3520 has a FAT HEAD

[Burt Alcantara]

I've begun to turn bowls again as hollow forms wear me out, even with the articulated arm. I've been turning on the 3520 for about 3 weeks now and one thing that is beginning to bug me is the width of the headstock.

For bowls anyway. No problem with hollow forms.

Once I mount the bowl on a chuck I find it very difficult to make any adjustments to the outside. I find myself pushing against the headstock to get onto the outside and none of my tools seem to work.

I've never seen any posts about this issue so I don't know if I'm doing something wrong, I don't have the right tools, or I'm just bone-headed (all of the above).

I'm considering getting a spindle extender such as the one sold by Best Woods, and using my tower jaws to give me extra distance but this seems to be extreme.

Does anyone else have this problem?

Burt

[David Christopher]

Bert, why dont you try putting your tool rest on the other side and run your lathe in reverse....this will put you away from the headstock

[Tony Greenway]

Burt, something you might try if you aren't already, is start out between centers with the bowl bottom pointing toward the tail stock. Shape all the outside including the tenon or recess. This allows total access to those hard to reach places that I think you're referring to. Then turn the blank around, mount in the chuck and hollow out the inside. This method works for most of the bowls that I turn. Good luck.............Tony

[Jon McElwain]

A spindle extension is not that bad a solution. I have a 3" extension and it really gives me the space I need. Like the previous post, I turn the bottom of my bowls first. I do not mount the blank between centers however, I start with the blank on a faceplate, turn the bottom to accept a jaw set, and sand or scrape to finish. Then I take the piece off, mount it with the jaw set and turn the top of the bowl. This way, there is no need to turn between the bowl and the headstock. I don't use the spindle extension with this method

Good luck.

[Steve Schlumpf]

Burt - I am with Tony on this one. I use the woodworm screw in my chuck and turn it so the tenon is on the tailstock side. I form the tenon, complete the outside of the bowl, then turn it around and mount in the chuck to hollow. Once I mount the blank in the chuck - I do not have to address the outside of the bowl again - just focus on the inside. Hope that helps.

[Don Carter]

Burt:
After rough turning and then remounting for finish turner, I do have the same problem. Was this a problem for you on the Nova 1624? I think the spindle extender is a good idea. Thanks.

All the best.

Don

[Ken Whitney]

The Robust headstock is "slimmed down" to allow better access from that side.

[Marc Himes]

Burt, I have had the same problem. I think it comes from the piece not sitting in the chuck correctly when it is reversed to do the inside of the bowl. I frequently have to true up the outside of the bowl once it is reversed and find the PM a little wide to give me free access. My solution is to pay very close attention to the base of the bowl around the base of the tenon. It has to be flat, very flat, where it rests on the jaws of the chuck. Even then you can compress the tenon asymmetrically and still be out of round a little. In these cases after truing up the outside, I will end up resorting to finishing the very base of the bowl when I turn a foot and use the Cole jaws. I find the tower jaws give me enough access for most bowls and I haven't considered a spindle extender.

Marc Himes

[Richard Bell CA]

Burt:

Just out of curiosity, which model 3520 do you have? Per this link, a chamfer was added to the headstock at this location on the "B" revision (new or modified feature "o" on the list).

http://www.aawforum.org/vbforum/showthread.php?t=909&highlight=3520

I have the B and have not yet tried getting in from that direction, so I cannot say if it is a problem for me yet.

Richard

[Burt Alcantara]

I have no problem turning a tenon, mounting it on a chuck and keeping it there. Perhaps, my technique, or lack thereof, is the problem. I'm not making regular salad/soup bowls but bowls with very wide flaring rims that have a reverse curve on the outside. Kind of like an inside out bowl.

Once I get the shape that I like and get a fairly good finish I reverse the blank and mount it in a chuck. Now, I begin to hollow the bowl. At this point I'm going for a paper thin rim that is about 2-3 times wider then the hollow. This is where I find the final shaping occurs. I shape the inside and outside rim, thin up the outside stem, all the while working both the inside and outside at the same time.

