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Here's what I made, here's a photo, and here's a link to the [[page]] on RepRaps wiki!
Re: Tripteron Implementation - 9 years ago
Quoteo_lampe I just stumbled across an interesting bearing type called "cam follower cf5" This might be a good solution for the z-axis dual rods? Hrm. Interesting. Could be a few uses for similar parts, perhaps. I think the challenge is still what to mount any kind of bolt/axle in so it doesn't tilt or deform the mount, if the mount is plastic. It's tricky. An ideal situation would be to find aby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
QuoteApsu Almost. I didn't get the side frame on it, just the back one. You can see it here pretty clearly. I should clarify that I *did* build a full cube frame and put the arms on it and the "bounce" was still present, both the 2020 arms and the 1515 ones. That's what I was referencing in my post a week ago or so about how frame rigidity wasn't the main challenge.by Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quotebrazenrain Ah you've been busy. Have you tested tripteron with the at least half-cube in the thingiverse model? Almost. I didn't get the side frame on it, just the back one. You can see it here pretty clearly. Quote The problem with only using bushings is they need to slide past each other at some point which limits how much you can preload the joint. Maybe ptfe washers as a substitute forby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quotebrazenrain Cool, sounds like we're on the same page. The arms are purely for extension, but their shape can be misleading. I had this crazy thought experiment that you could build a more easily enclosable tripteron using drag chains as arms. They have the exact same degrees of freedom freed, but backlash probably stacks up too easily for the X and Y axes that have to move in both directionby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quotebrazenrain ... Well, I was going to quote and respond to your post, but really you're right and I agree with everything you said The extreme hackability/flexibility is what got me excited about building a Tripteron in the first place. It's a wide-open space just waiting for more people to get involved trying to build 'em. Seems like there was a lot of static friction and my hope was if Iby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quotebrazenrain I've been using a lot of concepts from Tripteron/Delteron's development in my own design experiments. I'll probably end up with something that doesn't need the revolute joints, but my opinion is that a different geometry for the tripteron's Z-axis arm could make it a lot more rigid. The issue is that the effector's weight is cantilevered on just one (Z) arm, so the base joint hasby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quoteo_lampe I've been busy with my carbon rod version, too. But the rods I'm planning to use are still on their way, so I only made a mockup version based on a carrier I had left over from an older Delta printer and a set of 4x300mm long 6x4 carbon rods. ( The final version will be ~4x155mm long ) The carriers have a hole pattern of 20x20mm, so I'm planning to rotate them 90° on the MGN12 lineaby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
QuoteJonathanThompson I vote for a two-prong approach: 1. Go with your planned high-end machined joints, as expensive as they are: this will set the high-end expectations of what someone can reasonably do with custom machining that doesn't involve a full assembly line. 2. Once that has been done, find a way with design changes to accomplish the same quality results using more 3D-printed partsby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Time for an update, but first, Happy New Year! I must say I'm continually surprised by how much attention this thread and the Tripteron development in general have gotten. I get asked about progress and development constantly, and while the holidays definitely slowed me down and I worked on a few side projects, I wanted to say that I will definitely be continuing development on this platform. Mby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quoteo_lampe OT: This Sarrus platform, would it be a good starting point for an SLA printer? I've seen cantilevered platforms, but the Sarrus seems stiffer against z-deflection to me. Question is, will the resin run down the arms and mess up the whole printer? I guess, with the arms always below horizontal it would work. Laser would be below the VAT then. BTW, I think following the ortho-tripterby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quoteo_lampe When you do the sarrus folding_under_bed test, do you see a chance to use a leadscrew to move the arms like a reversed scissor lift? Sure, there's an arrangement where you could run the screw horizontally. Only problem is you lose Z height. With the arrangement I had in mind, it'd be driven vertically from a corner.by Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Small update, I've been dabbling with some other fun stuff, been busy leading up to the holidays. However, I've got some 2020 and leadscrew/coupler arriving tomorrow, enough to build a full, sturdy cube with a proper Z axis actuator. I think I'm going to give the orthogonal Tripteron another go with a full cube and try out the smaller 1515 arms I made for the Delteron on it. When I mocked up a Saby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quoteo_lampe It seems the collinear setup will be best with two parallel arms in 40-50mm distance. Almost like the normal delta rods looks like, but with cross-linked rods? Then use two separate screws instead of one long screw. Yeah, that is one thing I've considered, vertically or horizontally stacked arm links with cross-bars of some kind, just like a Delta. Might make carbon fiber more feasiby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quotenicholas.seward With a low enough jerk and acceleration setting, this could make amazing prints. Yeah, I agree. I could tweak the values and make it essentially not wobble at all, right now. I was just hoping for a lot better behavior and it's proving very difficult. Quote I think you just have to bite the bullet and go