Grizzly 4003G Lathe

[JerrySharrett]

Ya know, I've been lookin at them threads thinkin the same thing. I gotta tell ya, just last year I was trying to cut some threads and I just couldn't get them to come out right. I used a tool that Grizzly sells and I set my compound at 29 and a half degrees and went to cutten threads,IThanks...Jay Cutright

Jay, I didn't read all of this post because if you don't occasionally indent and double space the words run together (I have an unusual eye condition that requires a different concentration than most people depend on).

That said, why set the compound at 29.5 degrees for a standard 60 degree Vee thread? If a threading tool was ground with a "dish" on top to where there was a positive clearance all around there would be no reason to use the 29.5 degree setting. You could just feed straight in or feed in at 15 degrees or whatever as long as you stayed within that 60 degree envelope.

Since most threading inserts and hand ground tools do not have a positive top clearance all around, using 29.5 degrees works best. Why? Think about it, the 29.5 degree setting creates a "back drag" of 0.5 degrees. This back drag allows the back face of the Vee tool to burnish that face of the Vee. And where is the normal load on that thread is tightened? On that thread face.

Edit-there is also the issue of keeping the half-nut loaded in the same direction for each pass. The 29.5 setting helps with that but without getting deeper in the mechanics of machining, just set the compound on 29.5 degrees counter clockwise from a ZERO being perpendicular to the workpiece being threaded...trust me!!!

 

[Jay Cutright]

Thanks, Jerry

I am cutting my threads at 29.5 degrees.

The way the scale on my Asian made lathe reads I have to set up at 60.5 to get that 29.5 degrees.

My point in telling the story was to explain where I started & how I got to be able to cut the threads that brought on some kind compliments. I've had numerous e-mails & PM's that were generated from this forum so I would rather let it be known that I'm learning too.

I have heard some say that with the modern inserts that feeding strait in is appropriate and even the manufacture told me that was the intended use of my tool but that it doesn't hurt to feed it at 30 degrees or 29.5 if I choose to do it that way.

I keep using the 29.5 degree set up because I started that way and it works for me, also, I don't loose count and the compound is out of the way of the handle on the cross feed.

Now that your explanation has helped explain why this has worked so well for me, by all means, go deeper into the mechanics of machining.

 

[mike in co]

and this is suppose to be the BENCHREST COMPETITION ONLY forum......and we have a gunsmith forum....hmmmmmmm

 

[J. Valentine]

And how would you have custom BR guns without gunsmiths , amature or professional pray tell ?
Ask youself a question! Why is there only 5 people viewing this forum?

 

[Jay Cutright]

The barrels that come off of my lathe are very competitive in BR.
I agree the thread was started on the wrong forum, but, who can argue with a thread counting over 3000 visitors? Well, besides mike in co.
I have some more information to pass along soon about the G4003G, watch for it on the "Gunsmithing" forum. I'll start a new thread there soon.
Jay in Illinois

 

[eww1350]

Changing out my bearings today..!

I decided that it was time to get the new bearings into the headstock of my Grizzly 4003G...as you know this has been a source of aggrivation since it was new (made in June 2009)...but if it is going to ever cut decent threads...it had to be done...attached are some photos of the bearings and races.."grizzly" is an appropriate name for the condition of the original bearings..lots of metal particles...same as Jay Cutright found in his...I am suspicious that one of the gears was floating into the side of another...I will check the alignment and clearance when it goes back together...
Not what I had in mind when I bought a new lathe..
my favorite photo is the last one..a precision cut gasket.!..
Still want a new Grizzly 4003G..?????

 

[Shiraz Balolia]

I purchased mine this year...and the headstock bearings are junk...as is the bearings in my friends 4003G lathe...Oh they will send you a new set of bearings to put in if you feel so inclined..!

Eddie - I am sorry that you got a lathe with problems.

Our records indicate that your lathe was shipped to you on 8/17/09 and that you did not contact us until almost a year later on 7/21/10 when an activity was set up in our system. We promptly sent you a set of replacement bearings which you are just now installing.

It is obvious that there was some foreign matter in the headstock when your machine was built, causing the problem with the bearings, which are high quality NSK bearings. During the last year or so we have implemented an extra step in our inspection process whereby the headstocks are flushed prior to shipment. This eliminates the chances of filings or other foreign objects that may be left behind during the manufacturing process.

When machines are run for an extended time with bearing problems, the result is not pretty and can cause damage like what you posted in your photographs.

 

[mike in co]

And how would you have custom BR guns without gunsmiths , amature or professional pray tell ?
Ask youself a question! Why is there only 5 people viewing this forum?

maybe you have an issue reading and understanding ENGLISH. this is the BENCHREST COMPETITION only forum,,,,not the gunsmith forum...we have a GUNSMITH forum...for discussing such things as lathes as oppose to COMPETITION
this thread is in the WRONG forum .....THIS FORUM WAS CREATED BY THE OWNER to eliminate threads on subjects that were not about BENCHREST COMPETITION.
is that clear enough ?
now back to our regularly scheduled programming.....
nice pics jay....

mike in co

 

[Bnhpr]

Its good engineering practice too change and inspect gearbox oil after a few hours of operation, or if there is significant gearbox noise heat or vibration. Bevel gears are inherently noisy, but that's not always an indication of failure or immenent failure. In some machines I have added molybdenum dis. additive to reduce heat, noise and increase gearbox life.

 

[eww1350]

Eddie - I am sorry that you got a lathe with problems.

