Custom Tool for Dynafit, Plum, Etc.

Do your tech bindings look like this from kludgy screw driver use? At the least, use the biggest blade screwdriver possible -- or make a custom tool.
Ever notice how bogus most screw drivers are for spinning the spring cap on the rear of tech bindings such as Dynafit, Plum, and others? Too small a driver and you muck up the slot at best, or at worst have trouble keeping the cap aligned and end up stripping the plastic threads it sits in. Today was the day. I purchased a 1″ gasket scraper that appeared easily shaped to the required dimensions. About 45 minutes later, we now have the ANSI approved DIN/ISO certified tech binding rear spring cap tool.

The custom tool in use fits the rear spring cap to perfection, thus preventing slot damage as well as helping to prevent thread stripping when you screw in the cap.

Using calipers, I determined how far up the blade I'd chop to get the thickness correct. This can easily be done by eye and trial. Key is to cut up to the point where you get a blade that's snug in the tech binding cap slot. More, it's not a bad idea to file some of the taper out when you're done so the wide sides of the blade are closer to parallel. Important: A gasket scraper will have a slight angle to the blade, which isn't ergonomic when using as a srewdriver. Bend out the angle by heating first then tweaking.

I did the chop with a small cutoff wheel. A disk grinder would work as well but this sort of steel is usually too hard for a hacksaw. No worries about grinding heat wrecking tempered hardness since you'll only be using this tool on aluminum.

Completed tool for backcountry skiing tech bindings. I might do a bit more work on the blade so the sides are closer to parallel, but as is it works quite well. Nice addition to the WildSnow bench.

Looks like it was made to turn a tech binding cap, eh? Little things like this can make backcountry skiing easier and more fun.
Any of you ski techs out there have a favorite tool for turning the tech binding spring cap? Make a comment!
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32 Responses to “Custom Tool for Dynafit, Plum, Etc.”
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Most don’t need to adjust their DIN often enough to need this…
I did something similar with an old wood chisel…the gasket scraper approach looks better.
Hm…is it really necessary to have a special tool for this? It is easy to operate the cap with a regular large screw driver and a little patience. I maintain 3 sets of tech bindings and never felt any need for anything special. The less tools the better.
Great call, Lou. I was grinding down a large flathead screwdriver just a few days ago to be flatter and wider for the same purpose.
It seems like this might also make it easier to begin threading the cap properly, as they can be prone to starting crooked and stripping the housing.
I think its great. Maybe not a necessity but when you are taking care of your own bindings and your buddies it would be handy.
Less tools the better! Blasphemy.
About threading the cap in correctly, best method I’ve found is to do it first without a tool, by feel. But having something wider and more solid once you start with a tool does help as well, at least in my experience. Lou
great idea. if you could find another tool that isn’t offset like the gasket scraper, that would work even better.
agree on the more tools: all the better, especially custom made stuff
Brian, by heating and bending it feels aligned in use, but yeah, wasn’t good with the offset.
Ahem… a BD keychain/ bottle opener works best.
Mixed happy coincidence.
Definitely thread the screw by hand to start it off! I stripped a Plum heelpiece’s plastic body very easily once when starting it with a screwdriver.
I have seen several screwdrive slots with the curved bases. The deepest portion of the slot is at the center, the shallowest at the ends. Thus if your use a really large screw driver it is easy to cam out since you have a very shallow bite.
I always thought that the intention was to use a coin. My garmin Vista mount has a similar sloted screw. Penny/dime works well. Thoguh tough on the fingers to grip.
For the binding it is a weird size. Quarter would seem a little small, and any of the larger coins (firt cent peice, Saq $) would be too uncommon and maybe too wide. Maybe it fits euro coins perfectly.
I think your custom tool needs more of a curved edge to make it a perfect fit.
~fifty cent peice.
Thanks for the tip Lou.
I love it how it’s totally acceptable to HAVE TO RETRO FIT YOUR OWN TOOL to make a simple binding adjustment. How about a slight redesign to the binding?
What was that? No…We are dynafit, we tell you what you need and how you should use it.
Bill, indeed, I think the original intention of the spring cover slot on Dynafit is a coin, which works. A bit of history: The spring and cover were copied from and supplied by Iser for the first Low Tech (eventually Dynafit) bindings, 1987, 1988… Lou
Not sure I want to carry this around with me, could prove dangerous if someone fell on the screwdriver!
the 2 Euro Coin is a pretty much perfect fit.
Thanks for all the comments you guys, excellent getting all the different takes on this basic but important part of tech binding tooling. Lou
I tried a quarter. Works better than the majority of screwdrivers.
I’ve always used a quarter – never had any issues.
I’d agree about the quarter, main reason for my tooling up is we’re in more of a production environment and I want a solid tool I can reach for that takes minimal effort to really spin those caps, while removing and replacing them. Adjusting for RV value just takes a turn or two usually, that’s much different. One thing about the cap is it would be nice if the bottom of the slot had a slight curve to accept a coin better, but yeah, the coin does work.
A norwegian 20 kr coin is also perfect for this purpose:)
I unscrew these things quite often as i change the brakes from 110 to 130 when i want to use the bindings with skis of different width.
Taking of the brakes can be a bit challenging, but in the same line of thougth I have found a perfect tool to use to spread the the looking arms when pulling off the brakes:
http://www.biltema.no/no/Verktoy/Elverktoy/Slipemaskin/Nokkel-justerbar-20840/
It’s a key for removing grinder discs. Works perfekt and really takes the pain out of the job. And I have jet to mistrread the barrel
Was bummed to read about how the new dynafit brakes are unswappable….
Dynafit made, or at least had in their instructions, a brake spreader tool. I made one… probably won’t blog about it as it sounds like the removable brakes are history. Agree, that’s a major bummer. We love being able to move brakes around our quiver depending on ski width and such. Lou
I fashioned a similar phatty driver several years ago, as my former shop mounted gazillions of Dynafits. I found it indispensable, as handing over BRAND NEW GEAR to a customer, with a kludgy janked screw seemed ill-advised.
A little gruntled regarding the new brake schtick; however, maybe this will ensure that our glisse friends will put one binding on one ski and call it good?? I felt really bad last year upon cracking the baseplate (quite aged) on a customer’s 1st gen. Dynafit… luckily he was easily convinced that maybe a new pair of bindings every twenty years was reasonable.
I bet this would work pretty well…http://www.nrsweb.com/shop/product.asp?pfid=1329
The one thing I hate about Europe is all the coins they use. They just seem to fill up your pockets with extra weight you don’t want! That’s why this slot is designed for a coin, i.e. 2 Euro coin.
Thus not an issue for Europeans.
Any aircraft mechanic who worked on radial engine cowling fasteners (DZUS)…would recognize what tool is needed for this job. The military made a tool for that slot called the “Mickey mouse tool” it looks like a profile of Mickey. I can send you a picture of one from my tool box.
When you profile the end of your tool, it needs to be more convex to match the concave slot.
Mickey Mouse or some called it the Snoopy tool
The Euro started in 1999, Dynafit bindings with the slot as pictured pre-date 1999, so they were NOT designed for a 2 Euro coin. Probably for some Austrian coin. I’ll ask the man, he might be amused by the question.
As for the Euro, my theory is they make all those coins to try and cause people to take the currency more seriously. It’s said to need all the help it can get (grin).
Oh, and a FWIW, I have a 50 cent Euro coin here and it fits quite well, though I like my screw driver better.
Lou
Love it!
cool every shop should have one