Worn gib clamps on jet 9x20, and looking for other upgrades

[CGT80]

I have a Jet 9x20 belt driven lathe that I am trying to use. It is actually my dad's lathe and was bought used. He had used the carriage lock to take up the play in the carriage. It moves up and down quite a bit with the lock backed off. I took the carriage off the machine and cleaned it up and relubed it. I noticed the two bars that slide on the bottom of the ways are worn a lot.






This is the plate from the back of the carriage. I saw where someone made their own brass plates and I read another thread where someone made angled plates. It appears that the plate only needs to be flat and the wear has caused the raw/silver portion to become stepped (lower) than the side that has the mounting holes.

This lathe is pretty much useless with this much slop.

How should I go about fixing this?

Flip the plates over?

Machine the entire surface flat again on my import bench top mill?

Make or buy brass in the same thickness?

Buy new replacement parts, if they are even available?

Today, I cleaned up the surfaces on the mill with some 0000 steel wool and oil. The ways were nasty and had some rust as well as the carriage and cross slide, and the 8" chuck must not have been oiled so it started to rust with the rain we finally had. I assume the steel wool won't hurt any of the surfaces as the ways are hardened and I read of others using steel wool and oil to clean light rust. It also seems safe for blued gun parts. It did a good job cleaning up the steel, but it isn't new looking. I tried to clean up the bits of steel wool and keep it out of any moving parts. Maybe I will try scotch bright pads next time.

The ways have a few dings on top, but they don't appear worn to the naked eye. I have not put a rule on them yet. I read on this forum that scraping the ways can be quite costly. Hopefully, they are good and only the plates wore.

My dad has always wanted a QCTP for this machine. Now that I have used the machine, I see the use for one. I was thinking of the AXA 100 import set from https://littlemachineshop.com/products/product_view.php?ProductID=2280&category=-419988835 and a mounting adapter stud, and a 4 bolt plate for the compound slide.

Does anyone have input on this QCTP setup for a 9x20 lathe? I think my dad would like the larger steel version over the small aluminum versions that are made for this lathe. I would get the kit with the tool holders.

My brother bought a USA made set of indexable tool holders. They are Rutland tool and supply part number 20358000. The part number comes up on MSC as a $200 set: http://www.mscdirect.com/product/de...&pxno=29536509&refnum=29536509&rItem=78641081

If it is the same set (looks like it), then the inserts are: TT 321
Will these inserts work? https://littlemachineshop.com/products/product_view.php?ProductID=3698&category=-1550042347

The holders are 1/2" square stock and the edge of one side of the triangular cutter is just over half an inch. They are carbide and only one seemed to cut well on the aluminum project I did, which was turning a 1 5/8" piece of 6061. The best finish was when I took a couple thousandths off at a spindle speed of 1,000 rpm. The machine is too unstable to take more than 20 thousandths at a time at 600 rpm. I got some chatter and an ugly finish, but I was just roughing. I did the final few passes at the higher speed.

I understand that HSS is better for hobby work, so I would like to get HSS inserts. The few HSS bars we have are bent (don't know the history of them). I could learn to grind my own, but I really like the indexable set that we have.

We use a good amount of aluminum in our projects and also steel. We use stainless and brass on occasion.

The other items we don't have is a good borring bar and center drills. For the borring bar, I was thinking it would be nice if it used the same triangular insert. We don't have anything for threading either and I am not sure if we need a special tool or one of the tools we already have.

Here is a pic of the tool set we do have:



I have no idea what the tool on the left is, I don't remember if it has any stamping and I have not used it. The inserts are obviously different. It may be one that my dad or brother bought from a used tool supplier we used to go to. Unfortunately it isn't run the same as it used to be. In the past we could buy misc. milling tools by the pound.





Any guidance you could give me would be great. Thanks, Chris.

 

[CGT80]

I forgot one additional item: The spindle has three holes to insert a pin/wrench to take the chuck off the lathe. These holes are elongated and the pin will not stay in. Right now, I have an 8" chuck on there and don't know how I will get it off. What can be done to fix this problem? I thought about drilling the holes to a larger size. It seems there must be a better tool than a single pin to hold the spindle.

 

[JimDawson]

I forgot one additional item: The spindle has three holes to insert a pin/wrench to take the chuck off the lathe. These holes are elongated and the pin will not stay in. Right now, I have an 8" chuck on there and don't know how I will get it off. What can be done to fix this problem? I thought about drilling the holes to a larger size. It seems there must be a better tool than a single pin to hold the spindle.

I think you really need a Pin Spanner that fits your spindle, might be a good project to make one.

 

[CGT80]

That is what I pictured in my mind. My dad and I are working on building a CNC plasma table...................................that would be a great project. I will look around on the internet too. I can cut one by hand with the plasma and add a pin. It seems that design would be less likely to slip out of the hole.

Thank You

 

[chuckorlando]

I use a punch I have that fits the spindle just right. It makes a handle more or less.

I 100% disagree that hss is better for hobby. It is cheaper, allows lower speeds, and can be shaped by hand on a cheap grinder. So it's used alot by hobby opps. But none of that makes it better. I ue carbide that looks about like yours on my 9x and to date .05 of the radi is the most I have pulled off and I was just approaching chatter with carbide.

I'm not recommending you use carbide. But you can if you dont mind paying for them.

Your issues likely have more to do with lack of experience and a lathe that has to much play. If you dont calculate the proper rpm and feed, and minimize all the play in the machine you will kill carbide alot faster.

I have a bostar qctp on mine which cost a little less then what you linked. It works fine for 9x. I dont know about that one linked.

Them inserts look like they would work. You can stone the tops of them to bring back the edge.

I have not made new locks yet. But was informed by Bill G that they need re made. I'm sure he will have some good info for you on that and anything else 9x. He has built a fine fine 9x.

4 bolt clamp is very important. But you dont need to buy that bolt conversion thing. Just drill and tap the hole to fit the proper one that comes with the qctp.

 

[fixit]

Try a piece of large HEX stock in chuck, hold belt pulley with your hand and use IMPAC WRENCH on hex stock
or
Run chuck jaws out about 1.5 inches past edge of chuck and smack one with a soft face hammer while holding drive pulley

fixit

 

[CGT80]

I am fine with using carbide, if I can get good results. Carbide seems more readily available and less expensive than the HSS inserts I have found.


The impact is a great idea. I tried to hold the pulley on the spindle, but no luck. A bunch of small bumps from an impact would be easier to hold on to. Now I remember, my dad and I used an allen wrench when we swapped the chuck last week. It fit the worn holes better.

Looks like we have some work and learning ahead of us.


Hopefully someone will come along who has input on those gibs. They would make a huge difference in the machine, and yes, I was basically finding my cutting speed for the carbide by trial and error, but I couldn't take much of a cut with all that play. I might just try a new carbide insert and a HSS to compare. I was going in 0.010" on the cross slide, so I assume that is radius you referred to (the radius of the piece being turned). My cut was 0.010" but I reduced the diameter of the stock by 0.020". Looks like this lathe work will force me to remember some of the geometry I did in HS and community college.

 

[chuckorlando]

Most of the mods are covered here http://bedair.org/9x20camlock/9x20project.html