Sketchy Hanging CNC Router (Maslow)

During a Black Friday sale I gave in and snagged one of these.  They have intrigued me for a while.

This is a MakerMade M2 kit.  Its basically an upgraded version of the Maslow with a couple more precision parts, including a good Z-axis drive.  Its a hanging CNC essentially.  Instead of driving X + Y to follow a path like a traditional CNC, it manipulates 2 of the 3 legs of a triangle to target the path instead.

Monies spent so far (I will periodically return and update this)

MakerMadeM2 Kit: $849.15

Lumber for frame (delivered):  $116.54

Router: $101.62

0.250" Bit: $14.98

Dust collection:  $165.68

Total:  $1247.97

A long time ago, I bought into the home 3D printer craze.  This must have been approx. 2010.  I bought a 'ready to go' kit based on the RepRap.  It was not a pleasant experience.  I could never get it to level correctly, and just about everything about it was not straightforward.  I was very skeptical of this and hoping the same did not happen.

Well, it isn't straightforward, but not as bad as the old hobby 3d printer stuff.  The instructions skip a step once in a while, but overall are pretty decent.  I'd say it took me about 8 hours to do the frame correctly & setup the machine.  

Initially I had my motors plugged in backward, and it took me a while to figure that out.  My Y axis was flipped in the software, which I was assuming was just a simple setting.  It would move precisely in Y, but when moved in X, it would drift upwards in Y.  

After figuring that out, I was able to calibrate.  This requires fumbling through a process that really needs some clarity and some bugs worked out.  Once you've done it once, its super easy, but for someone just jumping into this it can be rather confusing.  It feels super weird to calibrate a precision machine while only measuring with a tape measure.  Thankfully the final step involves positioning the machine relative to the edges of the presumably accurate 4x8 sheet, and there I can measure the error to many decimal places with a set of calipers.  I was able to achieve what I think is a pretty decent calibration to start with:

No I don't know what "1mm" of accuracy means.  If that is between any two points, that is not so great.  If its across the 96" length of the cutting area, I'd say that is pretty good for hobby level stuff.  I'll do some experimenting with this soon, but in the meantime I intend to keep my fits a little on the loose side where possible.

These have my attention. Please keep us updated!

Last night I made my first test cuts.  The software I used to generate the G-code was Easel by Inventables.  Its a web based app that is super simple.  Rather than use one of my own designs, I just took one of their ready made plugins and have it a shot.  I used it to generate a 6x6" open topped box.

Cut #1 was bumpy.  The height of the bearing ring was a little too high, making it easy for the router to start to lift off the sheet.  The Z axis wasn't secure enough and I think during one of these tips, it slammed down on the sheet and knocked it out of calibration.

Cut #2 was smoother, although I was cutting too close to the RH edge of the part and there was no support for the router sled, so it would tilt, meaning the edge of the cuts got ugly.  I held it in place for the last 2 by hand just to finish it up.

Ultimately the biggest thing wrong with the cuts was that I didn't give it enough Z travel.  I told the software that my wood was 0.472" (as measured with calipers), but given that it isn't 100% flat, and my initial Z point could be off by a tiny amount, on some of the pieces it did not cut all the way through.

Lessons learned:

• Add a buffer to sheet thickness/cut depth.
• Secure the Z axis properly.
• Check the ring so that the chains are parallel to work surface.
• Don't cut so close to the edge of the sheet, or add scrap to support near the edge as necessary.
• ADDRESS THE DUST COLLECTION PROBLEM

I've never seen one of these, following with interest

I meant to look it up, but will this cut aluminum, or only wood?

People cut a lot of different things with them.  I'm betting you could do aluminum, but it would A) be slow and B) you'd need a different router/motor.  This is a wood router and the lowest cutting speed is like 10K RPM, I can't imagine that's going to work for aluminum.

If I wanted to make something out of aluminum, I'd use this to test-fit then just order a laser cut or water-jet part.

