# I stripped the T-nuts on my PM-1030V compound



## erikmannie (Feb 2, 2020)

I saw this coming because one of these bolts was almost entirely stripped last week; I have always had a habit of overtightening hardware. In machining school, they said "Tight is good. Too tight is f***ed".

Today I was facing some hard steel (ER70S-6, only a .005" DOC) and the freshly sharpened 3/8" HSS facing tool was pushed back by the workpiece. This in turn rotated the AXA toolpost. The toolpost was rigidly mounted to the compound so the entire compound assembly rotated on the cross slide.

There is a circular scuff mark on the (precision ground flat) top of the cross slide where the base of the compound assembly rotated. The compound was oriented as it is in the photos (i.e. perpindicular to the spindle) so the workpiece had maximum leverage in which to exert force on the compound assembly.

I took it all apart, hoping to bypass the compound and mount the toolpost directly to the cross slide. I did not see a way to do that; I would be interested in doing that sometimes because I rarely use the compound.

Anyway, I had already ordered a selection of appropriately sized T slot nuts which are on their way (photo below). My plan is to use Grade 12.9 (metric) bolts to use in place of the aforementioned stripped bolts. I will need to reduce the height of the bolt *head* so that it will fit under the compound upon rotation (one needs to use a cone wrench to tighten these).

Any thoughts about this? Maybe I should use a torque wrench the first time so that I can get a feel for the proper torque spec? I was giving it well over 60 ft. lbs. When I need a torque spec, I just Google the spec for that sized (and material of) hardware. The bolt will be an M8 or M10; I have to wait for my selection of T slot nuts to arrive in order to see if it is an M8 or M10.


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## erikmannie (Feb 2, 2020)

Here is a photo of the T slot nuts I plan on using and a chart for maximum torque for coarse steel bolts:


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## erikmannie (Feb 2, 2020)

The explanation of when the lathe went down is not to be confused with what caused the bolts to strip: they were stripped by myself when I overtightened them earlier in an effort to achieve maximum rigidity.

The point I was trying to make is that a compound assembly held down by stripped bolts is likely to rotate. I do lock the carriage when I face. The .005" DOC on hard steel is typical. I do about .010" on mild steel and .020" on brass.


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## erikmannie (Feb 2, 2020)

Looking at the values on the torque spec chart, I am 100% positive that I abused the factory T bolts.

The local steel yard almost always has Grade 8 or Grade 12.9 hardware in the size that I need.


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## davidpbest (Feb 2, 2020)

Make yourself a solid tool post like I did.  *Look here.*   I rarely have the compound on my lathe now.  The improved rigidity will astound you - especially deep parting operations and improved surface finishes.


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## darkzero (Feb 2, 2020)

Don't feel bad, I did the same on my previous lathe. Not really your fault IMO, the Chinese t-nuts and/or studs are soft. My lathe did not have t-slots like yours but instead of replacing the t-slot studs I converted it to use SHCSs instead of a stud with nuts. So much easier using a hex key instead of a wrench.

When I got my PM1236 one of the first things I did was convert it to use SHCSs instead of a stud with nuts. I quickly got tired of using a wrench cause I was so used to using a hex key. This reminds me, I need to make new t-nuts, keep forgetting.

BTW I think you are over thinking this a bit, no need for a torque wrench. Just get quality hardware & chances are you won't have a problem with it again. There's no need to crank down on those nuts hard. Making them super tight is not going to gain you any rigidity. A good cinch on them is all that's necessary.

If you want to increase rigidity consider making a solid plinth like some people do. It will make a big difference in rigidity over your style compound. Me personally with the stuff I do I didn't want a solid plinth. I use my compound a lot. Good thing about having t-slots on your cross slide is if you decide to make a solid plinth but any time you need to use the compound, you can mount it on the back side of your cross slide & still use it with the spindle in reverse. May be a bit awkward to reach though.


