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!)
Tail mold: 650mm radius early rise
Top molds matching tip and tail
Pretty heavy, but should be OK.
The mess that is my ski building warehouse
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
Base template 175cm rocker
Running length 18mm MDF board to the right
Closeup 175cm rocker
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.