How are you cutting you're p-tex?

[cliffhucker]

the way we are laying our skis up; the ptex shape, once wrapped with the steel edge, basically determines the shape of our ski, whether it will be straight, or whether it will be crooked. ;/

So far I've been using a larger pair of tin snips to cut the p-tex, after using a paper template to get the shape. Then I've stapled the two rough cut pieces together and freehanded them with a straight router bit, which leaves a lot of flared p-tex that I have to trim with a knife.. Surprisingly it has worked quite well but I would like to do better. I've played with just using a box cutter but I really can't get very smooth clean cuts all the way through.

I know a lot of people on here are using a jig that has been CNC'd, but we are playing with lots of shapes and don't want to drop $100 on a single jig. Does anyone know of a bigger industrial scissor with a longer blade than a tinsnips? Also, if you are using jigs, what type of router bit are you cuting with?

-Sam

[SkiTheNortheast]

can you attach it to a wood template then use a router?

[twizzstyle]

When I first started, I would tape a paper plot down on the ptex, then trace with an exacto or razor blade. What would happen is as I cut one side, it released tension in the paper that I had pulled tight, and I'd get curved skis, every time.

A wood (mdf) template is really the only way to go. Just use any flush cut trim router bit, like you would for Formica counter tops.

I use spray adhesive to glue the plot onto the mdf, using a laser to ensure it is exactly straight. Then I cut that out slowly on the bandsaw with a nice wide blade. If I go slow I can get near as good as cnc results. Even if you're doing lots of different shapes, I think it's still worth it as you're gaurunteed perfect results, and the actual routing of the ptex takes about 20 seconds.

[skidesmond]

If you're playing w/ lots of shapes then I can see the reluctance to want to cnc every template, that adds up. SnoCad-X can be used to make templates on MDF. It's time consuming to get the template just right. Expect to spend an afternoon cutting and fine tuning the template.

I explored another method using 2 thin strips of wood (3/8thick x 1.5wide x 72 long) then trying to devise a way where I could adjust the wood strips into a shape of a ski, hold the shape, tack it to MDF and then route out the shape. I finally abandoned the idea and had templates cnc'ed .

Use Snocad above until you get something you like, the get it cnc'ed.

[doughboyshredder]

For one off or prototype shapes you can use a paper template and trace out your shape on mdf. Then cut it out with a jigsaw and sand it as close as you can get to the line you traced. Obviously it won't be perfect. This is where my magic trick comes in handy. Glue an edge to the mdf template. This eliminates any imperfections from sanding and cutting. Then clamp your ptex to the mdf with the edge on it, and make sure that your bearing on your router bit runs on the edge. Voile. No cnc expense, and a good clean cut on the ptex.

[skidesmond]

For one off or prototype shapes you can use a paper template and trace out your shape on mdf. Then cut it out with a jigsaw and sand it as close as you can get to the line you traced. Obviously it won't be perfect. This is where my magic trick comes in handy. Glue an edge to the mdf template. This eliminates any imperfections from sanding and cutting. Then clamp your ptex to the mdf with the edge on it, and make sure that your bearing on your router bit runs on the edge. Voile. No cnc expense, and a good clean cut on the ptex.

Great idea. What about just tacking the metal edge down first along the line of the template and then use the jig saw or use the router right away and no jig saw.

[doughboyshredder]

For one off or prototype shapes you can use a paper template and trace out your shape on mdf. Then cut it out with a jigsaw and sand it as close as you can get to the line you traced. Obviously it won't be perfect. This is where my magic trick comes in handy. Glue an edge to the mdf template. This eliminates any imperfections from sanding and cutting. Then clamp your ptex to the mdf with the edge on it, and make sure that your bearing on your router bit runs on the edge. Voile. No cnc expense, and a good clean cut on the ptex.

Great idea. What about just tacking the metal edge down first along the line of the template and then use the jig saw or use the router right away and no jig saw.

Hmmmm, that's not a bad idea.

[skidesmond]

I used that method with wood strips and tacking with screws, then tried a brad nailer. The screws caused movement when attaching. The nailer left pull out marks when removing the wood strip. Not huge problems to over come, but I like the tacking of the metal edge.

[cliffhucker]

I've been using the snocad-x and I've been getting full size exact templates printed off at the local print shop, then tracing that onto the p-tex; but I really like the idea of tracing onto a wooden template; then cutting it out with a bandsaw. I already have a straight router bit, will this work or do I need a special bit that wont cause the p-tex to snarl...

[skidesmond]

A regular straight bit w/ a bearing will work ok. I have 1 bit that I use only for p-tex. When the bit gets dull you'll get little furls of p-tex that don't come off 100%, it's a pain.

[sir.orange]

i tried a few router bits with bearings and had best results with a bit that is two-edged, has a bearing and makes oblique shearings (the blades have a negative shaft angle): http://www.sautershop.de/Oberfraeser-HM ... Achswinkel


low speed rotation to prevent p-tex from melting. the cut is really clean, my templates are mdf

[ru-tang]

when making templates by hand, I add in extra steps. By first cutting templates out in masonite, you can sand the thin material much easier, faster and more accurately. When you are sanding something that is 3/4 of an inch thick, especially by hand, it is nearly impossible to get a right angle through the thickness of the material

step1- paper template printout

2- transfer onto masonite, you can glue the paper on with spray adhesive or watered down elmers

3- cut masonite out with jig saw/bandsaw what ever you use

4- sand to the finished line and tweak as necessary

5- trace masonite template onto final material (mdf)

6- rough cut with jigsaw

7-clamp masonite onto mdf, and use flush cut bit and trim to finished size with router

perfect templates every time!

Also you then have a 'master' template and can destroy/modify the mdf ones as you see fit! Easier to store lots of experimental templates and cheaper than making everything in mdf

[MontuckyMadman]

I would look at iggys posts regarding this and shif and some others. Pretty sure they outlined all this bits and whatnot but i like the edge and brad nailer application.
i have a plotter/ 2d cutter, and draw and cut cheap pe and staple and rough cut with a jig saw and router bit clean on the pe edge. Pretty sweet.
that might make sense to someone.

[strocka]

I use a dremel tool to cut around my template. Use a thin cutting head. Sand it up real nice. It dosen't take to much time and seems to produce a nice result.

[GoatBoySkis]

Hi new to the forum, but I've been watching for awhile.

This is more of a suggestion, but once you cut out the p-tex, whether with a router bit or shears of some sort and you have the basic shape...

Go to Home depot or harbor freight and buy a 3" hand plane. They are about 3" long and 1" wide (quite inexpensive). Once you're good with one they can make minor adjustments on p-tex shape, and core shape (and many other things) very easy and quick. with the p-tex making one long cut without taking the blade off works well to get a very smooth edge with no loose shavings sticking out (like you get with a router bit). Might be good to then sand the edge of the ptex or flame treat to promote adhesion.