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## mikey (Feb 2, 2020)

I agree with you that you probably over-torqued those nuts but was it necessary? If the compound is not seated well on the cross slide or if the parts of the compound are not machined for a good fit then things can move, even with a lot of torque on the nuts. If you had to crank down because things slipped in use then its time to evaluate fits because it should not take a lot of torque to lock down the compound. The wrench for mine is 3" long and mine has never moved, even with 0.100" depths of cut in steel.

I would third the plinth idea.


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## erikmannie (Feb 3, 2020)

davidpbest said:


> Make yourself a solid tool post like I did.  *Look here.*   I rarely have the compound on my lathe now.  The improved rigidity will astound you - especially deep parting operations and improved surface finishes.



I looked at your Flickr page. That seems like a good project to have a thread on; what material is that made of? I’m surprised that people don’t offer these for sale as an aftermarket add on. DIY would be fun, though; I have a mill.


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## ttabbal (Feb 3, 2020)

Well worth the effort. My plinth almost never comes off. Just if I want to cut a taper with the compound. PM1127.


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## erikmannie (Feb 3, 2020)

darkzero said:


> Don't feel bad, I did the same on my previous lathe. Not really your fault IMO, the Chinese t-nuts and/or studs are soft. My lathe did not have t-slots like yours but instead of replacing the t-slot studs I converted it to use SHCSs instead of a stud with nuts. So much easier using a hex key instead of a wrench.
> 
> When I got my PM1236 one of the first things I did was convert it to use SHCSs instead of a stud with nuts. I quickly got tired of using a wrench cause I was so used to using a hex key. This reminds me, I need to make new t-nuts, keep forgetting.
> 
> ...



I have never heard of an SHCS; I will Google it. It looks like what happened to me is a common occurrence. I don’t imagine that I am exceeding the capability of this small import lathe by cutting steel. I also plan to cut Grade 5 titanium, so we’ll see if this benchtop 10” can handle it.


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## erikmannie (Feb 3, 2020)

mikey said:


> I agree with you that you probably over-torqued those nuts but was it necessary? If the compound is not seated well on the cross slide or if the parts of the compound are not machined for a good fit then things can move, even with a lot of torque on the nuts. If you had to crank down because things slipped in use then its time to evaluate fits because it should not take a lot of torque to lock down the compound. The wrench for mine is 3" long and mine has never moved, even with 0.100" depths of cut in steel.
> 
> I would third the plinth idea.



What brand and size of machine do you have to be taking .100” cuts in steel? Our instructor in school did that on a Bridgeport, but he told us not to exceed .030” on the large domestic machines. Of course, when he wasn’t looking I cut .040” out of curiosity and impatience.

I just saw the word plinth for the first time in my life yesterday, and it was on this forum. It would appear that a plinth is a rigid spacer that is used to mount a tool post without a compound slide. I have a cross slide DRO, but it appears to not involve the compound at all.


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## darkzero (Feb 3, 2020)

erikmannie said:


> I have never heard of an SHCS; I will Google it. It looks like what happened to me is a common occurrence. I don’t imagine that I am exceeding the capability of this small import lathe by cutting steel. I also plan to cut Grade 5 titanium, so we’ll see if this benchtop 10” can handle it.



Sorry, SHCS is socket head cap screw, a hex socket screw. So instead of using a bulky open end or box end wrench I simply use a long hex key with a stubby short end.

You should be able to machine Ti 6-4 just fine. I machine Ti often and did even on my old 8x mini lathe. Drilling is what sucks the most. Keep an eye on heat & cutter sharpness. Use flood coolant if you have it. And keep caution not to ignite chips on fire. I caught my current lathe on fire once by a stupid mistake. Wasn't bad & only cosmetic damage that I was able to fix but quickly reminded me not to get careless. Can't put out Ti fires with a normal fire extinguisher.


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## erikmannie (Feb 3, 2020)

ttabbal said:


> Well worth the effort. My plinth almost never comes off. Just if I want to cut a taper with the compound. PM1127.
> 
> 
> View attachment 312480



Well, now I am taking to asking everybody what material was used for their plinth.


