How long do threads made in wood blocks last?

[Joshua Dinerstein]

I am looking at making a few threaded pieces of wood for mounting on my lathes spindle and I am wondering about durability.

The background:

I have the Beall spindle tap, in 1 1/4 x 8 tpi (For that matter I have an unused 1x8tpi I bought for the last lathe and never used... :mad:) I also have the 1 1/8 Forstner bit for drilling the initial hole.

I am getting ready to start try #2 looking to make a Longworth chuck. I made the last one rather terribly and the wobble and shake is something that I don't like. I found I was off by at least an 1/8th of an inch when I finished the bottom of a bowl. (You could literally see the hollow indentation for the bottom was off by that much compared to the base that I left and the sides.) My excuse is that I was new to wood turning and wood working in general when I made it and I didn't really understand the tolerances and how critical it is to center things.

Based on the last few years of experience I have come up with a very carefully ordered build plan/pattern that I think is excellent for try #2 and hopefully I will get something I can truly use.

I had purchased some faceplates for use in making try #2 on my old HF 34706 lathe. I actually have 4 Don Pencil 1x8tpi faceplates that are entirely unused that I no longer want/need. *sigh* But I don't have any for the 1 1/4" spindle I am now using. I was going to order some and then thought wait! I will go and ask online...

The Question:

So I have the Beall tap. I was thinking about how long a threaded block will last going on and off the lathe roughly once per bowl before the threads wear-out and die. I don't know that they actually will, but it seems likely that they will wear over time. I don't want to go to all this trouble to try and get it perfect to have it wear out. At least not too quickly.

So do any of you make threaded wooden blocks/jigs/etc? And if so how long do they hold up?

Is it better to just dedicate a faceplate to this device and never have to think about it again?

Any thoughts, comments or ideas greatly appreciated!

Thanks,
Joshua

[Steve Schlumpf]

Joshua - obviously, metal to metal contact will last a lot longer but I have the Beall 1 1/4" tap and used it for all my vacuum chucks and have not had a problem. I know some folks recommend hitting the threads with CA glue just to add some strength - but I never have and they are holding up fine for the past 2 years.

[Mark Hubl]

I use the Beall tap and have made a couple of chucks with it. Cheaper then several dedicated faceplates. I just make them pretty much the way they are made in the Beall vid's on youtube. I used poplar, but maple would probably be better. I put a little wax on the threads. Really have not seen any real wear, but I am not a production shop. Really don't anticipate a lot of wear and tear. My latest donut chuck is 12". Threads on easy. Shouldn't be wear and tear if you don't cross thread. If you seal with CA that will make them tougher.

Getting stuff square is key. The threaded collar needs to seat squarely on the bearing of the spindle. Once I accomplish this, I reround the collar and re square the face that will mate with the donut. I glue and screw the collar to the chuck. I used MDF on the last one, worked great, nice and flat. Once assembled it is running at around .002 at around the six in diameter. Not bad for me and did not even run a chisel across it yet to adjust.

There are wooden threads on vises that are hundreds of years old and still ticking. I also use the beall stuff to make wooden threaded rod. Works well.

I am pretty happy with this. I have also seen guys just put on a spigot and use their chuck or you can cut a recess and use chuck. I have a small donut with a recess (worried more about this wearing out) and a face plate with a spigot. I am going to use this for a jam chuck mount. See the pics.

Good Luck.

[Joshua Dinerstein]

Joshua - obviously, metal to metal contact will last a lot longer but I have the Beall 1 1/4" tap and used it for all my vacuum chucks and have not had a problem. I know some folks recommend hitting the threads with CA glue just to add some strength - but I never have and they are holding up fine for the past 2 years.

Wow. 2 years. That is long enough to make it worth trying to do it this way. Cool. So Steve, what kind of wood do you use to make the the threaded part?

I have some hard maple and some walnut. I was thinking about using the walnut. This walnut isn't Black Walnut. It has a very light color but isn't just a wide sap-wood piece. I am just not sure which ones is really best. I will do more research but thought I would ask.

Thanks for the reply. As always it was informative and prompt.

Thanks,
Joshua

[Joshua Dinerstein]

Mark,

Thanks for the reply and the pics. Some of those look pretty close to what I am trying to do with the base of the longworth chuck. Pics always help me. I have some maple that I can use. I was thinking about using some Walnut but I made do a bit more looking thru the wood pile.

It looks like your poplar for the threaded part was glued up. Is that the case? have you had any issues with using glue up to get the base threaded block made?

Thanks!
Joshua

[Steve Schlumpf]

Josh - given the choice between Maple and Walnut - go with the Maple as it is a tighter grain and that is something you want when it comes to threads.

