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DemonDeltaTube - A delta inside an acrylic tube... Build

Posted by DjDemonD 
Re: DemonDeltaTube - A delta inside an acrylic tube... Build
March 08, 2018 07:53PM
So I added some anti-backlash nuts and reprinted the carriages in carbon fibre PETG, makes no difference to the calibration deviation, it remains at 0.25mm.



However in terms of real world results I just printed this Marvin:



and the layer registration issues seen in the previous cubes seem to have vanished, in fact, he has visible facets (Nebbian's test of quality - where is he these days?)
So a couple of things I've learned:
-Use anti backlash nuts for leadscrews especially on any axis which is prone to rapid changes of direction - so less necessary with a heavy z axis, more so for X, Y or on deltas.
-Don't use Ngen for structural parts I have had several snap, I might be flamed for this, but it's overrated, its quite brittle and very stringy even when you are trying hard to tune the stringiness out.
-For printer parts consider using carbon fibre filled PETG (I am using Technology Outlet) this stuff prints well, hides the layer lines and seems very stiff and certainly stronger than unfilled PETG.
-I don't think I've said this enough - Don't build a delta printer in an acrylic tube.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions

Re: DemonDeltaTube - A delta inside an acrylic tube... Build
March 08, 2018 11:21PM
I think this would be a great printer if the prices for clear acrylic tubing in large sizes were cheaper. This company has OD sizes up to 27" and lengths up to 6 feet, but the prices are very expensive:

[www.eplastics.com]

The tolerances should be very good, and the cast tubes are much better than their extruded counterparts.

Edited 1 time(s). Last edit at 03/08/2018 11:25PM by klcjr89.
Re: DemonDeltaTube - A delta inside an acrylic tube... Build
March 09, 2018 02:20AM
Yes prices for cylindrical transparent plastic are very high.

I'd suggest that a transparent cylinder like a fishtank would make a very good delta enclosure placed over a more conventional frame, but using it as a frame makes for a tricky build. Although the next step if I was going to make more would be figuring out how to make assembly easier.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
Re: DemonDeltaTube - A delta inside an acrylic tube... Build
August 09, 2018 07:13PM
Just wanted to say this machine is now dismantled. It worked but not that well compared to many of the cheap, readily available and generally quite good printers out there. I'd like to build a leadscrew delta with a regular frame, as they were neither slow, nor inaccurate - how long they would have lasted given their much greater duty cycle compared to when used for a typical cartesian or corexy z axis is unknown.

The main issue was that the acrylic cylinder did not tolerate being heat cycled from ambient to 55 deg repeatedly and developed major cracking, it looked like it was about to fall apart.

Parts are on ebay [www.ebay.co.uk] as well as some other stuff, some of it 3d printing related.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
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