X-Axis & Extruder Carriage

I decided to redesign this area of Huxley, as i felt that all those bearings and RP parts was a bit over the top.

X-axis (http://www.thingiverse.com/thing:4831)

I took inspiration for the Prusa Mendel, but tried to make the part simpler and slightly more attractive!

 

The axis is now made up of only 3 pieces: Idler side, motor side & the extruder carriage. I have not used any bushings or bearings for the idler or motor side; drilling the abs hole out slightly larger than 6mm allowed the silver steel z-axis rod to slide through easily without any play. As the axis is moved only a small amount by a lead screw the torque is high enough to overcome the increased friction, and there was no chance of an increase of heat. 

Extruder Carriage (http://www.thingiverse.com/thing:5421)

I wanted to make a very low profile carriage so I could allow for a concurrent second extruder in the future, which could be used to extrude support material. I used the same PTFE bushings as I did with the y-axis. These were turned on a lathe from 16mm bar stock (M6 hole and 10mm long) and push fitted into the printed carriage. 

From thingiverse:

‘Insert a M6 nut into the slot to allow a M6 bolt (or grub screw) to lock the thermal barrier in place (If you have a shallow M6 hole on the thermal barrier then the bolt can locate the extruder head in place... will hopefully save recalibrating when the extruder gets fiddled with!)

Finally use a short bolt (M6x15) to self tap into the side of the carriage to allow the timing belt to be attached.

Bushings:

Machine/acquire some 16mm round PTFE into 4x10mm lengths with a 6mm drill (or use US drill size C for a really nice fit). Then simply push them into the recesses with a small drop of glue (be sure to use a length of M6 silver steel to keep the bushings aligned)’

Y-axis

For the original Huxley design i felt that the y-axis was over complicated, and required the use of a froglet (complex flat shape to hold the bearings etc) which was recommended to be laser cut. I chose the simpler option of using a square of aluminium sheet (160x160mm) and bonding 4 PTFE bushings to the underside (using long setting epoxy resin was worse than super glue; which is still holding firm!).

To hold the timing belt i was feeling lazy so i drilled a couple of holes in a bottle cap and bolted it to the underside of the aluminium sheet to clamp down on the belt. Simple but effective!

Finally i wanted to make the build platform quick release using magnets, so i can get on with a new build while i clean up the old platform. To achieve this i used a nut and bolt with a spring inbetween (to adjust the level of the bed) I glued a neodymium magnet onto the bolt head (M6 bolt & 10mm diameter magnet) and to the underside of the build platform (making sure they were the correct orientation!) This worked surprisingly well, i could use the head of the extruder to align the build platform buy turning the nuts.

Also working to researching composites has its benifits.. a carbon fibre build platform!

A quick and ugly video of changing the platforms: