# First Time Lathe Shopping.  G0602/0752 Questions



## SublimeRT (Apr 26, 2016)

Hi everyone.  My first post here.  I am shopping for my first lathe and have a few questions about the G0752/G0602 machines.  

I have many projects in mind, but right now I am working on building an English wheel and am looking to use the lathe to help make the upper and lower anvils.  I have two 8" dia x 2"W upper wheels, that I would like to weld together, then turn on the lathe to true up.  My guess is this is too large to turn on this lathe, but I just would like confirmation before stepping up to a bigger machine.  I see the machines come with a 5" and 6.5" chuck, but I do not know how far the jaws safely open.  I also see the swing is 9.5" to the bed and 6.125" to the carriage.  

With the cutting tool on the left side of the carriage, I do not know where its position would be relative to the carriage, and if it would provide enough clearance to turn something that large.  These wheels are also quite heavy as they are solid chunks of material.  I would guess 15-20lbs a piece.  So I'm not sure if the machine has the power to turn something like that or maybe would put too much stress on the spindle bearings.  

If the 8" wheel is too large, would a 6" wheel clear everything and be able to be machined?  A 6" diameter wheel vs. the 8" on the English wheel won't make much difference.  I would still like it 4" wide though.

I am also unclear on the threading information.  For the G0752 it has listed 8-72 TPI (teeth per inch?).  I have seen bigger machines go up above 100, even 200.  If it is teeth per inch those numbers seem very high to me.  Is this to compensate for diameter of material to be threaded?  

As far as the smaller machines go, I was also leaning towards getting the G0602 and changing the motor and adding a VFD, but I saw there can be problems with VFDs and GFCI outlets.  All the outlets in my shop are GFCI.  Any input on this?  Because of this I was looking at the G0752 also.

If a bigger machine is required, I am looking at the G4003.  I like the added features of the 4003G, but I do not want the supplied stand.  I started this adventure with the intention to stay under $2k though.  At the same time, I don't want to outgrow the smaller machines any time soon.

Thanks in advance for any help.


----------



## tmarks11 (Apr 27, 2016)

SublimeRT said:


> I have two 8" dia x 2"W upper wheels, that I would like to weld together, then turn on the lathe to true up.  My guess is this is too large to turn on this lathe....I see the machines come with a 5" and 6.5" chuck, but I do not know how far the jaws safely open.


A 6.5" chuck can probably only open to 5" (and that is pushing it in my book even if the chuck says you can do it).

Are these open spoked to closed wheels?  Because you can always reverse the jaws on the chuck and use it to hold the wheel (if it were open spoked) from the inside.  Alternatively, maybe you can make some sort of mandrel to hold the wheel through it's center axle and grip that in the chuck.

One gotcha here: since the 9.5" swing is to the bed (not the carriage), if you are trying to turn 4" wide wheels, I suspect that the carriage would hut the wheel before you could turn all the way across the width of the wheel. Bigger lathe?  You would have to super-size it.  Even my 13x40 lathe only has 7-11/16" swing over the cross slide.

Maybe you could turn half of it, flip it around and turn the other half.  Risk there is that you could have a ridge in the middle of a few thousands due to run-out of your chuck (if you go this route, definitely use a four jaw chuck if you have one so you can zero the piece in the spindle).


----------



## SublimeRT (Apr 27, 2016)

Thanks for the reply.  These 8" wheels are closed.  This is actually a Harbor Freight English wheel that I am modifying extensively.  I should have just started from scratch at this point because so far I have heavily modified the frame, the stand has been completely replaced with a much heavier and sturdier design, the lower adjuster is reworked, the lower anvil cradle will be of my own design scratch built, and the upper wheel mount will again be my own design and scratch built.  But I got it for very cheap.  The guy I bought it from just happened to have an extra 8" upper wheel that he threw in with the deal.  About the only pieces from the original HF setup that I'll re-use without doing too much to are the lower full radius anvils.  And I plan to make some 3" wide lower anvils with contact flats with the lathe also.  

The mandrel for holding the wheel is a good idea.  It sounds like I'm still going to have problems with clearance to the carriage though.  

