Thread: GMC Lathe modifying

I would not buggerize around with that lathe, believe me!

I was in Brasil for a time and took pen kits and tools with me with the idea of turning pens there.

Ha1

Only lathe I could get was a clone of that. Despite much chasing up of local macinists and so on
I simply could not get any degree of accuracy or satisfaction with the machine.

Cunvert the thing to what has been advised above.

If you've never used a lathe and this is what you have then you can always have a go.

Why spend 900 bucks on a midi and then find out you don't like it.
I agree I probably wouldn't do pens on it, But practicing is ok, I made magic wands for kids on one and they came out fine
(no worse than on the record or the jet).

And a few other things I also made on it when I needed things, all came out fine.

And you can always take the insert out of a chuck to make it fit a 1x10tpi lathe when he decides to get one, or if he gets a record they will all go over directly.

To a certain extent I am with all the above comments, however, when it is all boiled down a lathe only has to spin wood. Some do it better than others.

Whilst the GMC and its clones are probably at the bottom end of the market they could get you started and with a few tweaks will probably do light work ok.

Mount it on the strongest bench or stand you can. You may be able to strengthen the headstock with some angle iron bolted to it.

If things go awry, ask yourself this: Was it my technique? Are the tools sharp? Did I exceed the lathes capacity? Is it the lathe that is causing it?

I have seen some people that give up turning because they bought cheap equipment that was just so frustrating. At least you have the opportunity of using the better stuff at the club. Use this time to advance your technique.

For what it's worth, my first lathe was wooden using 2 bits of 4x2 as the bed. The spindle was a machined pin that ran in bronze king pin bushes and the tailstock was a bolt with a point ground on it. The tool rest was a piece of 2x1 hardwood that clamped to the head and tailstock. It had 2 speeds, 1440 (motor speed) or stop.

If I wanted accuracy I used my metal lathe, but it taught me good techniques.

As Robo said use it till you can get somthinng better I started with one like Robo, and made tools from screw drivers and carpentry chieles dont recomend you do that but i had a lot of fun and made some good stuffwhen i was 15 have fun and learn lots at the club we all do
Ian

Hey guys, I'm not too sure how to post numerous quotes to reply individually
as I am on an iPad at the moment and can't work out how but thanks moby, Ian, Fly and for all the helpful tips,

for those who are saying to get rid of it and upgrade I appreciate that but when I have the means and money to do so believe me I will, but at the moment that is not an option,
I am a wood machinist, so I have a better understanding than most as to what difference a quality piece of machinery can make, but as an apprentice I was also taught to use and make do with what ever you have on hand,

I am not out turn show stopping items or to try to make a living selling things I make. I just want to make use of what I have, I have already turned some nice handles and things on lathe.

So again thanks for the helpfull tips I have an idea of what I will do to proceed and i might Just post some pics of stuff I make,

I did my first pen on a GMC lathe.

A lathe's job is to turn things round, so I stuck a bit of wood between centres, and turned it round.
Then turned it smaller and smaller until it fit inside the pen tubes.
(Just like making a mandrel, hey??)

Unfortunately, it was a bit too small, so I enlarged it by wrapping masking tape around it until it was a snug fit in the pen tubes.

I think I did a couple of pens using this turned wooden mandrel, so don't think the only solution involves pieces of metal, engineers, or throwing money around.

This link shows the "upgraded" version of my made pen mandrel, which *did* involve a piece of metal (but no engineers, and no $$)


Cheers,
Andrew

Originally Posted by arose62

I did my first pen on a GMC lathe.


This link shows the "upgraded" version of my made pen mandrel, which *did* involve a piece of metal (but no engineers, and no $$)


Cheers,
Andrew

Very interesting concept Andrew,

Like I said before, sometimes you just make do!

Originally Posted by Beedeejay

Hi all,
i was given a Gmc lathe and all it came with was the centres and no other attachments, I want to modify it to be able to turn pens, does any one have any attachments or tips to give me an idea of how to do it??
i can get a piece made from an engineer to take a cordless drill chuck to put the mandrel in but it is a bit pricey, I only wan a cheap and easy option until I can save up for a decent lathe,

Cheers Ben

These: Newegg.com - Boltmaster Steelworks .88in. Right Hand Threaded Rod Coupler Nuts 11850

are used to put together threaded rods - allthread.

If you could find one to fit on the lathe spindle, turn a piece of hardwood just a whisker larger than the female thread of the nut, screw it in the nut 2/3rds of the way in, put it on the lathe and face off the front flat, then drill out the hardwood to fit the pen mandrel.

You might also try to find a spindle adapter from a chuck manufacturer. Here is a list of Vicmarc: Vicmarc - Woodturning Lathes, Chucks, Jaws and Accessories -

I have one from Penn State Industries, made in China, $19.95 that adapts my 33mm X 3.5 metric spindle to a 1 inch x 8 tpi thread that has a #2 Morse taper in the end. This was a pleasant surprise as my Hegner has a female 16mm thread in the spindle. I got the lathe used and it did not come with a 16mm drive center.

This might have a Morse taper hole in the end:

3/4" x 16 tpi Headstock Spindle Adapter at Penn State Industries

This is a US company, but the stuff is made in China and may be found locally.

I am in agreement with others that say use what you have until the bug has sufficiently bitten that you can justify more expenditure on equipment.

Most chucks have inserts so you can buy a chuck to fit your existing lathe and when you upgrade, change insert to fit the new lathe.

Originally Posted by

For what it's worth, my first lathe was wooden using 2 bits of 4x2 as the bed. The spindle was a machined pin that ran in bronze king pin bushes and the tailstock was a bolt with a point ground on it. The tool rest was a piece of 2x1 hardwood that clamped to the head and tailstock. It had 2 speeds, 1440 (motor speed) or stop.

So they did have electricity then!

Originally Posted by Paul39

I am in agreement with others that say use what you have until the bug has sufficiently bitten that you can justify more expenditure on equipment.

Me too! Better to have something than nothing. You will learn a lot about (cheap) lathes as well, & how to tweak what you have. They may test your mental resolve though. As an aside I know a very good turner who uses a GMC as a base for an ornamental lathe and plenty of cobbled up accessories to go with it. His work is pretty good! So it can be done, if you want / need to.

Originally Posted by Mobyturns

So they did have electricity then!

Nope, he used to get Captan Cook to peddle the lathe for him.

Originally Posted by _fly_

Nope, he used to get Captan Cook to peddle the lathe for him.

At 1450rpm, Cook was one fit guy then!

Originally Posted by Mobyturns

At 1450rpm, Cook was one fit guy then!

No just a good salesman