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## erikmannie (Feb 3, 2020)

darkzero said:


> Sorry, SHCS is socket head cap screw, a hex socket screw. So instead of using a bulky open end or box end wrench I simply use a long hex key with a stubby short end.
> 
> You should be able to machine Ti 6-4 just fine. I machine Ti often and did even on my old 8x mini lathe. Drilling is what sucks the most. Keep an eye on heat & cutter sharpness. Use flood coolant if you have it. And keep caution not ignite chips on fire. I caught my current lathe on fire once by a stupid mistake. Wasn't bad & only cosmetic damage that I was able to fix but quickly reminded me not to get careless. Can't put out Ti fires with a normal fire extinguisher.



It would appear to me that the way my compound mount is set up, I would not be able to get a hex key in there for most of the angles. I can’t even use a box end wrench—I use a 14mm cone wrench. Looking at your photos, you have a circular channel underneath your compound assembly so you always have access to the top of the SHCSs.


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## ttabbal (Feb 3, 2020)

erikmannie said:


> What brand and size of machine do you have to be taking .100” cuts in steel? Our instructor in school did that on a Bridgeport, but he told us not to exceed .030” on the large domestic machines. Of course, when he wasn’t looking I cut .040” out of curiosity and impatience.
> 
> I just saw the word plinth for the first time in my life yesterday, and it was on this forum. It would appear that a plinth is a rigid spacer that is used to mount a tool post without a compound slide. I have a cross slide DRO, but it appears to not involve the compound at all.




I can cut 0.100" on my PM1127. Not really difficult on the machine unless the steel is really hard. This is 12L14 3/4" bar in 2 steps to 0.030". Very sharp HSS tool. 

I have some unknownium that's stupid hard and requires good carbide to cut it. I think I got to 0.080 before things got a bit hot.


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## darkzero (Feb 3, 2020)

erikmannie said:


> It would appear to me that the way my compound mount is set up, I would not be able to get a hex key in there for most of the angles. I can’t even use a box end wrench—I use a 14mm cone wrench. Of course, if I used a plinth, there would be no angles.



Ah yes, I forgot that your style compound would swivel & cover the compound nuts instead of the entire base swiveling as one unit.


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## mikey (Feb 3, 2020)

erikmannie said:


> What brand and size of machine do you have to be taking .100” cuts in steel?
> 
> I just saw the word plinth for the first time in my life yesterday, and it was on this forum. It would appear that a plinth is a rigid spacer that is used to mount a tool post without a compound slide. I have a cross slide DRO, but it appears to not involve the compound at all.



I have an Emco Super 11 CD, an Austrian 11 X 24 lathe. It is made to a DIN tool room standard, has zero spindle run out, 2 HP motor and can take that 0.100" in steel, 0.200" in aluminum with HSS tools. I can go deeper but I have to slow down a bit to do it. It will also take micro-cuts in the tenths. Nice lathe and definitely not in the same class as an Asian machine. Stefan on Youtube has an older model of the lathe I have.


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## ttabbal (Feb 3, 2020)

erikmannie said:


> Well, now I am taking to asking everybody what material was used for their plinth.



The base is 7075 aluminum. The plate on the top is ground steel I don't have a spec for. It looks like a low carbon steel of some kind. Precision ground, had a Starrett sticker on the packaging, but the part numbers etc were removed. Post is 12L14, threaded to match the original.


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## mikey (Feb 3, 2020)

ttabbal said:


> I can cut 0.100" on my PM1127. Very sharp HSS tool.



Now that's the trick, isn't it? Try it with carbide.


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## erikmannie (Feb 3, 2020)

mikey said:


> I have an Emco Super 11 CD, an Austrian 11 X 24 lathe. It is made to a DIN tool room standard, has zero spindle run out, 2 HP motor and can take that 0.100" in steel, 0.200" in aluminum with HSS tools. I can go deeper but I have to slow down a bit to do it. It will also take micro-cuts in the tenths. Nice lathe and definitely not in the same class as an Asian machine. Stefan on Youtube has an older model of the lathe I have.



I was jealous of that machine even before I saw that it had zero spindle run out. I am saving up for a MUCH larger PM machine. I hope to one day have a machine where I don’t have to change out the gears to cut different thread pitches.

