Core Profiling

windsurfer · Post by **windsurfer** » Thu Nov 10, 2005 9:46 pm

i also have a belt sander. do you really think its better?

Alex · Post by **Alex** » Fri Nov 11, 2005 12:34 am

I used a simple hand planer (not eletric powered) to profile the core. But i used some preshaped wood strips (5x20mm and 5x40mm) i glued together in one layer at tip and tail and two layers in the middle. So i only had to shape tip and tail sections and a smooth transition from 10 to 5mm strength. Together with the Airex C70.75 foam shovel (3mm) it was pretty simple and fast (2h per core).

hafte · Post by **hafte** » Wed Jan 25, 2006 1:03 pm

I'm getting ready to make my tool for profiling using my thickness planer.

I was wondering if anyone has had issue with the part charttering/moving around on the bed of the tool.

The grabber screw tips to hold the part is a good idea. I was also trying to come up with a way to use the vacume to hold the part, but I don't like the idea of running the hose through the planer.

Seems the rollers in the paner would keep the part form moving too much. Is this the case?

Thanks

Greg · Post by **Greg** » Wed Jan 25, 2006 8:34 pm

I screw the cores down at the tips (from the top) and then in the middle (from the underneath). Additionally, I use clamps. I will profile half of the core, then move the clamps and profile the other half. I have had really good luck with this method.

littleKam · Post by **littleKam** » Thu Jan 26, 2006 10:14 pm

try using a hot glue gun.

brettf · Post by **brettf** » Wed Feb 08, 2006 12:35 pm

littleKam wrote:try using a hot glue gun.

If you leave your core a little longer on both ends, you could clamp or even screw it down, cutting off the excess later.

mattman · Post by **mattman** » Mon Oct 02, 2006 3:18 am

when using the thickness planer method, does it improve the problem of tip chatter if you run the wedge through narrow end first (so that the tips are the last thing planed). it seems like the damage might come from the cutters suddenly coming in contact bluntly with the tip head on. i am planning on using this method (since the jig didnt work so well last time) but the idea of putting screws in the tip makes me nervous, wouldnt the cutters hit the metal?

hafte · Post by **hafte** » Mon Oct 02, 2006 7:10 am

That's my plan also. Run the short end through first. The cutter head runs in the opposite direction from the feed heads. It should reduce end blow out of the core. Also do small cuts <1/8" several passes to the final thickness. It should only take 3-5 to get what you want. I also set my planner up in a table that extends ~4’ on each end to support the carrier table. I know I’ll have to push the unit most of the way through before the feed rollers catch, but it should work well.

For a hold down I plan to drill my insert holes first and use, possibly sacrificial, nylon bolts in two of the holes. At worst I figure I may hit the top of the bolt. When slot the table so it will have some adjustment. Maybe a dab of hot melt glue near the tip if I get any vibration.

Realize I have yet to cut on any real ski parts. I’m still making the tools, patterns and hold downs, so as I do I will try to post more details of how things work.

Hafte

mattman · Post by **mattman** » Mon Oct 02, 2006 7:59 am

the hot glue at the tip sounds good...i am thinking of clamping the core with a vacuum. i figure i can run a neoprene seal around the surface of the wedge for the core to sit on, then drill a hole through the top board of the wedge to run a vacuum line. as long as the neoprene holds an airtight seal, i can pull the vacuum, close off the line and release the hose so that the hose isnt running through the planer. the valve should fit fine right between the two wedge boards. with enough ribs of neoprene the core should hold without shifting or flexing....i hope.

hafte · Post by **hafte** » Mon Oct 02, 2006 11:10 am

I thought about trying that too. I’m new to vacuum pressing… using a vacuum in general and was not sure how well that would hold while the hose is disconnected. I really don’t like the idea of running the hose through the planer. I have seen what you are talking about for hold downs on a 5 axis machine. They used some sort of hard phenolic foam (I think) and a rubber gasket set in a routed groove to create the seal. Do you think it would be possible to use some automotive o-rings? Find a ¼ thick by as large of dia. as you can get o-ring. Set that under the foot area in the table and pull the part down. Maybe support the tips so the core stays flat as it goes through the planer. The neoprene idea might be easier to do.

I’m thinking there are a bunch of ways to use vacuum hold downs to help with cutting base to templating the core etc. I’m already going nuts making tools… I WANT TOGET SOME SKIS MADE. My wife is not going to like the sound of this…

Hafte

mattman · Post by **mattman** » Wed Oct 25, 2006 9:04 am

So i tested the vacuum clamping planer method for profiling...it worked beautifully on a test blank. I think this is the first tooling that i have ever made that worked first try! It worked so well I might have to start a Ski Building Journal...we'll see if i get my heat blanket thermoformer working first!!! but ya, if you have a vacuum setup and your plane-profile your cores, i definitely recommend vacuum clamping the core to your wedge!

Bambi · Post by **Bambi** » Wed Oct 25, 2006 12:45 pm

I used double sided tape to attache the ski to the wedge in the thickness planer.

Worked like a dream.

Narrow end first definitely - if you go thick end first then the planer is cutting diagonally 'up' through the grain which causes chunks to come off.

B.

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Core Profiling