How to turn a tapered cylinder

[Prashun Patel]

I apologize in advance for a lot of dumb questions. I'm brand new to turning.

I am trying to turn a tapered cylinder. Nothing fancy: 19" long tapering from about 2" to 1 1/4". What's the best way to get it straight?

I'll make a relief cut at the top and bottom down to the appropriate dimensions, and then I'll connect the dots, so to speak. But my test piece came out far from straight. Attempts to correct the bulges result in gouging too easily.

I'm thinking there's gotta be an easier way....

[Dick Strauss]

Shawn
A straight surface 19" long is hard to turn. I'd suggest you put in a few more reference points along the way (maybe two more at about 6" and 12" with a 1/4" diameter increase at each point). I'd also suggest you use a 12" toolrest as your guide. Angle the rest to match your cylinder shape and keep the turning tools exposed the same amount as you go along the rest.

I usually like to leave my reference points maybe an 1/8-1/4" larger than final thickness to allow for smoothing as needed.

[Richard Coers]

I agree with more reference points. I turned several canes that had really long tapers, (and thin) and they were driving my nuts. When I got close, I grabbed my little Porter-Cable belt sander and angled it along the taper. Ran the lathe at about 200 rpm and it worked great. I used to sand with a foot long sanding block with 80 grit to do the final sizing, but power is always better.

[Thom Sturgill]

Many many years ago I when I took metal shop in high school, I turned a tapered shaft on a ball-peen hammer. We did that by offsetting the tailstock. Since I have never seen a wood lathe with this capability, I would go +1 for Dick's suggestions.

[Bernie Weishapl]

I do agree and use Dick's method of turning long tapered spindles. Works well having more reference points. Easier to get straight.

[willie sobat]

A trick I have used on windsor chair legs is to turn it close with a gouge, then use a longish sanding block to sand it into final shape.

[Joshua Dinerstein]

I turned a 15" taper as part of a childs toy this last Christmas break. The key for me was to use my large skew and do it as one large cut from end to end, or top to bottom, if you prefer. By doing this I was able to maintain a flat taper from top to bottom. I had to really play with the tool rest to get enough room and it was uncomfortable as I was hanging off the end on each end. But it did work.

The good news was that mine was thicker than yours so I never had to worry about flexing. At 19" long I am not sure if will flex or not but it would be worth monitoring to make sure.

Also a spindle steady will help if it is...

Joshua

[Richard Madison]

Good advice about multiple reference points and a long tool rest. When you get close, you can make very tiny adjustments by shear scraping with the nose of your bowl gouge. Note that you are watching the shape along the upper edge of the work, not at the cutting edge of the tool. It may help to place a piece of white card stock or (?) behind the work to make the profile easier to see. Nothing wrong with using the ole 80 grit flat board gouge either.

[Baxter Smith]

Shawn, I don't if know its a dumb quesstion or not. I bet the number of turners who will benefit from reading the anwers is far greater than the number of turners who will answer it. I know there are at least two of us!:)

[Matt Hutchinson]

Another vote for the long sanding block. With using several reference points you can turn it really close, and then use a long block to finish it off. That's what I did here, and it worked like a charm.

http://sawmillcreek.org/attachment.php?attachmentid=137756&stc=1&d=1263001223



As for offsetting the tailstock, pattern-makers' lathes were made with this feature. Here's what my tailstock looks like. If you squint you can see there is a seam at the base where two mating parts align. In the middle there's a machined "runner" so that the top part can slide off-center, perpendicular to the bed. Then using a cutter in a special holder not pictured above, all you would have to do is crank the banjo/cutter to the right or left for a full pass, then advance it forward when necessary to deepen the cut, until the taper is complete. There is also a referencing pin to re-align everything.



http://i337.photobucket.com/albums/n389/hyperhutch/Tailstock-1.jpg?t=1263001844

Hutch

[Prashun Patel]

Thanks, Everyone. I'm going to try the long sanding block.

[Richard Madison]

Matt,
Look out the window. It is colder than bear's attachments there now. Get some insulation and dry wall and a heater.

[Jim Sebring]

That HAS to be a chilly place to work in the winter :(

[Paul Atkins]

I made 100 or so tapered pins for a timberframe 15" long by about 1" diameter by setting my tailstock over to get a .010" taper. I have a carriage on linear bearing, so it worked easily. However most of the time I have to measure each end and a few points in between and use my 1 1/4" roughing gouge to flatten. Sometimes I use a scraper to clean up the bumps with a rule for reference. One way I use once and a while is my plane. I set my 60 1/2 block plane at almost no cut and have it razor sharp. Skew cut at a medium speed and you'd be amazed at how flat and smooth it can be with straight grained pine, alder or maple. Not so hot on curly anything. Another major help is practice. Yeah, Matt! I thought it was cold here in California in my shop and I have insulation and double pane windows.

[Ed Thomas]

If high precision is a requirement, there's always the router jig method. :)

137788

[Matt Hutchinson]

I don't want to hijack the thread, but yes, my shop is closer to a shelter from the wind than a workspace right now. :rolleyes: If it's above freezing, working out there for a couple hours at a time isn't too bad. What you don't see is the mountain of insulation behind the camera. I planned on getting it all in before December, but I'm in the middle of renovating a couple rooms in my house.

Anywho, back on subject. Paul, I have heard of the hand plane technique before but didn't know anyone who has used it. Have you ever tried it with a larger plane?

Hutch

[Jim Underwood]

For making straight cylinders quickly on a lathe, nothing beats a belt sander.... says Jim Duxbury. :cool: I have yet to try it out, although I've seen Jim do it a time or two.

I imagine it would work for tapers too.

[Jerome Hanby]

Use a duplicator and cut the tapered template on the table saw?

[Paul Atkins]

Matt, yes I have used my #5, but I keep going back to the block plane. It's a bit hard on the blades, so I use the Stanley blade rather than my Hock blades for this.

[Richard Allen]

Start with a 2" square piece. Mount at the headstock centered. Mount at the tailstock so the live center point is 3/4" from one side and centered. As you turn the spindle pay attention to when the spindle just starts to become round. When the whole spindle is Just ROUND it will be tapered as you desire. Please note that the spindle will start off unbalanced. Work on the tailstock end of the turning first to eliminate most of the out of balance condition. Note that you may wish to start off at a lower speed to start. I have turned 39" long 2" to 3/4" tapered legs with this method. The process goes very quick and the results of a taper are easily achieved useing the flat side of the stock as the gauge for knowing when you have reached the desired diameter along the taper. This method is not of any use for a taped which occours in the middle of a spindle.

[Dick Strauss]

Richard,
Your method will work with one small correction...the small end should be 5/4*1/2 or 5/8" from one side so that he ends up with a 1.25" finished diameter.

You can taper part of the leg using your method but with multiple centers. You can turn the top half round between actual centers. Then you can remount using a second offset center on the tailstock end only. As long as you don't touch the first half, you can turn the second half and get the taper for that half only.