Alignment Issue help please.

[poolhound]

Not sure if this a question about turning pepper mills or lathe alignment but I guess it’s a bit of both.

This weekend I thought I would try my hand at a peppermill.

I was using the woodturners catalog instructions and all went fine until I got to the final shaping. I had the top and bottom registered together with a ‘spigot’ or tenon of the top and was driving using a jam chuck in the bottom and had a live center in the top. I was happy with the design I was forming until I took it off to review my work and noticed that when I rotated the top the outside was not true due to the fact the spigot and its associated mortise (which were tight fitting) were not concentric with the outside. At this point (other than uttering some choice expletives) I wasn’t sure how to proceed or how to diagnose how I had arrived at this point.

Undoubtedly the spigot, the hole or in fact any of the holes in the body or head were not in alignment. I had noticed while drilling that none of the bits, even the heavy duty forstner bits, would exactly follow the obvious dead center of the spinning piece. I brought the head and tail stock together and the points do not quite line up. They are not that far off but I guess the further they are apart the more the difference is magnified. I would also guess that the more holes you drill and the more times you chuck and recheck a piece (which happens quite a bit with a peppermill) the more opportunities for error there are.

At this point I am trying to figure out if this is a technique, process or alignment issue. I would guess possibly some of each.

I have a Nova Comet II so the headstock is fixed.

All help is appreciated.

[Bill in Buena Park]

Jon, for the benefit of the turners here, this was discussed at the WR site and we determined it was probably a process issue between the spigot forming step and introduction of off center drilling after rechucking the mill head.

As a next project, have you seen the pepper mill salt shaker combos at PSI? I made one for the LOML and she loves it. Seemed easier to me, but I default to chucking the pieces on long spigot jaws.

https://www.pennstateind.com/store/PKGRIND9.html

[leehljp]

I have a Rikon. Depending upon the technique I use, I can bring the tail stock up to the center drive point to point and make them be in alignment or out of alignment. While this is not what most experts will probably say, the inexperienced user can and will exert forces where there is "play" that he will deny. "Its not me!" - when it is. Having said that, yes there most definitely there are some mechanical issues that exist that "could" be the problem. I am not going into that part.

On my Rikon, the tail stock lock is on the side away from me. When I reach over the tail stock and down to the lock handle, I have a tendency to grab the lock lever and pull forward to pull the tail stock up and then lock in one motion, I also have a tendency to hug the tail stock with my elbow and introduce a 1/16" mismatch as I lock it. I would swear that I am not touching the tail stock. If I pull the tail stock straight forward, and then lock, I have perfect alignment.

The tail stock is loose enough to slide forwards and backwards. Most people will tell you that it should not have any lateral play. That is baloney when it comes to bearhugging and pulling laterally while sliding on a less than premium lathe. One other thing I noticed is that when I did that, there was a slight difference in the locking position of the handle. For me, my Rikon was just not properly adjusted, but that was noticed about 2 - 3 years after I had purchased it and begun to use it almost daily. So to me, it was not a mechanical defect but a needed adjustment along with my technique that caused the mismatch.

By the way, I have taken coffee tumblers / large insulated mugs and taken the outside casing off and then placed the inside wall in a drilled out and turned wood casing. Maybe 1/8 in wall from top to bottom - mostly forstner bit drilled on the lathe. Numerous duck calls with forstner bit drilled holes. All lined up fine. My technique is habitually checking alignment before each and every movement in and out. NEVER take for granted that it is aligned without checking. IF out of alignment somewhere, the turning is secondary importance until the alignment issue is fixed. Alignment issues are not to be worked out on the piece to be turned.

I am paranoid on preventing exploding wood from misalignments or a smidgen too much aggression or a suddenly dull tool or a little too lax grip.

[poolhound]

Good information Hank, as always, thanks. My Comet II seems to lock the tailstock down really solid with zero play that I can feel.

As Bill mentions I had also posted at the WoodTurnersResource site and got lots of good feedback there. I did check the bed with winding sticks and seems I have a small twist that I guess was introduced when I bolted it to the stand a few weeks back. I need to shim and retest at the weekend. I am also learning about the best way to cut the tenons for my particular chuck and making note of registration if there is a need to rechuck.

This turning game is a whole different learning curve than flat work but its lots of fun. I do really like the fact that you can spend an afternoon in the shop and go from raw wood to a finished project before dinner!