PDA

View Full Version : Noob Grizzly lathe help.



T.Hoffman
10-23-2009, 02:36 PM
Here at work we have a little prototype machine shop- I've done lots of milling on a crappy old smaller Jet mill over the last 7 years or so. We are getting a new Jet JTM-4VS DRO mill, which will be a welcome addition.

My boss had some funds leftover in this years' budget, and I suggested getting a smaller lathe for the shop. We have limited space to work with, so for the money and space available we settled on the G4003G Grizzly lathe.

My question is- are the supplied 6" 3-jaw and 8" 4-jaw chucks that come with the Grizzly any good? Would it be worth the money to upgrade to something like a Bison 4-jaw?

Or are the supplied chucks 'good enough', and spend the money on a Buck or Bison 6-jaw for doing some finer work?

mechanicalmagic
10-23-2009, 03:11 PM
I'm very happy with the 4 jaw on my 4003. The 3 jaw is about .004 TIR out, after about 10 years.

I don't know which 3 jaw comes with the 4003G, the online description lists a reversable jaw, meaning the top jaw comes off with two cap screws. The catalog lists separate jaws for outside vs inside holding. Some folks have sucessfully complained, and gotten the removable top jaw style.

With removable top jaws, you can install soft jaws, which are machined to fit your work. Since they are machined in place (remembering to load them properly), they run very true, and are easy on thin walls and don't mar the surface.

A 6 jaw is way out of my budget.

Walter
10-23-2009, 03:19 PM
3 jaws really aren't meant for precision, there quick and dirty tools. Ask yourself this. For the type and size of work that you do what would suit you better, a chuck or collets. Collets are really nice for better precision, especially when you have to pull a workpiece out and replace it. 4 jaw's the best bet there, but there slower. Would collets cover the majority of your stock size needs? personally I have a 3 jaw, 4 jaw, centers, and a faceplate. I use collets 75% of the time, 10 % to both the 4 jaw and the centers (5c center). and 5% to the 3 jaw.

I doubt the stock 3 jaw is "any good" but eh, you might luck out with a good one. A 4 jaw is a 4 jaw I had at one time bought a new Enco 4 jaw, heavily built 6 inch china import, it did just fine. you really don't need to spend money on a higher end 4 jaw. That said...

The BEST 3 jaw I ever had was a little 5 inch 3 jaw Bison, Enco offers it for $317.00 (http://www.use-enco.com/CGI/INSRIT?PARTPG=INSRAR2&PMAKA=271-4074&PMPXNO=1617206) , I snagged it for $50.00 in a box of stuff at an auction. I believe the advertised run out is .0008. That chuck was more like .0003 - .0004. Very very nice well built chuck, but I still went to collets and the 4 jaw for tight stuff.

Heres a pic of that 4 jaw from enco and also that 5 inch 3 jaw

http://pic100.picturetrail.com:80/VOL1167/4323122/17727806/276677098.jpg

http://pic100.picturetrail.com:80/VOL1167/4323122/17850766/285869683.jpg

T.Hoffman
10-23-2009, 04:14 PM
For the type and size of work that you do what would suit you better, a chuck or collets. Collets are really nice for better precision, especially when you have to pull a workpiece out and replace it.

Great point.

Here's the deal- None of us have much metal lathe experience, and we'll be learning quite a bit as we go. We have retired machinist in the neighboring dept that will be helping us along. We need to outfit this lathe with what leftover budget we have. There's two different "piles" of budget that we are outfitting this lathe and mill. One pile needs to have bigger chunks of money taken out, like around $500 or more at a crack. That pile has still has about $800 leftover for the lathe, that's why I was considering upgrading the chuck. But I like the idea of the collet chuck.

The other "pile" of budget will be for the smaller itmes, indicators, tooling, etc... Even though they can add up to total a lot, each item can't be over $500. Weird, I know. Just the way the big corporation works here...

So I have to figure out what upgrade to add to the lathe out what's left from the first pile. Bison 5C collet chuck?

smiller6912
10-23-2009, 04:39 PM
... We have a retired machinist in the neighboring dept that will be helping us along. We need to outfit this lathe with what leftover budget we have....

My first thought would be to include your in house expert in the decision. It seams to me he could be a very valuable asset in knowing what you will most likely be using it for and what you will need to do it.....

Alistair Hosie
10-23-2009, 04:39 PM
You've got that lathe in nice shape walter well done.I like the new belt .Did you have that made.I sincerely hope you have alot of fun with it.Alistair

mechanicalmagic
10-23-2009, 04:40 PM
I would get the Digital Readout for the lathe.
$675 H6095 page 627.

I'm assuming you are on a quick time frame, otherwise there might be better units that are under $800.

T.Hoffman
10-23-2009, 04:42 PM
My first thought would be to include your in house expert in the decision. It seams to me he could be a very valuable asset in knowing what you will most likely be using it for and what you will need to do it.....My first thought too- unfortunately he's out for a while, and our budgetary requirements need us to act fairly quickly, like in the next week or so for finalizing this.

