Moding / upgrading my JET Mini

Take a look at the bearings on the spindle and compare them to those supplied on bigger machines which are designed for the loads you'd like to turn. Then look at the headstock, tailstock, and banjo castings and see how much extra strength and rigidity have been built into them. Consider the banjo and tailstock locks -- how much stress are they able to absorb?

The project sounds like fun but I personally don't think it makes much sense. I'd rather see you build a bowl lathe from scratch with a proper spindle, some big bearings and such.

Bill

Moshe Eshel wrote:

. > > I will still be limited by motor power, but I can at least turn nice, > wide platters.... And later I can always upgrade only the motor... > > What do you think, is there something I missed here? maybe the exiting > bearings cant take the loads? has anybody done this before? >

Hi Moshe, You have a fine mini lathe. Don't ruin it by trying to convert it to a maxi lathe. Then it will be neither a good mini nor an adequate maxi. There are hundreds of these Jets in use. Your idea isn't crazy, but with respect, it isn't feasible. If so, I'm sure someone would have tried this successfully before you.

Turn to Safety, Arch Fortiter

. > > I will still be limited by motor power, but I can at least turn nice, > wide platters.... And later I can always upgrade only the motor... > > What do you think, is there something I missed here? maybe the exiting > bearings cant take the loads? has anybody done this before? >

============================= Moshe,

You can upgrade your existing lathe using Standard Jet parts by buying their bed extension. While this won't give you the ability to do platters, you can at least do longer spindle work than at present. Then you could look at the feasibility of putting risers unsder the head and tailstock. Google RCW archives, using "Spy in Hawaii", "lathe", and "riser" as search criteria. A few years back, Spy put 4 inch risers in his Harbor Freight Jet 1236 clone. That gave him a 20 inch swing, but he was still limited by the existing motor and bearings. Not ideal, but it will give you some insight on expanding. Hope it helps.

Ken Moon Webberville, TX.

Hi Moshe

We have a turner in our wood turning group that has a General International mini lathe, similar to your Jet, and he went ahead and put 4" risers under his head and tail stock,made from laminated wood blocks, and it is just no good, the small bearings and the short spacing between the bearings are the weak point in all those mini lathes, as is the high minimum speed, trying to turn larger platters give you so much movement at the outside edge that it shatters at all times, and the underpowered motor wants to stall if you try to cut the least aggressive , also the link belt would not work on the standard mini lathe pulleys, but you might be able to get the micro V-belt in the right length.

Moshe like Arch said you have a pretty good mini, and I say don't screw it up.

Keep on turning and keep on wishing/dreaming then you have something to work towards.

Have fun and take care Leo Van Der Loo

Moshe Eshel wrote:

. > > I will still be limited by motor power, but I can at least turn nice, > wide platters.... And later I can always upgrade only the motor... > > What do you think, is there something I missed here? maybe the exiting > bearings cant take the loads? has anybody done this before? >

I think you'll regret changing the mini... it's been refined over the years to do a great job with the 1/4 hp and small bearings that it has, but it's NOT built for heavier pieces of stock or more side pressure, IMHO...

What you might try is removing the head stock and reversing it on the bed for out board turning.. this would also involve taking the lower pulley off the motor and reversing it, also... not sure it would be worth the trouble and possible damage to the motor and bearings..

It does sound like you have some of the components for building a new lathe though... I like Leo's idea of a bowl lathe... pretty much a motor and headstock mounted on a bench... You could use your scrap metal for mounting brackets, free standing tool rest, etc.

Mac

Thank you all for your help on this question! I found your input very informative, and you managed to convince me that it would not be a good idea.

My original idea wasn't to turn the Mini into a VB36 :-) I know the bearings can't stand more load, they strain even now with the heavier stuff. I was planing on enlarging capacity mainly for avoiding the obvious discomforts of a small lathe (say you want to turn a small platter your starting blank should be less than 10" in diameter - it comes out to be a mini platter).