Tonight I tried to address the issues I discovered last night prior to cutting anymore.

Z-axis was hopefully an easy fix.  I returned the screw to where it should be then tightened the set screws.  The set screws are the only thing holding it in place, but set screw against a threaded rod is not the greatest idea.  Additionally, they are mega tiny so hard to tighten without destroying something.  Not a great design.

Dust collection is a simple fix, but I'm sure this is only the first iteration of it.  The first thing to address was preventing the chips from flying everywhere.  The hole in the sled is 2.99", but the largest bit I use is 1/4".  Now its nice to have that much area to see what it is cutting, but it doesn't need to be open.  I have seen people put plexiglass over this, but I didn't have any available.  However, the lid from a plastic cup fit surprisingly well.  I cut off the straw hole part of it then just stuck it in place with silicone.

Now for the actual dust extraction.  This is also not a great design.  I'm not sure what size this PVC elbow is supposed to be but it A) fits nothing at home depot and B) doesn't fit shop vac hoses.  So, either its metric, which would be odd because this is from a US company or its maybe some weird size specific to commercial grade dust collection?

Anyway I was able to find hose extension adapter that I could fit inside the elbow after trimming down the rib on the end.  Then I could put a hose in that.  So the air path now is CNC sled -> dust separator -> shop vac w/ bag insert -> shop vac filter -> exhaust.  I'm not sure if I should replace the shop vac filter with a higher grade filter, or if this 3 stage filtration is enough.  I wear a corona face mask since I have them around as another added layer of protection.

This is what it looks like behind the frame

From the front:

I do need to secure the shop vac better.  Not sure if I want to put wheels on it or not.  I also need to figure out hose routing.  What I have might be fine, but I am not 100% confident in it.  The PVC elbow is only press-fit into the wood sled and its pretty easy to knock out.  The hose is rigid enough that if it moves at the right angle it could pop out.  I have an idea for a c-clip style clamp I can cut out of wood to secure it better.

I've been eyeballing these for some time. Looking forward to seeing how you like it after some time.

thanks for posting , 

this looks like something I  want someone nearby to own so they can make something for me !

Good Luck with it ,  hopefully you find some neat things to make.......  I have a few ideas.....

I've wanted one of those but can't justify spending that much on a kit when the plans are open source and the only part that is difficult to find are the motors.

minivan_racer said:

I've wanted one of those but can't justify spending that much on a kit when the plans are open source and the only part that is difficult to find are the motors.

Certainly understandable.  I'm not sure how much it would cost if you built it yourself w/o a kit, but I can't imagine the difference being more than $200-300?  Either way, worth it in my case to get something already engineered to minimize the number of problems I have to deal with.  This is my first experience with a CNC - I might consider a more DIY solution in the future.

Definitely following with interest. Having Z control makes it a proper carving/engraving tool and not just a 2d cutter. 

Keith Tanner said:

Definitely following with interest. Having Z control makes it a proper carving/engraving tool and not just a 2d cutter. 

What type of projects usually utilize the 3rd axis?  I'll be honest, 80% of mine are 2d cuts.  The other 20% are basically 2d cuts at a couple of different depths.  No true 'carving' really.  I'd like to give that a shot if you have an example.

2D cuts at different depths is 3D :) For a really crude example, you can carve cup holders into a piece of wood. I've just found there have been a few times with the laser that I've had to stack parts to create a socket or recess. This setup makes it easier to hide joins. 

Keith Tanner said:

2D cuts at different depths is 3D :) For a really crude example, you can carve cup holders into a piece of wood. I've just found there have been a few times with the laser that I've had to stack parts to create a socket or recess. This setup makes it easier to hide joins. 

Haha fair enough.  Yes, thats what I do.I think some people want it to perform more like a 3 axis CNC, which in theory it could, but Z travel is pretty limited, so I'm not sure what they are carving with it.

