Kublai -- I-Beam Style Ski Press

For discussions related to designing and making ski/snowboard-building equipment, such as presses, core profilers, edge benders, etc.

Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp

rockaukum
Posts: 558
Joined: Fri Nov 03, 2006 9:23 am
Location: Placerville area

Post by rockaukum »

Looks very beafy! Solid aluminum, be careful because around here people will sneak in and take the aluminum for recycle $! Also, good choice in beer (on the table) and you do not need to post a safety disclaimer. I have a good recipie for a home brew to replicate the Pale ale if you are interested.
RA
User avatar
bigKam
Site Admin
Posts: 538
Joined: Tue Feb 01, 2005 5:15 pm
Location: Park City, Utah
Contact:

Post by bigKam »

obviously, i'm more excited about working on Kublai than devoting weekend time to my day job -- yes, i'm one of those work-alot-people... i have to just to maintain buoyancy.

i assembled the mold, cattrack, and hose. here are two photos of Kublai at 50 psi:
Image

Image


at this pressure, one would need either a laser interferometer or a capacitive sensor to measure the deflection of the beams -- Kublai seems solid, but i'll have it welded anyway.

again, i'll write up an article describing the press, as well as a method for layup. stay tuned...
rockaukum
Posts: 558
Joined: Fri Nov 03, 2006 9:23 am
Location: Placerville area

Post by rockaukum »

Kam,
quick question on the press. When the lay-up is done and it ts time to put the mold into the press, are you side loading or do you have to load the mold from the end? It looks like the mold is too long to side load and then how are clearances between the top portion and the bottom mold?
rockaukum
User avatar
bigKam
Site Admin
Posts: 538
Joined: Tue Feb 01, 2005 5:15 pm
Location: Park City, Utah
Contact:

Post by bigKam »

you're right, the mold is too long to load sideways.

the mold will remain in place. with no air in the hoses, the bungies pull the cattrack and squishes the hoses against the top mold. that leaves a nice gap between the cattrack's bottom surface and the top surface of the bottom (base) mold. now think of sliding a sandwich into the gap, where the sandwich is all the ski materials, expoxied and ready for pressing. i haven't tried this method yet, but a quick dry-run seems to indicate that it will work. here's how i plan to do it:

1. on a flat table, start with a thin sheet of hardboard, cover it with painters plastic.
2. lay the base material with edges attached, line everything up, apply epoxy.
3. continue to add other layers, finishing it off with the topsheet, then
4. cover everthing with a thin piece of uhmw and carefully wrapping the painters plastic around the sandwich like they do at the deli,
5. slide the sandwich in between the cattrack and top surface of the base mold, line it all up, then turn on the gas....

maybe i'll put together a short video to help illustrate this method...if it works.
G-man
Posts: 600
Joined: Sat Mar 25, 2006 3:58 pm
Location: northern sierra nevada

Post by G-man »

bigKam,

The method that you describe is pretty much the same that I have used on my last few skis. It works quite well. Here are my variations. Instead of hardboard at the bottom, I use a thin aluminum sheet that has been form bent to fit nicely with the mold contours. Instead of plastic, I've been using parchment paper, an idea I think that you posted at one time in the past. It lays nice and flat, doesn't get leaky little holes in it (like the plastic sometimes does), and is a bit more environmentally friendly than the plastic. Tape won't stick to it, so I use little clamps to hold it the the aluminum sheet until the whole lay-up is together. Then, I also use aluminum for the pressing layer, with parchment paper between the topsheet and aluminum. The whole lay-up assembly then slides nicely into the 2 inch'ish gap between bottom mold and the bladder. I use a pretty elaborate system of index pins along the way that I seem to be continually revising for improved efficiency. Oh, because the parchment paper is open along it's lateral edges, controlling resin run-off can be a challenge at times. I spray my aluminum sheets with mold release just in case things get a bit out of control.

Instead of building a cat-track, I took 3 layers of 1/8 masonite, spread glue on them, stuck them in the press and let the glue set up under pressure. Now I have a 3/8 thick, pre-formed masonite layer that stays bungied to the top mold, just the same as a cat-track. Cheap, quick, not too dirty, and has a really smooth bottom surface for pressing. One downside is that I'll have to make a different pre-formed layer for each different length ski, but it only takes about 30 minutes to make the layer. Also, my system won't evenly distribute pressure over a wider area like a cat-track will.

G-man
hydrant71
Posts: 61
Joined: Mon Sep 04, 2006 1:30 pm
Location: portland,or.

