Ouch.
I saw somewhere that you shouldn’t use less than 20-35% infill for PETG. FWIW. I printed mine in PLA, and at 10%, the infill wasn’t being consistent, either, but they seem pretty strong, and they look like marshmallows, so I’m OK with that.
I had to take off the extruder fan and heatsink since I literally ran out of filament, I had to work hard to get that last piece out. That, of course, messed up my carefully tuned height adjustments I made the other day, but I have it roughly working, and I’m pringing my first ZMountLR with black PETG, and it’s looking pretty good. Should I risk it and print the next three at the same time?
You can print petg with 10% infill. My spacers are 10% infill. They have 3 perimeters, tops and bottoms though. The stronger parts are 4 perimeters, 50% infill.
Regarding filament - If you can deal with issues some have with a smaller spool diameter, Dockwell filament from PC Rush is a good deal. Printed all my MPCNC parts with it. At $17.95/kilo with free shipping, it’s become my standard PLA filament. They have a “Buy 2 get 1 free” promo going on right now. Lot’s of colors and, unlike others I’ve used, the eight colors I’ve tried all print well at the same temp - 210°C on my Prusa i3 Rework variant, using an E3D-V6.
- Al
I think pet will be fine for the lowrider, not 100% sure, but the tolerances are much different.
Filament.
I was actually thinking about it last week. Those amazon prices are insane. They are so bad I signed up with hatchbox and have been getting it direct since October I think, At a pretty insane price. I could sell it on the site but I can’t figure out any way to ship it cheaply. I might be able to sell it separately and ship it first class instead of priority. What price would be awesome for a roll of hatchbox (be reasonable)? I have about 55-60 rolls on hand right now.
At the same Time I can drop ship directly to amazon and easily crush those guys, unless hatchbox tells me no…
I used to buy it for $25/kg, with prime. Yesterday I would have been willing to pay $30, but I would have just bought 2. I ended up buying some from maker geeks, so I’m good for now.
The pricing model is strange. On the Amazon Canadian site I can get Hatchbox PLA for $32 CDN (about $25 US) but if I want silver it’s $110. I recently bought some Hatchbox black PLA for $44 and it was terrible, really badly wound on the roll. It all seems so hit and miss.
I started with HB, just because it was so readily available on amazon. I’ve had the most consistent results from it. I seem to have to adjust everything for the 3D solutions stuff, but who knows if that’s a problem with the filament, or the printer. I also don’t like the huge hole in the middle of the spool on the 3D solutions stuff.
So much of filament reviews are a) subjective, and b) people blaming the filament when it’s completely due to printer issues, or temp issues, or tuning issues. There are people who print a lot (ahem, Ryan) who could care a lot more about it. Pretty much every time I print, I’m adjusting something, so I wouldn’t know if a problem I was having was the print, or something got loose, or something needs more tension, or a different temp, or the new filament. Or maybe that new slic3r setting works well for HB but not for MG…
I also don’t know much about the amazon pricing model, but I think there are always “opportunistic sellers” that will buy a popular product, and show it for sale on amazon at 2x the price, then when the original is out of stock, the only option is the shark, for $50. So $50 is basically saying, “Out of stock”. Which is why I can still get bright pink, but not black.
I did most of my MPCNC with MakerGeeks PETG, the rest with Atomic PETG. I’ve been really happy with the MG PETG and haven’t had any issues with it after going through most of half a dozen spools of it at this point.
However MakerGeeks PLA has not been as good for me. I’ve had issues with it jamming in my e3d v6 (full all metal version not lite) and acting like it’s clogged when it’s not. I think I finally overcame those issues though by adding a bit of paper towel with a few drips of vegetable oil on it attached over the filament with a clothespin as it feeds into my extruder. Since I added that on MG PLA I haven’t had a single issue even on spools that were giving me absolute fits before.
Still weirded out by the high temps MG suggests for their PLA as well…but it does seem to print well at those temps. And I’ve been doing their monthly geek box for $30 a month so my supply of their filament is building up pretty quickly. I’m probably going to have to stop the sub soon because I don’t go through two rolls a month and am running out of room to store it 
I tried makergeeks petg. I liked it, but it’s expensive. I drive past a microcenter every couple weeks when I go to a client site, so I pick up their Inland brand when I get low. Not had any issues with it so far.
I don’t have anywhere within a 4 hour drive that sells filament 
$15 a roll delivered for MG is about the cheapest I can get - I just don’t get to choose my color at that price (their grab bag or the monthly mystery box.) but for that price I’m happy with whatever color I can get
Right now you have to buy 4 rolls to get that price…but from time to time they offer that price on 2 rolls which is when I took advantage of it.
