A tutorial I posted
So I just sent this via PM to Jedi Knight Matatabi, but figured I would post it here as well. Maybe It'll help someone else when they want to cut their blades
Keep in mind this is what I did and found to work, others may have other methods or suggestions.
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Ignore my messy hot gluing, I was tired when I did it and I only had my old damaged hot glue gun which burns the glue making it yellow, couldn't find my new one and I had to get them glued up.
That is the inside of the blade- if you look at your new one (which wont be quite as messy on the gluing) you'll see that they also have a bit of a gap at the bottom of the blade between the blade and the film, it allows them to glue the film in place properly. Your original blade will probably be about 5-10mm (sorry, I don't know the inches conversion, but itll be small) so that's about what I did.
Use the pipe cutter to cut around at the length you want. Do it carefully and slowly, you are better off taking a long time than damaging the blade- coz it makes the blade bend quite a bit where you are cutting it. When you finally break through it, the section you are cutting off will still be attached to the film via the original hot glue- so when you pull that, the film will move out of the main blade (imagine the next picture as still attached, I didn't think to actually take photos as I went).
You can see that about 5mm of the film is sticking out of the offcut. What I did was pull the offcut down to expose that 5mm of film and used a very sharp knife to cut it flush with the main blade plastic - I used one of those box cutters/ safety blade with the trapezoidal shaped replacement blades, and used a fresh blade. Or you could use a snap and cut knife, craft knife, scalpel, scissors, but make sure they are very sharp coz there are A LOT of layers of thin film to get through and it'll take a while, and you don't want to make too big a mess of it!
The first time I attempted this I discovered that it was damn difficult to push the film back inside again- what I did was use the offcut to push it back in, since the offcut film hanging out the end is the same length as the distance you need to push the blade film back in. This was much easier than trying to push it in with my fingers, as all that did was buckle and warp the film without moving it. Then run a bead of hot glue around the inside of the base of the blade, making sure it contacts the film. Since my hot glue gun was buggered and the tip is all ruined anyway, I used the hot tip to smooth it out a little, then added a bit extra glue coz it didn't quite grab all the layers properly the first time.
If you are cutting your blade down a bit and have the space to do so, I would recommend doing a practice run at a longer blade length to get a feel for how to do it, that way if you do stuff it up you've still got the extra to fix it with. I was cutting my blades from 36" to 28" so I had plenty of room to practice on one. I also started with one of my older blades with warped film, coz if I ruined that one it wouldn't matter, I've got plenty of blades. As it was it actually fixed the warping and now you can't tell which was the damaged one
Cant for the life of me find the actual tutorial thread i made though
it had a few tool pics in it
EDIT: here we go, found the actual tutorial. For some reason I didn't get a hit with my first search
How to shorten your blades