# 9X20 Chuck



## Zeb123 (Apr 23, 2019)

When I bought my lathe, all I got was the 4" 3 jaw chuck with on set of jaws. I am thinking of buying a 4 jaw independent jaw chuck. Would a 6" be too big? The manual says that a 71/4" 4 jaw chuck came with the lathe but I cannot seem to find one on line. Also any suggestions on brands would be nice as I am a noob.
Thanks


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## mikey (Apr 23, 2019)

Zeb, a rough rule of thumb is to use a chuck about half the swing of the lathe. A 4 - 5" chuck would be about right. A big chuck doesn't give you much more capacity and it weighs more.


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## Ulma Doctor (Apr 23, 2019)

another problem with a big chuck on a relatively small swing, 
the stick out of the jaws when turning sizable work and trying to grip the od of the part.
if the jaws stick out too far, there is potential for collision with the ways


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## stioc (Apr 23, 2019)

This is the 9x20 lathe I have which also came with a 4-jaw 7-1/4" chuck - and it works great:
https://www.grizzly.com/products/Grizzly-9-x-19-Bench-Lathe/G4000 

If you look at the part nos in the back of the manual you can order almost any part for it right from Grizzly.


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## mikey (Apr 24, 2019)

Here is something from Logan Actuator on their Logan lathes: http://www.lathe.com/faq/#_Toc95180284

*What is the right size chuck for this lathe?*
2.13..      Logan supplied a 5” 3-jaw chuck and a 6” 4-jaw chuck for their 10” lathes.  Logan supplied a 6” 3-jaw chuck and a 6” 4-jaw chuck for their 11” lathes.  Larger chucks were available, but they are impractical on these lathes because the jaws would hit the bed when the chucks were opened.  Larger chucks are also heavier, so they put a strain on the spindle and spindle bearings.  In general, use the smallest possible *quality* chuck for the job.

Your choice, of course, but I use a 6", 3 jaw and a 6.5", 4 jaw on my Emco 11" lathe. I can use the jaws up to their safe maximum extension without hitting anything.


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## darkzero (Apr 24, 2019)

Aside from the jaws hitting the bed ways (what good is a chuck if you can't use it with the jaws opened up all the way), I like having my primary chuck smaller. Spins up & down fast, less weight to lug around.

Seems like the norm is to have a scroll chuck smaller than the 4 jaw. Of course this depends on the work you do. Lathes these days usually come with a 3 jaw one size smaller than the 4-jaw, except when you get into a certain size lathe & both chucks are the same size.

My 12x36 came with a 6.25" 3-jaw & an 8" 4-jaw. I felt these sizes were perfect for my lathe. So when I replaced them I stuck with 6.25" 6-jaw & 3-jaw and for my 4 jaw I also got 8" again but I went with a direct mount. That eliminated the additional weight & stick out from the adapter like on my original 4-jaw.

I primarily use my scroll chucks. I break out the 4-jaw when I need to hold something larger or of course when I need the independent jaws. I vote for the larger 4-jaw as long as the jaws clear but if I primarily used a 4-jaw and didn't need the extra capacity I would have choosen the smaller size.


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## mikey (Apr 24, 2019)

Actually, I think if I owned a 12" lathe I would go with an 8", 4 jaw, too. That 1" of additional swing makes a big difference in jaw clearance. For a 9" lathe, I would personally limit my chuck to 5" or so. As @Ulma Doctor said, you really can't use much more capacity without something hitting.


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## darkzero (Apr 24, 2019)

Yup, although I really didn't want a 10" because of the weight I think I recall checking to see if a 10" would fit my lathe with the jaws fully extended. 8" is perfect for my lathe for a 4-jaw. No way I would buy a chuck where the jaws wouldn't clear the ways. Not clearing the cross slide on the other hand I don't care as much.

When I had an 8x14 I put a 5" chuck on it mainly cause the chuck had a big through hole & helped me chuck up larger diameters that I couldn't pass through the spindle. That was bordeline too big for that lathe but it was fine for the most part. I've seen people put 6.25" chucks on those 8x14s.


