How to get natural edge piece balanced

[Don C Davis]

I've been working on a 12-14" log cut in half to end up with a natural edge-sort of-bowl. I got the bottom shaped up OK- the cut flat side piece of log, held between centers--a steb center on the headstock side and a 60 degree cone on the tailstock side, I dirlled a 2" hole with a forstner bit so the steb center is into good hard wood,not bark--suffice it to say that the balance is just not improving on this piece as I progress--never had this happen before, typically when I get this much material removed the piece starts turning with much better balance and I can usually turn the speed up close to 1000 RPM's, but this particular piece is giving me fits--I'm to the stage that I have put it into my chuck and am ready to start hollowing out the bowl--the bark side-- but the balance is no better at all on this piece. I can't figure it out, I can't get speed up past 400 RPM's without inducing horrendous wobble into my lathe.

I am curious if anyone has any thoughts one this, it is a piece of White Oak from a tree that was brought down by snow in my back yard, it was dead for at least two years, and has 10%+/- moisture in it--I just would like some help trying to figure out the balance issue.

Any input advice is appreciated---Thanks--Don

 

[Richard Coers]

That's the nature of the beast. I guess you could go in with power carving and remove some material on the heavy side before cutting on the inside. But, by the time you do that, a gouge would already have you there.

 

[Zach LaPerriere]

Assuming you have the visual balance you want, it sounds like it might be time for a good strong tenon. 400 RPM is fine. I've had to cut some very big heavy pieces at 250 to 300. It's great practice with a gouge and it sure lets you know when the gouge edge is even the slightest bit dull.

1000 RPMs might be a bit too fast anyway. I recently re-read Dale Nish's advice...take the number 9000 and divide the bowl diameter to give your top RPM.
So a 10" bowl gives you 900 RPM. This isn't a set rule, but you have to start thinking about the possibility of crazier things happening when you cross that threshhold. Especially with NE bowls.

 

[Don C Davis]

Thanks for the input Zach, good advice really—I’m finding a large knot as I begin hollowing that was not in evidence previously so I think that may be what is causing the imbalance—this wood is damn hard that’s for sure—I’ve found my largest round carbide tipped tool the best for hollowing this baby!!

 

[john lucas]

I've had bowls get that way with just more sap wood on one side than the other. I would think a knot might do the same thing.

 

[Emiliano Achaval]

I would switch to a faceplate with some nice heavy screws. Had one a while back, there was a pocket of rot that was a small branch, that made it impossible to balance.... Slower speeds is the way to go....

 

[tdrice]

Go to a welder and have him cut a circular piece of 1/4 inch steel slightly smaller than the maximum swing of your lathe and a hole in the center to match the diameter of your spindle. Drill several evenly spaced holes around the outside edge. (I suggest 1/2 inch holes). Buy two or three 1 inch bolts with nuts and lots of flat washers. slide the steel onto your lathe and screw on your chuck, faceplate, or a nut if you are using a spur driver. (You can get most any size nut at Fastenal or online.) mount your piece, let the lathe freewheel and put bolts and washers in the holes until the piece no longer turns to the same position when you spin it and let come to rest.

 

[olaf Vogel]

Ideally, I:

Start with a faceplate and low rpm

Cut your tenon
Reverse chuck the bowl and drive the tailstock in tight
Cut the outside to reduce weight
Cut the inside with the tailstock in place

When you can’t hollow any more, because the tailstock is in the way, pull out the tailstock.

At this point you will have removed most of the weight. It may not be balanced, but as close as you get
Finish the bottom.

An example is here, http://www.olafvogel.com/platters1.html

Personally, I won’t use drive spurs of any kind.

 

[hockenbery]

below a 15” NE mitten bowl crotch ( what you get when one branch is a lot smaller than the other) It never got balanced because 3/4 of the wood was always on one side even with the rims level to the table and walls turned.

I suspect yours (assuming it is fairly symmetrical and you balance the rims) has more than half the weight on one side.
Could be light punky wood on one side, wet wood on one side. Or an seen hollow on one side, or a big piece of metal ( hope it isn’t this one)

Here is what I do with those pieces

Put it in the Chuck. Bring up the tailstock turn out a good bit of the inside with the tailstock in place.
The idea is to leave a 1” pin of wood in middle and get th walls 1-1.5” thick. ( should be able to increase the speed some or a lot)
Then I turn the outside to get it true - it is likely out of round either due to tension wood movement when you hollowed or just not being quite true when reverse.
Cut the rim and side wall to thickness well down below the rim edge all around.
Remove the tailstock cut the pin away and finish turning the bottom.