My changed plan (back to the original) is to build a nice stand for the lathe, and maybe stock up on metal for future projects, problem is my SWMBO who doesn't mind me buying things, minds very much about what she calls garbage piles - mind you, very usefull and not even close to junk status :-). I know where the person lives so it won't be a problem to get more (as long as his house building business continues)

BTW you can see some pictures of my new house and my new daughter here:

Thanks again, for the caring as well as the help, I hope things will turn to the better around here soon, though it is hard to believe that it will happen fast. Moshe

Nice home, nicer daughter.... enjoy both..

From my experience, you're going to have a little less shop time and a lot of dad time for the next few years.. *g*

Thanks for sharing!

Mac

Hi Moshe

Thanks for the pic's It's nice to have a face with a name. And yes you have a few good reasons for living, beautiful.

Have fun and take care Leo Van Der Loo

Moshe Eshel wrote:

if you have time and no money, use the Soren Berger technique of building your bowl lathe out of old engine blocks - very cheap, and quite stable and heavy duty - don't butcher your jet lathe, you won't like the end result

. > > I will still be limited by motor power, but I can at least turn nice, > wide platters.... And later I can always upgrade only the motor... > > What do you think, is there something I missed here? maybe the exiting > bearings cant take the loads? has anybody done this before? >

I've seen Soren's engine-block lathe and think that it was probably not very cheap to put together. It is amazing, though.

Bill

Bill wrote:

. >> >> I will still be limited by motor power, but I can at least turn nice, >> wide platters.... And later I can always upgrade only the motor... >> >> What do you think, is there something I missed here? maybe the exiting >> bearings cant take the loads? has anybody done this before? >>

Moshe, Your beautiful little daughter couldn't be upgraded. Congratulations!

In retrospect however, I may have downgraded your idea. I seem to remember that Fred Holder used an outboard attachment on a comet or a similar size mini. I think he published an article in "More Woodturning" about it.

Anyway it seems feasible and wouldn't mess up your existing lathe. You could probably fabricate one out of the metal. Maybe a toolpost and a separate toolrest also.

If my memory served, I hope Fred or someone will read this and chime in.

Turn to Safety, Arch Fortiter

Agreed!

I'm not sure how you would get that to work on the Jet or Delta mini/midi. The handwheel on the outboard of the headstock acts as a pre-load for the two headstock bearings. One can't remove the handwheel without the spindle coming loose.

warning you to remove any and all rings from your fingers. Called degloving, extended hardware can grab your ring and rip it off your finger. A pic for the strong of stomach:

finished smoothness.

Hi Owen & Leo, I fully agree, and said previously, that the little lathe should be left alone to do what it does so well. However, I think Fred did use some sort of outboard attachment, maybe a commercial one, on his mini lathe and I respect his turning ability. If he did, probably the important difference was VS or at least a low beginning speed.... and using mini blanks on a mini lathe. :) Re your two quite valid objections and as a friendly argument among friends, two possibilities occur to me.

There seems to be enough outboard thread length on the Jet for a thin machined jam nut to serve as both a pre-load and a register for a disc/faceplate type of chuck. I don't know if the Jet outboard threads are RH or LH. Altho it would affect the lathe for resale or warranty, possibly the handwheel itself could be utilized for attaching a glue block, faceplate etc. to it.

I wonder if for face turning with no tailstock support, a modestly greater diameter but thinner outboard blank (plates etc.) would put any more stress on the machine than a lesser diameter but thicker inboard blank (bowls etc.). Maybe the start-up speed could be lowered and smoothly increased with a slipped belt clutch. Moving the control box on a VS model might affect resale/warranty.

Or maybe Moshe should just scrounge two pillow blocks and a spindle and make himself a proper bowl lathe. :)

Turn to Safety, Arch Fortiter

Yep.. the mini is best left alone, IMHO...

I'm constantly amazed at how well the mini works and how much it can get accomplished with only 1/4 hp...

Mac