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## Aaron_W (Apr 24, 2019)

Zeb123 said:


> Also any suggestions on brands would be nice as I am a noob.
> Thanks



I've bought quite a bit from Little Machine Shop. It is mostly no name import stuff but everything I've bought has been decent quality with good quality control (none of the customary Chinese sand and flypaper glue lubricant) and their prices are pretty reasonable. 

They cater to the owners of smaller machines up to about 10-11" lathes and medium size mills.

https://littlemachineshop.com/default.php


If you get into name brand chucks like Bison you can easily spend as much as that lathe costs new.


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## C-Bag (Apr 24, 2019)

My used 9x20 came with a 4" 3jaw, 5" 3jaw and a 6 1/2" 4jaw. I've just been trying to use the 4jaw and it is tricky to use because of clearance. 99% of the time the 5" 3jaw is what's in use for me. I'll bet a 5" 4jaw would be less scary for clearance.


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## C-Bag (Apr 24, 2019)

Ulma Doctor said:


> another problem with a big chuck on a relatively small swing,
> the stick out of the jaws when turning sizable work and trying to grip the od of the part.
> if the jaws stick out too far, there is potential for collision with the ways


While I've had first hand experience NOW with the clearance prob, as a noob my instinct was to think there's more ridgitiy with more chuck contact and not extending the jaws too far. I see spare jaws on CL and eBay but don't know the details of what works with what. Please don't laugh as there are giant holes in my limited knowledge being a piecemeal YouTube schooled wannabe, but would it be possible to get a spare set of 4jaws and carefully cut off the lowest step of the outside grabbing jaw to give you more clearance?


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## stioc (Apr 24, 2019)

All very valid points about the weight and interference. I always manually spin the chucks after mounting up the stock. Having said that my 9x20 can swing 8.75" without interference so with the 7.25" 4-jaw that came with it I have 1.5" of clearance or .75" of its jaws extending past the chuck. I don't use my 4 jaw 7.25" chuck all that much but when I've had to hold rectangle stock and such I don't ever remember having any interference issues but I sure appreciated having the capacity to hold larger stock. 

As for the weight, I'll check it when I get home but I think the 4-jaws are not as heavy as the scroll 3-jaws of the same size? But it's heavier than the 4" 3-jaw. As an aside a 5" 3-jaw scroll chuck is a popular upgrade for the 9x20s.

OP, perhaps more importantly make sure the spindle thread TPI matches the chuck you buy or make sure you have the right backing plate to mount a flat back 4-jaw chuck.


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## mikey (Apr 24, 2019)

C-Bag said:


> ... would it be possible to get a spare set of 4jaws and carefully cut off the lowest step of the outside grabbing jaw to give you more clearance?



Sure, you could do that but I wouldn't recommend it. The reason is because the chuck is designed to safely hold a work piece with a certain amount of thread engagement by the adjuster and contact between the sides of the jaws and the jaw guides. Reducing this contact may can lead to distortion of the jaws when clamping force is applied and the work piece can fly out of the chuck. 

Best idea is to get a larger chuck and if you cannot do that, then get a bigger lathe or come up with an alternative way to safely clamp the work piece.


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## f350ca (Apr 24, 2019)

Exactly what Mickey just said, so with that in mind why not go for the largest 4 jaw the lathe can spin. You'll hold the same work as a smaller one without the jaws sticking out.
My 16 x 80 Summit came from the factory with a 15 inch 4 jaw.


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## Bi11Hudson (Apr 24, 2019)

There are several variables involved in chuck size. Particularly with a 4 jaw. I have 2 lathes, a 9x19 and a 12x36. I am fortunate that both have the same spindle thread, 1-1/2x8. The issue here is that anything I acquire must (nominally) be usable on both machines. 

The 4 jaw that comes with many 9x20s looks like a face plate with woodworking jaws attached. 






