Round Top skis 19/20

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Wheatlpa
Posts: 33
Joined: Fri Feb 12, 2016 11:14 am
Location: Sutton, QC

Round Top skis 19/20

Post by Wheatlpa »

Hi All, Let me introduce myself. i am a long time telemark skier living here in south eastern Quebec just above the Vermont border. I have built a couple of pair of skis in the past 2 years but those were on other peoples equipment. I have wanted to build my own skis since visiting a friends company in Jackson, WY while on a spring ski trip. It has taken a while but i am finally getting around to building my own set up.

Although i have built two pairs of skis in the past couple of years both systems are different from what i would like to build. The first was vacuum but using tube bags and steel plates for the moulds. Simple and fairly straight forward but the plastic waste was a problem and having a bunch of steel plates for the press seemed to be more hassle. The second pair was done with a friend on his pneumatic press, very straight forward but he built it many years ago and it only does one ski at a time and i do not have room for a large steel frame press.

So, i have decided to build a vacuum table with a silicone sheet. I am taking the table design from the joewoodworker, and i really like the mould built by Wvmtnbiker. For the ski design my first attempt is just going to model it off of my pair of BD Converts, i like the length and the rockered tip/tail but for spring skiing it is tough to get on edge. I will be changing the dimensions from (133/105/117) to 125/95/116, this should make it much easier to get on edge and a lot more fun on steeper terrain. Not sure if i will go with a rocker tail so i have some more reading to do on that.

Feel free to comment, point out my mistakes and maybe suggest a better way of doing things. I have been reading through the forum but it seems like a lot of information is a little stale and being new at this i have no idea if the information is still valid. I have been asking questions but it has been pointed out that every question has already been answered on the forum...

My first step is to build the table and mould. This weekend i will be rounding up the 3/4 plywood for the base and the hardboard for the top. I will also be trying to teach myself how to use nanoSoft to create DWG files for the tip and tail profiles that some one from my town has offered to manufacture on his CNC machine. Once i have something to show i will try and post some photos. The problem is that my garage/workshop is unheated and working in -10c is no fun at the best of times!

Wheatlpa
Posts: 33
Joined: Fri Feb 12, 2016 11:14 am
Location: Sutton, QC

Re: Round Top skis 19/20

Post by Wheatlpa »

The first part of the press is on its way. I ordered a silicone sheet from SSCRubber.com. Their customer service was excellent and easy to deal with. I am getting 3 yds of the following:

ARP-T-50-062-36 Translucent FDA Grade 50 Durometer Silicone Sheet
.062” Thick x 36” Wide

at 32.69/yard which seems reasonable to me.

I am also in the process of getting a couple of heating pads from alibaba, trying to sort out the payment details which means calling the credit card company to let the transaction go through. I will post details once they have arrived.

Wheatlpa
Posts: 33
Joined: Fri Feb 12, 2016 11:14 am
Location: Sutton, QC

Re: Round Top skis 19/20

Post by Wheatlpa »

I picked up my pump and some cheap veneer (Cuban Mahogany) over the weekend and assembled and tested the pump. It seems to work well despite my rudimentary electrical skills, although my next step is to add in a switch to the wiring so i can turn it off and on with out unplugging it. I also bought the MDF and masonite for the press table. It looks like i will be building a table to accommodate my ski partners length of 195CM so the table will be almost 2.5 meters long and 76 cm wide. I will then get to work on a frame for the silicone sheet, if we have some warm temps over christmas i might be able to get this done in the next couple of weeks.

Here is an image of the pump wired up.
[mg]https://photos.app.goo.gl/MR3naJQBwuf1ew1u7[/img]

sammer
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Re: Round Top skis 19/20

Post by sammer »

Curious to see how your silicone holds up. It's time to replace my poly, and vacuum silicone is $$$$

sam
You don't even have a legit signature, nothing to reveal who you are and what you do...

Best of luck to you. (uneva)

Wheatlpa
Posts: 33
Joined: Fri Feb 12, 2016 11:14 am
Location: Sutton, QC

Re: Round Top skis 19/20

Post by Wheatlpa »

I am curious as well. i have seen a couple of methods of attaching the sheet to the frame but both of them require drilling holes through the material and at that price i really don't want to screw it up! So, still thinking about how to do it (under the frame and wrap around on top or sandwiched between two pieces of wood). I have been thinking about finding someone to weld up a simple steel/aluminium frame but that just adds more to the cost but in the long run might be easier to seal and easier to clamp to the table. I am trying to think long term and i hate wasting money....

One thing at a time, table build over the holidays and then think about the frame.

Happy holidays to all!

ben_mtl
Posts: 582
Joined: Mon Mar 31, 2008 1:47 pm
Location: Sherbrooke, Quebec
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Re: Round Top skis 19/20

Post by ben_mtl »

I'm in Sherbrooke, curious to see your vacuum setup !
If you need Epoxy let me know ! Not that I have some for sale but I need to get some, maybe we can get a larger qty and share, I have contacts for a nice supplier in Ontario.
A bad day skiing is always better than a good one at work...

Wheatlpa
Posts: 33
Joined: Fri Feb 12, 2016 11:14 am
Location: Sutton, QC

Re: Round Top skis 19/20

Post by Wheatlpa »

Hi Ben, Thanks for the offer on Epoxy, at the moment i still have a bunch left, although once i get the press operational i might go through it quickly as i experiment with the process. If you have a source for fiber glass locally let me know, ordering from the states and dealing with the border is a bit of a pain. I would also like to see how your CNC router works and maybe i can pay you for cutting out some templates for me...

project update:
This weekend i finished the table portion of the press. Two pieces of MDF with the top being ~30" wide and 7.5' long and the second piece is the off cut so same length but ~18" wide. I then made a frame underneath to support the weight out of 1x6 pine which will make it easier to attach legs to. For the top i put on a 1/4" thick layer of masonite with a hole in the centre for the vacuum port. The table itself is pretty flat although not perfect but it will do for a first try.