Turning half of it then flipping it around sounds like a good idea too if the setup is not too difficult.  A ridge would be bad though.  The English wheel acts like a printing press.  I've seen a paint chip from the wheel's frame land on the work piece and go through the rollers, and it imprints into the work piece.  But if this is an acceptable method that will work for me.  These 8" wheels are solid and there is plenty of meat to work with if it takes a couple tries.

I doubt I will need to turn anything this big very often.  All my other projects I can think of are smaller.  

One thing I saw the other night was a picture of a boring bar in the tool holder, used to turn the outside of a large diameter and wide piece.  A situation similar to mine, where clearance to the carriage is a problem.  Probably not anything to make a habit of, but is this safe to do with say real light cuts?  

Thanks


----------



## tmarks11 (Apr 28, 2016)

How much does the wheel weigh?


----------



## SublimeRT (Apr 28, 2016)

My scale is dead right now, but I'd guess 15-20 lbs each.  X2 after welding them together. 

If i cant figure something out to make the 8" work, my plan is to make a 6" diameter wheel out of a piece of thick tubing.  In a way it would be better than the 8" in that it would weigh much less and have much less inertia.  Wheeling a panel back and forth with a heavy upper wheel can get tiring.

With a 6" made of tubing, i could grab it from the inside with the chuck jaws, as you suggested.

Sent from my SM-T560NU using Tapatalk


----------



## tmarks11 (Apr 29, 2016)

Spinning 30-40 lbs off a mandrel held only in the chuck jaws probably would not be a great idea. 

You would want to make a mandrel that is gripped by the chuck, and supported by a live center in the tailstock to avoid wobbling.

You could also drill holes in the wheel, and bolt it directly to a back plate instead of using a chuck.  It would take a lot of work to get it centered correctly, though.


----------



## SublimeRT (Apr 29, 2016)

I was planning on drilling 6 or so ~1" holes in the wheel to lighten and give them a little style.  

I knew this particular project is ambitious for the 10x22 machines, but I had to ask, because I wasn't even sure if it was possible.  I have no experience with lathes, except for brake lathes from the dealership days.

As I said before, all the other projects I can think of are much smaller.  Little bushings, sleeves, spacers, pins, etc.

Any comment on using a boring bar in the tool post to make light cuts on the OD?


----------



## tmarks11 (Apr 29, 2016)

You would get some chatter, but that is not any different than using a boring bar to cut an interior surface.


----------



## RJSakowski (Apr 29, 2016)

SublimeRT said:


> ........I am also unclear on the threading information.  For the G0752 it has listed 8-72 TPI (teeth per inch?).  I have seen bigger machines go up above 100, even 200.  If it is teeth per inch those numbers seem very high to me.  Is this to compensate for diameter of material to be threaded?


The GF0602 cuts 23 different SAE threads ranging from 8 to 72 threads per inch (TPI).  This covers the majority of standard SAE threads in that range.  Threads coarser than 8 TPI would be used on shafts larger than 1" in diameter.  Threads finer than 72 TPI would be used on shafts smaller than size 0 or for special applications such as micrometer adjustments.  In addition to the 23 threads listed, the 602 can cut an additional 31  integral and half integral threads per inch ranging from 4.5 to 112 TPI.  Most of these are non standard but it will cut a standard  0-80 TPI and a 1-1/2 6 TPI thread.  All in all, I believe that every SAE thread from 0-80 TPI to 1 - 8 TPI is covered.

In addition, the G0602 will cut all the standard metric threads from M1.6 - .35mm  to M30 - 3.5mm.  I haven't worked through all the possible gear combinations for metric threads so it is possible the the range could be extended.


----------



## SublimeRT (Apr 30, 2016)

Good information guys, thank you for the help.

I've placed an order for a G0752, so now the wait begins.  I couldn't bring myself to spring for the bigger machines right now.  If it comes down to it and I can't figure out how to do the large upper wheel, I'll take it to a machine shop.  This machine will keep me busy though and get plenty of use with other projects.


----------