True, it was large enough to use on both machines, but about useless for holding serious metal work. Grizzly part number *H8048. *I wasn't real impressed with it. A far more useful one would be Item# H7605, for a much smaller machine. Only a 3", but at a reasonable price and much more useful. I bought a 6" 4 jaw chuck, a real metalworking chuck, that is usable on both machines. Small enough to be usable on the 9x19 yet large enough for the 12x36. But expensive, even as used.

In addition, I have a 4" and a 5" 3 Jaw and a 5" 4 jaw *scroll* chuck, self centering. Useful for what I use it for but not viable as a second chuck. There are some others, but for smaller work requiring absolute closure. Those are not really relevant in this discussion. Grizzly has a number of 4 jaw metal working chucks, but they also are right proud of them. I would say lay back and take your time to find one at a reasonable price that fits your machine. 

The big issues to consider are "will it or can be made to" fit the machine and the maximum *outside* size. As in can the machine swing it?  The rest of the concerns will be the _monkey on your back_.

Bill Hudson​


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## savarin (Apr 24, 2019)

Stuck a 5" 4 jaw on my 9x20. 
Fully extended the jaws do not reach the bed but can hit the cross slide on some jobs.
Dont ask me how I know.
All in all I am very pleased with the 4 jaw but would not go larger.


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## hman (Apr 25, 2019)

+1 on Bill Hudson's description of the "original" 4-jaw POS.

I bought a 6 1/2" 4-jaw chuck for my 9x20, and was pretty satisfied with it.  The photo below shows all the chucks I had for the lathe.  The original 4-jaw is at the lower right, the new one at the upper left.  Also in the picture are the original 4" 3-jaw chuck and the 6 1/4" (reversible jaw) one I bought for larger work. 

I've since sold the lathe.  No complaints from the new owner, with whom I'm still in contact.


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## savarin (Apr 25, 2019)

I can relate to the original 4 jaw as being total crap. Mine broke, was replaced, jaws were either too loose or too tight, no happy medium.


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## stioc (Apr 25, 2019)

hman said:


> +1 on Bill Hudson's description of the "original" 4-jaw POS.
> 
> I bought a 6 1/2" 4-jaw chuck for my 9x20, and was pretty satisfied with it.  The photo below shows all the chucks I had for the lathe.  The original 4-jaw is at the lower right, the new one at the upper left.  Also in the picture are the original 4" 3-jaw chuck and the 6 1/4" (reversible jaw) one I bought for larger work.
> 
> ...



hman, yep that's the 7" 4 jaw I have too, and I agree it's a cheapo chuck. What brand of 3 and 4 jaw chucks did you get? were they a direct fit on the 9x20's spindle?

Also what lathe did you upgrade to and why? I ask because I've been thinking about getting a 12x at some point in the future. Not necessarily because of the work envelope but for rigidity so I can take heavier cuts than .010-.020" (aluminum with carbide insert cutters) at a time. If the bits aren't super sharp the stock tends to gal and/or jump out of the chuck with heavier cuts.


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## mikey (Apr 25, 2019)

If your lathe can't take more than 0.020" deep cuts in aluminum then you need a better tool, not a bigger lathe. My opinion, anyway.


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## stioc (Apr 25, 2019)

mikey said:


> If your lathe can't take more than 0.020" deep cuts in aluminum then you need a better tool, not a bigger lathe. My opinion, anyway.



You may be right @mikey , it feels like the tools rub if I try to go with heavier cuts. The AXA toolpost I got from LMS extends the original center stud using a hollow shaft that's threaded internally and externally on the two ends. I think that hollow shaft causes some of the flex.

I'll try to find some garage time soon and give the little 9x20 a good tune up and see what can be improved.


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## mikey (Apr 25, 2019)

Hmm, maybe make a new stud? Your lathe is definitely capable of far more than you're getting. It is patterned after the Emco Compact 8 and I personally know that lathe can easily take a 0.070" deep cut in aluminum on the radius (0.140" reduction on the diameter) with the right tool. My Sherline lathe will take the same cut in aluminum and will take 0.050" cuts in mild steel. Your lathe should be able to do much better than my Sherline, right?

