New Grizzly gunsmith lathe 12x36

Hi all, I am new to this site and to machining. We just received our new 12 x 36 G4003G lathe from grizzly. I have worked on a 10in Craftsman and a Smithy before but there is no comparison. We (my brother and I) hobby on guns a good bit. This was a big purchase for us but so for we are very pleased.

I have been reading and learning from this site for sometime now. But wanted to take this opportunity to start my first post. All questions are welcome. And as time goes on I’m sure I will have many.

Our main objectives for now are to re-barrel and make a free float hand guard for my AR15, headspace a REM. 700BDL, make a stainless full length guide rod for a 1991A1 colt, and who knows what else.

Enjoy the forum and welcome.
Butch

The Grizzly is a nice machine I have the older 12x36. The only thing I have replaced was a worn half nut set.
Welcome as well.

Thanks

Tanks guy's. i am realy enjoying the lathe. but i have a question.

How do i cut left hand threads?

Turn your tool upside down and turn the spindle backward.
Butch

Hi There,

To turn left-hand threads, you have to reverse the
rotation of the lead screw (in relation to the spindle).

Good Luck!
-Blue Chips-
Webb

You also need to grind the angle on top of the tool to cut on the right side.

Thanks it worked like a champ. This machine cuts so smooth.

I am having some trouble with aluminum sticking to the carbide bits. Any suggestions.

Try a different grade of carbide.

Are you using cemented (brazed) C2 for aluminum and C5 or 6 for steels or indexable? For those you may want to look at a manufactures web site.

What are you using for coolant (lube). Some old timers use Kerosene. Tapmatic works. Steels use oils, something with sulfur, stinky but good. Indexables will want coolant.

Too slow will sometimes cause welding, I prefer to thread with HSS. But then I am old (well I am today, may not be tomorrow)

Thanks,

Using C6, didn't know C2 was for alum. I do like HSS.
I use water soluble oil but the C6 did not like it. I will try C2 but will have to order some we don't have a local distributor.
Thanks again.

cant you just turn a relief slot and start threading from the headstock side?

STEELPOUNDER said:

cant you just turn a relief slot and start threading from the headstock side?

Click to expand...

I'm not sure I understand what you are asking.

I'm turning a relief and threading from the headstock side to the tailstock side to cut both LH and RH threads. RH the chuck is spining forward/normal and the bit is cutter side up. LH the chuck is reversed and the bit is cutter side down. I'm not sure if this is right I am just learning to cut threads. It does seem to work if this is wrong maybe someone else can chime in and correct me. I have worked on guns for along time but never had a lathe with all the fancy stuf.

"It is possible to fail in many ways... While to succeed is possible only in one way..." Aristotle

HR

You can buy HSS inserts for your indexable tooling from http://www.arwarnerco.com/ They are an excellent choice for manual machines especially for aluminum. Also for threading where you are running 1/4 speed.

repeatability

I'm envious at your recent purchase. Ive been looking at that lathe for a little while and will probably end up with one soon. I hope (I think).

I was wondering, how good is the repeatability of the settings, i.e. crossfeed dial and compound dial for threading? Do they return the tool exactly to the same spot for the next pass?
Ive read that these lathes can have some issues with the marks on the dials not cutting what is measured. How has that been for you?

Is the machine ridgid enough for you?

One last question; the lead screw seems to stick out in the open allowing chips to fall on it. Is that true or is the screw tucked under the edge of the bed out of the way of chips? have you noticed this to be a problem?

I hope I havent burdened you with too many questions. Ive wanted to talk to someone who has one of these machines for some time.

RDurrant

I was wondering, how good is the repeatability of the settings, i.e. crossfeed dial and compound dial for threading? Do they return the tool exactly to the same spot for the next pass?

So for, the repeatability is dead-on. I don’t know much about threading but I use the three-wire method to measure my threads and store bought nuts for testing. Haven’t wiped or doubled any yet (knock on wood).

I’ve read that these lathes can have some issues with the marks on the dials not cutting what is measured. How has that been for you?

The dials seem to close but I stop and check often. So it’s hard to say there good or bad. But I will setup and check them and repost some time this weekend.

Is the machine ridged enough for you?

Yes but I have never used anything this heavy 1200lb +. I cleaned up the main journal on a motorcycle crankshaft and had no vibration.


One last question; the lead screw seems to stick out in the open allowing chips to fall on it. Is that true or is the screw tucked under the edge of the bed out of the way of chips? Have you noticed this to be a problem?

Yes it does stick out about half the thickness of the screw. And yes it does get some debris on it, this has not caused a problem yet but I’m sure I will have to make some kind of flex cover for it. If it came perfect what would I do with all my free time?

I hope I haven’t burdened you with too many questions. I’ve wanted to talk to someone who has one of these machines for some time

Not at all, I looked at Steve Bedair’s web site and talked to as many people as I could before we purchased it. Keep the questions coming, that way I wont feel so bad when I have to ask someone here everything about machining.

Thank you for your answers, I need a larger lathe to do my projects as I have a 9" Southbend right now. I love it but its too small for some of the things I want to do, like machine bull bbls. and turn my own receivers etc. I would love to buy American but just can't afford it. Any way Ive always liked the fact that someone made a lathe with the gunsmith in mind. This one seems to fit the bill.

Handcrafted,

If you are turning left hand threads it is not necessary or recommended that you reverse the direction of the chuck. You want to be able to see your work as it progresses, so keep the tool bit up. Instead reverse the direction of the tool carriage to run left to right (headstock to tailstock direction). Actually, if I understood your post, turning the tool bit upside down and reversing the chuck will still give you a right hand thread.

HANDCRAFTED said:

I'm not sure I understand what you are asking.

I'm turning a relief and threading from the headstock side to the tailstock side to cut both LH and RH threads. RH the chuck is spining forward/normal and the bit is cutter side up. LH the chuck is reversed and the bit is cutter side down. I'm not sure if this is right I am just learning to cut threads. It does seem to work if this is wrong maybe someone else can chime in and correct me. I have worked on guns for along time but never had a lathe with all the fancy stuf.

"It is possible to fail in many ways... While to succeed is possible only in one way..." Aristotle

HR

Click to expand...

What I have been doing is cutting a relief where I want the threads to stop. then for right hand threads I start my cut at the tailstock and thread towards the head stock. For left hand threads I start in the relief and thread toward the tailstock. I don't know if this is wrong or right but it seems to work very well. I grind my cutters for threading flat on the top so that they cut on either side.

Handlebar57
STEELPOUNDER

Thanks, I tryed it the way you explained it, your way works better. Thats why I posted here. Thanks again

cutting LH threads

SIR,
everything is nearly the same as for RH threads.
except, you are feeding from the chuck toward the
tailstock, and the compound will be set to the LEFT,
and you will be cutting on the RIGHT side of the tool,
rather than the LEFT side.
good luck witth your project.
wlbrown