Bandsaw

I've been tinkering with my circular saw cross cut guide. It doesn't always produce great results, and it's because the rails aren't all that strong. They aren't that strong because of the saw's low clearance, which make most conventional jigs impractical. Add to this the showers of aluminium chips it produces, and scatters everywhere, and the difficulty of adequately supporting some materials, and I am less than satisfied. It will still work for the other projects I had in mind for it, but for robotics, I've been looking for something else.

I'd nearly narrowed it down to two proxxon machines: The FET table saw and the micro band saw (MBS). These both have there down sides: basically the aren't all that powerful, and can only be used with very small work.

Then Axminster discounted there hobby bandsaw to £100, and I decided to buy it. This is not without it's issues. In truth, this was a bit of an impulse.


What makes the Proxxon micro bandsaw good for my purposes is that it's variable speed. The HBS205N isn't variable speed. I turns out the type of motor makes converting it tricky. It has a running capacitor, rather than a starting capacitor. This makes sense, because it has very low load when you start it, and it needs to be as smooth running as possible. However, the capacitor is chosen to match the intended running speed. If you slow it down with a dimmer, it will probably judder. A two phase driver, which can drive the secondary winding with lower power is needed, and I don't know if something like that exists. It's not that complicated to design, however I'm reluctant to do 240V electronics! Replacing the motor will make it definitely not a bargain. Re-winding for two equal phases might be a possibility.

It takes 1400mm blades, and there are plenty of saws around which use the same blade size, but sadly there's less variety of blades in this size than you might expect. Certainly, no bi-metal or tct blades. Again, Proxxon sell bi-metal blades for the mini band saw.

Finally, it basically hadn't occurred to me that machines without 3 bearing guides existed. Axminster sell an upgrade for £50. I'm not sure if it fits this model. Making one might make an interesting project though. I've seen a few people improvise 3 bearing guides, and I have the materials around to do it.

This all might not matter. People certainly use woodworking band saws to cut aluminium and plastic. My first attempts haven't produced very clean results, but I have a 6 TPI blade, and could try 14 TPI or 24TPI blades, and see how that goes. I might not have tensioned the blade adequately.

There are a few other niggles: Adjusting the lower blade guide really requires you remove the table. Removing the table requires removing the fence guide, and setting up the fence guide to be accurate is a fiddle. The manual tells you how to fit the table and adjust the fence guide before telling you you need to remove the table to adjust the blade guide, which definitely wasn't pre-adjusted on mine.

I'm overall glad I got an 8" band saw, so I can work on larger wood working projects. The table on this one is very solid, and it runs and cuts very quietly.


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