View Full Version : Grizzly g0602 10x22 Lathe Gearbox Use and Function
01-23-2008, 01:07 PM
Could someone explain how this gearbox works? The lathe has two knobs, one
lettered A, B, C and one numbered I, II, III. Does setting up a gear train involve just the two change gears a and b while the gearbox does the rest?
What does this gearbox buy you over a machine that lacks it?
Is there a variety of tasks that can be done with two particular
change gears installed?
There is little mention of this lathe anywhere but it has been available
for some time. Any ideas on why?
I tried to add a link to an illustration from the manual but I don't think
it's going to work.
Thanks a lot,
Though, I don't have this particular lathe, before I bought my lathes I read through the manuals of all of the Grizzly lathes (in my price range) to try to answer questions like you are asking. So, here is my opinion.
With the exception of the lathes that have the full quick change gear boxes (Grizzly 4002 and above) the partial quick change gear boxes do not appear very useful as you need to change the gears anyhow. From doing some calculations, it would be possible to make a quick change gear box such that there would be a range of useful thread sizes (i.e. 8, 9, 10, 11, 11.5, 12, 13, 13.5, 14) without any gear changes...just move a lever, dial, etc. For some reason (cost?) they did not do this.
So, personally, I feel that these partial quick change gear boxes are there for marketing reasons only and I don't see an advantage to having a partial quick change gear box.
That being said, the 0602 is probably a better lathe than the 9x20 if only due to it's weight.
From reading through other people's reviews of various lathes, if a larger machine (with a full quick change gear box) is not feasible, the lathemaster 9x30 gets good reviews. Optionally, you could probably pick up a used SouthBend 9A (with a full quick change gear box) for a similar price.
I *think* this may be how it works....
It appears that you must have a selection of change gears: 45, 48, 36, 27, 40, 44, 46, 52, 56, and 48 (I may have missed some). These can be put in positions "a" and "b" in the gear train, according to the first two rows of the chart.
The bottom three rows of the chart show what theads can be cut. The illustration shows 64. To get 64tpi, you want the 27-tooth gear in the "a" position, the 48-tooth gear in the "b" position, the first knob in the "I" position, and the 2nd knob in the "C" position.
This seems pretty cumbersome. On a lathe with a civilized gearbox, you select the thread you want by moving two levers, and that's it (there is one gear you may need to swap for very coarse threads, but that's rare). Perhaps the complexity is necessary to get both inch and metric threads, which your illustration suggests may be possible.
01-23-2008, 03:08 PM
Messy, messy, messy.
I was unfortunate enough to have a similar lathe a few years ago (only for about 2 weeks, but that's another story) - a DB10G from Chester in the UK.
If it wasn't bad enough working out the change gears for threading, you may well find (as did I) that they don't even put enough change gears with the lathe to do what you need.
The only benefit you get from the change knobs on the front is the ability to select different feed rates for a cut. To screwcut any threads you still have to open the back panel and change the gears, unless the ones on the quadrant arm happen to match what you want, and you still have to set this on the front as well.
On the bright side at least your chart is much clearer than the one I had on mine - another poor sod has posted a picture of it here: http://www.enuii.com/chinese_lathe/DSCF0005s.JPG
Just try and work that one out. :eek:
01-23-2008, 04:06 PM
Now that one looks hard to grip.
The 9x20 HF I have also has a 'half' box, but it is much easier and more usefull.
each gear change giving you double the thread count. (8-14 in 9 steps, with a couple half threads thrown in the mix, change gear gives 16-28, next change gives 32-56, more are possible)
Not sure how it works on the 10", but the levers should at least give a half/double thread/feed so each change gives a decent range of threads.
reading the chart brings up a lot of Hmmms. Looks like one of those that you realy have to play with to figure out it's operations.
I have two other change gear lathes, and the 9x20 is more convenient, IF the threads you need are in the range of the gears you have set up, otherwise it has no real advantage over a change gear lathe.
01-23-2008, 05:05 PM
Thanks for all the info.
I would love to buy a SouthBend 9A for similar money if one comes along. So far I have just seen some C models around.
Is it really that bad to use change gears for everything, like you would on a
01-23-2008, 05:19 PM
Kevin, change gears aren't really that bad. I don't have a gearbox on my Myford, so all threading and fine feeds are via change gears.
Gearboxes are more convenient, but not always more versatile.
The lathe you mentioned and the one I originally had are just a bit more fiddly in the way they do things. If you don't have all the gears necessary for the gear train needed for certain threads you will have to buy more.
01-23-2008, 07:20 PM
Kevin, I've taken a couple of more images from the G0602 manual just for everyones edification.
The first one is of the metric threading change gear and gearbox positions, and the second one is of the turning feed rate settings.
The lathe actually has a pretty good selection of threads, both inch and metric, as well as a decent selection of feed rates.
Let's face it 99% of the time you are going to have the gears for turning installed on the lathe. If you've gone to the trouble of setting up the tooling and lathe for threading, which is a pretty dedicated setup anyway, then surely an extra five minutes of you time will hardly be noticed. All in all, not a big deal.