What I am going to do here is try the Grade 12.9 bolts. If I see any more movement, I will make a plinth. If I want to cut a taper or threads, I guess I will have to temporariliy remove the plinth.

Looking at the size of it, I would imagine that a plinth would have to be mostly aluminum If one is to remove it from time to time.


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## erikmannie (Feb 3, 2020)

A little off topic, but I don’t have a whole lot of time to read for most of the year (because of working at my job and in the garage). It took me a whole month to get through the manual for my lathe.

I am going out of state to go to welding school here pretty soon, and I am taking the Machinery’s Handbook with me. For two months, I will have over 40 hours a week to spend reading it, which is a good thing because you know how many pages it has!

It has been a little challenging working on my machines without having been through that book too much. For example, I am almost entirely shooting in the dark with regard to speeds and feeds.


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## mikey (Feb 3, 2020)

erikmannie said:


> What I am going to do here is try the Grade 12.9 bolts. If I see any more movement, I will make a plinth. If I want to cut a taper or threads, I guess I will have to temporariliy remove the plinth.
> 
> Looking at the size of it, I would imagine that a plinth would have to be mostly aluminum If one is to remove it from time to time.



Personally, I would assess the fits of your compound on the cross slide with some Prussian Blue to make sure it has good contact. It does NOT make sense that it requires so much torque to lock it down; something is off. I would solve this first instead of using stronger bolts so you can crank down harder, Erik. Once you resolve the issue, then make a plinth. You can use the plinth for most work and then replace it with the compound for taper turning or threading. You can leave the plinth in place and feed straight in for threading if you prefer; it works pretty well, too.

Most plinths I have seen are made from cast iron or steel. Most of those are made in such a way that the tool post is fixed solidly; these guys mostly use carbide tooling.

I have a plinth half-way made and will complete it if I ever find the time. It is a solid block of aluminum very similar to the one @ttabbal made and also surfaced with a tool steel top plate. I use HSS tools mostly and even when I use brazed or inserted carbide tools I usually don't use them at the angles they were intended to be used in so my tool post has to be easily turned. I think aluminum is fine for a plinth, despite the difference in the modulus of elasticity between it and steel or cast iron. I just don't have enough power or rigidity to require a ferrous metal plinth.


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## 7milesup (Feb 3, 2020)

This is a super interesting thread.  The depth of knowledge on here is incredible.

Erik....  One book that I have is Tabletop Machining by Joe Martin.  It is geared towards the Sherline benchtop tools, but it is a very interesting read.  I am assuming that you are taking a computer with (laptop, etc).  I think that almost more information can be gleaned from YouTube videos and forums than books.  Sad to say in way.   Don't get me wrong, books are awesome and I am a prolific reader, but a video connects how the pieces go together sometimes.  This old Tony, NYC CNC, Oxtoolco, MrPete222, Clickspring and Abom79 are just a few of the great YouTube channels.


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## ttabbal (Feb 3, 2020)

erikmannie said:


> I am saving up for a MUCH larger PM machine. I hope to one day have a machine where I don’t have to change out the gears to cut different thread pitches.



I don't bother with the compound for threading. It works fine for me. I might end up with an extra pass or two, but no big deal. 

For gears, there's always this option as well..  










						Electronic Lead Screw
					

I'm going to attempt to adapt clough42's ELS to my PM1127. I figure I might as well do it publicly in case it ends up being useful for someone else. I have most of the parts now, and have the electronics and servo running on the bench. The first thing I decided to mess with is the rotary...




					www.hobby-machinist.com


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## francist (Feb 3, 2020)

erikmannie said:


> It would appear that a plinth is a rigid spacer that is used to mount a tool post without a compound slide.


In the context here, yes, although it has much older uses primarily in architecture and components of columns

*Definition of plinth*

1a*: *the lowest member of a base *: *SUBBASE
b*: *a block upon which the moldings of an architrave or trim are stopped at the bottom
2*: *a usually square block serving as a basebroadly *: *any of various bases or lower parts
3*: *a course of stones forming a continuous foundation or base course


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## erikmannie (Feb 3, 2020)

Because I am always striving for rigidity, I have a strong interest in building a plinth.

