JONG mounting question: Doing my own?

**smolakian** · 09-21-2007, 09:06 AM

Inspired by conundrums reusable jig/templates I am thinking of buying a few so I can do my own mounts.

I hate paying for such a quick job. Especially because If I don't have the time to go to the "right" shop around here they give you a BS 5 day turnaround and bend you over for $50.

Is it easy to fuck up when you do your own mounts? If I'm sober and careful is it a pretty easy process? Are there any experienced maggots that would be willing to hang out with me while I do my first one in exchange for free beer?

Are there any special tools needed and do I drill pilot holes or just sink the binding screws in?

I searched and couldn't come up with much (mounting position is a pretty popular subject!). Point me to the right thread, as I'm sure this has been discussed and is buried somewhere.

**anorangeapple** · 09-21-2007, 09:15 AM

It's not as hard as you might thinks I've done it a couple times. You just need to quadruple check that you have everything perfect.
Here's some how-to where some guy explained a way how to do it.

**lemon boy** · 09-21-2007, 09:23 AM

You definitely need to drill holes in the things. Tognar sells fancy schmancy drill bits that prevent you from drilling all the way through the ski but aren't 100% necessary (you can get by taping a regular drill bit of the proper depth). You'll also want to try and drill as straight a hole as you possibly can. And then you want to get the screws tight without tightening them down so much that the hole strips. If you take your skis to marshal he'll do them for cheap in literally 10 minutes and they won't be fucked up like if a shop did them.

Depending on the ski you'll want to use different size bits: 3.6mm is the "normal" bit, 4.1mm is for skis with metal in them, I think dps recommends 3.5mm bits for carbon. Metal skis probably should be tapped but wood doesn't. Epoxy v. wood glue is the eternal debate.

But it's not rocket science either. Take your time, measure carefully, drink beer, have fun.

**bio-smear** · 09-21-2007, 09:23 AM

I highly suggest getting a purpose-built drill (bit) that prevents you from drilling any deeper than 9mm. 3.6mm for non-metal topsheets, 4.1mm for metal top-sheets. Tapping of metal topsheets prior to sinking the screws is recommended to avoid blistering the topsheet. Also, critical to my tool quiver for mounting is the T-handle driver with #3 Pozi bit.

There are some tutorials on Wildsnow.com for AT bindings, but it's not really any different if you have a jig for alpine bindings.

Edit: Snooze to ponder a bit and Lemon Boy scumps you.

I'll add that the first few new skis you mount are a bit anxiety-inducing. For measuring on freehand mounts, I highly recommend using a slide caliper (the digital ones are especially dummy-proof). You can get them for cheap at Harbor Freight. Measure, double-check, compare 1 ski to the other, etc. With a jig it's a lot easier obviously, but even that can be fucked up if you are 3 beers deep.

**barnescli** · 09-21-2007, 09:42 AM

I use a drill press to make sure everything is straight, plus you can set the depth.

**smolakian** · 09-21-2007, 09:57 AM

Originally Posted by barnescli

I use a drill press to make sure everything is straight, plus you can set the depth.

Thats a pretty good idea. I have one here at work.

Hmm, I wonder if I could design a universal jig in solidworks and get it machined for me?

Squatch · 09-21-2007, 10:28 AM

Drill press is ideal, actually. Generally overkill and unnecessary, though, but you'll have perfectly vertical holes.

**Idris** · 09-21-2007, 11:00 AM

Never used a drill press.

2nd the purpose built drill bits, they make life safer and much easier.

If you are unsure about having metal in your ski. Drill 3.5mm if metal shavings come out then widen the hole with the 4.1

I use epoxy, more as a just in case I over tighten and strip the holes than anything else.

Whilst it is bad for to be out of alignment by a few mm (screwing up the mount just a little). I challenge you to notice this whilst skiing. A certain large heli ski operation a had one of the four little rubber feet on their mounting jig missing for at least 4 years. 100's of pair of skis were mounted slightly out of align - No one noticed whilst skiing - even when these skis were retired to being non heli skis did any one notice the missmount!

Practice on some dumpster skis or a 2x4 before messing up your ride

**yooper** · 09-21-2007, 11:01 AM

Originally Posted by smolakian

?
Are there any special tools needed and do I drill pilot holes or just sink the binding screws in?

This one was my favorite question!!!

