How have you guys found to best make the molds adjustable to different sizes without remaking any parts? Is there a way?
Getting much close to having this project getting to construction. The press frame is going to be made this weekend (I hope) and then it's onto the molds.
i'm sure others have a much better method for an adjustable mold but here's a simple method:
1. first make just the camber portion with no tips or tails.
2. make the tip and tail molds separately. these tip and tail portions simply sit on top of the mold and are held in place using any of following methods: double-sided tape, bolts, nails, etc. i found that the strength of attachment doesn't need to be that strong. the force from your bladder will actually hold it place.
3. put a smooth, relatively thick piece of material (i.e. HDPE) covering the entire mold to make the transition from the tip/tail to the camber section smooth.
hope this helps.
note this mold is only adjustable for the ski length and tip/tail curvatures only. it doesn't allow you to adjust the camber, which would be difficult to design if you intend to use a pneumatic press.
thats pretty much what i did
I can get a lot of different thicknesses of HDPE. Would something like .025 be thick enough, or are you talking 1/8-1/4 of an inch?
you might want something a little thicker so it smoothes out the transition and any bumps in your ribs. For our molds, we have a couple of sheets of 1/8" melamine or hardboard (cheap at Home depot) with a 1/8" sheet of hdpe on top.
Why is MDF used? what is it about it that makes it the material to use over anything else?
I'm guessing it is because it doesn't compress or change under the pressure that a press puts on it, but couldn't you just make it out of some plain wood? Just looking for some info. for when I talk with the carpenter(s) who is(are) gonna help me make the molds.
We use mdf because it is:
1. relatively cheap (~$35 for 4'x8')
2. easy to machine
3. stable and very flat
4. strong in compression
the bad thing about mdf is it creates a lot of fine toxic
as alwys, thanks a ton for the info. I picked up (hopefully) the final load of i-beams tonight, and will start building the frame this weekend. I can do one of two things. I have enough i-beams to make a 2 8" wide sections of press with the top and bottom having no space between, OR I can have one 16-20 inch press with no spacing between the beams (16") or small spacing between the beams (>16"). What would you reconmend? is 8" enough to use for a mold?
If you make the adjustable bottom mold would you still need to make a different top mold?