This is the first that I’ve heard of threading without the use of a compound; I find this to be really great news.

I would add Blondihacks to the recommended YouTube channels for machining. I watch and listen to YouTube videos a great deal. I download them on my phone and listen to them while I drive. Sometimes I wonder why I pay to go to school when there is so much exceedingly high quality material on YouTube.

I find this forum to be tremendously responsive and helpful. I appreciate the responses.


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## markba633csi (Feb 3, 2020)

I have seen this before- the fit is bad between the compound and the slide:
That's one reason you needed to torque the bolts so tight
The factory really should fix that
-Mark


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## erikmannie (Feb 3, 2020)

It seems to me that I caused this by abusing the factory T bolts. I have had the lathe for five weeks and used it quite a lot. As I recall, it functioned properly before I overtightened the bolts. We shall find out in a few days here when I properly install fresh hardware.

In my experience, I am rough on my tools and machines. I really should care for my equipment better. My Miller welders, however, have withstood my rough treatment so far.


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## erikmannie (Feb 3, 2020)

markba633csi said:


> I have seen this before- the fit is bad between the compound and the slide:
> That's one reason you needed to torque the bolts so tight
> The factory really should fix that
> -Mark
> View attachment 312502


One should note that the nuts are not tightened in all of the photos above, this due to the fact that the bolts are very stripped out.


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## erikmannie (Feb 3, 2020)

I noticed that an M10 bolt is too large to pass through the compound mounting base.

The steel yard only had Grade 10.9, so I will be using Grade 10.9 M8X15 bolts threaded into an M8 T slot nut.

Earlier, I tried a 7/16” T slot nut and it was too large to fit into the T slot on the cross slide. These T slot nuts use 3/8” threads so Grade 8 bolts are readily available.

I am anxious to see if an M8 T slot nut will fit in the T slot of the cross slide. If it doesn’t, I will go back to the 7/16” T slot nut, mill it down to size, and use a 3/8” Grade 8 bolt.


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## macardoso (Feb 3, 2020)

It looks like the compound is only making contact on a small ring vs. the entire bottom surface. This will greatly reduce the holding strength. Can we get a picture of the bottom of the compound?


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## erikmannie (Feb 3, 2020)

macardoso said:


> It looks like the compound is only making contact on a small ring vs. the entire bottom surface. This will greatly reduce the holding strength. Can we get a picture of the bottom of the compound?


You bet. As you can see, you would only want the circular bottom to touch the top of the cross slide. If the plate (or "bezel") that clamps down the circular base were to contact the top of the cross slide, the compound would be free to move.

As one can imagine, the angle of the compound is changed by loosening the T-nut hardware in order to allow the compound to rotate. Once in the desired position, the operator tightens the hardware so as to clamp the circular base firmly to the top of the cross slide.


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## erikmannie (Feb 3, 2020)

Here is the assembly with the plate clamping down the compound. I am waiting on 8mm T slot nuts.


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## erikmannie (Feb 3, 2020)

One possibilty is that I tightened the nuts so much that the clamping plate _did_ contact the top of the cross slide. This would have the effect of _introducing additional clamping surface area _(on both top and bottom), thereby reducing the amount of clamping pressure in the area where it is intended to be. After all, there is only so much clamping pressure provided by the two bolts.

I don't believe that there is anything to be gained by the clamping plate coming in contact with the (top of the) cross slide.


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## T Bredehoft (Feb 3, 2020)

My 10-30 has the same compound mounting system as  yours. I thought about SHCS and T nuts, but can't see how I'd tighten them with a shallow angle on the compound.  My solution will be to open the hoes to .378 or so, and make screws similar to the originals from ETD150. I have some .920 in diameter, long enough to make two.  I'll find some hard 3/8 24 nuts and shorten them so they fit.


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## erikmannie (Feb 3, 2020)

T Bredehoft said:


> ...screws similar to the originals from ETD150. I have some .920 in diameter...


Do you mean .920" in length?

