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Author Topic: 24" saw stopped feeding  (Read 322 times)

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robirdman

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24" saw stopped feeding
« on: July 10, 2019, 05:39:48 AM »

This is my saw mentioned if other posts, where I got the motor wiring fixed and had working very well and cut a lot of big slabs.  It has a chain pull to shut off and after an abnormally long time of hearing it running, I checked and it had only gone about 3" into a rock, when about 10" would be cut through.  So it stuck at this position.  The saw runs, blade plenty of life, the feed mechanism is working.  I pulled back the rock about an inch and put tape on the long feed bolt to check whether it was turning internally, (after checking the external gear feed first) and after 30' stopped and the tape showed it had turned but the vise hadn't moved at all.  So now after the recent total cleanout of the basin, vise etc., I'll have to dissemble further and see what is wrong with the split feed nut, maybe needing rethreading?
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catmandewe

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Re: 24" saw stopped feeding
« Reply #1 on: July 10, 2019, 09:11:40 AM »

Your feed dogs might be getting worn or your spring may have lost its tension and letting the feed dogs slip when under pressure. Try replacing the spring first, if that doesnt fix it then take the feed dogs off and clamp them together and then run a tap through them. You may have to grind a little bit off of them to let them close a little better.

Tony
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robirdman

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Re: 24" saw stopped feeding
« Reply #2 on: July 10, 2019, 09:23:37 AM »

Thanks. Great suggestions.  I'll have to wait a bit, to prepare mentally for taking it all apart so soon after cleaning the whole saw basin, and though I took the top of the vise off to clean also, I didn't go all the way down to the lower mechanisms.  So messy!
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robirdman

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Re: 24" saw stopped feeding
« Reply #3 on: July 28, 2019, 10:44:46 AM »

Today, I faced the dreaded task, and found it wasn't very much to take off at all.  I took off the vise base, and then 2 bolts holding the thread apparatus in, and pulled up off the long threaded bolt. Wasn't sure if that was the best way for the threads.  Took the bolt and springs out after, but the threads don't seem very worn. I suppose I would take the nut halves to a store to figure which size cutter to use.
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peruano

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Re: 24" saw stopped feeding
« Reply #4 on: July 29, 2019, 04:47:11 AM »

They are pretty worn, and yes have threads enough if the springs holding the halves together on the feed rod were strong enough to keep them from jumping apart under stress. I'd get the correct tool and chase (clean-up) those threads. The spring on the left looks flakey so before I reinstalled the feed dog, I'd open up those springs and see if it might be broken or just weak.  I have a Covington saw that I have to force the feed dog jaws to stay closed. If you had a small clamp that would hold them closed, it might help diagnose your problem.  When you have thread problems you can often see the jaws opening and closing as the feed rod rotates and instead of moving forward, the brass jaws just flex open and then drop into the next groove for a second. 
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robirdman

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Re: 24" saw stopped feeding
« Reply #5 on: July 29, 2019, 08:57:06 AM »

I wonder if forcing the mechanism off the feed bolt was not the best way to remove.  It just seemed that there was so much tension in the springs, that if I just pulled the bolt out it would still be hard to separate the parts, very awkward angle and if I could do, they'd probably fall into the oil.  The one spring is stretched more and seems like it would have been applying a lot more pressure.  If I re-thread and put back, what is the usual way?  I don't know if I would be able to assemble in the saw instead of when the unit is out.
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peruano

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Re: 24" saw stopped feeding
« Reply #6 on: July 29, 2019, 03:33:40 PM »

If what you are saying is that the jaws did not totally separate and rubbed on the threaded feed rod when the vice was moved forward or back in the disengaged mode (scratch-scratch-scratch) , then you probably have an explanation as to why the threads are worn down.  It is always essential to have the feed dogs centered so that when they are opened, both sides clear the center rod.  The right side spring would appear to be a replacement (someones attempt at cutting the right length spring).  I'd try to find a better match similar to the one on the left.  Maybe go to your fav machine shop or Graingers.  Clearly the amount of effort it takes to keep the blade engaged with the rock affects the amount of tension that is on the threaded jaws of the vice so consider all factors, not just thread depth, or spring tension.  If something is causing your vice to not want to move forward, it will resist the force created on the threaded feed rod, and feed dogs.  Keep probing and you will arrive at the solution. 
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catmandewe

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Re: 24" saw stopped feeding
« Reply #7 on: July 29, 2019, 08:37:18 PM »

In the assembled photo the spring on the left is sprung or stretched, it needs to be replaced.
In the photos of the threads you can see that the bottom part of the threads are not engaging, only the top section is engaging the rod. If you can find the right springs I would replace both of them and see if it helps. You definitely need to rethread the dogs, should be a pretty easy fix.

Tony
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