Hi Folks,
Awesome site!
I'm thinking about teaching a ski building class to 8-12 middle schoolers (12-14 yr olds) and wanted to pick you all's brains about some ideas. We'll meet next year 3x/wk for about 1.5 hrs each time for 3 mos (30 classes or so). What are some good ways to super-simplify the process so they get some ridable skis and have a good time at it? I've either got or can build most of the tools, so that's not an issue.
Here's what I've been thinking so far. Let me know if I'm crazy:
1. Have the students pick their own graphics, ski length, and sidecut and use the same core profile, material, and camber for all of them (they generally ride 150-165 lengths -- I'm imagining that we'll make an adjustable mold).
2. Use a standard core for every ski -- I've heard of bamboo flooring panels working, maybe baltic birch cabinet grade plywood? It would be a real big time saver not to have to laminate and glue up a bunch of cores. Also, if there's any 'pre-made' options out there it might make it more affordable for them -- I'd hate for someone not to be able to take the class because of $$.
3. Use a vaccuum press -- one student came up with the idea of a water press (think big bag of water sitting on top of the mold). Maybe do multiple sets of skis in the same bag.
4. Make a drilling template for mounting inserts -- I'd like for them to attach their own bindings instead of sending them to a shop. That way we can also experiment with binding position on the hill (I also teach science, so I'm sure there's a lesson in that somewhere . . .)
5. Rivet the tips & tails K2-style, just in case of explosive delamination.
What else might trip us up?
Any good core profiles/sidecut profiles for young beginners?
Thanks folks! You all rock.
Middle School Ski Building Class
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
great project!
my thoughts:
- use a vacuum press
- with a vacuum press it should be much easier to build an adjustable mold (concerning the length of the ski and the thickness of the core, the width doesn't matter that much)
- it should not be a problem to get cores you just have to process. Ask the guys from skibuilders.com, I'm sure they know where you can get some of those in the US. In Europe you could easily order them from http://www.si-core.si/ Maybe at PM-Gear or Praxis or DP-Skis they can help you.
- let the kids have 3-4 choices of the cores thickness, the core thickness is essential to the skis stiffness, the thicker the core the stiffer the ski. I'm sure a little 12 year old girl wont be able to ride the ski a fat 14 year old boy can handle with ease. With those 3-4 different thicknesses (is that an english word?) you can cover a biiig variety, and you can produce templates beforehand so the kids just have to root the cores down to the chosen thickness. I'm not used to kids skis but my guess is something about 5 millimeters for a 35kg girl and 9 millimeters for a 60kg boy. (if they arent the best skiers)
- it will be much harder to determine the sidecut and ski length for every single pupil, I think you should use sidecuts already existing and common within the skiing industry. sidecut is pretty much something you know from experience ... you have to know the level of skiing, the preferences etc. etc.
- use one piece of triaxial fiberglass at the bottom and one at on top of the core, that will be enough for kids. 400g will be fine. if someone wants a super stiff ski let him put some glass rowings into it, he will believe its stiffer ...
- all the kids will want twintip skis!
- graphics will be a big issue to the kids I guess. Maybe you can get a good deal with someone who can sublimate youre topsheets ... looks really professional
- I dont think rivets are needed, they just look rad. Usually the epoxy holds everything together really well. Explosive delamination never happend as far as I know ...
- what might become difficult is the glueing of the sidewalls and tip/tailspacers ... maybe you just stick with wood, worked pretty good for me so far, not the most durable stuff when abused however. (and doesnt look as professional)
- be careful about the mixing of epoxy and the hardener. If not done really precisely it wont stick at all, epoxy is a real bitch about that.
- the time budget is close but its totaly doable in 30 hours, if everything workes really fine and is well organised a ski can be done within just a few hours, its the thinking that takes most of the time ...
- epoxy is not good for health ...
- this will be a lot of fun!
my thoughts:
- use a vacuum press
- with a vacuum press it should be much easier to build an adjustable mold (concerning the length of the ski and the thickness of the core, the width doesn't matter that much)
- it should not be a problem to get cores you just have to process. Ask the guys from skibuilders.com, I'm sure they know where you can get some of those in the US. In Europe you could easily order them from http://www.si-core.si/ Maybe at PM-Gear or Praxis or DP-Skis they can help you.
- let the kids have 3-4 choices of the cores thickness, the core thickness is essential to the skis stiffness, the thicker the core the stiffer the ski. I'm sure a little 12 year old girl wont be able to ride the ski a fat 14 year old boy can handle with ease. With those 3-4 different thicknesses (is that an english word?) you can cover a biiig variety, and you can produce templates beforehand so the kids just have to root the cores down to the chosen thickness. I'm not used to kids skis but my guess is something about 5 millimeters for a 35kg girl and 9 millimeters for a 60kg boy. (if they arent the best skiers)
- it will be much harder to determine the sidecut and ski length for every single pupil, I think you should use sidecuts already existing and common within the skiing industry. sidecut is pretty much something you know from experience ... you have to know the level of skiing, the preferences etc. etc.
- use one piece of triaxial fiberglass at the bottom and one at on top of the core, that will be enough for kids. 400g will be fine. if someone wants a super stiff ski let him put some glass rowings into it, he will believe its stiffer ...
- all the kids will want twintip skis!
- graphics will be a big issue to the kids I guess. Maybe you can get a good deal with someone who can sublimate youre topsheets ... looks really professional
- I dont think rivets are needed, they just look rad. Usually the epoxy holds everything together really well. Explosive delamination never happend as far as I know ...
- what might become difficult is the glueing of the sidewalls and tip/tailspacers ... maybe you just stick with wood, worked pretty good for me so far, not the most durable stuff when abused however. (and doesnt look as professional)
- be careful about the mixing of epoxy and the hardener. If not done really precisely it wont stick at all, epoxy is a real bitch about that.
