Grizzly G4003 12x36 Lathe Depth Stop Widget · Dec 30, 21:55

The 12×36 is a great medium-sized lathe for the home shop. It’s a lathe that can be mounted on a rolling stand or fixed in place. Either way, its size and price make it easy for the home shop machinist to consider when upgrading from the 7×12, 8×12, 9×20 and other smaller lathes.

While the lathe is not quite suitable for production work (not like a Hardinge turret lathe or similar 2nd op lathe), it has the range that to do small, large and long work.

Did you know that the 12×36 (for example, the Grizzly G4002 and G4003 lathe) has a collet closer that’s sold by Grizzly? That’s right, it’s the G4026 sold for $299.95. That’s a pretty decent price indeed. There is, however, one slight problem with the system. It mounts using the existing studs which means that the lever itself is oriented vertically instead of outward towards the operator. Awkard!

Here’s the collet closer from Grizzly. We’ve read reports about fitment issues, but it looks pretty solid.

In our quest to solve the collet closer issue, we realized that until an actual collet closer system was put into place, we could simply use the stock chuck but would need a decent depth-stop of sorts.

Something that mounts to the outboard end of the spindle tube?

While Kalamazoo sells their 5C collet chuck holder (model 1CC) which in essence is a 5C collet holder with mounting holes on the bottom for fixturing as well as a method of using a chuck key to tighten the collet, it’s $300. The advantage to this tool is that you can use this with an existing lathe chuck – no need to change chucks.

Here’s the 1CC 5C collet chuck:

Then there are the Bison and Chinese knock-off 5C chucks which essentially replace the existing lathe chuck (in the G4003 case, the stock chuck is removed and a D1-4 adapter plate is mounted onto which this 5C chuck is mounted). There’s something about replacing chucks that doesn’t seem all that appealing.

Here’s the Bison 5C collet chuck:

The above two methods still use a chuck key, so there’s really no appreciable time-savings. The advantage to them is that you could use a depth-stop for those short production-runs. That being the case, what the G4003 needs is a depth-stop until a proper collet closer can be mounted with its own depth-stop.

What we decided to do was to make a block that screws into the outboard side of the spindle tube into which a rod of some sort (we may go threaded or not) is inserted into the center of that while offering some form of finite adjustment. Since the headstock is rather long at over 12”, we don’t want the rod to bang around inside the tube, so we’ll most likely go with an adapter sleeve that sits nicely between the rod and inner diameter of the tube. That’s the plan for now!

Stay tuned to see some tips on using the G4003 for metric threading (there are some important tips here!) as well as the revealing of the non-standard 42mm x 1.50mm thread of the spindle-tube. Oops! The thread’s been revealed! :)

Well, we’ll show you more about this little project and we’ll be sure to post up a drawing so that you can make your own. This is sure to be a time saver!

Comment

Commenting is closed for this article.