Stummel drilling on cheap wood lathe

For discussion of the drilling and shaping of the stummel.
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Walldepartment
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Joined: Sun May 26, 2013 12:24 pm

Stummel drilling on cheap wood lathe

Post by Walldepartment »

I have a cheap wood lathe from harbour freight. I tested drilling a mortise hole with a 5/16" forstner bit on a small piece of briar. It was a really good fit for a piece of delrin.

After that, I put some briar for making a pipe on the lathe, turned a shank, and drilled a mortise with the same forstner bit. This time, the mortise was just a little loose. The lathe did seem to vibrate more with the bigger piece of briar, which may have been the cause.

Also, when I turned the shank, I used a live center to keep it in place. After turning the shank, I switched out the live center for a jacobs chuck. The jacobs chuck seemed to be on a slightly different center from the one that was on the live center. I don't know what's up with this. Maybe because it's a cheap lathe? Can anyone help me here?
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Sasquatch
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Re: Stummel drilling on cheap wood lathe

Post by Sasquatch »

What are you chucking the briar with?

Have you got the lathe bolted down?
ALL YOUR PIPE ARE BELONG TO US!
Walldepartment
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Re: Stummel drilling on cheap wood lathe

Post by Walldepartment »

Using a 4 jaw chuck. The lathe is not bolted down.
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Sasquatch
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Re: Stummel drilling on cheap wood lathe

Post by Sasquatch »

I would bolt it down to something heavy, and then make sure that the tailstock is pointed at the center of the headstock. Put your live center in and see where it touches either a drive spur or the center of a chuck on the headstock - I'll bet something is misaligned and the tailstock assembly needs a shim.
ALL YOUR PIPE ARE BELONG TO US!
Walldepartment
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Re: Stummel drilling on cheap wood lathe

Post by Walldepartment »

I haven't bolted it yet, but I checked the tailstock. I should first say that the tailstock has a very slight wobble. I always push it to one side so it will be in the same place. In that same place, it is off center just a scratch.
Walldepartment
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Joined: Sun May 26, 2013 12:24 pm

Re: Stummel drilling on cheap wood lathe

Post by Walldepartment »

It may not be completely level on the table it was on. Not sure if that matters, but I put it on the flat floor and it seems to match up with the chuck. I'm not sure. I think it's inconsistent.
Walldepartment
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Re: Stummel drilling on cheap wood lathe

Post by Walldepartment »

Fooled around with it some more. It seems the only time it's out of alignment is when the jacobs chuck is in. I guess it's just a bad chuck?
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Sasquatch
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Re: Stummel drilling on cheap wood lathe

Post by Sasquatch »

That's possible but unlikely. More likely the fit of the ram in the tailstock is sloppy and it just allows things to move a little bit even when everything is tight.
ALL YOUR PIPE ARE BELONG TO US!
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LittleBill
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Re: Stummel drilling on cheap wood lathe

Post by LittleBill »

Walldepartment wrote:I have a cheap wood lathe from harbour freight. I tested drilling a mortise hole with a 5/16" forstner bit on a small piece of briar. It was a really good fit for a piece of delrin.

After that, I put some briar for making a pipe on the lathe, turned a shank, and drilled a mortise with the same forstner bit. This time, the mortise was just a little loose. The lathe did seem to vibrate more with the bigger piece of briar, which may have been the cause.

Also, when I turned the shank, I used a live center to keep it in place. After turning the shank, I switched out the live center for a jacobs chuck. The jacobs chuck seemed to be on a slightly different center from the one that was on the live center. I don't know what's up with this. Maybe because it's a cheap lathe? Can anyone help me here?
This is my very first post here. I am a babe in the woods when it comes to making pipes, but I do know a thing or two about wood lathes. Harbor Freight lathes are not built to tight specs. Check the tail stock where it sits on the ways for slop. When it is not locked down it will probably have play in it from side to side. Once you lock it down, you may not be able to move it with your hands, but there is no promise you got it locked down pointed in the direction you wanted it to go. A couple degrees of misalignment will cause runout enough to make you tear your garment in frustration. And then there is the mechanical advantage of the ram. Even when the tail stock is locked in place, operating the ram can cause it to move. The ram itself can move while drilling, or even when holding a piece between centers.

There are some things you can try. The first thing to do is bring the headstock and tailstock centers together and see if they match up. It is likely that they don't. Even on some fairly expensive lathes they will be off a little. And sometimes the misalignment is in the centers themselves (i.e. the spur and the live centers) and not the bore of the taper on the head and tail. The good news about that is, the farther away they get from one another, the less important that becomes. However, for short distances like pipe shanks, misalignment can have an adverse effect on your accuracy. Shimming the tailstock is an option for both vertical and horizontal alignment. You can also shim the tailstock where it sits between the ways to see if you can remove play.

While drilling, keep the locking lever on the ram just loose enough to let it move. If it gets loose enough for the ram to move easily when you crank it, the ram can shift while drilling and cause you frustration. This usually happens on first contact with the wood. Once you get into the wood, a little movement is not too bad for many of applications. Drilling precise mating holes is not one of them though. Drilling for the bowl would not really be affected unless you have some very tight tolerances in mind.

If you are holding a piece between centers, always tighten the locking lever on the ram to prevent it from wobbling as much as possible. It is convenient and popular to leave it loose to make it easy to advance the ram when needed, but then you get wobble on less expensive lathes.

Good luck with it. I can't answer hardly any questions about pipes yet, but if you have lathe questions, I can probably answer some of them.
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