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energy116
Posts: 9
Joined: Wed Apr 15, 2009 11:27 am

Post by energy116 »

Nice temp 43 <wow> now in Poland I have -23 C lol
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falls
Posts: 1458
Joined: Tue Oct 27, 2009 5:04 pm
Location: Wangaratta, Australia

Post by falls »

A bit more progress before and after a nice 2 week trip skiing in Japan.
I have had tip and tail molds CNC cut by a local CNC service. It has worked out OK I think. Didn't start out that well when the first sheet of MDF actually caught on fire when allignment holes were bored through. The wood was glowing red and smoking!! Change of router bit and a slowdown of the feed rate and things started to work out better.
The pieces seem pretty consistent. Unfortunately the allignment holes ended up oval shaped rather than circular which has made threading the bolts a bit tough. All in all tip and tail molds are OK for a first go. Need a bit of a sand now they are fixed together.
Chris (carnold) was kind enough to do the CNC cutting for my ski shapes (best investment of a case of beer so far!). Thanks Chris. I have stolen an idea from Kingswood that I haven't trialed as yet. Instead of cutting the base shape completely out of the MDF it has a groove around it that the flush router bit can run in. On the island in the middle are vaccuum channels with a central vacuum inlet point. Plan is that the rectangle of base material will be held down by the vacuum and the router can buzz around and cut it to shape. Fingers crossed.

Pictures paint a thousand words....


Tip mold: 25cm by 2cm rocker (wide arc) then standard tip with 20cm radius ( I think!)
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Tail mold: 650mm radius early rise
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Top molds matching tip and tail
Pretty heavy, but should be OK.
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The mess that is my ski building warehouse
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Heat blanket (hiheat industries) 15"x80"
PID controller (ebay, auger brand)
SSR (ebay)
Digital scales - unfortunatley still being used for weighing cooking ingredients at this point
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Base template 175cm rocker
Running length 18mm MDF board to the right
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Closeup 175cm rocker
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Outer channel for router bit with flush bearing to run in (radius on edge allows easy entry and exit). Inner channel connected to central vacuum hole to hold down base material.

I have 2 sizes of the same shape drawn up for the first few pairs.
A true 175cm and a true 185cm
Design is S7/JJ/billy goat inspired.
140-110-120 dimensions. Early taper at tip and tail, pin tail shape. Taper begins 40mm after rocker begins.
Flat camber
Running length is 1100mm and 1200mm respectively

I thought these were beyond fat for me, but I skied some 189cm hellbents on the trip and after thinking they would be way too big for me I absolutely loved skiing on them. 30-40cm fresh snow. Bluebird conditions. Off piste, some sparse trees, pillow drops etc. They even went really well on the groomer to the bottom at the end of the day. They were hopeless in hard moguls though.
So I am officially a megafat ski convert and the next design may reflect this, even though a good day in Australia is 20cm of kind of powder snow!

Now all I am missing is a press!!
Next few weeks hopefully get the steel and welding done. Spaceframe type planned.
Cattrack of 20mm square aluminium coming too.
Stand alone tip and tail molds allow me to adjust length of skis by placing different length MDF boards between them.


4 months from first thoughts about building skis to this point. I think I'm going OK.
Last edited by falls on Sun Feb 28, 2010 1:56 am, edited 2 times in total.
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falls
Posts: 1458
Joined: Tue Oct 27, 2009 5:04 pm
Location: Wangaratta, Australia

Post by falls »

A few pics of the "research" trip to Japan!

My friend Benny testing out his new PM gear Lhasa pows (poach ninja special edition)
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My girlfriend Bridget in the trees. Real powder skiing breakthrough this trip for her. Not sure who is more excited about this, me or her! I like the massive grin in this photo. Says it all about skiing the trees on a fresh day.
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Myself
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Matsumoto Castle.
Japan is great for rest/down days. So much to see, but so much ti ski too
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skidesmond
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Joined: Tue Apr 07, 2009 3:26 pm
Location: Western Mass, USA
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Post by skidesmond »

WOW!! My kind of research!
carnold
Posts: 84
Joined: Thu Jan 15, 2009 6:39 pm
Location: Australia, Melbourne.