I’ve actually got some cool colors that way too. First time they sent me my daughters favorite turquoise and a yellow (which was a color I had been wanting) and the second time they sent me “bomber jacket brown” which is almost black and glow in the dark which were both pretty fun
BTW - Looking forward to seeing the low riders up and running. Seriously considering building one myself since I just won a DWP611 at Instructables with my instructable on making the needle cutter for my MPCNC Would love to shrink my MPCNC back down to 2’x2’ for milling and build a low-rider to use for cutting foamboard and other bigger things instead. Would also let me use more of my table as a workbench when I’m not cutting which would be great since space is at a MAJOR premium in my shop!
You won!!! No way so awesome!
Jason I put you on the front page, hope you appreciate the humor. Thanks for entering, and using the MPCNC.
Hahahahahahahahahahahaha!
Oh man that’s great Most definitely appreciate the humor, almost woke her up laughing as I read it!
And thanks again for designing this, a year ago I thought the idea of a 3D printed CNC was ridiculous, then thought it was way more printing than I wanted to tackle…then wound up printing all the parts twice and now love having a machine and wish I had room for more than one
BTW - On the topic of the Low Rider…I was thinking on my way home from work today. I wonder if 3D printed wheels in TPU would work. Looks like it would be printable…and with enough infill TPU is surprisingly stiff. I’m tempted to draw one up and try printing it just for fun.
Tpu should work, could probably even make them more narrow.
That’s a great Instructable. Maybe I should take my MPCNC and move it into the basement for needle cutting once I have the LR working.
I’ve been thinking more about my table… I saw that the calculator is up, and I’m going to make the first piece 60"x40" because it will give me at least 48"x24", and the numbers are round.
@vicious1, The calculator adds 14.6" to the Y length. On your build, it looks like you just made those triangles extend that distance, is that right? It seems like a good idea, not just for saving material, but also for getting the edge clamps in towards the workpiece. If I make some removable triangles, then my first cutting area will be 48"x40", which is pretty nice for that space.
The one thing I’m concerned about now is clamping the workpiece. I’m thinking of upping the top skin to be 1/2" material instead of 1/4", which would make the whole thing be 4.25" thick. Then I could use a screw or two when I get in a tough spot. I can also drill 7/8" holes for my F clamps through the whole thing, but unless they clamp over one of the supports, I’m guessing they could deform the box… I should stop worrying and just build it, I think.
Glad to hear you liked it!
The needle cutter is a lot of fun, with 20x30 sheets of foam only costing $1 it’s quick and cheap to work with. The biggest issue I have with it is the noise:
It’s not THAT bad when it’s just idling…but once it starts punching holes in the foam…it’s a bit obnoxious. Thankfully my shop is in a detached outbuilding so I can make all the noise I want out there - even if I have to wear hearing protection when I do so 
I’ve been having even more fun with the laser lately since it’s silent and I have piles of scrap cardboard I can cut. But the smoke and smell are a drawback - need to upgrade the ventilation in my shop now and that will spoil the quiet 
Think I may work on a wheel design I can print in TPU while I wait for you guys to get your low riders built. Been beta testing too many things lately to dig in on another just yet! But really thinking a low rider for the needle and a smaller MPCNC for my spindle and laser will work out a lot better for me overall.
Yeah, I wanted to mute that video by the end. Not terribly loud, but super annoying. I would wear earmuffs too. I have made a few D$ foamies with a knife, and I’m a terrible plane pilot, so I go through them quite quickly. 
At some point I’ll get back into that.
My space for this kind of stuff is kind of disjointed.
- I have a 16’x10’ shed out back, which is basically the table saw, miter saw, band saw, drill press and router.
- I have the garage, which has to still store 2 cars, and gets the most scrutiny from my wife. The garage has the MPCNC, my bike (pedals, not motors) tools, Circular saw, and small mechanical stuff. It also stores my bikes, and my hockey gear, because no one wants that in the house.
- I have a large area in the basement that I have my soldering, electronics, quadcopters, 3D printer, etc. I also have an area in the basement for doing some finishing of WW projects, but that depends on the project fitting down the stairs.
I would have preferred to keep my MPCNC in the basement, but it makes too much dust. Some dust is OK, but the amount of MDF dust this thing makes with a 1/8" bit is too much.
I’m planning on putting the LR in the space that the MPCNC is, ready to cut “small” stuff, and then roll it out where my car was to cut big stuff. But who knows…