- the time budget is close but its totaly doable in 30 hours, if everything workes really fine and is well organised a ski can be done within just a few hours, its the thinking that takes most of the time ...
- epoxy is not good for health ...
- this will be a lot of fun!
hi,
well there's not much left to say :lol:
- I would also recommend wooden sidewalls. I've tried both methods (abs sidewalls and wood), and abs gives you a lot more pain to do ! I just treat the wood in the end with a product that fill in the pore (holes ?) of the wood.
- Concerning graphics, the cheapest way is to use clothes/fabrics, but of course it's probably not "fashion" enough for kids. Using ink printed (not laser printed !) paper that you paint in white on the "back" gives you a very fine result also and makes it possible to add some logos/images...
- Another idea for the graphics and that also could de very fun for the pupils is to paint the core ! If you use only glass fibers (not carbon for example), fibers get transparent when wet and let see the core. We used that technique with acrylic paint and the result is awesome.
nice project, good luck !
well there's not much left to say :lol:
- I would also recommend wooden sidewalls. I've tried both methods (abs sidewalls and wood), and abs gives you a lot more pain to do ! I just treat the wood in the end with a product that fill in the pore (holes ?) of the wood.
- Concerning graphics, the cheapest way is to use clothes/fabrics, but of course it's probably not "fashion" enough for kids. Using ink printed (not laser printed !) paper that you paint in white on the "back" gives you a very fine result also and makes it possible to add some logos/images...
- Another idea for the graphics and that also could de very fun for the pupils is to paint the core ! If you use only glass fibers (not carbon for example), fibers get transparent when wet and let see the core. We used that technique with acrylic paint and the result is awesome.
nice project, good luck !
What an ambitious plan!!! I teach elementary school and am eager to see the results from your class.
At home depot I've seen pine laminated shelving that was 18" by 72" This material could be cut into 6" by 72" wide strips that could have a hardwood strip attached to either side, with wood glue, for sidewalls and then be profiled into a usable core. This would be a pretty cheap way to make a bunch of cores. There are probably other wood options in shelving but I only saw pine. Snowboardmaterials.com sells unprofiled poplar cores for 25$.
There are threaded inserts that you can screw into a completed ski. The cheapest are brass and the most expensive are stainless steel. Check out mcmaster or a really good hardware store. I would not try to preposition inserts into the core because your students will undoubtedly experience some shifting during layup.
You could probably get a ski shop to drill or mark clear plexiglass sheets with various hole patterns for various sizes and types of bindings. This would meet your needs.
I would make sure your students wore tyvek or heavy coveralls especially during the finishing process. Those plastic dippped blue gloves seem to keep out most of the fiberglass fibers. In my experience I only use a respirator when I'm sanding or cutting fiberglass. During layup I just make sure my space is ventilated and I don't wear a respirator. What is your school's policy about using "dangerous" materials with students? I can't imagine using these materials in my building. I'm probably just paranoid about bizarre allergic reactions.
It would be great if you could build your own base sanding machine to level out your rough skis. If you do this please post photos.
If your school has a graphics/printing shop or an art teacher you could have students make their graphic layer with those teachers. Maybe you could have your students commission art students to do their graphics work. Make sure to test for UV resistance.
At home depot I've seen pine laminated shelving that was 18" by 72" This material could be cut into 6" by 72" wide strips that could have a hardwood strip attached to either side, with wood glue, for sidewalls and then be profiled into a usable core. This would be a pretty cheap way to make a bunch of cores. There are probably other wood options in shelving but I only saw pine. Snowboardmaterials.com sells unprofiled poplar cores for 25$.
There are threaded inserts that you can screw into a completed ski. The cheapest are brass and the most expensive are stainless steel. Check out mcmaster or a really good hardware store. I would not try to preposition inserts into the core because your students will undoubtedly experience some shifting during layup.
You could probably get a ski shop to drill or mark clear plexiglass sheets with various hole patterns for various sizes and types of bindings. This would meet your needs.
I would make sure your students wore tyvek or heavy coveralls especially during the finishing process. Those plastic dippped blue gloves seem to keep out most of the fiberglass fibers. In my experience I only use a respirator when I'm sanding or cutting fiberglass. During layup I just make sure my space is ventilated and I don't wear a respirator. What is your school's policy about using "dangerous" materials with students? I can't imagine using these materials in my building. I'm probably just paranoid about bizarre allergic reactions.
It would be great if you could build your own base sanding machine to level out your rough skis. If you do this please post photos.
If your school has a graphics/printing shop or an art teacher you could have students make their graphic layer with those teachers. Maybe you could have your students commission art students to do their graphics work. Make sure to test for UV resistance.
Do you and the kids have access to a woodshop. I am a high school wood shop teacher and am really excited about having students do boards and skis as well. It will make great senior projects.
My strategy has been to build a set of skis myself first and create the jigs and fixtures along the way. Once you have the steps perfected the whole process will be much more clear. Yes you want to do things easily, but I would suggest uilding out of quality materials. When you put in time and your boards fail because the pine cores rip out inserts and break it makes the money for materials fairly minor.
Would your local Woodshop Teacher support your project by cutting poplar and ask strips. He probably has a lamination table which would make the whole process really clean.
I agree with the no sidewalls idea.
My strategy has been to build a set of skis myself first and create the jigs and fixtures along the way. Once you have the steps perfected the whole process will be much more clear. Yes you want to do things easily, but I would suggest uilding out of quality materials. When you put in time and your boards fail because the pine cores rip out inserts and break it makes the money for materials fairly minor.
Would your local Woodshop Teacher support your project by cutting poplar and ask strips. He probably has a lamination table which would make the whole process really clean.
I agree with the no sidewalls idea.