Post by hydrant71 »

wow big kam,

do you have an army of oompa-loompas in your shop cutting, routing,
and assembling?????? you put that together quick. looks really good, nice work. as g-man was saying a indexing pin system will make loading your
cassette much less of a chore. it will ensure that your running length
starts and ends exactly where you intended, without eyeballing and
guesswork while epoxy is oozing everywhere. i like going with a flat
lay-up (flat cassette) which eliminates the need for prebending tipspacers
and edged bases. both methods work well, each has its own +/-.
keep us posted on the heating system. plan on heating my press soon
but am confused with what type of controller to use.

looking forward to seeing the first pair.

jason
G-man
Posts: 600
Joined: Sat Mar 25, 2006 3:58 pm
Location: northern sierra nevada

Post by G-man »

hydrant71,

I went back and forth between the flat cassette system and the formed one a bit, myself. As you say, they both have their own benefits and little problems. I use a short length of 6" diameter PVC pipe to pre-bend the edged bases... very fast and works like a charm. I clamp the nose of the base to the roller with a bit of bar stock and roll away. I don't anneal my edges, and a 6" pipe works perfectly to get the needed tip curve. I made some long tipped squeeze clamps to temporarily hold down the core ends during lay-up. I also use the clamps to hold the whole sheebang together while I'm loading it into the press. I just found that the pre-formed cassette fits into my particular index pin arrangement better.

G-man
User avatar
bigKam
Site Admin
Posts: 538
Joined: Tue Feb 01, 2005 5:15 pm
Location: Park City, Utah
Contact:

Post by bigKam »

hydrant71 wrote:...looking forward to seeing the first pair.
done. :D looks like the cassette-layup method works well. i'm going to consider G-man's AL sheet next.

Image

i have a name picked out, but need to think about it more....
they are twin-tip skis, but they don't appear that way. that's because the shape of the tip/tail molds were more relaxed than i intended. but viewed from the side the skis look fine; and i thought about G-man when i designed the shape of the tips -- now you can use tip and tail clips to attach skins to 'blunt' tips/tails :D.

i used a new technique for the graphics (not sure if this approach has been mentioned -- too lazy at this point to search). anyway, i'll describe it: at Michael's craft store i found a packet of special paper where you can print graphics (like mirror images) and then iron them on a t-shirt. what a neat idea i thought. and it works beautifully. but what i discovered was: like die-cuts, you will have to cut out the graphic then carefully arrange them on the fabric and iron. otherwise the areas that should be 'clear' will actually be a semi-opaque film that sticks to the fabric. not pretty. oh, the paper works well with color ink jet printers. i just used black (a laser printer too). the color does not bleed either. very nice. it would be nice to get a hold of a roll of this stuff, or i suppose you can print multiple pages and stitch them lengthwise to cover a ski... hmmmmmm....

these skis have two kinds of metal: thin sheet of steel (0.002") and a couple pieces of AL (0.016" thick). i also added an entire layer of VDS rubber between the wood and base material. the metals are also sandwiched between the wood and base. i wanted to create skis with more damping. let's hope they work. but don't think that they are heavy. they're very light, in fact. i used pine (cheap and with knots too!) and D. fir. the core thickness is at most 9.5 mm.

the sidecut is deeper than usual for me. i modeled this ski after one of my favorites: Rossi Mega Bang. i intended to use rubber for tip/tail spacers and also planned to router a slot in the core to add rubber, but initial tests indicated that it was difficult to bond rubber to epoxy. i'll figure it out... (btw, Kelvin and i have the answers from Roy at QCM and we're in the process of putting the info together to post....such good answers from the epoxy expert!...stay tuned; next expert is for base materials!)
hydrant71 wrote:wow big kam,
do you have an army of oompa-loompas in your shop cutting, routing,
and assembling?????? you put that together quick.
well, i get bored if i take too long on a project, so i work fast. besides, when you're excited about something, it goes fast. surprisingly, i assembled most of the press myself -- the two top beams i managed to lift and bolt (i wouldn't recommend it, but there are clever ways...i enjoy problem solving.)

i'll write all this up soon... now i need to think about testing my new rides...
G-man
Posts: 600
Joined: Sat Mar 25, 2006 3:58 pm
Location: northern sierra nevada

Post by G-man »

Ey Chihuahua!! Absolutely gorgeous.!
and i thought about G-man when i designed the shape of the tips -- now you can use tip and tail clips to attach skins to 'blunt' tips/tails Very Happy.
That made me laugh out loud and I woke my wife up. Now I'm in trouble.

Your ski designs and graphics are always so creative and different... and you're so incredibly prolific. Interesting choice of materials. I'm anxious to hear how you like the pine. Oh, a suggestion for the name... knotty boys!... except I don't see any knots on the clear topped ski. Wow, super thin. How's the flex with all that metal in the mix?

