When Gun Regulations Fail

I have long held that our weapon laws are sensible and functional – not too strict, not too loose, and I still think they are more on the reasonable side than not. But they do sometimes fail, as they did just now.

Czechia had yesterday the worst mass shooting in our history. Mass shootings do occur here, unfortunately, every once in a while. This one was perpetrated by a person who held multiple firearms, legally, because he had no criminal history or mental health diagnosis. His motives are so far unknown, he did not appear to be targeting any specific demographic – his goal was apparently just to cause as much pain as he could.

This does not happen here even remotely as often as in the USA, but even once would be too many. And I am afraid that this incident will be used to argue for further loosening of our already loose gun laws by idiots who think adding more guns to the situation would somehow prevent it, instead of multiplying it.

Improvipairing mah Belt Grinder Again – New Platen

The steel platen behind the belt has been a bit problematic since the start. As you can see in older pictures, it was a piece of angle iron that was on the left side attached to the belt-grinder arm with two screws. The problem was that when I exerted pressure on the right side, it bent ever so slightly and the belt started to wander off and the whole thing behaved a bit unpredictably. I learned to work around the problem, but it was a problem and it needed solving. So this week I finally solved it.

© Charly, all rights reserved. Click for full size.

I bought two hinges and screwed them on a piece of 3×40 mm mild steel at a distance slightly bigger than the thickness of the belt grinder arm. Then I drilled two holes through the arm and put in them two carriage bolts with winged nuts. Then I cut slots into the hinges that I could slide under the screw heads and the nuts. Because the hinges are slightly more apart than the thickness of the arm, when I tighten the screws they work as flat springs with a slight bend and it all holds together very nicely.

To serve as the platen I have screwed a piece of 10×50 mm mild steel on. It works perfectly. It is stable regardless of which edge of the platen I work on and I can exert as much pressure as I want, although admittedly, I have only ground bone on it and not steel. I might either harden the platen by carbonitriding it or I can weld a hardened steel plate on the face, but mild steel works just fine too and with my rate of making blades it will hold for a long time as it is.

There is one last problem that I need to solve, and unfortunately, I do not know how. It is also difficult to describe, doubly so in a foreign language, so if you do not understand what I say, the problem is probably not at your end.

I need a reliable and stable way to adjust the belt’s traction. The spanning arm was a bit wibbly-wobbly, and when I fixed that, I got new problems. When I optimized it for a forward-running belt and tried to run it in reverse, it wandered off to the right and fell off. And when I optimized it for a reverse-running belt, it wandered to the left and bit into the arm. After a lot of faffing around I managed to get the belt stable in both directions – but then it was off-center and the sideways position of the spanning wheel had no influence on it whatsoever. The spanning wheel is crowned and that should make the belt tend towards its apex and thus I should be able to move the belt sideways, but it did not have any influence – the same thing happened whether it was near the arm or as far from it as it could go. Only the tilt of the wheel had an influence, but when I fixed the wobbliness, I lost the ability to tilt it.

I have managed to get the thing running by bending the screw on which the spanning wheel is fixed. When I turn the screw now, the wheel tilts, and I can adjust the belt. The problem is that it is too responsive and not very stable, just like it was before. I am wracking my brain for solutions, but so far I have not come up with any that are doable with my equipment.

Belt Grinder Re-Wheeeeeeled

The belt grinder has now all the wheels newly surfaced with micarta and all 30 mm diameter wheels were increased to 60 mm.

© Charly, all rights reserved. Click for full size.

Subjectively it runs quieter and smoother now, unfortunately, I did not make a noise measurement before to have an objective comparison. I still have the previous tracking and spanning wheels, but not the motor wheel, so I cannot get it to the previous state now – shame that I did not think of that but whatever. Maybe I will try it with the smaller wheels, maybe not, because when I was at it, I ground even the previous wheels to better roundness than they were, so even they should now run smoother. I will keep the 30 and 40 mm wheels to grind fullers and finger grooves.