I could do this on the Nova without a problem because the spindle was much closer to the turner side. On the 3520, the spindle is more centered which means the FAT HEADstock gets in the way. On the Nova, I could approach the outside at a fairly steep angle. On the 3520, I'm at about 45 degrees if that.

One solution is to get reverse handed tools, specifically scrapers so I can access the outside. The other solution is the spindle extension and tower jaws, unless someone can come up with a better idea that doesn't involve buying another lathe.

Burt

[Nathan Hawkes]

Just tagging along here; I'm at the edge of a new lathe purchase, and still haven't decided.....
anyway, I don't know if the spindle extender is a great idea in the long run for all your projects; I understand that even a very well machined thread extender will have a small degree of runout, which on a larger piece will end up creating some chatter if you try to refine the shape without re-truing the walls of the bowl, right? I've had the same problem with my current lathe, when I've used a mcnaughton to core a tall blank between centers from the lefthand side--with the straight cutter. Even with the lathe's very skinny headstock (a homemodified riser blocked rockwell-delta that has 1.5HP and a 17" swing. The cost of the extender would still probably be worth it if you only had to use it once in a while. I hate not having the right tool(s) for a job.

[Jeff Nicol]

Burt, I really need to see a picture of what you are turning and what it looks like on the lathe to make the call. I use my 3520B every day and have had no trouble with taking a little off here and there on the headstock side while finishing. But like Steve said I finish the bottom before I turn it around and rechuck it to do the inside. The way it sounds the style of bowl you are turning is difficult no matter what.

So if you could show a picture of the bowl on the lathe it might help.

Thanks,

Jeff

[Jack Mincey]

Burt,
I never had any problem turning bowls on a 3520B, but the head stock does cause me problems when I turn crow call bodies. Doing the back side with a spindle gouge you run out of room swinging the handle around. The small Head stock on my Oneway is great for this. I think that I will make a storage tray to mount on top the OneWay head stock some day. That is nice on the 3520B.
Jack

[William Payer]

Burt,

The spindle extension is a good idea. I use tower jaws on my chuck to brin the piece ot from the headstock another inch or so. If your chuck has them available, it might be another possibility for you.

[Reed Gray]

Burt,
I never had that much of a problem with that. I do finish turn the bottom, and am done with it before I reverse and remount for turning the inside. So what if you have 1/16 inch run out, which translates to + or - 1/32 inch? The wood can easily move this much as you turn because it 'adjusts' to having the wood removed. This is only critical if you are going for a really thin piece, say 1/8 inch or less. The biggest thing here to me is doing all you can to have the piece true before you reverse it. One thing I do is a light shear cut all the way down the outside. There is always some excentricity/out of roundness due to the different way the end grain and side grain cut. The final shear cut, not riding the bevel takes care of most of this. Also, when forming the tenon or recess, do the same type of final cut before reversing, hold your scraper/gouge/skew very lightly against the wood, just barely removing any wood, to help trim up some of the out of roundness. Most of the time when I reverse, I have less than 1/16 run out. If you have more than that, some thing is off. Any particle of wood between the chuck jaws and wood will add to the run out. If your chuck jaws are loose, it will add to that. If your tenon or recess angles don't match exactly the angles on your chuck jaws, it will add to the run out. When mounting on the chuck, have the jaws cross grain as opposed to 2 on end grain and 2 on side grain as the wood will compress differently this way. Also, the chuck has to seat on a shoulder that is flat and square, cured by a good finish cut on your tenon/recess. I would not recomend a spindle adapter. You are farther away from the headstock, and this will add more run out, and more vibration to the wood as you cut, more so on the inside of the bowl, as you remove wood, and the walls get thinner and more flexable. Simply, you are on a longer lever. Plus, it is an added production step.

robo hippy