Tip/tail molds

[Rowa]

Hi, i'm building a pneumatic press with adjustable molds(camber and length). I was wondering how people here make their adjustable tip/tail molds.

Thanks.

[skidesmond]

There's lot's of posts here about adjustable tip/tail molds, and for an adjustable mold to accommodate the ski length. Do some searches, there's great info here. I have adjustable tip/tail mold that you can see in my build. There are many others too. There's some great adjustable camber molds to accommodate ski lengths too. This should get you started, http://www.skibuilders.com/howto/equip/mold.shtml

It's all here!

[Rowa]

I've searched the forum, haven't really found what i was looking for.
If there has been a post with what i'm asking, i must have missed it(there's like a 1000+ posts here?)
It looks like everyone CNC's their tip/tail molds. I'm wondering if there is an easy way to make it without CNC..


Btw: i mean tip/tail molds for snowboards.

[doughboyshredder]

you need to ask more specific questions.

answer to is there another way besides cnc. Yes.

tip for searching the forums. Use google for site search.

Oh, and those 1,000 plus posts. Read them.

[Rowa]

My bad, don't need to get pissed off.
I thought my question was pretty specific: is there an easy way to make a tip/tail mold for an adjustable pneumatic press(ways to make it etc..)?
I apologize for not wanting to read 1000 posts. I thought the people that have been on this forum for years, could have just pointed out the link to a post that could help me or just give me some tips.


Thanks.

[skidesmond]

My tip/tail molds are adjustable in the way the slide over the bottom form to accomdate different ski lengths. They are not adjustable in the curvature, if that's what you're looking for.

I made my tip/tail molds using a router. I used Sno-CadX for skis and board designs. I printed the profile of the tip and tail, glued it to 3/4 MDF and rough cut it w/ a jig saw, then sanded it down to the profile line. That became my model piece. Then I made jig to hold the model piece firmly in place. Then used a router to cut/trace out all the other MDF pieces with a straight cutting bit with a bearing. The bearing rides along the model piece.

Once all the pieces were cut I bolted them together and gave a final touch up sanding.

It took a better part of a day to make the molds from start to finish.

If you've never worked w/ MDF, a mask is a must even if you're working out side.

Hope this helps.

[Rowa]

Thanks! Thats exactly what i'm looking for.
But i need a 35cm wide tip/tail mold, so i'll have to make lots of pieces.

How about making like..4 pieces, glueing the back of the pieces to a straight piece of wood and then glueing a thin sheet of wood on the pieces?

[skidesmond]

That might work...... I'd be worried that the mold will flex under pressure, which would be bad. Don't under estimate the force that the press will exert.

All the work is really in the making of the first piece perfect and the jig to hold it. After that it's just using the router to cut the pieces.

btw- You can use the same process to make your bottom and top molds too.

[Rowa]

K, thanks alot for helping.
And will it deform the base if my surface isn't smooth(when the tip/tail molds are on the bottom mold)? Should i just put a thin layer of wood over the entire surface?

[skidesmond]

If you cut out the molds as described above you should be good to go. Just give everything a light sanding afterwards to take out any minor irregularities. That's how I made my molds and they are holding up well.

[Alex13]

Are you using a cat track, and what pressures are you pressing at?

I would try to use as many ribs as possible, make a solid mould if you can for a pneumatic press. 4 pieces and a thin bit of wood should work OK for vacuum moulds but pressing at 50psi or so it will get smashed to bits.

If you're using a cat track that will help distribute the pressure more evenly, but I'd still look at using a lot of ribs. For a 350mm wide mould using 25mm ribs you'll need 14 pieces to make a solid mould. If you were dead set on making ribs with gaps, you should use at least 8 ribs and a decent sheet (16mm or so) of ply or something similar over the top. Even then, depending how you hold it all together, you may have issues.

[falls]

People have had a fair bit of trouble with non solid bottom molds and pneumatic presses. Like alex said you don't want much of a gap between each rib. Prob max 20mm. Then a thick layer of mdf on top.
I found that the major cost of the molds was in the mdf rather than the CNC. I got bottom and top molds + two templates CNC'd for 300 bucks. Of that 200 was mdf and 100 CNC time.
Making adjustable molds is ok. You can either make separate tip and tail molds then place a flat piece of mdf in between them ( the length of thus piece will adjust length of the skis) or you can make the tip molds that can slide in between the camber mild like on this sites how to section.

[falls]

To make a truly adjustable mold that can accommodate different camber, length and tip shapes in one piece is a major undertaking. This is like what the pros (egK2) have.
Dough boy shredder has a post somewhere that shows how he built a mold that can be adjusted for camber using a heap of carriage bolts and a piece of heavy sheet metal. It looked like a big job though.
Generally even mid size commercial buildershave a growing number of tip and tail blocks and several solid camber molds.

[Rowa]

Well..i'm not gonna use a cat track, way to much work. I'm gonna try something different.
And i'll be making a solid tip/tail mold without gaps.

I've seen what doughboyshredder made, its really insane(great).

[Rowa]

I couldn't find a bearing for my router, i looked everywhere. Is there something else i can use? Or another way to make the molds?