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I Forge Iron

Another DIY 2x72''


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Well, since you are a smith who likes to do his own work I would recommend that you use a torch, or forge, to uncoil one wrap of your torsion spring then reharden it in oil and temper it in an oven.

The tracking adjustment should ideally be made using a fine thread rather than a coarse one.  This will also help with the number of threads you engage in the tapped tube.  I would have probably welded on a fine threaded nut rather than tapping the tube in the first place, but it isn't clear that you have a welder.  You could tap and mount a small piece of 1/2" plat to the outside of the tube using additional bolts on either side of the plate to accomplish the same thing.  Another thing that you can do is put a little spring pressure on the adjustment screw by adding a concentric spring in between the hand knob and the tube. Of course then you would need a longer adjustment screw...

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I have to ditto Latticino's assessment. The tension spring is one wrap too large. If cutting and re heat treating doesn't work you'll need to buy another. 

Your adjustment screw needs to be fine thread at a minimum. Longer tapped segment in the arm will make a big difference as well. I had to put a jam nut on mine to keep it from loosening in use, now I have 3 little wrenches as part of the bench grinder kit. 

You have a nice looking build, a little tweaking is to be expected. Well done.

Frosty The Lucky.

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Hi guys,

Yes I like to do things on my own but the torsion springs are 4$ a piece and so I won't try to rework it. The new ones are also less then half the width of my actual one. So I will order two and can decide if I need one or two for proper tensioning.

I don't have a welder and I also can't weld myself. But if have some friends who can weld and they will help me. And yes I will use fine thread nuts. The idea is to weld one nut in place, screw the screw in and then screw the secon nut on applying a little pre tension. Maybe this can also help with the self-loosening. But I will also order a concentric spring to have another possible solution.

End caps are also planed but I couldn't wait to start a test run :D

Yes it is a TEFC, 3 HP, 2860 rpm motor with an 8'' drive wheel. So power won't be a issue. I just need to learn to handle it.

And tweaking was expected and is also good to understand how the machine reacts.

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  • 1 year later...

Here is a little update after some hours of usage. Since day one i had tracking issues. The belt was moving most of the time and i thought the tilting mechanism was responsible for that. Due to the fact that I used a standard threat the adjustability was not fine enough and due to vibrations it unscrewed itself during usage. I tried adding additional springs, nuts, locknuts to get rid of the self loosening effect but never really got it fixed. But I kept working with that situation until i got a small wheel attachment. With this the belt cuts into the small wheel holder when the belt moves to far left/right. 

2x72_small_wheel_1.thumb.jpg.b922a2d6950cb21996682ce833e2e693.jpg 

2x72_small_wheel_2.thumb.jpg.ee267d1a29d264a7ef2c48a1958b92b0.jpg

Then I saw this video from Brian and tried that way of tracking because i already had build that mechanism but didn't used it.  

Link removed due to advertising

This helped a bit but still to much belt movement. Then i took the tracking arm, tracking mechanism apart and double checked wheel alignment/positions. I could reduce the clearance of the tracking arm and the tracking wheel by adding washers. Additionally the position of the tracking wheel was of by 2 mm / 5/64''. The axle of the rubber wheel for the small wheel attachment was out of angle. I added a width across flat to turn the axle and adjust the angle with a digital angle meter.

After everything was aligned... no big improvement... 

I checked everything again and found no major errors. It took quit some time to find the error. The screw holding the tracking mechanism to the tracking arm was locked to tight and the small modifications didn't transfer directly to the tracking wheel. Instead the system flexed until friction was negotiated and the a big adjustment was transferred to the tracking wheel. As soon as I loosened this screw tracking works as expected.  

Still I'm very happy that I build this 2x72'' and it gets used more and more often. The next project is already in planning. I want to build a heat treat oven and because it needs some welding I will take this opportunity to buy a stick welder and try welding it on my own. 

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