Printable y-axis carriage

I'm working on a printable y carriage for a number of reasons. First of all I want to improve the positioning of the LM8UU bearings and so make the y carriage move smoother and improve accuracy. I also want to lower the y-carriage deck height and thus gain some more z-axis printing envelope plus it is a good opportunity to improve the print table levelling system. Finally I want to make more of the printer printable and not rely so much on acryilic sheet or ugly bits of MDF.

My current setup has the glass clipped to the PCB style heater which is on stand-offs from a sheet of acrylic and that in turn is on 20mm adjustable springs from another sheet of acrylic to which the LM8UU's are attached. The whole lot must be 50mm above y-axis rails and reckon that should be no more than about 15mm even with good adjustment.

It should incorporate the belt clamps and limit switch trigger and some sensible way of terminating a cable bunch on the carriage. I have been playing with cable chains but 'm not sure I can be bothered going that far.

There are a number of designs alread on Thingiverse but all of them have one or more things I don't like. Most of them have a belt tensioner which is a good idea but unecessary if you use the adjustable y-axis motor mount. The rest of them are too narrow, in my mind the wider the y-axis rails the more stable the design. I also don't want to print it in two halves like another otherwise good design has done.

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Richmond, New Zealand
Thingiverse ~ YouTube

Main issues are HBP vs printed y carriage... ie its going to want to melt...
And you cant print something wider than the print bed for the lower print bed... thus they are normally in 2 parts

But good luck!

I use LM8UU printed bearing carriages from Thbingiverse, 9mm MDF on top of them with 5mm aluminium plate and use 4 2.2ohm housed resistors as the heat, it is all nice and low can have never needed to level it but can just by using shims between the mdf and aluminium. Heats to 60C easily in about 10 mins and just works nicely. I don't have belt tensioning just pull it tight by hand and fix works really well.

The MDF acts as a thermal barrier between the hot bed and the PLA carriers, tbhe whole thing sits above the rails by max 20mm

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Experimenting in 3D in New Zealand

That sounds quite efficient Gary, I am keen to reclaim as much of that height as I can.
Thanks Dust for pointing out the unsolvable problem of printing something larger than the print area .

My first attempt does not go wide enough to take the hotbed heater directly (I am using a printerbot one that looks like a pcb) but it does do several of the other things I wanted to do so I will print it out and see how it looks. I have gone for full-width 150mm spacing on the y rails so hopefully it can be printed, it is still inside the print envelope.
Part is here: [www.thingiverse.com]

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Richmond, New Zealand
Thingiverse ~ YouTube

Are your Y rods under or over the base ends?

Mine are under, which means most of the lower y is still below the usable area.

Another option is [www.thingiverse.com]

Yes my y-axis rods are under the threaded rods too.The lowest you can have your y carriage is limited by the print table clearing the y-axis idler at each end on the threaded rods and this is a shade over 20mm, probably 25mm to be safe. I like the idea of that raised z-motor mount to clear the print head motor but I would worry about the wobble it might make. The obvious way to get more height would be to scale up all the threaded rods but the stability thing again.

I still want to be able to print the y-carriage in one go but at the same time I want to mount the bed heater directly to the carriage via height adjusters so I might have to look at a two-part carriage much as I dislike the idea. Either that or make very strong out-riggers for each corner. The problem with heat tansmission might be sorted with the stand-off distance from the hotbed through the adjustable corners to the PLA y-carriage, I am not sure how hot the screws get so will have to test this. They do make ceramic spacers that would fix this problem too.

And Gary you have got me wondering how much adjustment we really need, I might not need height adjustment if I set it up once right like you have done. It might change when you move the machine so it will be interesting to see how yours prints once you set it up again in Chch.

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Richmond, New Zealand
Thingiverse ~ YouTube

Solved the problem of mounting the hotbed onto PLA - just bought a 100 m3 screws made from nylon 66 which has a melting point of 265 degrees C.

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Richmond, New Zealand
Thingiverse ~ YouTube

I don't know I'm not using a Prusa as I sold the last one before I left Nelson I'm back using my Sells Mendel again or at least I will be once I'm all settled in here, have even been donated a desktop from another forum I'm on to see if it solves the step problem I have had since having to use my netbook.

Ever since going over to printing from my netbook I have suffered from missed steps which is why I'm making up a SD attachement for one of our sanguino boards.

I never had this problem when I was printing with my old crappy desktop so will see how it goes once I pick up the donor one and get going again

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Experimenting in 3D in New Zealand

Had a problem with printing my carriage, it is under 200mm but is a tight fit on the printer bed. I have redesigned my end stops to get the maximum bed now and will try it without the skirt.

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Richmond, New Zealand
Thingiverse ~ YouTube

Version 2 came out better, thicker walls and LM8UU clamps.

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Richmond, New Zealand
Thingiverse ~ YouTube

Version 3 works really well.

[www.thingiverse.com]

Edited 1 time(s). Last edit at 09/05/2012 06:05AM by Wired1.

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Richmond, New Zealand
Thingiverse ~ YouTube