HydraRaptor’s Second Child

Chris Palmer of the HydraRaptor project just printed us a copy of parts for RepRap – the 3D printer that can print a copy of itself. Chris is an avid developer on the RepRap team, and the documentation of his work is superb. He has already printed a copy of RepRap for himself, so the Factor e Farm RepRap is HydraRaptor’s second childbirth. Edward Miller is putting our RepRap together – see the RepRap wiki page. With that said, I’m copying Chris’s blog post on this proud moment here:

Back in March I had a visit from Marcin Jakubowski, the founder of Open Source Ecology. He was over here in Manchester presenting at a conference and asked if he could come and see HydraRaptor, as he wants to use RepRap machines on Factor e Farm. Like RepRap, his project aims also aims to change the world.

He asked lots of questions and made a couple of videos of my answers for his blog, which you can see here.

I volunteered to print a set of Darwin parts to help get Factor e Farm up and running with 3D printing. I was confident that I would have my Darwin running in time to churn out the parts. However, because I spent a lot of time experimenting with extruder designs in an attempt to get something more reliable, I ran out of time and had to print the parts on HydraRaptor.

Here they are, all 109 of them: –

ensemble

All the parts were printed with 0.5mm filament at 16mm/s with 32mm/s moves. Most were sliced with Skeinforge set to 25% fill and larger objects have double outlines to maintain strength.

Here are some stats: –

Build time Plastic volume Quantity required Total build time Total plastic Weight Cost Percentage of total
Corner bracket @ 90% 02:44:44 29.1 cc 8 21:57:49 233.1 cc 291 g $5.83 29%
Diagonal tie bracket-chris 00:27:00 4.8 cc 20 09:00:06 96.4 cc 120 g $2.41 12%
Bed corner 01:32:06 15.5 cc 4 06:08:25 62.1 cc 78 g $1.55 8%
Z-motor-bracket-chris 01:23:12 14.6 cc 4 05:32:47 58.2 cc 73 g $1.46 7%
X motor bracket 03:56:35 37.2 cc 1 03:56:35 37.2 cc 46 g $0.93 5%
X-carriage 03:51:39 40.2 cc 1 03:51:39 40.2 cc 50 g $1.00 5%
Y housing 00:56:36 9.9 cc 3 02:49:47 29.8 cc 37 g $0.74 4%
Extruder drive block 02:30:44 26.5 cc 1 02:30:44 26.5 cc 33 g $0.66 3%
X idler bracket 02:28:06 25.4 cc 1 02:28:06 25.4 cc 32 g $0.64 3%
Y motor bracket 01:51:06 19.6 cc 1 01:51:06 19.6 cc 25 g $0.49 2%
Bed constraint 00:43:20 7.5 cc 2 01:26:39 15.1 cc 19 g $0.38 2%
Bed clamp 00:21:39 3.7 cc 4 01:26:36 14.7 cc 18 g $0.37 2%
Extruder base 01:13:19 13.1 cc 1 01:13:19 13.1 cc 16 g $0.33 2%
Z-coupler-airpax 00:14:21 2.6 cc 4 00:57:26 10.2 cc 13 g $0.26 1%
Opto bracket @ 50% 00:19:00 3.1 cc 3 00:56:59 9.4 cc 12 g $0.23 1%
X-belt-clamp 00:10:46 1.9 cc 5 00:53:50 9.5 cc 12 g $0.24 1%
Wiper-diagonal-bracket 00:43:50 7.6 cc 1 00:43:50 7.6 cc 9 g $0.19 1%
Wiper-brace 00:13:24 2.3 cc 3 00:40:11 6.9 cc 9 g $0.17 1%
X-constraint-bracket 00:38:10 6.6 cc 1 00:38:10 6.6 cc 8 g $0.17 1%
Pulley 00:12:35 2.2 cc 3 00:37:44 6.7 cc 8 g $0.17 1%
Bolt plug 00:04:36 0.8 cc 7 00:32:11 5.8 cc 7 g $0.14 1%
Tall foot 00:14:27 2.6 cc 2 00:28:54 5.3 cc 7 g $0.13 1%
Y motor coupling 00:25:02 4.5 cc 1 00:25:02 4.5 cc 6 g $0.11 1%
Z-adjuster-housing 00:24:12 4.1 cc 1 00:24:12 4.1 cc 5 g $0.10 1%
Short foot 00:11:21 2.1 cc 2 00:22:42 4.2 cc 5 g $0.10 1%
Fan base 00:22:29 4.0 cc 1 00:22:29 4.0 cc 5 g $0.10 1%
Y belt clamp 00:03:43 0.7 cc 4 00:14:50 2.6 cc 3 g $0.07 0%
Fan-leg 00:15:48 2.8 cc 1 00:15:48 2.8 cc 4 g $0.07 0%
X-motor washer 00:15:27 2.8 cc 1 00:15:27 2.8 cc 3 g $0.07 0%
Z-flag-slider 00:13:00 2.3 cc 1 00:13:00 2.3 cc 3 g $0.06 0%
Bearing 360 run 00:02:47 0.5 cc 4 00:11:09 2.0 cc 3 g $0.05 0% HDPE
Extruder PCB holder 00:09:45 1.7 cc 1 00:09:45 1.7 cc 2 g $0.04 0%
Z-opto-flag 00:08:45 1.6 cc 1 00:08:45 1.6 cc 2 g $0.04 0% Black ABS
X-carriage-bearing 00:08:39 1.1 cc 1 00:08:39 1.1 cc 1 g $0.03 0% HDPE
Y-opto-flag 00:07:43 1.4 cc 1 00:07:43 1.4 cc 2 g $0.03 0% Black ABS
Bearing 360 jam 00:02:49 0.5 cc 2 00:05:38 1.0 cc 1 g $0.03 0% Black ABS
X-opto-flag 00:04:43 0.8 cc 1 00:04:43 0.8 cc 1 g $0.02 0% Black ABS
Wiper-lever 00:04:26 0.7 cc 1 00:04:26 0.7 cc 1 g $0.02 0%
Z-flag-clamp 00:03:20 0.6 cc 1 00:03:20 0.6 cc 1 g $0.01 0%
Circlip 00:01:26 0.3 cc 2 00:02:53 0.5 cc 1 g $0.01 0%
Bearing 180-x 00:02:38 0.5 cc 1 00:02:38 0.5 cc 1 g $0.01 0% HDPE
Bearing 180-z 00:02:03 0.4 cc 1 00:02:03 0.4 cc 0 g $0.01 0% ABS
109 74:28:04 778 cc 973 g $19.47 100.00%

