Assembling An M8 Rroofl Frame

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Revision as of 19:09, 15 August 2013 by Vikolliver (talk | contribs) (X Axis and Carriage)
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A Rroofl RepRap can be fabricated in a number of different ways. The closest to a true RepRap is probably the version using M8 threaded rod. This is extremely adjustable and great for experimentation, though could in theory be replaced with a cheaper, simpler stick-and-socket system for mainstream production. Americans can use 5/16" threaded rod if M8 is not available in your country.

Overview

Viewed from the front the Rroofl has all electronics on the left hand side to avoid long cable runs. The Y motor sits at the front of the machine.

608z assemblies

Rroofl 608z assembly.jpg
This pattern is used throughout the Rroofl design.

Y Carriage

Rroofl y carriage parts.jpg
File:Y bed runners.scad Easy bit first. This is composed of two Y Runners held together with a couple of 130mm lengths of M8 rod. As with this entire assembly process, put a washer (usually M8 x 17mm) between the flat, plastic surface and every nut so the nut does not chew into the plastic. Bolt the two Runners together finger tight so they are spaced equally apart at the ends of the rods and the whole contraption will sit flat on the table. Then fully tighten.


Rroofl y carriage complete.jpg
Clean the 4 flat pad areas and to these stick on one side of 4 small pads of double-sided adhesive foam as shown. Do peel off the second adhesive side yet. We need to make the rest of the frame to ensure alignment before fitting the deposition bed.


Frame Side

Each of the two sides has a Foot Vertex, Double Foot Vertex and a Top Vertex all bolted together as before with M8 nuts, washers and two different lengths of M8 rod: 2 x 380mm and 1 x 310mm.

It's a good idea to start by threading the 4 Mendel Frame Adaptors
MendelAdapter.jpg
on the lower rod and nutting them in place so you do not forget them!
Rroofl side vertex alignement.jpg
Make sure that when you bolt the last top vertex in place that you have one vertex with a hexagonal nut inset on each side - both a left-handed and right-handed version. The insets will be on the inside of the assembled frame. The single foot is the front, the double height feet at the back.

Make one side, then temporarily hold the second side's parts to the first before tightening the second frame's nuts. Use the M8 bolts needed later for the X axis. This will allow you to assemble two frames with the holes in the same place, so thing stand a fighting chance of being parallel.

Y base rods

All are 320mm rods.

Rroofl Y rods.jpg

Rear upper

One Y rail clamp, a 608z assembly, and a Y switch holder (the extended Y rail clamp). The Y switch holder will be on the right when viewed from the rear.

Rear lower

A 608z assembly, nothing else.

Front upper

One Y rail clamp, the Y motor bracket + a 608z assembly (the motor branchet takes the place of nut + lock nut on one side), and then a second Y rail clamp.

Front lower

The second rod just has the lower end of the motor bracket.

Joining Frame Sides

Rroofl joining frame sides 1.jpg
Rroofl joining frame sides 2.jpg
Rroofl joining frame sides 3.jpg

Fit all the horizontal rods - the Y ends, Z axis brackets, top joiners and the Z axis top brackets.

Note that the smooth vertical rods (300mm long) in the images are just for alignment - they need to be partly to install the X brackets.

X Axis and Carriage

Rroofl x carriage underside.jpg

Important: First task is to put two of the PLA bushings on each of the X rail smooth rods (370mm long). Secure them in place with cable ties. The bushings may look like clips, but they'll break if you try to clip them on later. If you're printing a kit for someone, give them a spare for when they discover this.

Check the X rails fit into the pits on the X Motor and X Idler Bracket - if they don't, you may need to warm up the X endpoints -very gently- to ensure they fit - you want a snug fit though! Assemble the two endpoints and the rods, then...

Slide the vertical smooth bars up and slide the X ends - motor on the same side as the Z motor (left when looking at the front of the frame), idle on the same side as the Z idle (right when looking at the front of the frame) onto them, then slide the vertical smooth bars back into place.

Once you have fully assembled the chassis, go back and look at the endpoints gripping the rail. They are tapered and have a 3mm slot in them. This is so that you can put M3 screws (washer, endpoint, washer, nut) in the slots and make sure that the rails cannot be pushed any further into the endpoints, which would cause the belt to go slack and the X axis to become misaligned.

If the PLA bushings are still lose when the X axis is fully assembled, fix them in place with hot glue or Polymorph.

Rroofl x idler end.jpg
Rroofl x motor end.jpg


Z Axis

The current gears make a lot of noise and stick until all the little bits of misprint get knocked off.

Frame Completion

Belting The Y Carriage On

Rroofl y carriage belt.jpg
Ease the frame into shape on the rails, temporarily slackening the nuts if necessary. Y Slider legs can be compressed with a bolt or zip ties if it is necessary to level the bed. The actual deposition bed is attached by using 4 small double-sided foam adhesive pads. Clean the bed before sticking pads to it.

The Y belt goes from the Y Runner, around the Y idler pulley, under the RepRap, back up around the Y motor drive pulley, over the Y motor idler and to the other Y Runner.

The Y belt is attached to the Runners with zip ties; Make loops in the belt ends and secure with zip ties. Thread another zip tie through the small holes in one side of the leg of the Y carriage, pass it through the loop in the belt and then use to tension the belt to your requirements. Note that if you leave a large loop of zip tie this introduces unwanted springyness, so you'll have to cinch it with a zip tie or two.

Back to Rroofl.