Lindstrom Cutters - can I repair the cutting edges?

[Reprobyte]

I've got quite a few of these Lindstroms that have damaged cutting edges and as such dont always cut well

Any advice on how to effectively fix these? no warranty you see!

[Dubbie]

The geometry of the edges means that it will be very challenging to regrind and have the blades still meet precisely. If the nick is at the end, you could possibly grind a long taper and have the snips close a little more. You'd probably need to side wheel grind it because there won't be access otherwise. You'd have to be super careful setting up the correct angle to grind. You'd probably want to indicate it in.

[Reprobyte]

The geometry of the edges means that it will be very challenging to regrind and have the blades still meet precisely. If the nick is at the end, you could possibly grind a long taper and have the snips close a little more. You'd probably need to side wheel grind it because there won't be access otherwise. You'd have to be super careful setting up the correct angle to grind. You'd probably want to indicate it in.

Yeah I will take a shot at side wheel and see if that works on them, thanks, don't mind them closing slightly

[eKretz]

Yes it can be done but it isn't the easiest thing to do by hand. I did a couple sets of Erem cutters only to find out later that they offer lifetime sharpening for free. Well, for the cost of shipping anyway. The sharpening turned out well enough that they can cut cleanly through .03" 60/40 solder without crushing it.

[Reprobyte]

Yes it can be done but it isn't the easiest thing to do by hand. I did a couple sets of Erem cutters only to find out later that they offer lifetime sharpening for free. Well, for the cost of shipping anyway. The sharpening turned out well enough that they can cut cleanly through .03" 60/40 solder without crushing it.

That's really nice work!

I been trying to grind with the dremel, can you explain how you did yours?

I've only got 3 pairs that really need work to fix, one can't cut well after dremel failure, while another seems half decent

[Dubbie]

Sorry I made the mistake of assuming that you had some sort of grinder like a tool and cutter grinder.

[eKretz]

Well,  I took the old school approach,  since when grinding with a power tool by hand it is very easy to make a mistake that can't easily be fixed.  They cut so fast that a little error quickly becomes a big one, especially when you're working on a near razor edge.  I used hand held coarse diamond hones to reshape the dull edges and then brought them up through finer grit to something like 5,000. I also took them apart and did one side at a time, fitting them together as I went to make sure the edges lined up parallel with each other and closed correctly. It ended up working out great. If the cutters didn't come apart it would be a LOT more difficult,  access would be a problem. A tool and cutter grinder would really be nice,  but don't have one of those.  I have also sharpened knives and straight razors for quite a long time and was a machinist and tool & die maker for a couple decades,  so it might just be easy for me,  don't know.

[Dubbie]

I have also sharpened knives and straight razors for quite a long time and was a machinist and tool & die maker for a couple decades,  so it might just be easy for me,  don't know.

That helps 

[Reprobyte]

Sorry I made the mistake of assuming that you had some sort of grinder like a tool and cutter grinder.

No, had one at my old work but not at home, but I could get one very easily from a local store, I was just guessing the variable speed of the dremel may have been useful

They're very cheap so I'll prob pick one up anyways

[Reprobyte]

Well,  I took the old school approach,  since when grinding with a power tool by hand it is very easy to make a mistake that can't easily be fixed.  They cut so fast that a little error quickly becomes a big one, especially when you're working on a near razor edge.  I used hand held coarse diamond hones to reshape the dull edges and then brought them up through finer grit to something like 5,000. I also took them apart and did one side at a time, fitting them together as I went to make sure the edges lined up parallel with each other and closed correctly. It ended up working out great. If the cutters didn't come apart it would be a LOT more difficult,  access would be a problem. A tool and cutter grinder would really be nice,  but don't have one of those.  I have also sharpened knives and straight razors for quite a long time and was a machinist and tool & die maker for a couple decades,  so it might just be easy for me,  don't know.

Diamond hones, thanks good advice, I havent used but seems like sharpening a knife etc, I think I may give a go! Hope I haven't made too much of a mess with the dremel

[eKretz]

Lol, you won't be picking up a tool and cutter grinder from any local store.  Those are specialized machines used in precision grinding of cutting tools like endmills. Unless you get very lucky,  we're talking several thousand dollars minimum even for a used machine.  A bench grinder isn't even in the same galaxy - let alone ballpark - as one of these. I'd recommend trying the hand honed approach.

[nanofrog]

I'd suggest sending them in to a precision cutter manufacturer such as Erem, Bahco/Lindstrom, ... in the EU for their reconditioning service (they'll all do other brands). Not only will it be done correctly, it's not expensive either (they'll contact you if they're too far gone IME). Turn-around is usually quick too.

Another possibility is to look for a local independent shop/person (i.e. someone that works out of their garage or back of a small cutting tool shop for decades). Especially useful if you're in a real hurry (i.e. same or next day). If you can't turn anything up in your Google-fu, you could check jewelry sites for recommendations.

[JamesLerch]

With regards to a Tool and Cutting Grinder, Steve Summers on YouTube got one recently, video link below.  Even with the machine you'd still have to fabricate a jig to hold and align the geometry.   

I did once successfully sharpen a pair myself by using a disk sander and a crude alignment jig, but it was challenging and the cutters were significantly smaller when I was done

https://youtu.be/C6s62QWjQ30?t=97

[Dubbie]

Yeah, thats what I was meaning.

You'd want to jig it up so that you could open and close the blade to press it against the wheel. That will give the correct geometry.

With the time and effort required, unless you have a bunch to do, it's probably better to buy some new ones.