with wide joints. I think I would jump right to 40-50mm joints. Maybby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Alright, round two complete. YouTube Link Small amount of backlash/bounce present still, it's really hard to do this successfully with printed joints. Will have to think about the material design a lot harder. But it's an improvement!by Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quoteo_lampe I lost track of your actual joint design. It's based 0n 15x15mm beams and uses M5 bolts. But what kind of bearing do you use? Simple brass bushings? I weighted the first carbon-arm of my project, and the two 608 bearings add roughly 50% of the overall weight 5x30mm shoulder bolts, 625 radial bearings, same setup as the orthogonal, just slightly different model design. And yeah, thby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Shoulder print is looking and behaving well. Going to proceed with the other two and draw up a 2nd pass effectorby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quoteo_lampe I just found another motivation for me than just curiosity to build an ortho-tripteron. I think it's a good platform for a huge laser engraver. The focus of the laser allows a small amount of deflection in z-axis and the "bed" could be anything I want to engrave on. DC42's new firmware allows to scan a height map of the surface, which would help ironing out any imperfections of it.by Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Small update, my beams came so I got one arm assembly together for testing, seems to be pretty much ideal. Here's a video of how smooth the rotation is under a decent preload: YouTube Link And some pics: Printing the rest of the arm brackets and then I'll get new shoulders/effector with matching tongue fixtures finished up. Should be assembled and moving again in a day or two. Hopefully pby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quoteleprud QuoteApsu Not a bad start! I'm sure you see what I see, which is the Z tower wobbling, just like it did in my build. If you brace that up it should improve the behavior quite a bit. Looking decent! Oh yes! It shakes like it always wanted to make a "harlem shake" I hope more brackets will help me, as now only one bracket is supporting Z tower. Also, need to rethink of joints, maybe loby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quotekayrangandhi Quoteleprud So, quickly put the belts on and gave it a test run. Well, could be better.. Isn't it lacking an elbow joint on z arm? Looks like without that your workspace is limited to a cilinder around z tower. Good job though, I can't wait for my linear rail to arrive to try a drop in adaptation for my Kossel. I see elbows on all three arms. Take a closer look.by Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quoteleprud So, quickly put the belts on and gave it a test run. Well, could be better.. Not a bad start! I'm sure you see what I see, which is the Z tower wobbling, just like it did in my build. If you brace that up it should improve the behavior quite a bit. Looking decent!by Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quoteleprud Hello! I'm also trying to buid tripteron. At first i wanted it to be without any linear slides, only trapezoidal screws, but failed to mount arm on nuts, that it won't move, so i had a "leaning" sideways arm, as nuts "tickle" on screw. Of course used two nuts, different rubbers, screws, elongations, etc. Nothing helped.. So i ordered linear slides and this is what i've done today.by Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Small update, I've decided to try out a similar joint arrangement to what I did on the orthogonal Tripteron, except using 15x15mm OpenBeam which is light, cheap and strong. Amazon had a great deal with 180mm length pieces which is basically perfect, and they're arriving today. I've also got some 5x30mm shoulder bolts coming, but I'm going to try testing with plain M5 bolts in the meantime. I modeby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quotezelogik Hi, First, fantastic work! But why ? :p No seriously, design new concept is really interesting but with this concept what is the advantage again delta/corexy/simple cartesian ? Seem like there is many effort/torque on that joints that can be problematic with precision. no? I really curious about repeatability and precision. To me (and just to me), the only pro for a machine likeby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Something like this might be ideal, actually. They're pretty cheap, $1.82 each (for 5mm ID). I could even fit 2 per link end, with the flanges out, and only end up with 1.5mm more link-link separation than I have now, and just let the oil-impregnated surfaces slide against each other under moderate preload, with some washers big enough to ride the flanges under bolt/nut. That makes the sliding suby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Quotenicholas.seward Awesome work! Side thought: All of those joints have pretty low angular velocity. A pin joint could perform very well here. Thanks! And yeah, I wasn't sure what a good way to design fastening would be, yet. I feel like bushings and smooth axles (shoulder bolts or e-clip rod or similar) would work fine, but I'm not entirely sure. Right now, I printed a smaller/thicker effecby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Alright, got a little delayed and had a few setbacks, but my proof of concept prototype took her first steps! YouTube Link Several things aren't working great yet, but I am confident they can be tweaked and refined successfully. The first major thing I noticed is the bearings tend to bind a bit when tightened sufficiently to avoid tilting a lot, and it seems to be because their shields are wayby Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Got the beast together. At least enough bolts to stay put, while I go sleep off the hours of hunching over disassembling the old frame and assembling the new one ;P Arms and movement tomorrow!by Apsu - Look what I made!
Re: Tripteron Implementation - 9 years ago
Endstop mounted up and configured and working great! YouTube Link Waiting on final bracket set to finish printing then I'll finish frame tonight.by Apsu - Look what I made!