Methods to keep core/ base still during press.

For discussions related to ski/snowboard construction/design methods and techniques.

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

gketcham
Posts: 103
Joined: Mon Sep 13, 2010 3:28 pm

Methods to keep core/ base still during press.

Post by gketcham »

My last pair (#3) of skis had a core shifting issue. Before this pair I used small brad nails through the sidewall down into the bottom mold to keep everything in line throughout the process. I stopped that after the second pair of skis had a nail going through the base. So I tried another method (base material on either side of the base/edge to butt up against) which did nothing for keeping the core from shifting, but it kept the base from moving. I would love to know what methods other people are using and how they work/ didn't work.

The nail in the base has great aesthetic value by the way!

gozaimaas
Posts: 655
Joined: Fri Feb 10, 2012 4:17 am
Location: Nagano Japan

Post by gozaimaas »

Superglue 2 inserts to the base.

User avatar
vinman
Posts: 1362
Joined: Fri Nov 09, 2007 4:16 pm
Location: The tin foil isle
Contact:

Post by vinman »

Drill 2 11/32 holes through core, glue 5/16 poplar dowel pins to base. Just be sure they are big in your mounting zone and they are sanded flush or slightly recessed to the core.
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com

User avatar
MontuckyMadman
Posts: 2394
Joined: Fri Jun 20, 2008 9:41 pm

Post by MontuckyMadman »

There only like a few meelion ways to skin this cat, posted on here a bunch. The method shown in my thread is one of the better options.

mammuth
Posts: 377
Joined: Tue Oct 28, 2014 3:48 am
Location: somewhere in the alps

Post by mammuth »

The dowel pin method works quite well with good accuracy if the hole and pin are a tight fit. But even with schablone every time i have to fiddle with the glueing of the pins (except the first time, then it was working perfectly and smooth).
One time i tried to make life more easy and drilled the holes 0.5mm bigger then the pins ... got an offset of more then 1cm on tip and tail. Lesson learned.
Tom

MadRussian
Posts: 703
Joined: Thu Sep 30, 2010 12:32 pm
Location: USA

Post by MadRussian »

MontuckyMadman wrote:There only like a few meelion ways to skin this cat, posted on here a bunch. The method shown in my thread is one of the better options.
Your tread???????????????? where????
I have not failed. I've just found 10,000 ways that won't work.
Thomas A. Edison

User avatar
chrismp
Posts: 1338
Joined: Fri Feb 13, 2009 9:00 am
Location: Vienna, Austria

Post by chrismp »

In the journal section, duh. It's just a few pages back: http://www.skibuilders.com/phpBB2/viewt ... c&start=30

User avatar
vinman
Posts: 1362
Joined: Fri Nov 09, 2007 4:16 pm
Location: The tin foil isle
Contact:

Post by vinman »

I use base pins as described above and I also use a version of MM's method. I just use some scrap MDF hot glued to the aluminum sheet. I leave about 1mm between the sidewalk and the block to allow for the base layer of glass to firing there. Between the pins and the blocks things don't move. Be sure your blocks are thinner than your core.
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com

User avatar
SHIF
Posts: 272
Joined: Sat Jul 14, 2007 7:43 pm
Location: Wasatch Mountains
Contact:

Post by SHIF »

On my single-wide ski press my cores are located using thumbscrews. These fit into shallow dimples drilled into the sidewalls about 1 mm deep.

Image

Image

After aligning the core as shown above during my pre-build set-up, I trace along the sides with a Sharpie pen to mark the aluminum hot plate. Then when affixing the base/edge assembly to the hot plate I visually center it relative to the pen marks.
During the ski build, the thumbscrews on one side are backed out to allow installation of the core. Once tightened again the ski core is perfectly registered and can not move.

I've recently added three pairs of alignment blocks above the hot plate surface which serve to align the printed top sheet material. I only need to ensure its aligned in the longitudinal direction during lay-up. So far all of my ski graphics have great registration.

Cheers,
-S

RYM Experimentals
Posts: 85
Joined: Fri Dec 21, 2012 8:57 pm
Location: Fall City, Wa.
Contact:

Post by RYM Experimentals »

In our snowboards we went away from using guide screws or supergluing inserts to line them up, instead we just take the extra time during layup to get everything lined up right and haven't had any problems since. Just be careful moving and loading the cassette, that's were I find that shifting occurs. If it goes in straight and you press it slow at first, it should line up fine. Much quicker than dealing with guides
www.rymexp.com
On the edge of control is a good place to be!

MadRussian
Posts: 703
Joined: Thu Sep 30, 2010 12:32 pm
Location: USA

Post by MadRussian »

Ryme IIRC from your other posts you using vacuum.
Vacuum workdifferent compare to compression press. And force created by squeeze out much greater. Without securing in place base and core it's impossible not to get one or both of them shifts during pressing unless using three-dimensional cassette
I have not failed. I've just found 10,000 ways that won't work.
Thomas A. Edison

gketcham
Posts: 103
Joined: Mon Sep 13, 2010 3:28 pm

Post by gketcham »

Thanks all. I think spending a few more minutes during layup and have a better blocking method. All of my equipment is super ghetto too but I will update all in good time.

User avatar
skimann20
Posts: 345
Joined: Wed Feb 27, 2008 8:28 pm
Location: Taxachusets

Post by skimann20 »

chrismp wrote:In the journal section, duh. It's just a few pages back: http://www.skibuilders.com/phpBB2/viewt ... c&start=30
I felt confident saying that I have read every post on here and can remember most. this location method... i do not remember. @MM I really like this idea!

I do what Vin does with the dowel pins. not sure if it is the same size but you get the idea.

User avatar
vinman
Posts: 1362
Joined: Fri Nov 09, 2007 4:16 pm
Location: The tin foil isle
Contact:

Post by vinman »

Pins work well, but I'm always looking for a different method. I'd like to eliminate this. I can eliminate side to side movement no problem, but the front to back movement and locating the core on the base is the issue.....
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com

User avatar
Akiwi
Posts: 370
Joined: Thu Jan 15, 2015 7:48 am
Location: Olching (Near Munich) Germany

Post by Akiwi »

I don't know if this is a relavent answer, to your line up issues, but I boought one of those laser level things that have a cross to mount things on walls. I mounted it on the ceiling looking straight down. For snowboards / longboards etc it is great. For skis I would need either two, or create a simple jig to move it left/right for each ski.
It shows the exact middle for ligning up bases, cores, topshets.
Image
I am nobody. Nobody's perfect, so I must be perfect.

Post Reply