G-man
plywood
Posts: 499
Joined: Fri Oct 13, 2006 2:13 am
Location: wilen, switzerland
Contact:

Post by plywood »

these skis are awesome! i really like the grafics - and very special design! but it looks great. i suppose this kind of tips will also create a lot of uplift in powder...
i`m planing similar tip and tails for my next pair, well,actually just "straight" and not with that kind of butt-like shovel. what was your idea behind this design?
plywood freeride industries - go ply, ride wood!
powdercow
Posts: 76
Joined: Mon Jul 31, 2006 1:35 pm
Location: Orem, Utah

Post by powdercow »

Awesome press Kam. I think you got a fairly good deal on the steel since I spend more than that I my press is considerably smaller (I think using W16 beam increased the cost a lot). My steel also came from a yard and had a “nice patina” on it. I started to clean it up but after only a minute decided to just use some rustoleum and paint right over the surface rust. It ended up looking good after two layers and was a whole lot easier so that is a solution you might want to think about.
You mentioned a layer of vds covering the whole ski. Was this done with multiple strips or did you find a source for wide vds?

One more thing, Is the cattrack for snowboard making? I have been looking into this and the solution I like best is a 10” diameter hose I found locally. 9’ is going to cost just under $400 but I think in the end it will be worth it.

Oh and as for color my money is on kublai becoming a green machine.
- Ben
User avatar
bigKam
Site Admin
Posts: 538
Joined: Tue Feb 01, 2005 5:15 pm
Location: Park City, Utah
Contact:

Post by bigKam »

G-man wrote:.. except I don't see any knots on the clear topped ski. Wow, super thin. How's the flex with all that metal in the mix?
here you go:
Image
Image
if you look closely at the yellow ski, you'll notice a hint of a knot on the left edge about 6-inches above cord center. so far the flex feels really nice. i'm quite excited about skiing them. i think the layer of VDS will make a difference (powdercow: i just used three wide strips to cover the base) i'll give a test report after this weekend --- a large group of friends (including Kelvin and Allyson) and i will be at Whistler to ski. there's new snow on the way!! today i cleaned them up at Kelvin's, using the wet-belt sander. oh, i'm sure you've noticed that the core appears shifted in the yellow ski. as i was profiling the wood core, the router splintered the D. fir along the outer edge, effectively reducing the width of the core at the tips. since the core no longer covered the tips, i had to compensate by shifting the core during layup. at the tip one side has wood sidewall and the other is glass. no big deal.
plywood wrote:...what was your idea behind this design?
something different. Kelvin thinks i'm going to 'pitch-fork' a tree in the backcountry with those tips. maybe so, but i'll have fun doing it...
powdercow wrote:One more thing, Is the cattrack for snowboard making?
it's a surprise. i'm tinkering with something, and it'll be ready toward the end of March!! it'll be fun and it'll make you laugh, i promise! ;)
I have been looking into this and the solution I like best is a 10” diameter hose I found locally. 9’ is going to cost just under $400 but I think in the end it will be worth it.
whoa. i want one.
Oh and as for color my money is on kublai becoming a green machine.
how in the....what in the...?? did you find my skibuilding project book?

YES. but specifically lime green.
G-man
Posts: 600
Joined: Sat Mar 25, 2006 3:58 pm
Location: northern sierra nevada

Post by G-man »

Gnarly knots... dude :) .

G-man
powdercow
Posts: 76
Joined: Mon Jul 31, 2006 1:35 pm
Location: Orem, Utah

Post by powdercow »

how in the....what in the...?? did you find my skibuilding project book?

YES. but specifically lime green.
This my friend will be money. Pictures are of course required (once it is done).

Ilene is black now but eventually I would like to "dress her up a little bit".
I narrowed my color selection down to either a lime green (great minds) or something a little more feminine. It is low on the priorities list but I think at this point I will go the girly route.

Oh and I am definitely looking forward to the cat track surprise. Something we might be seeing in March?
- Ben
User avatar
bigKam
Site Admin
Posts: 538
Joined: Tue Feb 01, 2005 5:15 pm
Location: Park City, Utah
Contact:

Post by bigKam »

more updates:

heater blanket is on its way (15"x75", 220V, 3000W, Type J TC) with 8' long wires. i found a controller and SSR (from ebay). i was surprised to find an abundant number of controllers available. the price range for controller and SSR is between $50 - $150. the trick is to make sure all the parts are compatible.

the new skis pictured above skied very well. i immediately noticed how damp they were -- most likely because of the rubber layer, and also the steel and aluminum. i enjoyed the soft flex very much, and the pine seems to work well. the tight sidecut made them carve nicely, but the tails felt like they were grabby, especially after exiting from a turn. maybe i need to bevel the edges more or shift the mounting of my bindings. i have some videos of Kelvin and i at Whistler this past weekend that will post soon. oh, it was great to run into people that recognized our work! seems like the community is starting to grow!

Image
Post Reply