Oddly, enough, I do need to make a cup holder out of wood for my current project, but I haven't figured out an easier way than stacking a bunch of rings on top of one another, with a cap on the bottom.

Lots of experimentation this weekend.  Some minor success, but overall things are not great.  I'm seeking help on the Maslow forums.  My chains have too much slack toward the bottom corners.  Almost like the sled has too much friction or not enough weight.  Its making getting a good calibration (since I moved the board down 3") difficult.  And I basically can't cut on the sides.  Bad cut:

In the meantime I can use the center of the machine for cutting stuff.  Good(er) cut:

The tension still impacts in the center, as those holes aren't as round as holes should be.  Anyway, this is what the end product will be:

Test fit of the first part:

I did secure the dust elbow better though.  I cut this horseshoe about 0.050" undersize so it has a really good grip on the elbow:

Using the tool to make parts for the tool is a true DIY rite of passage  :)

Keith Tanner said:

Using the tool to make parts for the tool is a true DIY rite of passage  :)

I feel like most projects I see from woodworkers are better ways of organizing their woodworking 

For the same reason that quilters and sewists are always making bags to hold their sewing stuff.

If I'm seeing this right, you can cut a 4x8 sheet and you can screw a smaller piece to it if necessary. How close can you get to the edge?

Right now the chain slack is preventing me from getting too close.  But otherwise I would be limited by the sled wanting to tip over the edge.  I can add support around the edges to fix this, just haven't done that yet.  What I see most people do is shift the cutting board back and forth and mostly use the center 6ft.  I'm ok with that, but I would prefer to be able to use the whole thing.

As it is right now, that top cut could go maybe an inch or two up toward the edge without adding any additional support.

Some updates:

I spent a lot of time recalibrating last weekend but had lots of trouble.  I couldn't be sure my Y travel was moving straight up and down (which hinges on the chains being centered).  The calibration process seems to not be very precise.  I finally redid it in a way where I achieved "1mm" calibration again, but the weird thing is... I don't know what I did different.  I've been very meticulous.

Anyway, I finally got around to cutting some more stuff.  I pulled the plastic soda-lid out of the middle after someone suggested I may have too much vacuum, preventing the sled from sliding down - contributing to error in the bottom corners.  Unfortunately, now its way messier.  I might try some middle ground where I poke some holes in it for air to pass through but hopefully minimize the sawdust flying out.  Otherwise I could make a small spacer with radial air passages to raise up the top.  This could be cut in a way that air passages allow air in but not chips out.

I also sanded and waxed the bottom of the sled to make it slide a bit easier.  I don't think that the wax was terribly effective as my garage was only like 55F when I tried to apply it and it was pretty hard.

Some of my recent cuts:

Dinosaurs, because... well... Dinosaurs:

KB tray for the sim mods I posted earlier.  The cupholder will go inside the pivot on the left.  I looks a bit oversize, but it needs to accomodate a glass from my kitchen as well.  It definitely needs some love from the sander though :)

Note that the knob is just a piece I cut as well.  I put a hex in it and then pressed a bolt through it.  I worked out well.

ProDarwin said:

Anyway, I finally got around to cutting some more stuff.  I pulled the plastic soda-lid out of the middle after someone suggested I may have too much vacuum, preventing the sled from sliding down - contributing to error in the bottom corners.  Unfortunately, now its way messier.  I might try some middle ground where I poke some holes in it for air to pass through but hopefully minimize the sawdust flying out.  Otherwise I could make a small spacer with radial air passages to raise up the top.  This could be cut in a way that air passages allow air in but not chips out.

If you google "CNC dust skirt" you'll get a whole boatload of ideas to choose from.

Something like this would probably work well.  It will flex enough to allow airflow. https://store.shopbottools.com/products/dust-skirt-replacement

Thanks. I was looking at doing something like that using a brush-type material but I like the clear plastic better. I need to think of a solution that makes it easily removable so I can change the bit, verify Z distance, etc.  Might be as simple as a velcro ring around the router.