I am referring to HSS tools, of course, and I suspect that your lathe will perform much better with HSS tools vs carbide. You might consider switching tooling and see how that works for you.


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## hman (Apr 25, 2019)

stioc said:


> hman, yep that's the 7" 4 jaw I have too, and I agree it's a cheapo chuck. What brand of 3 and 4 jaw chucks did you get? were they a direct fit on the 9x20's spindle?
> 
> Also what lathe did you upgrade to and why? I ask because I've been thinking about getting a 12x at some point in the future. Not necessarily because of the work envelope but for rigidity so I can take heavier cuts than .010-.020" (aluminum with carbide insert cutters) at a time. If the bits aren't super sharp the stock tends to gal and/or jump out of the chuck with heavier cuts.


I bought both of the larger chucks from Enco back in 2014.  The chucks had "plain" backs.  Bought backplates from LMS and machined them to fit the chucks.

I used to divide my time between Oregon and Arizona, had machines in both shops.  A Grizzly 12x14 lathe in Oregon and the Grizzly 9x20 in Tempe, AZ.  We sold both houses late in 2017/early 2018 and combined into a new house and shop in Chandler, AZ.  I decided I didn't need both lathes, so I sold the 9x20.


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## C-Bag (Apr 25, 2019)

mikey said:


> Hmm, maybe make a new stud? Your lathe is definitely capable of far more than you're getting. It is patterned after the Emco Compact 8 and I personally know that lathe can easily take a 0.070" deep cut in aluminum on the radius (0.140" reduction on the diameter) with the right tool. My Sherline lathe will take the same cut in aluminum and will take 0.050" cuts in mild steel. Your lathe should be able to do much better than my Sherline, right?
> 
> I am referring to HSS tools, of course, and I suspect that your lathe will perform much better with HSS tools vs carbide. You might consider switching tooling and see how that works for you.



There are just so many details to the 9x20 it's hard to come up with hard and fast rules as I think because of the lack of QC they can have different problems. Mine was bought used by a guy who liked the idea of the machine being a hobby in and of itself. There was a lot of stuff with the machine one being a big binder of the different websites on the 9x20 and all the different mod's. It's thick! 

So one of the many things I chased was chatter when trying to take a decent cut in steel. The first thing I got from LMS was the heavy duty 4 bolt compound mount. That helped. Part of it was the sloppy way the compound was. It was not machined even close so it was really hard to get it where the dovetails were not floppy no matter how tight I got the gibs. I did a minor scraping on it and it was much better. 

But I started noticing chatter again and it turned out that pivot bolt for the QCTP (which was solid, I guess he made) didn't want to really tighten good. I realized the pivot bolt under pressure pulled up on the top of the compound causing it to "dome" up under the middle of the QCTP making it not sit flat on the top of the compound. Took the QCTP off and machined a relief of about .020" off the bottom around the hole for the pivot bolt so the QCTP now sat flat on the compound. 

So with each tweek it got better and better being able to take .060"+ cuts in steel no problem once I got the right configuration HHS tool bits. Then I tried to do a part which had gotten to be no big deal finally until this one. I just bulled ahead and things were not right after that. I decided to change the spindle bearings and that has revealed another kettle of fish. I just got done fitting the new back bearing to slide properly so the preload could be set properly which it seems is impossible the way it comes from the factory. Hopefully this will at least get me back where I was pre part chatter catastrophe.


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## mikey (Apr 25, 2019)

Good points, C-Bag. One assumes the lathe is workable as is but as you pointed out, this is not always the case. 

My good friend owns an Emco Compact 8 and that lathe is amazing for such a small lathe. It was built to a tool room DIN standard, or so Emco says. That sucker took a 0.060" cut in 304 stainless with no problem, which impressed the heck out of me. No hint of chatter or strain with that cut, either. We then took a 0.070" cut in 6061, then shaved 0.0005" off the diameter. 

I tend to forget that although the 9X lathes are clones of the Emco lathe, they are not built to the same standards. Thanks for reminding me.