I have some more 2x6 pine that i will be using for the frame to hold the silicone sheet. I will be working on this part later this week with the warm temps here in Sutton.

The photos from the build are all store here on my google album. https://photos.app.goo.gl/KX1ctzDuPpw3Qiu49

ben_mtl
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Re: Round Top skis 19/20

Post by ben_mtl »

Sorry I don't have any source for fiberglass, I bought 20ish rolls of 22Oz triax from a manufacturer a few years ago, sold half of it so I still have a lifetime supply of fiberglass considering how much I build skis/boards.
I can definitely help you with CNC cut templates. PM me of you have specific questions.
A bad day skiing is always better than a good one at work...

Wheatlpa
Posts: 33
Joined: Fri Feb 12, 2016 11:14 am
Location: Sutton, QC

Re: Round Top skis 19/20

Post by Wheatlpa »

It is proving hard to get my MDF table flat, so i have some aluminium angle struts that are dead flat which should hold the MDF flat and support the top at the same time. Too bad it is started snowing and the backcountry is starting to open up (this is a good thing) but it is making work on the press a little slow!

I am also going to start building the mould. i have decided to build a flat mould and work on getting the camber through heat differential. This will allow me to build a very adjustable mould which should cut down on the lead time for different sized skis.

Ben, i will PM you about the CNC template. Once i am finished with the table (and it is flat and holds a seal) i will let you know and if you feel like coming over to check it out you are more than welcome. Maybe we can get a day of backcountry in as well...

Wheatlpa
Posts: 33
Joined: Fri Feb 12, 2016 11:14 am
Location: Sutton, QC

Re: Round Top skis 19/20

Post by Wheatlpa »

slow progress on the table. It is now as flat as i can get it (on both sides...important!) so i have moved onto the frame to hold the silicone sheet and the templates for the mould. I have also got two designs done for a spring/resort ski and a fatter powder ski. Ben has been kind enough to offer to cut them out on his CNC which is awesome!

Here is a shot of the tip/tail templates rough cut out of 1/4" masonite, i still have to sand them smooth and make sure the transition portion on both templates is the same height and will match with the flat template i am going to make next. I have left roughly an inch from the bottom which will allow me to drill holes in the mould to make it adjustable. The tip/tail rise measurements were taken from my BD Converts and i used a set of french curves to draw a smooth line connecting them all as best i could.

Image

Here is a shot of the table with the frame on top. The frame is 2x6 pin ripped in half with mortice and tennon joints for the ends. I was a little sloppy on the joints but i have decided to pass the silicone under the frame and wrap it around on top to secure it so i don't have to make the actual frame airtight. I have closed cell foam gaskets to go between the table and the frame which i hope will create a strong seal. My only concern is sealing up the hole that will be used to thread the wires from the heating blanket from inside to the control box.

Image

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chrismp
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Joined: Fri Feb 13, 2009 9:00 am
Location: Vienna, Austria

Re: Round Top skis 19/20

Post by chrismp »

You could use so-called hermetic wire connectors or hermetic wire feedthroughs to connect the wires and keep things airtight.

Wheatlpa
Posts: 33
Joined: Fri Feb 12, 2016 11:14 am
Location: Sutton, QC

Re: Round Top skis 19/20

Post by Wheatlpa »

Interesting. I guess there is a solution to almost every problem out there. Now, i have to do some research and figure out which connector is the one i need. Although the list on the Pave Technology site seems pretty comprehensive there is almost too much choice.

Now i just have to figure out how to connect these wires from my heating mat to the PID. I am going to assume that they are K type thermo couples which should just attach right to the PID but again i have some homework to do.

Image

OAC
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Re: Round Top skis 19/20

Post by OAC »

Good job!

Just a tip/thought for the future. When you're done testing the frame consider change it to a robust steel frame. It will spare you time from searching leaks around the frame. It will not solve the issue 100%, but much better than a wooden frame. :)
And for the top of table, use some airtight "plastic combination". I use "paper laminate". I don't know if there is other name/type of it. I heard of phenol as one option. It handles heat better. I used PVC at first, but it just warped and was useless after one pressing. I press at 90C.
You can seal/cast it with a couple of layers epoxi also.

Cheers

Wheatlpa
Posts: 33
Joined: Fri Feb 12, 2016 11:14 am
Location: Sutton, QC

Re: Round Top skis 19/20

Post by Wheatlpa »

OAC: steel frame is the goal, for a first try wood was easier since i already have a pretty well stocked woodworking shop and this is only table mark one. The white top is masonite and which is coated MDF and should deal with the heat with no problems...i hope. My plan is to press at 65c so not an outrageous temp but i will be watching it like a hawk.

I contacted a company that makes hermetic wire connectors for some more information, they sent me a price list and i decided that for a first go i will just stick with small diameter holes for the cables with lots of silicone to plug up the gaps. Once i figure out what i am doing then maybe i will spend 200 - 300$ on the connectors!

We finally got snow instead of rain so looking forward to making turns this weekend!

ben_mtl
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Re: Round Top skis 19/20

Post by ben_mtl »

Great job !
I might have something for your wires when you come for your templates... pretty sure I have some cable glands left from when I wired the solar panel on my van... I'll check !
A bad day skiing is always better than a good one at work...

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