I could not find a picture of these in Google image. Can you post a picture, please?

I also thought about opening up those holes for either an M10 or 3/8" bolt.

The 3/8" studs commonly used for T slot nuts are 16 tpi. As you know, 16 tpi is coarse and 24 tpi is fine, both of which are easily sourced in Grade 8.

I wonder if fine threads would provide an advantage over coarse in this application.


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## macardoso (Feb 4, 2020)

Weird... I've never seen that system. I would consider taking apart the compound assembly and make sure the surfaces are clean of oil. This will probably help increase your clamping.


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## erikmannie (Feb 4, 2020)

macardoso said:


> Weird... I've never seen that system. I would consider taking apart the compound assembly and make sure the surfaces are clean of oil. This will probably help increase your clamping.



In fact, there was a layer of way oil on both surfaces when this occurred. You would think I was trying to lubricate it. Of course, I was just trying to prevent pitting.

Another way to avoid the issue would be to make sure that I had a sharp cutting tool, shallow cuts, cutting fluid (certainly for steel) and proper feeds and speeds.


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## pdentrem (Feb 4, 2020)

Rough up the two surfaces after making sure there is full contact. Bead or sand blast like surface will help.
Pierre


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## mattthemuppet2 (Feb 4, 2020)

looks like a 9x20 style 4 bolt mod would be a good idea. Probably find some plans on Steve Bedair's website.


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## T Bredehoft (Feb 4, 2020)

Do you mean .920" in length?

The stock I have is .920 diameter.  Just long enough to make two studs from. I'll cut it town to .875 and cut flats on teh sides to fit the T Slots.


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## erikmannie (Feb 5, 2020)

The eBay seller that sold me the T slot nuts lied about their location. They said they were in Los Angeles (I am just outside of San Francisco), but it turns out these T slot nuts are being shipped from China.


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## mikey (Feb 5, 2020)

Please tell me you weren't surprised ...


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## darkzero (Feb 5, 2020)

erikmannie said:


> The eBay seller that sold me the T slot nuts lied about their location. They said they were in Los Angeles (I am just outside of San Francisco), but it turns out these T slot nuts are being shipped from China.



I'd cancel if you can.

The few times I have purchased new T-nuts, I purchased them from Mcmaster. Good quality, hardened, available in pretty much any size you need, imperial or metric thread, fully or partial threaded, and they get delivered the next day. They sell quality studs too. I only buy them when I want hardened ones. Otherwise I just make my own (I have never tried hardening stuff myself yet). Not worth the time to buy China ones IMO.

I just got home from a trip Mcmaster, haha. Not to buy T-nuts though.


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## erikmannie (Feb 5, 2020)

darkzero said:


> I'd cancel if you can.
> 
> The few times I have purchased new T-nuts, I purchased them from Mcmaster. Good quality, hardened, available in pretty much any size you need, imperial or metric thread, fully or partial threaded, and they get delivered the next day. I only buy them when I want hardened ones. Otherwise I just make my own (I have never tried hardening stuff myself yet). Not worth the time to buy China ones IMO.
> 
> I just got home from a trip Mcmaster, haha. Not to buy T-nuts though.



I should have bought them from McMaster Carr. I can’t now; I am broke because I just bought six Starrett micrometers.


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## erikmannie (Feb 5, 2020)

Here is what I believe to be my backing plate and the Grizzly lathe dogs. The fasteners were inside the box with the backing plate.


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## darkzero (Feb 5, 2020)

erikmannie said:


> I should have bought them from McMaster Carr. I can’t now; I am broke because I just bought six Starrett micrometers.



That's what happens when you hang around here. You need to stay away if you don't want to be broke. But it's too late, we've already got you!  

I've had/still have plenty of other expensive hobbies but this one is by far the worst for my wallet. I'm pretty much good now on tooling & stuff and have no more room but yet I keep buying more stuff!


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## erikmannie (Feb 5, 2020)

darkzero said:


> That's what happens when you hang around here. You need to stay away if you don't want to be broke. But it's too late, we've already got you!
> 
> I've had/still have plenty of other expensive hobbies but this one is by far the worst for my wallet. I'm pretty much good now on tooling & stuff and have no more room but yet I keep buying more stuff!