Post by carnold »

Hi.
Now if that kind of research doesn't get your ski building going nothing will!!
Cheers.
C.
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falls
Posts: 1458
Joined: Tue Oct 27, 2009 5:04 pm
Location: Wangaratta, Australia

Base material vacuum hold down jigs.

Post by falls »

After a nervous moment wondering if this idea would actually work with our household vacuum cleaner I am pretty confident it will be a success!

Base material jigs were cut with CNC to create a groove for the router bit to run in against the desired shape outline. On the "island" created in the middle are 5mm deep grooves offset from the edge by 20mm. There is a central hole through the MDF board to accept the vaccuum cleaner nozzle and distribute its suction along the channels.
Like most of my ski building experiments so far it took place in the living room after work. The vacuum holds the base material down very snuggly. In the video you can see the board moving from side to side rather than the base material shifting.
Vacuum is a 2400W cyclonic type (like Dyson brand).

Don't want to cut the base material yet because I am still a bit of a way off pressing a pair and don't want the UHMW to warp before then. I am pretty sure though that the router will cut it neatly without the base material shifting.

Thanks Chris for the CNC work. Didn't need to seal the MDF either.

Vacuum hold down base jig
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Vacuum nozzle in place
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Vacuum nozzle entering board from below
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Base material on top
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Video (beware vacuum noise)
http://www.youtube.com/watch?v=-f_AjOAa0aM

Pretty pleased with the project tonight.
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shopvac
Posts: 160
Joined: Sun Oct 12, 2008 2:23 pm
Location: Colorado

Post by shopvac »

damn that is awesome. I like the small channel you have for getting into/out of the main channel for going around the ski. very well thought out and also it could easily be modular using the same port and vacuum.
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falls
Posts: 1458
Joined: Tue Oct 27, 2009 5:04 pm
Location: Wangaratta, Australia

Post by falls »

Picked up a few more things today

100 pieces aluminium square tubing for cattrack - 3mm wall, 20mm by 20mm by 400mm long.
Best thing was they had an automated cutter so they made the 100 cuts for me!!
Unfortunately I still have to drill the 400 holes :(
$240 including cutting for 2m long cattrack
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Also read one of iggys posts about cutting fibreglass. I think this is the type of rolling cutter he recommended at that point in time.
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Last but not least the steel for the press was delivered. I got a quote then got it ordered through my girlfriends company and they got $120 off the price I was quoted. Pretty happy with that.
Don't wait up, I'm off to kill Summer....
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falls
Posts: 1458
Joined: Tue Oct 27, 2009 5:04 pm
Location: Wangaratta, Australia

Post by falls »

Press construction started today with metal cutting

2 x 8m lengths of RHS for upper and lower frames
2 x 6.5m lengths of 50mm by 10mm flat bar to resist deflection in cross pieces.
3 x 6.5m of 50mm by 5mm flat bar for vertical stabilisers
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Band saw cutting
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Looking OK
Ready for welding
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Don't wait up, I'm off to kill Summer....
ben_mtl
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Location: Sherbrooke, Quebec
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Post by ben_mtl »

Great work ! Might be a bit heavy but you shouldn't have problems with the frame bending !
I'm also super jealous of you CNC cut molds... It's a nightmare for me to find a "not-too-expensive" and reliable CNC service. Actually I still haven't found the good one :(
A bad day skiing is always better than a good one at work...
plywood
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Location: wilen, switzerland
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Post by plywood »

always interesting to see your progress AND the airplanes in the background ;)
plywood freeride industries - go ply, ride wood!
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falls
Posts: 1458
Joined: Tue Oct 27, 2009 5:04 pm
Location: Wangaratta, Australia

Post by falls »

Those top and bottom sections pictured should weigh about 44kg each. Each will have the vertical stiffeners added which will be another 13kg.
So about 114kg for top and bottom pieces.
Another 31 kg in the steel for the vertical stays.
Total = 145kg (319 pounds).
Obviously before stacking in a heap more weight in MDF!
Don't wait up, I'm off to kill Summer....
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falls
Posts: 1458
Joined: Tue Oct 27, 2009 5:04 pm
Location: Wangaratta, Australia

