If you had all the mechanical pieces for a Prusa i3, but had to start over on the plastic parts, what set of designs would you use?
Our office Prusa i3 has just gone horribly wrong. Can’t seem to keep X-axis steps consistent, and the X-axis bearings are making a lot of noise. So I’m going to tear it down and rebuild from the ground up. The plastic parts we have are a little shabby, and we made a lot of evil hacks to get the thing to print well. So I’m looking at getting a new set of plastic parts.
Whats the best state of the art for Prusa i3 builds? Or is there a better printer I could make with the same mechanical parts?
Ah probably not worth that then. I’m just wondering if there’s a better plastic set for the i3 single plate, or perhaps a completely different style of printer we could make with these parts and minimal additional parts?
Yeah it looks pretty sweet I have to say. Hadn’t seen this one before. Love the animation they made for assembly, best I’ve seen yet. I might have to get a set of these parts made up.
@Ben_Delarre silly question, but did you try grabbing parts and trying to wiggle them (extreme care must be taken if you do this when the hotend is heated because that shit could hurt bad)? Do you know what parts are actually bad? Are all of your thread and rods still good? I just figured I would put out those questions to help you properly plan this. It could be something easy. If it is heat related, perhaps a snipped piece of soda can (sharp stuff) could be folded on the edges and then used as a heat sink.
@NathanielStenzel Not silly at all! Yeah I’ve poked around on the machine, I’m not entirely sure but I think we might have lost some balls from the linear bearings. I suspect there hasn’t been enough maintenance over the last year and some plastic has got chewed up inside them. Honestly though we’ve had so many issues with this machine that it really does need a rebuild. Thankfully I have loads of linear bearings, and I think we’ve got some spare smooth rods for this machine.
@Ben_Delarre I would probably start with the bearings and eyeball all rods and the frame after that to make sure everything is straight and that the bearings move smoothly. I would also check to make sure that none of the screws, nuts and bolts came loose. Prepare to use thread locker if they are loose. After doing that stuff, I would try another wiggle test. Granted, I have only had my printer for about a year and I have had it idle some, but I figured I would share my opinion.
Only problem I’ve had with my badly made i3 kit(A 3dCzar one) really is finding the right lubrication for the linear bearings, quite frankly I’m surprised something hasn’t gone wrong yet.
I’m using a heavy gear oil to lubricate them as I can’t find the NLGI 0 greese that is recommended for these.
And yes, the i3 ReWork will be my goal too, at least on what parts will not be custom.
I’ve been struggling with finding the right lubricant. ‘Heavy oil’(Like a W80-90) or a very light(As in, damned hard to find as it’s hard to get level light grumble) grease if you want longer term protection seems to be the trick. And according to local professional bearing shops, avoid anything with graphite/teflon/solid stuff in it.
And cleaning your bearings well first to get rid of the protection coatings.
Brass bushings also seem to be around. Much easier to lubricate, long life, reliable, I suspect more sliding resistance though. http://reprap.org/wiki/Lubrication#Linear_bearings http://reprap.org/wiki/Linear_bearing
A LOT of i3 kits have really crappy bearings and rods. It’s worth checking them more closely and trying to replace any that have gone bad, and double check the replacements to make sure they really are smooth, as well as pack some silicone or teflon grease in before assembling.
@Jeff_DeMaagd yeah the first set of rods we got in the kit were not flat at all. Second set were better but the bearings have run a good groove into the rods now so I doubt I’ll be able to reuse them.
I would get the smooth shafts from VXB. Ground and hardened, it’s smooth, straight and going to hold up. If you can swing it, maybe get the linear bearings from them too. I think you’ll find it pays in smooth operation and longevity.