:: View topic - "shouldering" cores for edges

Hello,

I feel there's not so much activity on this forum lately...so I've decided to post any questions I had

So, I've seen many brands and also some amateurs machining each side of the core in order to compensate the extra height due to the edges glued on the base.

A little drawing below in case of my english is too bad to make myself undesrtandable

Do you think this might make the ski stronger ? Less disposed to delam ?

Do you guys do that ?

Or do you think this does not bring anything special ?

the reason for making a recess in the core is to prevent the base from becoming slightly convex when pressing.

many people here in the forum (including me) router out this recess, but i've also read about people who don't do it and still get a flat enough base.

i don't think it makes the ski stronger, though.

We have cut out the "shoulder" on one pair out of 7 now. The bases have been flat on all 7 pairs though so I don't think it is necessary. To get flat bases you need a flat bottom mold for your press (and maybe a cattrack if you have a narrow or wide hose). At least that is what I can determine from reading other posts.

If you have an easy way to put the "shoulder" into your wood cores, then I think it is a good idea. I didn't have a really easy way to do it so that the depth was the same each and every time so we stopped doing it.

I think the edges just get pressed into the core so maybe the shoulder is a good idea if you are using a harder wood than ash or poplar (that is what we use).

freehand with a laminate trimmer is easy as can be.

I didn't do it on a few boards and it visibly indented the base. Still flat as a board.

we did it freehand with a small bosch colt "bably" router. It wasn't too bad but it was an extra step.

DBS - are you going to do it on your boards?

yeah, for sure. I shaped my core so that the sidewalls were over the edge. Makes running the laminate trimmer by freehand super easy. You could also clamp your cut out template to the core as a guide for a router.

I do think it's a good idea to do it.

After having brought my skis to the skiman last week, I've seen that my base was slighly concave, and we did not made that recess for the edges...

Do you have any idea why ?

I guess the best way would be to use a shaper.

DBS, can you explain to me what a trimmer is ? I have no clue

Is it some kind of small router ?

yep, a laminate trimmer basically is a small router.

i've used a regular router to make this recess. i just drew a line one the sidewalls/core along the inner side of the edges and then routered along that line. i set the depth of the cut by trial and error using a scrap piece of sidewall.

Worth doing for sure, IMHO.

We incorporate it into our sidewall profile, which are temporarily attached to the cores before layup. After pressing, everything sits nicely.

iggy -> can you develop on how you attach your sidewalls ?

Thanks !

Actually...sorry...but no. A few other people would likely hunt me down and kill me if I did so. It is one of the few trade secrets in here I really am not supposed to share.

Hi

I've done both. Made no difference to the 'flatness' of the base. I now recess it for all the ones I make.

C.

No problem, it was worth a try :p

our sidewalls are profiled a few thousandths thinner than the core, to compensate for the edge teeth. Its' never really been a problem with mashing into the tip fill, just along the sidecut if we dont do it, we get the teeth dents, no problem to sand out, just an eye-sore, and yea can sometimes make for un-flat ness that can usually be ground out.

This is a good way to shoulder your edges, just be careful when starting as the tip is vulnerable - two passes each side and you are done. Placed a piece of mdf on top to hold the tips in the correct position on the second pass. One small slice and then another.

Sorry, the photo is a really crappy - but you get the picture. Using the same jig used to make the core. I'm going to remake the jig. Template from Snowcad, smaller radius than ski.

Controlling the width of the cut - clamps are ok. I might end up screwing to the bench in future.