I actually just posted a freehand mount tutorial of sorts over on Epic. Look under "tuning and maintenance" I believe the thread title is "drill bits"

**Odin** · 09-21-2007, 11:05 AM

I measured off a piece of the drill bit I used and applied tape in a circle around the bit to ensure that I wouldn't go any deeper, worked pretty well.

Also, I drank when I mounted my tele binders, and didn't when I mounted my markers.

I had WAY more fun mounting the linkens so take that for what it is worth.

**Griz** · 09-21-2007, 11:48 AM

Originally Posted by smolakian

Thats a pretty good idea. I have one here at work.

Hmm, I wonder if I could design a universal jig in solidworks and get it machined for me?

Smolakian, I've been practicing my own homegrown mounting skills on some old PREs - and found the drill press a pain in the ass, but I found a pretty cool jig at harborfreight for drilling perfect 90s with your hand drill. Plus, if you ever need a self-centering jig for tubing, it works too.

Edit: If you go to harborfreightdotcom it's item 95622

**bio-smear** · 09-21-2007, 12:01 PM

^^^^ that is a cool device.

**birdboatboy** · 09-22-2007, 01:37 PM

anyone ever go so far as the use a mill, or better yet, cnc controlled? that would be pretty cool.

**Idris** · 09-22-2007, 02:06 PM

Originally Posted by birdboatboy

anyone ever go so far as the use a mill, or better yet, cnc controlled? that would be pretty cool.

No but I have used a screwdriver as a drill. Slow but doable, if you get stuck.

**smolakian** · 09-24-2007, 09:12 AM

Originally Posted by birdboatboy

anyone ever go so far as the use a mill, or better yet, cnc controlled? that would be pretty cool.

If you had a cnc it would rock! You could import your skis into solidworks or any CAD tool. Then you would have EXACT measurements. You could probably then tap multiple inserts on the same ski. I don't know the patterns. But, with the added accuracy that the cnc provides you might be able to do touring and alpine on the same ski. It probably could be done easily enough without the CNC though. But, those kinda toys are fun for us engineering nerds.

What I'd really like to do is model the skis in solidworks and do some Finite Element Analysis. You would get a definitive characterization of the ski flex and actually model the effect different bindings and mounting positions have on the flex. Of course it would only be as accurate as the information you have to build the model and without a TON of data from the manufacturer it would probably require an autopsy.

It would be the most accurate when the skis were new. But, after some time of tracking ski days and having a standard flex test you would have a decent function of rigidity vs. ski days.

**lemon boy** · 09-24-2007, 09:13 AM

^^why is it that when you're holding a hammer everything looks like a nail?^^

**smolakian** · 09-24-2007, 09:22 AM

Originally Posted by lemon boy

^^why is it that when you're holding a hammer everything looks like a nail?^^

'Cause it's really fun to hit things.

**pechelman** · 09-24-2007, 09:51 AM

Originally Posted by smolakian

If you had a cnc it would rock! You could import your skis into solidworks or any CAD tool. Then you would have EXACT measurements. You could probably then tap multiple inserts on the same ski. I don't know the patterns. But, with the added accuracy that the cnc provides you might be able to do touring and alpine on the same ski. It probably could be done easily enough without the CNC though. But, those kinda toys are fun for us engineering nerds.

What I'd really like to do is model the skis in solidworks and do some Finite Element Analysis. You would get a definitive characterization of the ski flex and actually model the effect different bindings and mounting positions have on the flex. Of course it would only be as accurate as the information you have to build the model and without a TON of data from the manufacturer it would probably require an autopsy.

It would be the most accurate when the skis were new. But, after some time of tracking ski days and having a standard flex test you would have a decent function of rigidity vs. ski days.

wow
youre almost as much of a nerd as i am

or you could just use the ole paper\pen method and use a calculator

pretty simple forumlas honestly and just a matter of the added stiffness of the binding\boot interface added to the skis stiffness times the distance from the midplane. (ie moment of inertia effects)

**smolakian** · 09-24-2007, 10:12 AM

Originally Posted by pechelman

wow
youre almost as much of a nerd as i am

or you could just use the ole paper\pen method and use a calculator

pretty simple forumlas honestly and just a matter of the added stiffness of the binding\boot interface added to the skis stiffness times the distance from the midplane. (ie moment of inertia effects)

I'm a COMPUTER engineer. I let the machines do the thinking for me.