Post by falls »

Finished cutting all the steel for the press today. Next job is on the mill drilling all the half inch holes for the bolted section then friendly reminder to my friend the welder!
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new compressor: 37L 2.5hp, 121L/min free air delivery. Had to adjust the pressure switch straight out of the box, but seems to be doing the trick.
Having the new compressor and doing a proper soap and water test on the hoses didn't bring great news. Air was leaking audibly. In hindsight the problem was obvious. I had used head monkeys technique but been unable to get any of the green aramid/buna n washers. So I just didn't use them. I ended up with leakage between the brass fitting and steel washer that then tracked up the fitting and out between the brass nut and steel washer on the outside. Pretty silly to think brass on steel would be airtight! The other interesting thing was that as the air coursed up the brass fitting it got into the fibre reinforcing between the inner and outer layers of the hose. This presented as bubbling around the bolts on the angle iron and most notably it bubbled the soapy water on the very ends of the hose where the frayed reinforcing fibres emerge between the layers. All seems solved now with the green washers in place as per the suggestions! Anyone in Australia the place I got them was industrial gaskets in Melrose park south Australia. http://www.industrialgaskets.com.au/ they were about $1.50 each. I specified the dimensions and they cut them out of a sheet of aramid reinforced nitrile rubber. this was the actual sheet they cut it from http://www.industrialgaskets.com.au/?pa ... =&offset=0
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Final setup is brass, aramid/rubber washer, steel washer, rubber washer, hose, rubber washer, steel washer, aramid/rubber washer, brass nut.

I have also accumulated the parts for the enclosure and heatblanket wiring. I ended up getting these IEC inlets like the ones used on computers.
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The inlets incorporate a fuse (5x20mm) and a rocker switch with neon light and have the benefit that the power cords can be disconnected leaving just the box to store. They will clip into the wall of an enclosure up to 3mm thick. The back of the outlet has 1/4 inch tabs that female connectors can be attached to to route the power away. They were about $15 each I think from http://australia.rs-online.com/web/. I think they will be good and make the wiring a lot easier.
I got thermocouples with quick disconnects and panel mounts from http://www.tcdirect.net.au/deptprod.asp

Also got a small benchtop drill press and made a jig for drilling the aluminium cat track pieces (not looking forward to this job). Built a pine mid section for the upper mold 105cm long. I have MDF upper mold tip pieces. The pine mid section is for the 170cm skis I am planning. Will use pine 4 x 2's as spacer for longer models. I was also interested to find in Australia that "4 x 2" is actually 90MM X 45MM which put a bit of my design out of whack.

Anyway slowly but surely making progress. Nothing too exciting for you all in this post unfortunately. Was hoping to press the first pair at Easter, but that deadline will sail past, as probably will the next one that I set!
Don't wait up, I'm off to kill Summer....
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falls
Posts: 1458
Joined: Tue Oct 27, 2009 5:04 pm
Location: Wangaratta, Australia

Post by falls »

A bit more boring progress, but good for me to log it to prove I am making ground.
Finished drilling the 100 aluminium pieces for the cat track today. Actually wasn't too bad in the end. I made a jig using the router and some MDF so I could just slide the Al piece in and drill. Will need to deburr the holes a bit then thread all the pieces together. I am going to thread them using 6mm elastic shock cord. Will see how this goes in place of metal wire and springs.
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Drilling Al pieces with the jig.
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100 pieces, 400 5/16" holes, 6mm shock cord
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Tidied up too. We have a rental inspection coming up so trying to disguise the fact I am building skis in our back room!

I have all the bits for the heat blanket wiring now too. Unfortunately the plastic enclosure I ordered is too small to fit all the parts in comfortably so need to get a larger one.

Hopefully will be milling the steel for the press shear joints over easter then getting the welding done soon after. 2 months til ski season starts here in Australia...........
Don't wait up, I'm off to kill Summer....
Alex13
Posts: 238
Joined: Wed Dec 09, 2009 12:01 am

Post by Alex13 »

Great stuff reading your progress mate, especially since I'm starting mine too and can steal all your tips and suppliers :P

My Journal will start soon 8)
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