# Lathe Rigidity Testing (determine upgrade benefits)



## opensourcefan (May 3, 2022)

So... My little 8x16 isn't the stiffest machine around. It came with 10mm indexable tool holders. I've upgraded the tool post to an "A" type Multifix.

Possible plans to increase rigidity:

1. Remove the compound and fix tool post directly to the cross slide (with a solid riser block) until the compound is needed.

2. Increase the size of my cutter holders to 12x12, 16x16. Multifix holders will take 20mm.

3. Bed stiffness modification of some sort. Ya, crazy I know but there's gotta be some bridge building physics that can be applied somewhere.

However, all grandiose plans aside, do you guys have any techniques for testing rigidity in advance of doing all the work? I thought about physically clamping the compound down to see if it'll help at all. As well as temporarily bracing the bed.


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## Dusty (May 3, 2022)

@opensourcefan , for what its worth a couple of positive suggestion that help with machining. A lock on the carriage and the same for your compound slide when in use. My Busy Bee Craftex 10"x18" lathe came with a good carriage lock so I added a lock to the cross slide following Steve Jordan's style found in his video. Check them out here, good luck!


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## Dabbler (May 3, 2022)

@opensourcefan I think you are doing all the right things.  Here's a few thoughts:

If you make a solid tool post, the very next thing is the adjustment on the cross slide gibbs.  If you can get them 'just snug' you will feel less vibration.

I think you won't get much better performance going to larger shank tools.  It will improve, but not very much. I still do a fair amount of work with 1/4" and 3/8" HSS tooling... Better quality tools that are properly heat treated vibrate with less intensity.  That's because properly heat treated tooling is stiffer, due to having higher tensile strength.  You might consider getting a single 'best quality' tool in a size you can use, and compare.

"Dave M" on youtube has 2 of these small lathes in this category and he does great work with them.  It is all too easy to be seduced by the 'bigger lathe syndrome'  (boat owners call it twofootitis)  A bigger lathe won't substitute for skill.

That being said, a lot of my turning is bigger than 2" in diameter, and having bigger lathes makes it easier to get good finishes and take bigger chips.  I like my big machines, but for doing tiny work, they suck.


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## David_R8 (May 3, 2022)

Dabbler said:


> @opensourcefan  You might consider getting a single 'best quality' tool in a size you can use, and compare.


I second this. I have a cheap set of 1/2" shank insert tool holders and import inserts but decided to splurge on a decent tool holder. Drooped some change on a Micro100 SCLCR CCMT 1/2" shank holder and some Iskar inserts. I tried the import inserts in the new holder and the finish is slightly better. The new inserts in the old holders are also slightly better. The combination of the new tool and new inserts is quite remarkable.

Edited to add the tool shank size.


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## Tom Kitta (May 3, 2022)

Dabbler said:


> @opensourcefan I think you are doing all the right things.  Here's a few thoughts:
> 
> If you make a solid tool post, the very next thing is the adjustment on the cross slide gibbs.  If you can get them 'just snug' you will feel less vibration.
> 
> ...



Yeah, if I do not stick out cheap 3/8 insert holders too far they are fine on a lathe with about 4x the mass. I have stuff up to 3/4 if I need it. For boring bars I managed to get 1 1/4 holder on AXA. 

Generally machine struggles to take a cut on say more then 80 thou per side on mild steel bar 2" with feed say 0.004 running at around 500 - 600 rpm. These are standard positive inserts. 

Generally on larger lathe its more of an issue with the cross slide setup (even on the smaller one sometimes) flexing then actual tooling flexing. I.e. on my big lathe with 1" tooling when going with heavy cut with negative insert I can see visually flex in the tool post to cross slide attachment (!) With interrupted cut its terrible - so have to take light passes. 

I do most of my work on the small lathe - main issues are with say limited bore size on smaller lathe or needing to remove a lot of metal quick - luck of power.


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## DPittman (May 3, 2022)

On my little 10x22 lathe I believe most of the flex is in the compound and not so much in the tooling.  However I really like my diamond tool holder and hss inserts on tool holders that normally take carbide inserts.


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## whydontu (May 3, 2022)

About four years ago I replaced the compound on my BB 10x18 with a solid toolpost. The solid post has an eccentric so I can snug the toolbit very close to centre, or far outboard.