(note: table is cut off. See source for weights and costs of materials)

The times and weights are calculated, and don’t include the raft time, which is significant, or the time waiting for temperature changes and raft cooling. I weighed the parts on kitchen scales and they came out at 931g, so pretty close to the calculation. The cost shown is on the basis of ABS at $20 / Kg.

I save all the rafts for the day when we get recycling working. I weighed them in at ~ 200g, that is about 20% wastage and will bring the actual printing time up to about 100 hours.

rafts

I also wasted 150g in failed prints, for silly reasons, more on that later. It gives a measure of the reliability I am achieving at the moment, i.e. 8 parts failed out of 117 prints so 93% success rate. Of course the bigger the part is, the more chance something will go wrong, so by weight and time it is much worse .

duds

I used plain ABS for most of the parts because it seems to bond better than coloured. I used black for the opto tabs. No guarantee that they will be opaque to IR, but I think black ABS usually is. The green parts are just ones I had left over from experiments.

I made some of the bearings in HDPE as that should be a better bearing material than ABS, lower friction and longer lasting. The black ones are “jam” bearings so I left them in ABS as they want maximum friction.

bearings

Some of the parts are my own design. Most significant are the z-axis parts described in the previous post. Here is a list of the other design tweaks, with links to the article describing them:- simplified diagonal tie brackets, X-motor washer, x-carriage bearing and the feet.

Some parts I had never printed before. The Pinch wheel extruder: –

extruder-parts

The nozzle wiper assembly has appeared in the latest Darwin release but I can’t find any assembly instructions. I leave it as an puzzle for Edward Miller, the guy who is actually going to build this machine.

wiper-parts

Similarly the new adjustable z-opto flag assembly: –

z-opto-parts

1 Comment

  1. David

    It’s great to see steady progress.

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