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## stioc (Apr 26, 2019)

Do you guys use HSS over carbide for any particular reason? because carbide inserts are just so much more convenient.

I'll admit part of the issue is user error too. I have so many hobbies that by the time I come around to using the lathe for a project I forget the basics sometimes (same thing happens with my other hobbies too). See my previous comment was based on a couple of projects I had recently done and was less than impressed with the lathe. Well last night I checked and I noticed the spindle speed was set to 400 RPM which was probably fine for whatever I previously did but the recent projects were aluminum and I only use carbide insert tools so 400 was way too slow for that combination. I probably should've been around 1000 RPM minimum. The machine will do 2000 RPM but I usually don't run it that high because the gears sound noisy and frankly I don't want something to come flying at me at that speed. Even at 1k RPM I usually stand off the to side just in case.

I also built a beefy four bolt compound mount for my 9x20 (using my CNC mill) but I didn't notice a big difference to be honest. I think part of the reason I also want a 12x36 lathe is because they are just better built, require much less fiddling and improving so you spend more time making projects on the lathe than for the lathe. Like the hand wheels etc are so smooth and just feel higher quality.

Don't get me wrong the 9x20 is a fantastic lathe for the price (it's the little guy of the bigger lathes, doesn't feel like a toy) and it's all I can fit in my garage/budget for now but I do dream of *upgrading* when/if I have more room. In the meantime I'll be giving my 9x20 some nice cleaning, lubing, adjusting and spending time tightening the nut behind the lathe.


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## C-Bag (Apr 26, 2019)

The whole clone thing is insidious and it seems a misnomer. I rarely ever see an Emco but tons of Enco. There are so many different tags on the 9x, HF, Jet, Grizzley, Busy Bee etc. and each one would have you believe there is a difference. Some would have you believe their QC is better and others get the rejects but I'm not sure that's true and it's not more about chance that all the details align and you get a good one. They have to justify the huge price difference. Now it seems the 9x is going away as almost nobody carries it anymore.


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## stioc (Apr 26, 2019)

Look what I just found in the manual...I guess I wasn't too far off in my .020" cuts? Alum alloys says rough feed rate should be between .015" to .030". It'll probably do more especially with carbide but this is what they recommend.


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## mikey (Apr 27, 2019)

stioc said:


> Do you guys use HSS over carbide for any particular reason? because carbide inserts are just so much more convenient.



HSS is cheaper, sharper and can be ground to cut with much lower cutting forces vs a carbide insert. A good HSS tool will allow a small lathe to cut like a bigger one, and it will also take micro-cuts that and insert cannot make. I've been using HSS, brazed carbide and inserted carbide tooling for over 30 years and there is no question in my mind that for most applications on a small lathe, HSS is usually the better choice. Like I pointed out before, my little Sherline lathe will easily outperform your 9" lathe with the right tool. It isn't the lathe; its the tool that makes that possible. The only thing about HSS tools, good ones anyway, is that you have to learn to grind them. For all the benefits they provide, I would encourage you to do so.



stioc said:


> ... Well last night I checked and I noticed the spindle speed was set to 400 RPM which was probably fine for whatever I previously did but the recent projects were aluminum and I only use carbide insert tools so 400 was way too slow for that combination. I probably should've been around 1000 RPM minimum. The machine will do 2000 RPM but I usually don't run it that high because the gears sound noisy and frankly I don't want something to come flying at me at that speed. Even at 1k RPM I usually stand off the to side just in case.



I turn aluminum at 2200 rpm all the time, with both HSS and carbide. Higher speeds reduce cutting forces, regardless of the tool type so chuck the work up tight and have at it. Your lathe is capable of far more than you might think.[/QUOTE]


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## mikey (Apr 27, 2019)

C-Bag said:


> The whole clone thing is insidious and it seems a misnomer. I rarely ever see an Emco but tons of Enco. There are so many different tags on the 9x, HF, Jet, Grizzley, Busy Bee etc. and each one would have you believe there is a difference. Some would have you believe their QC is better and others get the rejects but I'm not sure that's true and it's not more about chance that all the details align and you get a good one. They have to justify the huge price difference. Now it seems the 9x is going away as almost nobody carries it anymore.