The belt grinder has done a lot of work over the years and it shows, but it needs more improvements. The spanning wheel still does not work as well as it should and the belt is not entirely sideways stable.  I do not know how to do that yet, unfortunately. But I do know how to improve the platen behind the belt to make it more stable. That should be done next week when I get some 50×10 mm mild steel that I ordered. I had to order it, because I had nothing suitable in my scrap pile to use, which sucks since money is short.

Improvipairing mah Belt Grinder Again – New Tracking Wheels

My tracking wheels made from alu-tubing had a diameter just 30 mm, so the ball bearings were running really rough when at full speed. and they chattered and were generally noisy too. I have been thinking for a long time about how to make bigger and better wheels. I tried to glue soft PVC on the surface. That stopped the chattering and added ca. 1 cm in diameter, but when it ran at full speed, the PVC was ripped off. I tried to glue on leather, and the same happened. And now I hope I have finally found a solution – to make them from micarta.

I have used a technique that I learned from my older brother as a child when making paper car models. To get nice and sturdy wheels for those models I wound a glue-covered strip of paper around a wooden skewer until I reached the desired diameter. One could get nice, sturdy, and round-ish wheels that way. Later in university, I used the same technique to build a complete chess set (I still have it). So for the wheels for my belt grinder, I soaked strips of cloth in epoxy resin and wound them around the (scoffed and thoroughly de-greased) alu-tube that is the core of the wheel until the diameter was approximately doubled (that should halve the rotational speed of the ball bearings and thus reduce noise and prolong their life).

© Charly, all rights reserved. Click for full size.

After that, I put the whole thing in a plastic bag and I sucked out as much air as possible with my vacuum pump. I could not do a very good job of it and I also could not seal the bags very well, but I think it was good enough.

© Charly, all rights reserved. Click for full size.

After the epoxy was thoroughly hardened, I cut the excess on the sides and pressed the ball bearings in the tubes. I did not cut the sides very well on one wheel, but that should not be a problem. The wheels also were not exactly round at this stage. This was the snag that stopped me from doing this a long time ago. I knew they wouldn’t be very precise and I do not have a lathe that would allow me to make them really round. But last week I finally got an idea of how to make them round with my belt grinder.

© Charly, all rights reserved. Click for full size.

First I have made a fixture for the wheels from 5 mm mild steel and a piece of board. I could span the wheel on it and push it against the platen of the belt grinder, fix it with a clamp, and then with a slowly running 40 grit belt (and very carefully) I could grind it to a roughly circular shape concentric with its rotational axis. The result was a rough and round-ish wheel and I managed to not hurt myself too badly, only one fingernail is now thinner than it should be. I did not take pictures of that, because I forgot.

© Charly, all rights reserved. Click for full size.

To get a smoother surface I ran the wheel against a slow 100-grit belt a bit and then I changed the direction of the belt and used wood turning chisels and fine abrasive cloth to further improve the surface.

© Charly, all rights reserved. Click for full size.

And it worked reasonably well. The wheels are not perfect, but they chatter less than the previous ones and I expect that with wear the surface will get smoother. If not, I will try to coat them with epoxy mixed with a fine sawdust and polish them again. The advantage of micarta is that It glues well so I can re-surface the wheels at any time. It is also tension-strong so there is no risk of the wheels exploding or cracking mid-work.

Now I will make a new, thicker spanning wheel this way too. And I will add a few mm micarta on the motor wheel as well because it too is not exactly concentric and that too introduces vibrations and noise. This opens a lot of opportunities to make better concentric wheels of different diameters – I still need 3 and 4-cm wheels for grinding fullers and finger grooves and I might need other diameters in the future too.

It unfortunately also means I have to make a new platen. I have jerry-rigged the old one so I can do some light work on the grinder as it is now, but It is not as stable as it used to be because it was built with smaller wheels in mind. But I am working on that problem already and I do have ideas that I think will work. I am also planning on making a new jig for grinding fullers.