Turning slow is frustrating not a bad thing

 

[Don C Davis]

Great input folks--Tdrice, that's an interesting approach, I will keep that in mind. Olaf thanks for your input--those pics you provided the link to are impressive--that is one hell of a lathe there, what kind is it?? I may go to a faceplate in the future, but the steb center has driven this piece and many others I have done very well--any reason you folks are recommending a faceplate instead of the steb center?

 

[hockenbery]

any reason you folks are recommending a faceplate instead of the steb center?

I personally start my large (16-17” about the largest I do) Natural Edge bowls between centers.
I find the center In the top drill a 1 1/4” Forster bit hole through the bark to solid wood.
I then use the center guide point to center a hardboard disk of 16” or 17” to follow on the bandsaw where I cut the ends round.
Spur drive Hit into the blank with a mallet and into the Head stock. Cup center in the tailstock with pin removed. Have to have a lathe with a good tailstock.

This lets me positon the tailstock center to balance the blank for weight.
Do some roughing then move the tailstock to begin to balance the heights of the rims
Refine the roughing balance the rims. Turn the tenon refine the shape.
Then into a chuck.

A large Steb center is ok if you don’t have to tilt the blank much.
A 4 spur drive wil still hold well with 3 spurs.
Tilting a blank a lot on a steb will compromise its hold.
You do use a deep recess so some safety there.

A between centers hold with a spur drive and tailstock in solid wood is quite safe.

 

[Mike Johnson]

What is the size of the lathe that you are using to turn the piece? Depending on the weight of the wood blank
and how out of balance a piece being turned is, some lathes will require additional weight/ballast to be added
to the base to prevent the lathe from dancing across the floor. A bigger lathe usually solves this on average sized
pieces but is still a concern when you turn larger blanks that might be out of balance.

 

[Don C Davis]

Hockenberry, thanks for that info--makes a lot of sense, Mike this in fact may be part of the problem--I am turning these on my NOVA DVR XP which is mounted on my benchtop--it weighs 180 lbs--I've gotten my Laguna Revo 24-36 but my shop extension where it is going isn't finished yet, and the contractor who is doing the work is going to help me get it set up--unfortunately probably about a month to go.....Hoping this bigger lathe will make a difference--this is one of the reasons I upgraded to it--I really like turning NE pieces.

 

[Glenn Lefley]

What about putting a piece of plywood on out turn side of lathe on a faceplate and screwing on weight in certain places to counter balance work on inside of lathe. I have not tried but makes sense to me! If anyone has tried this let me know so I don’t waste my time in the future.

 

[john lucas]

I had a Nova 3000 mounted to a very heavy wooden stand that I filled with sand. I still had vibration problems. The reason was the wood itself. The connection between the lathe and wood is where the vibration was coming from. I attached it to a very heavy steel storage cabinet. The cabinet alone was so heavy I could barely move it and that was without any of the heavy metal drawers that fit in. No more vibration. That was just a test. I sold that lathe with it's wooden stand and kept the cabinet. I purchased a Powermatic after that. There's just no beating the mass of a big lathe with all metal support. Even then when I turn off center pieces like Al I get vibration. One of my friends who turned purposely off center hollow forms had the same problem. He added 8 foot long 1/2" thick by 4" angle iron to the legs. That essentially made the footprint 8 feet. No more vibration. He did cut the angle off of 3 feet of it on the tailstock end to keep from tripping over it every time he went to the grinder. I don't have room to do that but might go with 6 feet one of these days. Of course I rarely have a mirror bounce the lathe that much.

 

[Curt Fuller]

Coincidentally, this video just popped up on my facebook feed.

View: https://www.youtube.com/watch?v=bjPCshbxPrQ&feature=share
There are lots of ways to do NE bowls which have already been mentioned but this is a pretty good primer and it appears to be about the size of bowl you're trying to do. From a personal perspective, I think a natural edge bowl with uneven sides is more interesting than one that has purposely been balanced. But learning to do them is probably easier if they're balanced. From there you can gradually get used to turning with a more and more "challenge".

 

[Leo Van Der Loo]

What about putting a piece of plywood on out turn side of lathe on a faceplate and screwing on weight in certain places to counter balance work on inside of lathe. I have not tried but makes sense to me! If anyone has tried this let me know so I don’t waste my time in the future.

Done that a time of two Glenn, but need to only with the larger pieces, as my lathe is a heavy weight, and bolted to a concrete floor,smaller pieces do not rock her .

 

[olaf Vogel]

Hoping this bigger lathe will make a difference--this is one of the reasons I upgraded to it--I really like turning NE pieces.