Our records indicate that your lathe was shipped to you on 8/17/09 and that you did not contact us until almost a year later on 7/21/10 when an activity was set up in our system. We promptly sent you a set of replacement bearings which you are just now installing.

It is obvious that there was some foreign matter in the headstock when your machine was built, causing the problem with the bearings, which are high quality NSK bearings. During the last year or so we have implemented an extra step in our inspection process whereby the headstocks are flushed prior to shipment. This eliminates the chances of filings or other foreign objects that may be left behind during the manufacturing process.

When machines are run for an extended time with bearing problems, the result is not pretty and can cause damage like what you posted in your photographs.

Yes...you are correct on the purchase date and info...I guess I should have expected to have foreign material in the headstock, and should have dissassembled and thoroughly cleaned my headstock and bearings when I purchased this machine "brand new"...I am at fault here for assuming that a newly purchased lathe should have 10-15 years of trouble free life when used in a light duty machining application...
I guess...it is the way of the future now all purchased equipment will have a free parts warranty...Hope Chevrolet and Ford don't go that way too soon...I would hate to replace engine or transmission parts during a warranty period...Im just gettin' too old for auto mechanicing...

 

[IndianaJames]

Is it Chevrolet or Ford that will come to your garage and replace parts in your transmission?

My guess is they would require you to hire someone to transport the vehicle to their maintenance facility.

I'm getting too old for that to be fun anymore, also.

Jim

 

[Hal]

Bnhrp

On one of these forums it was recommended NOT to use a MOLY additive in precision bearings.
The guy worked with precision bearings in a big turbine and when Moly was added to the lube it took the HIGH dollar bearings out.

Hal

 

[eww1350]

Is it Chevrolet or Ford that will come to your garage and replace parts in your transmission?

My guess is they would require you to hire someone to transport the vehicle to their maintenance facility.

I'm getting too old for that to be fun anymore, also.

Jim

Yep...if it is still in the warranty period they will send their tow vehicle, or if it requires they will pay an independent towing company...and provide me with a loan vehicle while mine is being repaired....that is why I buy a new vehicle instead of used...I am expecting a trouble free item during the warranty period...
I have friend that purchased the exact same lathe prior to my purchase...he also has the same issues...he is a retiree and wanted a lathe to do his own rifle chambering only...he does not have the skills or the health to dissassemble a repair his lathe...I guess my thoughts would be that a company would provide the repair or re-imburse the cost to repair the lathe...I am chalking this one up to my education at "the school of hard knocks"
If I am the one "at fault" for the problems with the lathe then I offer an appology to the folks at Grizzly...I think I will let the results that I have found stand on their own merit...
Maybe the next person that has a similar issue will have a very possitive take on repairing and upgrading their "new" lathe as did Jay Cutright...

 

[JerrySharrett]

Bnhrp

On one of these forums it was recommended NOT to use a MOLY additive in precision bearings.
The guy worked with precision bearings in a big turbine and when Moly was added to the lube it took the HIGH dollar bearings out.

Hal

Sounds about right. Molybdenum Disulfide (Moly) is slick BUT is is a solid. Solid particles don't work well in carrier type bearings, especially roller bearings.

 

[Shiraz Balolia]

Its good engineering practice to change and inspect gearbox oil after a few hours of operation, or if there is significant gearbox noise heat or vibration.

You are absolutely correct about that.

In fact, we call out for an oil change in the headstock in our manual under "Test run and Break-In". Page 17, Item 12.

http://cdn1.grizzly.com/manuals/g4003g_m.pdf


Cars, trucks, engines and just about any piece of machinery require an oil change after an initial break-in period so that the gears etc. all seat correctly and any particles that may come off in the process are washed off during the oil change.

Reading the manual is always a good idea.

 

[eww1350]

Yep...did the oil changes as required...twice...have wittnesses to look at the metal particles during oil changes...went thru proper initial break-in...

 

[Chisolm]

ew
Sorry you are having so much trouble. I have had such good luck with my G4003G that I am getting ready to order a grizzly mill, having a little trouble deciding which one though, probably the 1007. Yes I would prefer a Bridgeport but I think that model will accomplish my current needs, a 60" table sure would be nice though.
I am quite sure though that my lathe does have Timken brgs instead of the NSK if it makes a difference. I did have some filings in the case when I first changed the oil but having some experience with tractor transmissions that had incredible amounts of metal filings in them without any internal damage I wasn't concerned at all.

I hope I didn't just jinx myself.


James

 

[Ian_Owen]

When I got my new lathe at the first headstock oil change I lifted the top cover and positioned a few magnets in the bottom of the headstock, that way any metal particles hopefully would stick to the magnet and not circulate through the bearings.

Ian

 

[Bnhpr]

Bnhrp

On one of these forums it was recommended NOT to use a MOLY additive in precision bearings.
The guy worked with precision bearings in a big turbine and when Moly was added to the lube it took the HIGH dollar bearings out
Hal

Turbine bearings and bevel gearboxes, roller bearing are different animals.

I have used ts90 in gearboxes for many years, with engineering support from the oems, lubricant suppliers etc.

It's something to look into if your concerned with noise and fretting of the faces.

My g4003g runs fine, I'm just trying to help.

Ben

 

[eww1350]

Well...new bearings in the headstock...and threads still have chatter on them...have had couple of machinist friends (old timers) come by and we are all "stumped"...
just have to keep looking for the root cause...going to the motor and mounts next...try to eliminate one factor at a time...
"Here we go" again...


Eddie in Texas

P.S. if your out this way in West Texas...stop by and I'll give you a shot at it too...