Issue With Re-assembly Of Heavy 10 Gearbox

[Hozzie]

Hi Everyone,

I have taken my Heavy 10 apart to change the felts and while apart I am refinishing it. I am in the process of re-assembling parts of it and I am working on the gear box. It is the extended threading double tumbler gear box.

I took the brass shims out (should have left them in) thinking I was going to replace them, but they measured out to be ok, so I ended up putting them back in. They are lined up with the oiling holes as expected. I have brand new open and closed bearings I will be using.

My issue is that after trying to install the first shaft (top) and the gears for it, the shaft is very tight and will not rotate. I did get the two gears that are supposed to turn freely to turn fairly well as I oiled them after they were install and they loosed up a bit, but the keyed gear and shaft will only turn using a wrench. In the manual I have for refurbishing the lathe, it says that even after all of the other gears are in, one should be able to rotate them by hand. There is no way I could do that.

I am wondering if this is normal and that maybe I just need to let the oil soak down for a while. I have also thought that maybe the shafts need to be turned to 'set' a bit into the brass shims. I was thinking of maybe using my drill to turn the shafts and let them oil up well and work their way back in.

Am I missing something or is this somewhat normal. It all came apart fairly well, but I can't say I tried to turn the shafts or gears by hand at that point to know how stiff they were. I don't want to ruin anything, but also think it probably has as much to do with not being oiled well yet either.

Thanks in advance for any info.

 

[woodtickgreg]

Something is not right, are you sure the shafts are not bent? Pics may be helpful to see where you are on the install portion of the rebuild. And yes you should be able to turn them by hand. check each shaft for this as you re assemble it. If it is tight do not move on to the next step until it is corrected. I would remove the shaft and gear assemblies and start over one assembly at a time to find what the problem is.

 

[Hozzie]

Is there an easy way to check if the shafts are bent? I only have my mill as an option and even that isn't much of an option right now because it isn't completely setup meaning it hasn't been leveled so I am not sure I can tell much from that. I was thinking of putting the shaft in a collet and using a dial indicator, but that will only tell me how out of round it is, not how bent it is (I think).

Here is a couple of pics (it's a bit dark, but everything is clean). I had the shaft completely in, but I did have to give it a few good taps with a hammer. I used my drill on the nut to turn it to see if it would loosen up some. It may have a little, but no where near being able to turn it by hand with the keyed gear. I did oil it before putting the shaft in to try and help it, but something is still amiss. It may very well be a bent shaft, but I am wondering if I also could have screwed up the brass bushings.



I took the shaft back out and you can see a bronze rub on it.


I am wondering if when I put the bushing back in if they deformed a bit from being tapped in. It did take a bit of force to get them back in. I am not against just buying new shafts if they are available.

 

[Kroll]

When I purchase bushing they are cheap enough that I order extras just for that thought.Tapping on them is taking a chance,if possible maybe use a bolt and nut to pull the bushing into place.Try to remove it then check to see if it will slip onto the shaft,then maybe that will let you know one way or the other.Sorry about the bold print

 

[woodtickgreg]

One easy way to check the shafts is to lay them on a known flat surface like a granite plate or a piece of glass. roll them across the surface with a light shining from behind them and look to see if you can see light coming from under the shaft as you roll it. You can also see if a feeler gauge will pass under it at various thicknesses. It does sound like your bushings need to be reamed in alignment though. but checking the shafts is the first thing you should do, if they check out then an adjustable reamer may be whats needed to tweek the bushing alignment. It's the little things like this that make taking your time to do it right so worth the effort. When you get it right it's so rewarding and you'll be happy you did it.
Edit: just a thought, you might want to buff those shafts up a bit just to clean and smooth them out a little. I did that on mine and it made a difference.

 

[Hozzie]

I got it figured out. It was the bushings. Once I cleaned them up a bit with a little sandpaper and polished the shaft, it went together as expected.

I also cleaned up the other gear shaft and bearings. Now I am fighting with the Keyed gears and getting them on the key in the shaft. I will get it eventually.

Thanks for everyone's feedback.