I haven’t used the compound since.

Photos of various versions (including mine) are at


Your Active Projects!
Solid Toolpost and Rear Toolpost​


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## Susquatch (May 3, 2022)

@opensourcefan - I second what @Dabbler said. 

But I'd be more emphatic about not bothering with trying to stiffen up the bed of your lathe. It will take HUGE changes for only very minor incremental improvements. 

If you want you can add some weight to dampen vibrations but even that won't change the fact that you have a small lathe. 

Overall, I'd suggest that you celebrate your small lathe for how great it is for small work and don't try and use it like a the big lathe it is not. For big stuff, just take small cuts. For hobbiests like us, there is no rush. The joy is in doing. 

I know lots disagree with me, but I really do believe you will also love the way SHARP HSS cuts on a small lathe. I usually prefer it even on my 14x40.

Btw, Arthur Warner makes small indexable HSS inserts and tooling (including threading tools) so you can have the best of both worlds if you want it. Their bits are razor sharp right out of the box! 



			https://www.arwarnerco.com/default.asp


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## David_R8 (May 3, 2022)

HSS on my 10" South Bend is magic. The only carbide I've found to work well are CCMT with a very small nose radius.


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## gerritv (May 3, 2022)

Solid tool post, tighten up your spindle bearings, sharp HSS tools for the win on small lathes. If you take a look at Tyrally's videos on YT with a Sherline and HSS tools you will be amazed. 




I'm about to grind up some more 8mm diameter HSS for cutting some drill rod  on my 1022 lathe


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## Dusty (May 3, 2022)

David_R8 said:


> I second this. I have a cheap set of insert tool holders and import inserts but decided to splurge on a decent tool holder. Drooped some change on a Micro100 SCLCR CCMT holder and some Iskar inserts. I tried the import inserts in the new holder and the finish is slightly better. The new inserts in the old holders are also slightly better. The combination of the new tool and new inserts is quite remarkable.



You don't mention the size of the CCMT shank used?


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## David_R8 (May 3, 2022)

Dusty said:


> You don't mention the size of the CCMT shank used?


It's a 1/2" shank, same as the import holders. I just edited my original post for clarity.




__





						MICRO 100,SCLCR 0808 F2 MICRO100 INDEX. TOOLHOLDER,1-428-103237,KBC Tools & Machinery
					

MICRO 100,SCLCR 0808 F2 MICRO100 INDEX. TOOLHOLDER,1-428-103237,KBC Tools & Machinery




					www.kbctools.ca


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## opensourcefan (May 3, 2022)

Thanks for all the info fellas!

I already have the HSS inserts ready to go, they're shiny and sharp.
I'm going to add those compound lock screws cause that's super easy. 
I will buy one high end holder and use it as my general go to and see how it is. Where's the best place to buy in Canada?, can't seem to find much north of the 49.
Before I mess with adding more locks though I need to consider a DRO first, will need to work around the scales.


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## Susquatch (May 3, 2022)

opensourcefan said:


> Thanks for all the info fellas!
> 
> I already have the HSS inserts ready to go, they're shiny and sharp.
> I'm going to add those compound lock screws cause that's super easy.
> ...



Good stuff.

Doesn't your lathe already have locks? 

FWIW, I've been holding off of putting a DRO on my lathe. I've used lathes for over 20 years without one and done just fine. I'm not sure the pain is worth it.

But I would put a DRO on my mill again in a heart beat!

I have a number of concerns on the lathe.

1. How to mount a scale on the cross-slide that won't interfere with the tailstock when I'm drilling.

2. How to mount a scale on the bed that won't interfere with a taper attachment.

3. The DRO I have on my mill has a lathe mode. The lathe mode has an automatic calculation for the compound angle setting. Very attractive. But the compound is small. How do I mount a scale on the compound without getting in my own way? I wish they made a teeny tiny scale for that.

Anyway, my point is really that I'd be focussing on my lathe technique and tooling before I worried about installing a DRO.

In my mind, my lathe priority is an upgraded VFD Ready motor so I can get speeds under 70rpm.

But who knows, after I put a DRO on my lathe I might wonder how I lived without it. Which is pretty much how I feel about the DRO on my mill.