[Mark Hubl]

In the pics there is one that is a laminated piece and one the is an 8/4 piece. Lamination is fine. (Lamination is done before boring or threading.) That is how Beall does his. Just mill 3 or 4 pieces of stock and glue them up. I rough round them up on the band saw. If the blank is too large for your jaws, then mount between centers and cut a spigot to fit your jaws. Mount in chuck, bore it, thread it, cut a recess to go past threaded part of spindle and seat, square it, take it out of chuck, thread on spindle, round and square, done.

Walnut is ok. I used poplar cause it is pretty stable, although softer than walnut, it is a little tighter grained and less prone to any splinters. I have used walnut for threaded rod and nuts without problem. If longevity is your concern, then you can't beat maple, I have used oak and ash as well.

[Bernie Weishapl]

Maple works well Joshua. I have one that has been threaded almost 3 yrs now. It is still holding up fine. I have both the 1 X 8 and the 1 1/4 X 8 for my big Nova and the two midi lathes.

[Allen Neighbors]

Joshua, I made several faceplate-type glue blocks out of Oak to use on my Old Griz, and used them for two or three years. When I sold the lathe, I sent them with it, and as far as I know, they're still being used.
I made the 1x8 threads in the wooden nuts with just a tap that I bought at a hardware store. I did use a good amount of CA in the threads, allowing plenty of curing time between threadings, and then I turned the face flat, reversed it, turned the face, reversed it, turned the face, did this 'til it ran completely true, then glued the blocks to them. I shaped the nuts with six sides like a normal hex nut, and then used a small filter wrench to tighten and remove them from the lathe. They worked well.
I'd have some for my Oneway, but the 33x3.5 tap is just to expensive for my blood.

[Thomas Canfield]

Joshua,

I have made several in both 1" and 1 1/4" out of MDF by gluing a couple of thickness together. I use a 1/2" boss for the 1" and 3/4" boss about 2 1/2" diameter to make the 3/4" MDF work with recess at headstock for thead relief. I coat the faceplates with a couple of coats of shellac soaking the threads well and then retapping. I have made several 9" diameter x 1" thread for sanding disks, and the others are from 3 to 7" diameter and used for jam chucks to finish off the bottoms of bowls and hollow forms. Shellac works well and cheaper than CA. The MDF is from scraps and cut with circle cutting jig on bandsaw with 1/8" center hole that allows stacking the boss on the disk with 1/8" dowl for gluing and then drilling. Very cheap faceplates.

[Jeff Nicol]

Joshua, Back before all the world was a steel and aluminum world, many of the clamps and stools and other items had wood threads on them. Many of these items are still around to this day! I have seen old wood clamps with large wood threads in them at auctions that go for a pretty penny and still work like the day they were made over 100 years ago. So like Steve and everyone has said use good wood and orient the grain correctly and don't over tighten or abuse the threads you should do just fine. I have a little vacuum chuck with 1x8tpi cut into a piece of Douglas fir that I have been using for 4 years or more and it has not lost a bit of wood. Just make sure that there is plenty of wood around the hole and that the flat mating surfaces to the headstock or what ever are nice and flat. Thin CA puts some extra strength to all the threads also.

Good luck and have fun!

Jeff

[Joshua Dinerstein]

Thanks guys for all the help. I had I think a flawed perception of the strength of wooden threads. Not sure why I had it... but it is definitely gone now. My goodness! (I think it might have been there because I had a few threaded wood toys as a child and they didn't last long. Probably cheap super soft wood combined with the rather mindless brute strength of a young boy.)

So based on everything said here I made 2 solid walnut threaded bases last night. It was hard to cut the threads but only in terms of the force needed to rotate the cutter. A little bit of elbow grease and Shazam! I had some lovely turned bases. Came together beautifully. Facing both ends off was a bit of a challenge. I guess I have rarely made things totally flat before. But it worked well in the end with just a bit of patience. I am at work now so I can't put up any pictures but I will take a few tonight. See if there are any comments on ways to improve it.

I threaded it on and off a number of times last night testing things. Seeing how well it would re-seat and how true it would spin etc... I am extremely impressed with the Beall tap. A finely made tool! I am even more impressed with how well it threads on and how well this whole thing works! I expect to get years of successful use out of these!


I didn't follow some of the advice but now I want too. So I think the next one or two I will make a little differently. What I want to try:


From Allen Neighbors:
and then I turned the face flat, reversed it, turned the face, reversed it, turned the face, did this 'til it ran completely true, then glued the blocks to them. I shaped the nuts with six sides like a normal hex nut,
I like that idea. Going back and forth until completely true. I think what I have now is pretty darn true but I wouldn't say 100%. I like the idea of trying to improve and that and this seems like a good way to try.

Thanks guys, as always, for all of the help. If any one has anything else to add please feel free.

Joshua