I am the proud owner of a Makerfront i3-pro-XL printer. This is a Prusa i3 clone from 2016. It has a
solid metal frame and a 8-inch by 12-inch bed. Makerfront alas seems to be out of business, and if I want to improve it, I’m on my own.
I have been using a glass bed - it fastens to the heater substrate with binder clips. One pecularity of this printer - although the bed is 12 inches long, the piece of glass really needs to be a bit longer - more like 12.5 inches. Otherwise, the binder clip system won’t work. Getting 12inch by 12inch pieces of glass is easy - you just buy mirror tiles at the store. 12.5 inches - not so easy. I had been using cutoff mirror tiles, and holding the bed with modified clothespins - which have a longer reach than binder clips.
I recently bit the bullet, and bought a custom cut piece of glass.
Have been lusting after a PEI top. I’m told with that, you don’t have to mess with hairspray or glue sticks… actually, the only thing I’ve found that works consistently is high-strength glue sticks… but they stick so hard that it can be a pain to get the print off. Now they have “systems” - Buildtak etc - that
use a big refrigerator magnet to hold the print-on plate - which is coated with PEI.
With my nonstandard-sized Makerfront, I can’t order a correctly sized build plate system. So I bought one that’s too big and plan to cut it down. It’s a “Fulament”. Pricey, but it has thicker steel than the cheap ones, and PEI top & bottom - textured on one side, and smooth on the other.
So now I need to cut down 12x12 Fulament to 12x8. How to do it? It needs to be a nice clean cut.
The magnetic sheet is easy - it’s soft, I can cut it with shears or even an artistic paper cutter. Spring
steel, not so easy.
Options given the tools on hand:
4 inch angle grinder with a cutter wheel. I could clamp the build plate between a couple of angle irons to guarantee that the tool wouldn’t wander. I worry about putting heat into the plate and damaging the PEI
Dremel with a cutter wheel. As above, somewhat slower, possibly less heat input
CNC engraver. I could mount the build plate on a spoilboard with the “masking tape and superglue” technique. Wouldn’t even need a gcode file - just set the height and jog the tool over. I have the engraver bits that came with it. Also have some 1/16 inch carbide end mills.
Bandsaw - it’s a ten-inch benchtop unit made for cutting wood. I might be able to get away with it if I
install the finest-tooth possible blade, and cut VERY slowly.
Sherline mill. It is 12 inches wide, so I suppose it could work, if I could figure out a decent holding arrangement. Probably same as the CNC router - spoilboard, masking tape and superglue.
I have a just bought a similar machine - zonestar m8r2 - very cheaply and will be interested to hear how you get on.
The Zonestar actually produces pretty good results, but there’s a lack of rigidity (in shear on the frame outlined by X and Z axes) that’s due to a lack of bracing at the top of the Z axis. This is despite the sheet steel Z uprights : they have folded edges that make the strt itself stiff but the crossmember at the top of Z is a single-dimensional bend which is quite poor.
I have ordered a PEI and magnetic sheet but it’s fairly close to the required size (225mm for a 220mm square heated bed) and I’m hoping it will work. If not, I’d try tinsnips on the spring steel sheet. It’s not thick. The idea of it is that it’s flat, but very easy to spring into a curve which releases the part. Think in terms of biscuit tin rather than clock spring.
I’m trying not to do too many mods : in theory I have a bigger unit in the works. But I will probably do something about the X axis. Currently tightening the belt bends the Z guides. This could easily be avoided by tightening against the X rods but floating them so the tension is kept against the left hand side and doesn’t apply any force to the right hand Z rods.
I’m not even considering tin snips ( which I do have ), because I’m afraid of warping or curling the steel sheet. I’ll be interested to hear how that works out.
That Zonestar looks like an interesting machine. Multiple colors would be great for printing embedded text on a panel. The Makerfront is far stiffer; all the steel members are laser-cut 1/8 inch thick sheet.
