Is recessing the edges into the core important.

[hadley]

Should i be creating a chanel in the core for the metal edges to fit into the core. On my last pair of skis I had a concave under tips and tail. There are other possible causes.

[jono]

I've always routed out a part of the core for the edges to fit into. This usually works pretty well.

On my most recent pair I encountered a problem that led to a slightly convex base towards the tips of the ski.
My theory is that if the routed out part is a little too deep, or there is no raised area, there is a slight gap between the core and the materials underneath. Where the core is thick and stout this area of the core will not compress towards the underlying materials that much and there will be a less dense area between the core and the base and/or edges. Towards the tips the core is thinner and deflects/compresses towards the edge/base during pressing and then rebounds up when the ski comes out of the press. This is what I think led to a slightly convex base on my last pair and a concave base on your skis. I am hoping the convex portion will come out when the bases are ground.
I think it is important to get just the right height on your router bit when you rout out the base for your edges. I also think I used a bit too much pressure (60psi) on this last pair and this played the biggest role in the problems with the shape of my bases.

A flat base is ideal. A concave base is ok because you can fill it in with base welding material and then grind it flat. A convex base is the worst because there may not be enough base material to grind out the convex areas.
Has anyone tried using thicker base material with routed out edge areas? This seems like a better solution since it would lead to slightly thicker (and more durable) bases.

[rockaukum]

I have done both as far as the core goes. I now perfer to route out a recess to accomidate the edge. The base will be flatter from the press.
ra

[hadley]

Should I recess the side walled cores first or should afterwards?

[jono]

I'm not sure what your question is but I recess the core before I profile it. It is difficult to rout out a core where it is only 3mm thick.

[mark]

I recess mine after profiling. I use a dado blade on the table saw. Works well.

[Easy]

I don't route out a space for the edges. I have only produced a single prototype and 1 pair, but I don't have any complaints about my method. The base might be a little concaved, but minor sanding takes care of it. Towards the tip and tail you also get a slightly convex topsheet, but I don't have any mayor disformations and I don't think that it affects the performance or functionality of the skis.

[APS]

Mark-

How are you using a dado to recess the edge? I can't seem to imagine how you would make it work with the sidecut. I've only used a dado to make straight cuts, what am I missing?

[hugocacola]

i all, i recess my cores after profiling. for that i set a litle table with my router.. tomorow ill post some pictures

[mark]

I've only used a dado to make straight cuts, what am I missing?

Mad skilz baby, mad skilz!

I clamp a piece of scrap to the rip fence. The scrap is rounded on the edge toward the blade so the core only touches it right where it's over the blade. I think I have a pic somewhere and will post it when I find it.

[mark]

Hey, look at the dumb-@$$ with no safety glasses.


At least I'm using a stick instead of my bare hand to hold the work down. Same set-up would work for a router table too.

[hadley]

Your picture shows you cutting the core without side walls attached. Am I missing something. Is this just a core without sidewalls. Part of the problem I am gaving with students is their side walls becomeing ripped off during during profilling. I like the idea of using the table saw for recessing to recieve the metal edges because the cut should cause less stress to the already thin side walls.

Any ideas...

Hadley

[mark]

Your picture shows you cutting the core without side walls attached.

They're there. I made them out of cherry.

Am I missing something.

See three posts up.

[APS]

You're right, mad skillz. I wouldn't have thought of that. Any advantage over a router table? or just what you had on hand?

[mark]

I like it better than my router table because it's easier to set up and adjust, and is less likely to tear up the core. Also, routers scare the piss out of me.