It does....to a point.
Mine is about 2000# and I've had it hopping up and down. Once...

There's just no beating the mass of a big lathe with all metal support. Even then when I turn off center pieces like Al I get vibration. One of my friends who turned purposely off center hollow forms had the same problem. He added 8 foot long 1/2" thick by 4" angle iron to the legs.

The best thing I ever did was pour concrete right over the feet.
So now its cemented into the floor.

BIG is a relative definition - Its a slippery slope.

 

[olaf Vogel]

any reason you folks are recommending a faceplate instead of the steb center?

I do larger pieces, so more torque is needed and from green, so the wood is soft.
Hence a drive spur does not get good bite and won't spin the piece adequately (for my needs).

A faceplate has tons of holding power, right from the beginning.

The ONLY exception is my DIY drive spur.

Its a 8" plate of baltic birch, with ~ 40 screws from the back, that stick out about 1.5".
One version can be held by a chuck.
The second version is permanently screwed to a faceplate.

That gets sledge hammered into the bowl blank.
It grips like hell and will not spin loose (unless the bark is very thick and loose - only happened once)

All that is still with the tailstock rammed in tight.
And its only used to rough in the shape and cut the tenon.

 

[Bill Boehme]

What about putting a piece of plywood on out turn side of lathe on a faceplate and screwing on weight in certain places to counter balance work on inside of lathe. I have not tried but makes sense to me! If anyone has tried this let me know so I don’t waste my time in the future.

If you mean the outboard side of the lathe, that would statically balance the load, but it would worsen the dynamic balance which is the most important thing.

 

[Glenn Lefley]

If you mean the outboard side of the lathe, that would statically balance the load, but it would worsen the dynamic balance which is the most important thing.

What do you mean

 

[Emiliano Achaval]

I had a Nova 3000 mounted to a very heavy wooden stand that I filled with sand. I still had vibration problems. The reason was the wood itself. The connection between the lathe and wood is where the vibration was coming from. I attached it to a very heavy steel storage cabinet. The cabinet alone was so heavy I could barely move it and that was without any of the heavy metal drawers that fit in. No more vibration. That was just a test. I sold that lathe with it's wooden stand and kept the cabinet. I purchased a Powermatic after that. There's just no beating the mass of a big lathe with all metal support. Even then when I turn off center pieces like Al I get vibration. One of my friends who turned purposely off center hollow forms had the same problem. He added 8 foot long 1/2" thick by 4" angle iron to the legs. That essentially made the footprint 8 feet. No more vibration. He did cut the angle off of 3 feet of it on the tailstock end to keep from tripping over it every time he went to the grinder. I don't have room to do that but might go with 6 feet one of these days. Of course I rarely have a mirror bounce the lathe that much.

How about balancing something like that? My cement floor is from the 1900's, not level at all, so I have to lift the lathe, play with the legs and height and level till I like it... I'm close to 800 lbs or more with the sand, steel plate and steel beams welded to the plate, and of course I can still get vibration when starting pieces or doing off set turnings... I'm just thinking 8 foot is like a sled, I would have several parts not touching the floor evenly, unless you have a perfectly smooth balanced floor, I guess that is possible...

 

[hockenbery]

I think a natural edge bowl with uneven sides is more interesting than one that has purposely been balanced.

I agree and most of my NE hollowforms have uneven rims. The key for me getting the unevenness of evenness is turning between centers so I can control how the rims situate relative to the form by relocating the tailstock center which reorient the rim about the drive center.

In extremely rare situations I can relocate the drive center. However I spend time deciding where the center of the opening will be before I cut the blank to size so it is rare that I would move it unless there was some structural integrity issue.

Of course the more uneven the less balanced the piece will be.

 

[Don C Davis]

Good feedback folks, Curtis I've seen that video--assuming that that is a PM 3520 lathe that piece is significantly smaller than this piece--it also is way softer wood of whatever kind he is working with--I starting to think that this 2 year dead White Oak is absolutely one of the hardest woods you can come by!!!
Thanks for the input though, for sure.
Olaf, I aspire to do some items like you do sir--what kind of lathe do you have if you don't mind me asking---I haven't even gotten my new Laguna 24-36 set up yet, and I thinking I might want a more stout one someday.

 

[olaf Vogel]

Olafwhat kind of lathe do you have if you don't mind me asking---I haven't even gotten my new Laguna 24-36 set up yet, and I thinking I might want a more stout one someday.