Alas, I did not get a deal on it; I paid full retail. But it paid for itself on one job…
My babies ( twins, a boy & a girl ) were 2 years old. Mommy was giving them a bath. The tub had a fancy sliding frameless tempered glass door. Mommy closed the door, and it exploded. Tempered glass can do that. All the glass fell into the tub with the babies. They panicked and started trying to climb out. Mommy panicked and screamed for Daddy.
I rushed up, pulled the children out of the glass-filled tub. We patched them up the best we could, and headed out to the ER, where the doctors patched them up for real.
My children didn’t want to bath in a tub with glass doors anymore. So we went with a lower technology variant - a shower curtain.
But how to mount the curtain? The tub had this nice frame for the glass doors, and a very nice marble surround. I didn’t want to tear it all apart and bugger it up with a shower pole.
So I measured the extruded rail that the exploding glass door had hung from, and designed an item shaped the the letter T, with a hook at the bottom. The top of the T fit perfectly in the extruded rail.
Printed up 13 of those with the Makerfront, and hung the shower curtain.
The curling didn’t occur to me - good point. In fact, I’ve checked my order and there’s more to cut off than I recalled, so I will have the same problem. I do have some aircraft snips which might be a bit better than the larger, straight-blade metal shears. There’s also a straight-blade guillotine at my hackspace which may be OK.
The M8R2 was chosen because it was conveniently close by and cheap rather than with careful selection of it’s features, but I did think I might use the second extruder for printing support material.
Tempered glass is indeed inclined to explode. My most traumatic experience was with a pinball backglass - an old one (1986 Strange Science) with silkscreen colour rather than a plastic translite, so loss of the glass was the end of that. Cue a very sad owner (me) and a long search for a replacement … out of production for 30 years. Painful, but doesn’t quite compare with a bathful of babies … and I did get one eventually.
Oooh. I’d start a test cut near the edge with the guillotine to see if it introduced any curling, and if not then cut it to size with the guillotine, if I had this project and that option.
If for any reason the cutting operation goes south, I’ve purchased I think eight beds from these folks; they’ve shipped promptly and responded to inquiries. I sent them an inquiry about my custom size and they told me which actual size of similar area to order and to put the real size in the comments, and for the non-square beds to put my request for whether the tab went on the long or short size also in the comments.
I cut down my “Fulament” sheet with a Dremel & cutter wheels. Came out OK. Using the newly cut sheet as a guide, I cut the magnet with an Xacto knife.
I started an 8-hour print yesterday. No hairspray, no glue sticks. Came down to the printer armed with my usual razor blades and scrapers…and just picked my print up and took it away!
Wow…it wasn’t stuck AT ALL. This stuff is amazing.
It is however sensitive to extruder height. I had adjusted the height before starting, and it was obvious that the sled wasn’t adhering well. So I adjusted the height on the fly, while the bed was going back & forth. Managed to get it sticking before it got to the actual part. I think in the future, I need to preheat the bed, and THEN level it/adjust the height.
Yeah, a big sheet metal shear would be great. My friend Ron had a really nice one. I think it was 6 feet wide. Standing right near his giant bending brake, and his TIG welder that was the size of a home refrigerator. Unfortunately, Ron passed a few years ago, and I have no friends or acquaintances with that kind of stuff.
It’s a bit of a spend for one cut but occasionally I’ll see throatless rotary cutters like this one from Eastwood on Craigslist or eBay for less than $50. I have the Eastwood one and it works well.
Also, good snips will leave a clean and level edge but if you do end up with rough or curved edges then it’s quick work to place the metal on a hard flat surface and use a mallet to strike it flat. Don’t use a hard hammer, though. That’s a good way to scrap the part by leaving even more dents!
*** That’s a cool tool, I gotta say. But I don’t think it would work
on this application. The steel is covered with a relatively soft PEI
plastic, and the tool would surely leave marks on it.
