Petzl Lim'ice

This is an unsolicited plug for the new Petzl Lim'ice ice-screw sharpener. Mine arrived yesterday and I've just tried it out. If you own more than half-a-dozen screws you should consider getting one, or make friends with someone who's already got one. Cost is about the same as a single ice-screw. It consists of a sliding file and a guide that holds the screw at the correct angle. Insert the business end of the ice-screw into the guide, slide the file back and forth, and repeat for each tooth surface.

It doesn't do quite as good a job as Ouray Mountain Sports with their Grivel machine, and it takes a fair amount of work if your screw is badly dulled. But it's a great device if you only need to sharpen a couple of screws at a time, or for light touch-ups.

petzl.com/us/outdoor/vertic…

Petzl Lim'Ice

Did it change the bite of that BD Express? Most of my screws are BD, so I'd be interested to hear how they perform when sharpened to Petzl specs.

Peter Jackson wrote:Did it change the bite of that BD Express?

Yes, there's a difference, but it's very slight. It'll take longer the first time you sharpen a non-Petzl screw because you'll have to file until the tooth angle matches Petzl specs. (It helps to mark the original surface with a Sharpie before you start, then stop filing when the Sharpie ink is all gone). Subsequent re-sharpening will be faster.

There's a similar issue if you send your BD screws to Ouray Mountain Sports, because their machine is made by Grivel. In practice I've never noticed a difference, and the folks at OMS say the same thing.

But you might want to avoid alternating between the Petzl device vs sending your screw to OMS (Grivel), because more of each tooth will be ground away each time.

I was just looking at this device yesterday oddly enough. Decided to pass on it for the time being, but next time we get out would love to see how it works. Certainly looks like an inexpensive way to keep em' sharp! Thanks for the post Martin

Where did you order it from?

David Appelhans wrote:Where did you order it from?

From the Interwebz. Mountaingear.com and Backcountry.com have them in stock, you could probably find a few others.

They are a brilliant piece of kit.

anyone got a pre/post pic to show how it does?

Big thumbs up from me. Put my screws away at the end of last season with lots of dings and dullness. Sat in front of the TV a couple weeks ago and sharpened 'em all up to factory original sharpness.

Easy to use, but a bit unwieldy. On balance, I figured if I saved myself from having to replace one screw, it pays for itself.

Recommended.

I picked one of these up a couple of weeks ago. They do not sharpen to Petzl specs! They are closer to the Grivel specs or the old BD. They are great for touching up an ice screw at the crag but that's about it. At the end of the day you turn a new generation tooth angle into an old school tooth angle. Still better than a dull screw but not as good as a professional sharpening job.

Over all it's a good tool for touch ups.

rocknice2 wrote:They do not sharpen to Petzl specs! They are closer to the Grivel specs or the old BD.

Why wouldn't a Petzl sharpening tool not sharpen to Petzl specs?

I don't know but they don't.

rocknice2 wrote:I picked one of these up a couple of weeks ago. They do not sharpen to Petzl specs! They are closer to the Grivel specs or the old BD. They are great for touching up an ice screw at the crag but that's about it. At the end of the day you turn a new generation tooth angle into an old school tooth angle. Still better than a dull screw but not as good as a professional sharpening job. Over all it's a good tool for touch ups.

I'm having the same experience. I experimented with an older black-hanger BD turbo express, a newer silver-hanger one, and a fresh Petzl laser speed. It does a pretty slick job of sharpening the older BD, but it's way off on the two newer screws. Basically it just starts to flatten out the very tip of the point instead of equally sharpening the whole face angle. If I kept going I'd end up with much shorter teeth with a flatter angle, just like the older BD has.

By eye, the new laser speed and current turbo express have almost the same angle, so I would imagine whatever device works on one would do a decent job on the other.

The Lim'ice does NOT reproduce the same specs as found on Petzl screws. Why? I have no clue. If one can get a file and sharpen it to specs on a vise they can surely make a file guide to respect the same angles. Maybe at those angles it's very hard to slide the jig back and forth. Maybe they don't want you to replace the screw often. The tool is kind of clunky to use especially when filing the trail edge and that's the one in question.

Quote from NEice.com
iceclimbingforums.com/showt…-(link)/page2
"The guy at Petzl was very friendly and helpful and noted that my Lim'ice was, indeed, working as designed. He agreed that it was sharpening the slanted part of the tooth at an entirely new angle. He said this change shouldn't make any noticeable impact on the screws performance and that sharpening only the very tip of the point was necessary and that the new angle wasn't an issue as long as the tip is sharp."

He's right to a point. Let me try to explain. What I found when experimenting with different angle is, the pointier the easier it goes in but wears out faster. To elaborate why the new generation of deeper tooth design works much better at starting a screw. It has to do with how much pressure it takes to sink a tooth into the ice. The old design had a tooth depth of about 6mm and the new ones are about 9mm. Now there is no way you can sink in a screw 6mm at the start in one turn, not even the new designs. The advantage you get is that a steeper toothed screw will displace less ice and sink into the ice deeper than a shallow tooth. That's before you start to twist it. Once the twisting starts, each twist will result in deepening the hole more the a lesser angled tooth. It's sort of like an ice pick, the thinner it is the deeper it penetrates the ice.
So getting back to what the Petzl guy said. If you just touch up the trailing edge slightly, this should effect the performance only slightly. If you notice the new Lasers have a notch at the root of the tooth. To keep up the maximum performance it would be wiser to file the leading edge more and only remove the burr from the trailing edge. Keep in mind that you should keep the teeth balanced so you need to do all 4 teeth. Not easy to say the least.
Like I said on MP.com it's a great touch up tool to have at the crag but it has it's limitation if you want to return a rack full of basket case screws. Don't throw out your table vises just yet.

As some of you know I have an ice screw sharpening service and return a screw that is sharper than factory. I bought the Lim'Ice and I use it personally at the crag. I have a table vise to keep my screws sharp between my batch runs. Hey I hit rocks too and that's why I started this service. I recommend the new device, I've seen some of the butchery that goes on. Or better yet "Give me your tired, your poor, your trundled rack yearning to breathe free"

A side note: the Grivel screw sharpener only sharpens to the older shallower tooth specs.

Has anybody tried the Lim'ice on the Grivel Helix (Speedy)?

I bought one of these devices recently as well. I used it to sharpen some older BD turbo express screws that were so dulled I wasn't even using them. I touched the screws up and they are now very sharp, I even sharpened one screw to the point where the tips were uneven by 2-3mm, it bit just fine in hard ice conditions.

The screws that I had considered good and were in service for leading were like butter knives compared to the touched up beater screws! It works just fine on the newer BDs as well.

I would recommend this product to any climber with with their own ice rack(of BD screws at least). Maybe they are not the factory profile, but they come out plenty sharp.

Martin le Roux wrote: Insert the business end of the ice-screw into the guide, slide the file back and forth, and repeat for each tooth surface.

just wanted to hop on this old thread and mention that you should not sharpen anything with a back and forth motion! Whether by hand or by equipment.
in the user guide for the LIM’ICE it states: always sharpen in the same direction. Do not sharpen using a back and forth motion on the file.