Hi Don

Well...might have a bit of trouble finding same version.
It’s made by Cant Brothers, around 1880.
http://vintagemachinery.org/mfgindex/detail.aspx?id=155&tab=4

Technically, it’s a post and beam lathe.
Back in those days, tools needed to be portable. So they made the head and tailstock, toolpost etc. But no bed. You hewed a couple of big beams and bolted it all up.

And it was typically powered off a waterwheel, maybe a steam engine.
Flat belts off the ceiling. Lots of noise, no safety measures.

Most are long gone, trashed or scrapped.
Mine got lucky. Seems it never left the factory until 1970’s.

It was used, in-house, as a pattern lathe. And went through many modifications.
Steel I-beams for a bed. A very well welded frame, 5 hp motor and a Jeep tranny, huge banjo. Lots of faceplates. No chuck.

You may notice that it’s not a true pattern lathe. No carriage, or feed mechanism.
But it was used to make patterns.

When the firm was bought by Ingersol Rand, the patternshop closed and the patternmaker took it home. At that time, the bed was 24 feet. The guy cut it down to 9 feet to fit his garage.

He retired and sold it to me about 6 years ago for $800. He was 80+
There were many patterns around his shop of dizzying complexity, including a violin (just to see if he could do it). A very talented craftsmen, although not very creative.

I did a full restoration. He was extatic that it will remain in use and not see a scrapper.
I should have bought more of his tools...sigh

I’m now in discussions on how to modify the headstock further, to
A) get more swing, ideally 36”+
B) more stiffness to do big unbalanced pieces
C) finally retire the original Babbitt bearings. Hey! They lasted 140 years!

If I make it work, l’d be happy to share the plans.
As for mounting a 400 lbs bowl blank...your own your own.

 

[Don C Davis]

Gee whiz Olaf, that is simply incredible--surprising, but very entertaining, thank you for sharing that detail. I guess a more realistic question--to you and other members, would be what lathes (commercially available in the US) would you folks recommend as an upgrade from the Laguna 24-36--or should that even be considered. I would love to see some pictures of you lathe if possible Olaf-just because!!!

 

[hockenbery]

For turning Large pieces the field is pretty narrow.
I think a ONEWAY 2436 (850 lbs) with the outboard table and you have machine that weighs in at about 1000lbs. You can add the tailstock riser and get to about 1100 lbs
Probably the best commercially available lathe for turning big stuff.

The vb3 with the bed attached weighs in at over1000 lbs Not sure anyone is selling it in the us.

The huge vicmarc would be worth consideration but i don't think it is in production

A used Nichols is a possibility if you can find one.

 

[olaf Vogel]

Laguna 24-36--or should that even be considered. I would love to see some pictures of you lathe if possible Olaf-just because!!!

There's more pics on my site, address below.

As for bigger commercial lathes...this is a game I played as well.
Robust
American Beauty
Oneway
up to a VB 36

All of which a wallet busters. All excellent.

You'll have to decide how big you want to go (can afford to go).

The other option is to look for a old metal lathe, add riser blocks.
(and yes you can run them speeds high enough for woodturning)

I have an 80 year old ATW lathe set up that way.
At 7 feet long it weighs in at 4000 lbs. Pretty solid.
Cost my $500 and a lot of sweat.

These are available all over Craigslist etc.
Most are cheap - they don't meet modern standards.
And if they are worn out of spec for metal work, thats still plenty accurate for wood work

 

[Don C Davis]

Olaf, thanks for that intel, I spent a good while perusing your web-site, your lathe is very impressive to say the least--how is the banjo anchored to the bed--does it have a typical offset cam that tightens a plate up against the bed--just curious. I think I must get my Laguna 24-36 going and see if that is going to be stout enough for what I aspire to do--my final option may be to contact a friend that runs a machine shop, and discuss with him how we would build a lathe out of heavy industrial components--he does some aerospace machining, and personally he like to build car engines--so he is plenty capable with the stout stuff. I have found that turning the few 14-16 inch NE bowls out of the white oak from my back yard is plenty challenging, but I really like the end results so far--I'm very envious of the wood you get access to Olaf!

 

[olaf Vogel]

I have found that turning the few 14-16 inch NE bowls out of the white oak from my back yard is plenty challenging, but I really like the end results so far

I'd suggest spending some time at that stage. Going larger gets exponentially more difficult.

And mistakes become much more....interesting.....
Wait til you have a 80 lb blank come loose, bounce off the ceiling and the oposite wall.
Your duck-and-cover reflexes become sharper.

There is a significant learning curve.
During that time you can figure out the next steps.

I;m very envious of the wood you get access to Olaf!

Its all urban salvage. Trees are bigger in the city. Inverted logic, but true.