I have spent over $10,000 for equipment PLUS $2000 for tuition in the last six months. Worth every penny! I plan to enjoy this stuff for the next 40 years.

I am out of room, though!


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## ttabbal (Feb 5, 2020)

If you have a mill, t-nuts are super easy to make. It can be done on the lathe as well, but you need a way to mount a tool...  

I believe littlemachineshop.com is in CA. They always ship quickly when I order from them and they have a good selection of t-nuts.


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## erikmannie (Feb 10, 2020)

So I spent about 10 hours today on my machine tools today, mostly the lathe. The Chinese T slot nuts that fit were M8. The T slot nuts were too tall, so I had to mill them down .040".

M8 X 20 Grade 10.9 bolts torqued to 41.3 Nm resulted in NO problems in a solid 9 hours of lathe work, mostly on mild steel. It is easy for me to tell if the compound has rotated because the compound is set to exactly 30 degrees. It never moved.

I used a torque wrench at the perpindicular angle (where there is room for a 13mm socket). When I rotated the compound to 30 degrees (where I like to keep it), I used a 13mm open end wrench and kept track of how much I loosened it (so that I could maintain the 41.3 Nm torque). Loosening these bolts 90 degrees allows one to rotate the compound. I made sure to tighten it 90 degrees after I set my compound angle--easy!

41.3 Nm is pretty tight, but not crazy gorilla tight.


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## darkzero (Feb 10, 2020)

erikmannie said:


> torqued to 41.3 Nm



Nm? What's that? Is that Nano Monkeys? Oh, wait, that's metric right? I'm in the US, we use shoe sizes but for the compound I use GG. 2 GGs to be exact. Gorilla Grunts.... 2 grunts is good enough for me.


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## erikmannie (Feb 10, 2020)

darkzero said:


> Nm? What's that? Is that Nano Monkeys? Oh, wait, that's metric right? I'm in the US, we use shoe sizes but for the compound I use GG. 2 GGs to be exact. Gorilla Grunts.... 2 grunts is good enough for me.



When I set up my shop, the very first 2 tools that I bought were the large and small Park Tool torque wrenches. I have always been one to overtighten the fasteners. I lack finesse!


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## darkzero (Feb 10, 2020)

erikmannie said:


> When I set up my shop, the very first 2 tools that I bought were the large and small Park Tool torque wrenches. I have always been one to overtighten the fasteners. I lack finesse!



I see. I have never thought to use a torque wrench on any of my machine tools. I really only used my torque wrenches when I worked as an auto mechanic and on my own vehicles.

Not bad practice though if you tend to overtighten fasteners.


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## mikey (Feb 10, 2020)

I have to ask - why the need to overtighten anything? Precision machined surfaces typically do not require excessive amounts of torque. In fact, too much torque often distorts things. Why are you doing this?


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## erikmannie (Feb 14, 2020)

mikey said:


> I have to ask - why the need to overtighten anything? Precision machined surfaces typically do not require excessive amounts of torque. In fact, too much torque often distorts things. Why are you doing this?



Most vehicles that I have worked on travel at high speeds, and I am afraid that a fastener could vibrate loose and cause injury or death.

A good mechanic knows not to overtighten a fastener. A hack mechanic will tighten it, and then tighten it extra to “make extra sure that it is tight enough”. I want to be a good mechanic, but I need a torque wrench to keep me reined in.

When I went to bicycle mechanic school (UBI), they said that most people need to use a torque wrench in order to get the torque within spec. Of course, many people think that they can obtain the proper torque spec without the use of a torque wrench. I have no doubt that a lot of people can do this; I am not one of them.


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## erikmannie (Feb 14, 2020)

I have used this lathe to cut mild steel for at least 22 hours since I installed the new fasteners, and the compound hasn’t moved one iota; I can tell because I set it at exactly 30°. I am really happy about this.

Out of the 4 welders and 2 machine tools that I have, the lathe is far and away my favorite machine.


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