|Robin Graham||20/02/2020 22:28:54|
|669 forum posts|
To follow up on this, I replaced the (quite new) Axminster blade with a bimetal 10/14 Vari-Tooth from Tuffsaws. I was reluctant to believe that the blade was a problem because the Axi blade had seen very little use, but this completely cured the problems of the blade snagging and/or jumping the wheels. In fact the machine is now cutting better than ever.
Encouraged by this result I am revisiting the accuracy problem, which is still with me. To recap, the machine cuts about 2mm off square vertically over 50mm. This is how the arm is mounted to the base casting:
As you can see the arm pivots wrt the vice to allow angled cuts, but I don't really need that feature - I'd be happy if the ducking thing just cut square.
My first thought is just to put in some shims somewhere (I need the tilt the arm about 2 degrees towards the camera), second to drill and tap for jacking screws, third to take it all to bits and try to mill or file the base of the casting which holds the arm so it sits right. I suppose that would be the 'proper' way to do it? But it might be tricky.
Any thoughts? There could well be snags with my naive approaches which I haven't seen.
Axminster are now selling what appears to be the same machine, but re-badged as 'Engineer Series' and painted a different colour (mine was 'Hobby' ) for £546.96. Gosh.
Edited By Robin Graham on 20/02/2020 22:30:43
Edited By Robin Graham on 20/02/2020 22:31:16
|Howard Lewis||20/02/2020 22:49:20|
|2885 forum posts|
My bandsaw is a generic 4.5" machine. A failure of the lower bearing and seal (caused by a failed mbearing separator ) I made sure that all the guide rollers were correctly aligned and that the drive and idler wheels mran true, but it still did cut true mor consistently.
I made a tension meter for the blade and since using it it will cut straight, and blades last much longer They now wear out instead of breaking!
But, if I try to force the cut, the blade runs off making a curved cut, just like that shown.
|174 forum posts|
Hi Robin I have a copy on blade tracking for band saws By John Pitkin
I have found this invaluable please add credits if you post the contents on line.
|Paul Ainsworth||22/02/2020 11:19:45|
|96 forum posts|
Mine did the same just before the belt snapped, changed to bi metal and fine now.
|Robin Graham||25/02/2020 22:51:08|
|669 forum posts|
To draw a line under this I stuffed a random bit of brass about 1.5mm thick between the base and the arm just to see what would happen:
I took a few of slices off a 50mm steel bar and the error seems to have gone down from ~2mm to ~60 microns over 50mm I can't believe that either, but it does seems to be cutting square now. Lucked out perhaps. I suspect that this is one of those lash-ups which will become permanent!
Eric - thanks for the link. Interesting reading, but not directly relevant to my problems. The Axminster saw has no provision for adjusting blade tracking, tension, guide angles or anything else. As MichaelG suggested they should have made it right or made it adjustable. In this case they did neither.
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