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Forum topic by Flemming posted 08-31-2010 07:57 PM 1081 views 0 times favorited 7 replies Add to Favorites Watch
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Flemming

417 posts in 2359 days


08-31-2010 07:57 PM

Just some silly questions for the turning experts out there :)

first of all… what RPM on the lathe is typical for wood-turning? I have turned my fair share of metal and I know there are various speeds required for different metals, and different thickness’s. there’s also rules about how much material you can remove at once. i cant imagine it’s the same with wood? i’m not so sure turning speed is so important? i’m probably wrong.

second question… I have access only to metal lathes, and I dont think there will be a problem using the tool post fitted with a cutter for metal? i am a little bit worried about chipping the wood instead of cutting it though. simply because the toolbit used on a metal lathe is perpendicular to the piece and doesnt exactly “cut”, rather it scrapes. does anyone have experience with this?

next question.. I am uncertain about the type of glue to use.. the idea is to do a couple of segmented pieces. I know most wood glue forms a stronger bond than the wood itself, but i’m unsure about the centrifugal force, and the possible effect of heat on the glue joints… I want to use normal wood glue, but if anyone has experience with the joints coming apart and the piece separating and practically exploding on the lathe, i’d like to know before hand ;)

will appreciate any and all feedback :)

best regards
—flemming

-- Flemming. It's only a mistake if you can't fix it.


7 replies so far

View fernandoindia's profile

fernandoindia

1081 posts in 2406 days


#1 posted 08-31-2010 08:48 PM

Hi Fleming, I am not an expert at all. Having said that, let´s hope an advanced turner friend crop out here.

However I´ll give you my view, which is the opinion of a guy who turned only a couple of pieces.
1. When rounding any piece, disregarding the wood, I would set the lowest speed possible. Since the piece is square, I noticed I have a lot more control at this slow speed until the piece enters in equilibrium. Thereafter, I only increase the speed by a little for fine shaving or sanding.

2. I started strapping the wood at the beginning. It sounds as a Flintstones approach. Getting to know the approach angle of the gouges is something that just practice will give. I did also find that gauges quality and sharpness is a must. If a hand plane becomes dull after 30 meter wood planning, imagine that 30 meters in a lathe at 500 rpm in a 2×2 piece means just less than a minute turning.

3.In the two rolling pins made, I used PVA glue. Left to cure one day. So far, didn´t fly away. But I think next time will use polyurethane or other strong glue. No because of the flying away issue, but for any movement in the wood pieces.
I posted yesterday a squared rolling pin made a couple of months ago. If you pass your nail through the surface, you will feel the unions between the squares. That wouldn´t happen when finished.

Bonus track. I read this article, out of which I learned how to plug the lathe

http://www.gutenberg.org/files/15460/15460-h/15460-h.htm

-- Back home. Fernando

View richgreer's profile

richgreer

4541 posts in 2537 days


#2 posted 08-31-2010 09:41 PM

Ideally, you will get the wood fairly well balanced before you turn the lathe on. If the wood is balanced (or close to it) the faster you can run the lathe from the beginning. In some regards, speed is your friend (if you are balanced). I like to start around 700 – 800 rpm when doing spindle work. On bowls, the bigger the bowl the slower I go. At 8” in diameter and above, I start as slow as my lathe will go (500 rpm).

As you move from roughing to shaping to finishing, I keep going faster. However, I seldom go about 2000 rpm.

I know they are a little pricey, but check out the easy tools. These are carbide tipped cutting tools that do not need to be sharpened and they are very easy to use. Here is a link.http://easywoodtools.com/ Check out the videos.

My standard glue when turning is CA glue. If you use it with an activator you can get almost an instant bond and it works great for most turning applications including fixing mistakes. If you are working with a natural edge some thin CA glue can secure the bark so it does not come off.

-- Rich, Cedar Rapids, IA - I'm a woodworker. I don't create beauty, I reveal it.

View Padre's profile

Padre

930 posts in 2951 days


#3 posted 09-01-2010 02:38 AM

I am in the camp that you should turn your wood as fast as the lathe will allow you to turn it. That means you turn the speed up until the lathe starts becoming unbalanced, then turn it down a scootch until it’s smooth, then start turning.

Of course, BIG stuff like Rich is talking about you will HAVE to go a bit slower. For my pens I turn at top speed. For my bowls, as fast as possible.

It is interesting to see that turners in Europe turn much faster than the turners here in the USA and Canada.

And a bit of information I give every new turner is this: KEEP YOUR TOOLS SCARY SHARP. Dull tools make the work so much harder and I believe dull tools are the utmost reason most people get frustrated and give up turning. The second most important tool in your shop after the lathe is your sharpening tool. Slow speed grinder, Worksharp, Tormek…..whatever you use, keep ‘em sharp.

Learning to turn and learning how to sharpen your tools goes hand in hand.

Get some good yet inexpensive HSS tools at PSI (Benjamin’s Best) or at other online sources. Your first tool, and I think you should get a very high quality one, is a gouge. A 3/4” roughing gouge would be a great start then adding some bowl gouges as you go along.

I have the easy wood tools as well, and I love ‘em.

A good place to go to learn about turning, etc. is the American Association of Woodturners.

-- Chip -----------http://www.penmanchip.com-----------------Micah 6:8

View Knothead62's profile

Knothead62

2581 posts in 2423 days


#4 posted 09-01-2010 02:43 AM

The LJ’s are right on the money. The AAW site is fantastic! It is amazing what can be done on a lathe! Also, get the name of a local AAW club near you. They can be a great source of information.

View lew's profile

lew

11337 posts in 3218 days


#5 posted 09-01-2010 03:46 AM

You asked about using cutter designed for metal.

When I started making French rolling pins, I had a terrible time getting the arc symmetrical. Couldn’t afford a duplicator so I made a jig to duplicate the arc. It is fitted with a 1/4” x 1/4” tool stock cutter. I tried using a grind that was similar to the grind used to reduce the diameter round metal stock. This really chewed up the wood and left a very rough finish. I reground the cutter to a rounded end. This works much better. The surface of the wood is much smoother and the cutting goes faster as there is not as much chatter between the cutter and the wood.

Hope this helps a little.

Lew

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

View Moron's profile

Moron

5032 posts in 3356 days


#6 posted 09-01-2010 04:05 AM

metal has a comsistant weigh through out the piece

wood is neither consistant through its density, wieght, grain….............

its the challenge of taming that which refuses to be tamed that makes it fun.

The first thing I do is start low on RPM thing and onc it starts to be tamed the speed increases.

the rest is all experience and judgement…..................neither of which is easily taught

-- "Good artists borrow, great artists steal”…..Picasso

View Flemming's profile

Flemming

417 posts in 2359 days


#7 posted 09-03-2010 08:52 AM

Thanks for the tips guys!!

the websites have really helped a lot.

I really appreciate all of the feedback, thank you :)

-- Flemming. It's only a mistake if you can't fix it.

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