The press - I've gone for the big is big approach. To be honest I found this box section at a powder coating factory, they do bridge parts, so went with it. I was able to pick up the steel for less than the scrap cost, it's 10 mm thick, but these were just splinter by their standards. Everything is bolted together, although some adjustment was necessary. Lucky, because my welding sucks!
The relief valve is set at 65 psi - reclaimed from an old compressor. The silver sheets is insulation and I have filled the cat tracks with Kingspan ... I know, but I had a couple of free hours and I was feeling particularly eco that day
The insulation is important because I'm heating the press using two carbon underfloor heating element, 160w/m2. This is my cheap heat alternative and so far they have been able to reach the required temperature when pressing: 40 degrees C and 60 post cure. I'm still testing, but they seem quite durable.
I'm still fleshing everything out, posting as I go, hence the post and would appreciate comment and pointers
The carbon heaters are powered by the usual PID controller and SSR. I have earthed the box using the earth provided by the power cable. The press is earthed to the box and the aluminium sheet to the press. I have found this helpful - static discharge!
This is my planner jig, I'm 99% there! I'm happy with the results, as a blank core takes about 10 mins and the error is in the region of 0.05 of a milimetre. The way it is made allows for as many variations in height. I printed the profile from snowcad and cut using the method below.
I've made the jig for cutting the base material in the same way i.e. using the same strip of uhmwpe. The uhmwpe is screwed to the blank and the desired pattern is cut using a bearing flush trim bit. Putting a paper template on top of the blank and screwing the strip on top will work too. Little or no finishing is required, although a much longer piece of PE would be better.
So that is the stuff that has worked - this is the stuff I learnt from
Due to cost complications lol, I started off testing PVC hose, 2.5bar burst pressure ... confirmed. Initially it was £2.00 per metre versus £20.00 for fire hose.
My experiments (honest, I was running a test on this) have shown that without a relief value, the pressure of the connection around valve becomes critical... obvious I know. Relief valves don't get mentioned a lot, but its worth serious consideration. Anyway, the first image is the resultant tear, the second is a bang. As I preferred the tear I have avoided going super tight on the coupling now that I am using fire hose - the bolts and the angle iron at the end of the hose would never fail. Its a bit of redundancy in the system because I have the relief valve, but I used to Kitesurf a lot, so I am always thinking about secondary systems. The conclusion was that the absence of a suitable safety margin when using the PVC hose meant that I got in touch with a company that repairs fire hose. They supplied about 20 metres at the best price in the UK - I'd been looking for about three weeks. I asked for 6 metres. The guy had a local appointment and spent an hour and half in the garage explaining the way he would do things - really useful. He mentioned that the hose will form its own washer if you grind a grove (ring) into the coupling. I varied the approach and drilled a series of dimples into the steel washer, not the brass. No worries at 65 psi - no leakage or movement. Oh yes, no sealant required at the ends or around the coupling. At the ends, I used really thick angle iron, 6 - 7 mm, which ensures the ends are clamped shut. I had this hanging around the garage. Initially, I folded the ends back on themselves when testing the PVC hose - it works with water right. and it works, but its unnecessary. The bolts are to the usual standard specified throughout the site.
This is my attempt to flame treat engineering grade uhmwpe. One section clearly failed, abraded only. The way the material reacts to the flame - distorting the plastic, means that I'd have to think long and hard before trying it again on material this thin. I guess it's a bit of an art.
I'm running tests at the moment and still making a few revisions. Hopefully I will source the rest of the materials (next week), I'll be up and running a few weeks later. Please feel free to ask questions. I'm more than happy to post more photos
Thanks again for such a great sight and content!!!
Rich
Update
I thought what I was saying about my planner jig was correct, but I was relying on too few results. I'd been told by all the woodworkers I've met that wood was the way to go, but mdf is more accurate - blunts your blades over time ... anyway, I measured the two sets of skis and the results showed that the planner will produce highly accurate results. I have revised the jig and the results are further down - left and right side. I've run five mdf blanks through the planner, making minor changes each time. One more minor revision to go and then I'll be happy with the results.
Eighteen separate points of reference:
Left and then Right side
target 3.50mm: 3.46mm 3.55mm
target 3.71mm: 3.75mm 3.81mm
target 4.71mm: 4.77mm 4.72mm
target 5.71mm: 5.80mm 5.75mm
target 6.71mm: 6.69mm 6.71mm
target 7.71mm: 7.79mm 7.74mm
target 8.71mm: 8.68mm 8.73mm
target 9.71mm: 9.60mm 9.85mm
target 10.71mm:10.89mm 10.75mm
target 11.00mm:10.99mm 10.98mm
target 10.71mm:10.75mm 10.81mm
target 9.71mm: 9.83mm 9.79mm
target 8.71mm: 8.77mm 8.78mm
target 7.71mm: 7.77mm 7.80mm
target 6.71mm: 6.77mm 6.79mm
target 5.71mm: 5.78mm 5.79mm
target 4.71mm: 4.78mm 4.78mm
target 3.71mm: 3.86mm 3.70mm
Final set of results - same targets. There's still a bit of variety within these results, but I think I've max'd out the accuracy of the tools.
3.43mm 3.56mm
3.68mm 3.71mm
4.78mm 4.72mm
5.78mm 5.72mm
6.70mm 6.71mm
7.79mm 7.79mm
8.75mm 8.72mm
9.79mm 9.82mm
10.81mm 10.75mm
11.00mm 11.00mm
10.71mm 10.80mm
9.77mm 9.68mm
8.75mm 8.73mm
7.72mm 7.73mm
6.72mm 6.74mm
5.77mm 5.74mm
4.71mm 4.71mm
3.75mm 3.70mm
Getting the same results with ash/poplar and maple. Maple throws up a few faults every now and again. Douglas fir isn't a accurate as I would like - went it get really thin.
Mold release is expensive and I'm trying to save cash so I can buy he right materials. Had a bit of car wax hanging around, it does work but I should have applied more. Switch to briwax, floor polish - high in carnauba.
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