I suspect that what happened is that the Chinese cloned the Emco Compact 8 after Emco split off their smaller lathes division, which was taken over by Profi Heim. The Compact 8 is still made by the Chinese but it is called a Compact 8E. They are NOT made to a DIN standard like the Compact 8 was, nor are the clones. Trust me; the Compact 8 is a fine lathe built with attention to detail that no asian clone has. I do agree with you that it is really difficult to sort out the better ones from the herd, what with all the marketing hype.


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## mikey (Apr 27, 2019)

stioc said:


> Look what I just found in the manual...I guess I wasn't too far off in my .020" cuts? Alum alloys says rough feed rate should be between .015" to .030". It'll probably do more especially with carbide but this is what they recommend.



Stioc, are we talking about depth of cut when we refer to the 0.020" cuts or are we discussing speeds and feeds? Your chart refers to cutting speeds and feeds. It lists, for example, a cutting speed of 200 SFM for aluminum when roughing and 300 SFM for finishing. It cuts finishing feeds to 1/3 that used for roughing, which is fine. What this says is that for a 1" diameter piece of 6061, you would rough at 200 X 3.82 / 1 = 764 rpm and 300 X 3.82 / 1 = 1146 rpm to finish. You would feed at whatever your gearing dictates. This has nothing to do with the DOC you use, right?


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## stioc (Apr 28, 2019)

mikey said:


> Stioc, are we talking about depth of cut when we refer to the 0.020" cuts or are we discussing speeds and feeds? Your chart refers to cutting speeds and feeds. It lists, for example, a cutting speed of 200 SFM for aluminum when roughing and 300 SFM for finishing. It cuts finishing feeds to 1/3 that used for roughing, which is fine. What this says is that for a 1" diameter piece of 6061, you would rough at 200 X 3.82 / 1 = 764 rpm and 300 X 3.82 / 1 = 1146 rpm to finish. You would feed at whatever your gearing dictates. This has nothing to do with the DOC you use, right?


You're right! I meant DOC initially but didn't realize the chart was for feed rate.


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## stioc (Apr 29, 2019)

OK spent the weekend cleaning the lathe and looking things over to see why I haven't been able to take deeper cuts and I think I've found the problem (more on that below). I also put the 4-jaw chuck on and got this round stock dialed to .001" after about 10mins of fiddling. However, if I moved the dial indicator down the length it would show more like a .010" out of concentric.




OK so looks like the problem has always been that I can't seem to tighten the tool post down well. If I take a deeper cut the whole toolpost rotates. I've been working around it by just taking shallow cuts never thinking about how to fix that. The reason why I can't tighten the LMS QCTP is that the tool post stud that came with the lathe doesn't seem to have a locating pin nor splines nor any other kind of a stop https://www.grizzly.com/parts/Grizzly-TOOL-POST-STUD/P4000908 so as I tighten the toolpost nut down it starts to spin the whole stud. Upon doing research it seems the older versions of the 9x20s came with bottom of the stud splined. Not anymore 

To fix this I'm thinking of cutting a flat slot across the bottom of the toolpost stud and a matching slot on the compound body underneath then welding a section of a drill bit into the slot on the stud to sort of make a T. That will prevent the stud from turning once the drill bit section finds the  matching slot in the compound body. Never welded a hardened drill bit before but should weld like any other steel with mig?


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## mikey (Apr 29, 2019)

Okay, that is a problem. Rather than burying this issue at the bottom of this thread where the 9X20 guys can't see it, why not start a new thread and label it to draw their attention? You'll get a better response and then we can see what the other 9X guys did to deal with this issue.


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## stioc (Apr 29, 2019)

mikey said:


> Okay, that is a problem. Rather than burying this issue at the bottom of this thread where the 9X20 guys can't see it, why not start a new thread and label it to draw their attention? You'll get a better response and then we can see what the other 9X guys did to deal with this issue.



Yeah good idea, I'll do that. Thanks.


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