Either we use it or lose it. So I'm trying to ask all the questions I can and get this purchase made vs. not having it happen at all.


I would get the Digital Readout for the lathe. $675 H6095 page 627.That crossed our minds too. That one, or the Meister like this:

http://www.bedair.org/Grizzly12x/DRO/GrizzlyDRO.html

Black_Moons
10-23-2009, 05:09 PM
lol at the total fail consept of 'use it or lose it' budgeting. Lets waste lots of money this year or we won't have money next year when we need it... WUT?
In reality I do believe that should be the other way around.. Lets NOT waste lots of money this year so we'll have EXTRA next year.

But then, I only took common sense and sanity class in school, not beancounting.

Anyway, enough of that rant and on to some useful advice.
the 3 jaw is good for quick and dirty, but they tend to wear out over time and get worse with wear and get harder to adjust. the 4 jaws and collets and to some extent 'Set true' 3 jaw chucks (thats a 3 jaw chuck with some kinda X/Y runout adjustment on the body. im not sure how praticaly/easy they are to use compaired to just using a 4 jaw but maybe someone else can chime in on that) are where its at.

the cheap 4 jaw chucks are probley ok if nothing is blatently wrong with em.

a 5C collet set+chuck (or make your own) is likey what you want to spend your cash on.
ER40 collets is more 'tool' holding im told. (But you might find out your mill allready has an ER40 collet set, and in that case you could get a ER40 straight shank holder and slap that in the 4 jaw chuck for a cheap introduction to collets)

Or, a DRO, but I think most good DRO's are a little more expensive then $600~

PS: expect to put aside at least $500 for all the little extra tooling you'll wanna buy for the lathe. Insert holders, HSS toolbits, possabley additional grinders or bench sanders.

Oh, forgot one super important thing! a quick change toolpost! you pertty much will want that before all else, you can often get a cheap phaseII one on sale for like $200~300 I believe. then another 10 holders for $100~ a set or something on ebay.

6 jaws im told are awsome for thin walled pipe and such, but they can still have similar runout problems as 3 jaws, unless you get a 'set true' 6 jaw or just some totaly awsome 6jaw.

Theres lots of ways to do thin walled stuff without 6 jaws of course, like making your own custom collet outta scrap metal and holding it in your 3 or 4 jaw chuck to compress it. Or using a 5C/ER collet if its small enough.

Basicly though 3 and 6 jaws relie on a 'scroll' plate and have problems with accuracy due to wear and any debrie or manufacturing defect.
4 jaw chucks relie on user adjustment and are as precise as you wish to waste time getting them precise.

Collets.. are as precise as how much money you spend buying them and the holder for them, and afaik should'nt wear unless you do something nasty to them to deform them.

T.Hoffman
10-23-2009, 05:17 PM
lol at the total fail consept of 'use it or lose it' budgeting. Lets waste lots of money this year or we won't have money next year when we need it... WUT?
In reality I do believe that should be the other way around.. Lets NOT waste lots of money this year so we'll have EXTRA next year.

But then, I only took common sense and sanity class in school, not beancounting. Agreed on all points! But I can simply work within the 'system' I'm put in. The massive wheel of the company goes 'round so that little voices like me saying 'this is silly' fall on a forest of deaf ears. Got to play with the hand you're dealt.

So, that being said- if I'm offered the cash to buy some toys for our shop, I'm gonna do it!

We'll have ~$2k for tooling from the other pile of money, I don't need to finalize that list just yet. Jussst possibly I might be able to squeeze out both the DRO and collet chuck because I found a nice deal on the Jet mill for a lower price.

I appreciate the input so far. THANKS!

gnm109
10-23-2009, 07:01 PM
The standard three-jaw and four-jaw chucks should be fine. Even the best of the three-jaw chucks have some amount of runout. If you are turning a piece and finish turnng it with no intention of removing and replacing it during the process, the errors really are of small consequence.
If you want perfection every time, a four-jaw will do the job. the only issue is the time it takes to indicate the work and get it down to zero. It can be done with some practice.

In any case, the standard chucks should be OK.

GKman
10-23-2009, 07:04 PM
I have had one about 4 years. Only lathe I have ever had or run. Don't know what to expect from a top of the line chuck but machining, fit, finish, material on the Grizzly seem fine to me. Holding grip seems good. Sometimes I'm mad if it slips, sometimes grateful. Not difficult to center 4 jaw to 0.001" if my brain works right. Use two wrenches on opposite jaws at the same time, push with one and pull with the other, works for me.

Boucher
10-24-2009, 12:30 AM
I would opt for a six jaw set true chuck. I use mine for most operations. The collets and four jaw are necessary for certain conditions but most of thetime my first choice is the six jaw.

Walter
10-24-2009, 12:46 AM
You've got that lathe in nice shape walter well done.I like the new belt .Did you have that made.I sincerely hope you have alot of fun with it.Alistair

Alistair,

Thanks for the compliment. The belt is actually a custom cut multi ply I ordered on e-bay. worked wonderfully, no slippage as compared to a leather one. I had a ton of fun with that 9 inch, but she's been gone to a new home for better than a year now :(