartment I built an enclosure. As a good engineer this is obviously a version 1 but I was able to take the dB from around 105db to 74db. A vacuum runs around 80db. This should also greatly help contain the dust to the enclosure. Currently there aren’t any plans to hook up a vacuum as I’ll just open enclosure and clean as necessary.

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Nice box. I have been toying with the idea of a dedicated, smaller laser set up in a box like this. Air tight and vented outside. This looks like a good design for that.

Thanks. I stole my idea from the Shapeoko guys and their enclosures on their wiki page.

Perhaps adding some kind of acoustic suppression on the inside of the box might help to lower the decibels even further. Egg cartons, a layer of foam, etc.

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I definitely like your egg carton idea. It’s cheap and I can add as I go as this is something I don’t want to put a ton of money into so any cheap hack will be awesome. Thank you!

Wondering if I can get some help and clarification. I made my first cuts today using Fusion 360 and using the v10 post processor. Everything went really good until the very end. Instead of clearing in the positive Z direction (-13 to +9.8) the Z-axis instead plunged to a further 9mm which I thought was odd. I’m wondering if I could get some help on this. In the picture please disregard the almost complete facing operation, I gave up on that one as it was going to take forever to get from 1" to 0.5"…

I should mention that the steps used are 2D adaptive clearing, 2D circular, 2D contour as the operations with the 1/8" single flute bit purchased from here.

 

RoofRackFoamv4.gcode (1.42 MB)

What do the last few lines of gcode look like? Do you have it end at the clearance plane or the bed?

G1 X171.266 Y69.064 Z-13.09 F1000
G1 X171.249 Y68.999 Z-13.067 F1000
G1 X171.234 Y68.941 Z-13.029 F1000
G1 X171.222 Y68.892 Z-12.978 F1000
G1 X171.212 Y68.856 Z-12.918 F1000
G1 X171.206 Y68.833 Z-12.851 F1000
G1 X171.204 Y68.825 Z-12.781 F1000
G1 Z15 F400
M84; Turn steppers off
%wait ; Wait for the planner to empty
Everything looks good until the G1 Z15 F400 when it then seems to reverse polarity and goes into the workpiece 15mm instead of in the normal positive plus direction. I'm in the same boat as you of trying to find it out but haven't yet. When I do press the +Z direction it then proceeds to go in the proper direction.

Get rid of that M84.

That’s what I have been thinking. I tested a 2D contour only without the M84 command and it worked correctly. Why would that be affecting things though?

When the steppers get disabled, gravity may be enough to cause the z-axis to drop, particularly if you have the lead screw (instead of the all thread). My LowRider whirls down at a pretty good clip that looks like it is being driven down.

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Thanks BT. Will give a try after I make some adjustments to my model and go from there. I’m really impressed with both EtslCam and Fusion 360 for getting my creations made.

So here is my first true “production” cuts on my MPCNC. These are spacers for my SUV’s roof rack to be able to put 8020 extrusions between the factory rails without hitting the roof and have mounting capabilities similar to a product that a company called Front Runner offers.

Material - Seaboard (essentially King Starboard I think). The tolerances were pretty much spot on. https://www.amazon.com/gp/product/B00JPHTPCI/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Bit: 1/8" single flute end mill purchased from this great site.

CAM: Fusion 360 CAD designed and then used the MPCNC post processor v10 (I think) to get the cuts made. It was a goal of mine for this project to learn Fusion 360 better as I’m familiar with solidworks and then learn how to use their CAM profile.

Speeds and feeds - default which I think are the defaults that Ryan specifies for any material and had the dimmer switch controlling the dewalt at full speed.

Material Hold down - double sided tape or blue painters tape super glued together. Both worked beautifully. I love these.

Cutting Time: About 2 hr 50 mins for the big pieces and 2 hrs for the small pieces. So total for the production pieces only about 16 hours of cutting time. This in no way takes into account the foam that I used as tests. Foam is awesome for test cuts and will have to stop at HD to get more soon.

I cut down the 12" x 24" board down to 12" x 8" boards and was able to get multiple pieces off of one board. I really used the opportunity for the dual end stops to get the off-sets in the starting code to maximize my material usage. This material cuts like a dream without any melting and it finished really well. In the pictures you can see some non-finished passes which were rework and you won’t see anyways. I’m looking forward to using this material again for something.

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