LaserCut Mendel Assembly Blog
Photographs of Laser Cut Replacement for RepRap Mendel Printed Parts GPL3 parts Kymberly Andrus of Tech Zone Communications
A call to all users of these parts, please post, add, edit, update, whatever you can contribute. We will all be better with more information. Thanks
LIFO order please, newest stuff at the head of the article.
May-16-2010
The following assembly was done over the course of two days, 18+ hour days. It was slow, because I had only one photo to work from at the start and I'd never done it before and there were no instructions. There are many hours of re-measureing and adjusting to come. I could plug in the tested MakerBot electronics and Plastruder and make everything go right now, but the belts would fall off.
A huge thank you to Kimberly and Lambert Andrus for making this all possible and for answering my questions.
Someone was asking for Y-axis pic help, as I was. Almost completed Mendel will have to do. Those remaining pieces must be belt clamps :)
Deburr every cut bolt stud and smooth rod or you will bleed later.
Here's what I used initially.
I just threw these in straight from Speedy Metals 6 x 18" 8mm ground 303 SS bearing rod. ~$32 to your door. They are very sharp and should have been rounded off, cut me twice all ready.
Initial McMaster Carr order. You'll have "... too much of some things and not enough of others."
I use marine epoxy and quick set epoxy, silicone, white glue, Loctite, hot glue, but Not Here! Intentionally using the weakest glue I have, Latex Fabric glue (tree sap the original rubber cement). I'll move on to firmer adhesives as needed.
Weakest glue, on purpose.
Bearing fabrication. I made this up, just got lucky with washers and using both metric and SAE sizes. M6 and 10-32 nuts were used as stand-offs. M4 washers nest inside of 5/16" SS flat washers and 10-32 washers don't fit through the hole. I believe that I will be rewarded for paying close attention to the washers. They are cut and so have a smooth edge and a sharp edge. Always put the smooth face towards bearing, moving or turning surfaces, sharp face to dig in. This way the belts slide against smooth edges.
Z-axis assembled. The Z-axis 8mm ground rod has been left 'wild'. I may leave long. I glued the toothed pulleys together on an all-thread stub and then glued them onto the bottoms of the Z-axis lead screw with latex. Both the Z-axis lead screw and the captive nuts are stainless steel which is usually more accurate than zinc plated. Mine's bent. The pulleys are set so that the upper flange is lower than the all interference. The lead screw is about 5-7 mm off the base plane.
Z-axis tensioner
Z-axis drive Note: the end stop/blocks for the X-axis rod stick out. I did not see about making sure they were flush and so used spacers to drop the belt out of interference. M6 and 10-32 nuts slip over M4 bearing support nuts and make nice standoffs.
Z-axis belt
The Y-axis is the most delicate and difficult. When you begin it may not slide at all, be patient. Once adjusted it slides very well. Thanks to Lambert and Kimberly Andrus the designers and makers of Tech Zone Laser Cut Replacement Parts for RepRap Mendel. I asked for help and they set photo set of how it works, here are my shots of their solution.
The key is 12 @ 1-1/4" 10-32 machine screws, these are round heads. 36 nuts, get lots of washers, I used the10-32 washers in my bearing mounts too. I could not find fender washers, so I made my own - M4 inside 5/16 SS.
Move slowly, adjust the Y-rods to fit the Y-bearing. Keep everything finger tight. Help the Y-axis 180 bearings onto the rod. Then go back and adjust the bearing mounts relation to the Frog plate. The Frog may be hitting the rod. Adjustment in these pictures is to 0.5 mm clearance from Frog plate to rod.
I had a another problem. Even with my best adjustment the Y-axis 180 bearing holder brackets were hitting the all-thread in 3 locations. They were too tall.
The fix was an old piece of 120 grit sand paper wrapped around the offending all-thread and the held while the entire Y-axis was moved gently back and forth across the abrasive until there was enough clearance.
Here are the geared extruder parts included in the assembled kit.
Photos by stevew may-13-10
Package Arrived
Opened box
McMaster Carr belt in pulley
[Needs info] carriage parts and geared extruder parts
Bed springs
Y Axis Bearing 360 and Y Axis Bearing 180 [Need assembly info, please. The Post Processing pictures help.]
X Axis Vertical Drive Plate 360 endt
X Axis Vertical Drive Plate 180 end
Z Axis Belt Tensioner and Z Axis Motor Bracket
X Axis Carriage
Z Axis Leadscrew Base
parts laid out.
frame assembled +/- 0.5 mm, nuts tight.
1600 x 1200 Link:http://reprap.org/wiki/File:TZone_LCut_DSCN4029big.JPG
I'm impressed with the accuracy of these parts, compared to hand made. I stripped parts from two partial wooden Mendels to assemble this much. With everything adjusted and tightened, a single threaded rod I could still be removed to add a missed nut. On my (oak) RepStrap attempts this would have meant partial disassembly of the entire frame, because of my inaccurate drilling caused everything to bind.
Right now the best guide appears to be the Post Processing photos by the designers. Hopefully there will soon be photographs posted to help with the assemblies that are unique to this version of the RepRap Mendel. A photo set of a completed one would be wonderful.