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## opensourcefan (May 3, 2022)

@Susquatch 

It's funny you say that because initially I didn't want one (and might not still) because I really wanted to just go manual. That is why I went through the trouble to make this an imperial machine. Maybe I'll just install a dial indicator stop for the time being.


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## chip4charlie (May 3, 2022)

Artisan Makes on Youtube has a 7 x 14 mini lathe. He did a video about a month ago on stiffening his headstock. Not sure if applicable to your 8 x 16, but his videos are quite well done:


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## Dabbler (May 3, 2022)

opensourcefan said:


> Where's the best place to buy in Canada?,


I have a bunch of offshore tool holders, and a bunch of Kinnemetal, some Sandvik, and one or two Seco.  I bought all my holders new, so my local Kinnemetal dealer.  My first tool holder was a king's ransom, but now K tool holders are a lot more reasonably priced (than in 1980)

I'd try my local K dealer frist, then try online.  You could also try ebay.ca, but you need to be sure what you are looking for, and (small) risk of getting fakes.


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## Susquatch (May 3, 2022)

opensourcefan said:


> Maybe I'll just install a dial indicator stop for the time being.



Now that particular improvement I totally endorse. It is on my list of projects. I've looked at a few different versions but I have not actually decided how I want to do it. As soon as I decide, it will become a priority project. 

And while we are on that subject, I also want to make an adjustable one for the quill of my tailstock.


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## Degen (May 3, 2022)

The Logan lathe I just sold I cut 4140 with a 1/2HP motor and carbide tooling.  I used HS tooling where I needed custom cutters.

You need to learn how to grind your own HS tooling, master this and a lot of your problems diminish. Learn feeds and speeds that work best with your machine. Sometimes increase sometimes decrease, what ever gives the best cut and least vibration.


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## Tom Kitta (May 3, 2022)

I would stay away from some more exotic ways to stiffen the lathe. I tried that with a mini mill and it was a waste. If your lathe after some minor changes is not stiff enough, just get a bigger machine.


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## whydontu (May 3, 2022)

Susquatch said:


> Good stuff.
> 
> Doesn't your lathe already have locks?
> 
> ...


So many ideas! Every time I surf CHMW I get sent down a rabbit hole of things to do.

#1 - I have the DRO scale mounted on the tailstock end of the cross slide. It adds about 3/4” of width, so the tailstock can’t get as close to the chuck. <However>, going to the fixed eccentric toolpost means I can swivel the eccentric outboard and move the cross slide right up against the headstock.

#2 - on my BB 10x18, the cross slide extends past the back of the bed. The DRO reader mounting bracket is connected to the base of the cross slide, with the DRO scale mounted underneath the bed rail overhang. I don’t think it would foul a taper attachment.

#3 - I don’t use the compound, so I don’t need a scale. I think the slim glass scales could be fitted to the inner face of a cross slide. It probably wouldn’t interfere with the cross slide use, it would be hanging underneath the tool bit projection.


And now for the new project. My DRO cross slide scale covers up the carriage lock that’s on the tailstock side of the cross slide base. So when I want to stop the cross slide from moving, most of the time I just engage the half nut with the lead screw disconnected from the lead screw gears. It’s not very rigid. But Dusty’s 8:00 AM post showed me a solution. Just fabricate a lock plate, and drill the headstock side of the cross slide base.


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## Susquatch (May 3, 2022)

whydontu said:


> So many ideas! Every time I surf CHMW I get sent down a rabbit hole of things to do.
> 
> #1 - I have the DRO scale mounted on the tailstock end of the cross slide. It adds about 3/4” of width, so the tailstock can’t get as close to the chuck. <However>, going to the fixed eccentric toolpost means I can swivel the eccentric outboard and move the cross slide right up against the headstock.



I think what you saying here is that you eliminate the loss of space by tucking your cross slide under your chuck. It's a good solution but I like my tool post and it would be a pain to remove it whenever I needed to drill something. So I dunno about this solution. 





whydontu said:


> #2 - on my BB 10x18, the cross slide extends past the back of the bed. The DRO reader mounting bracket is connected to the base of the cross slide, with the DRO scale mounted underneath the bed rail overhang. I don’t think it would foul a taper attachment.



That would not work for me. My saddle does not overhang the base. 



whydontu said:


> #3 - I don’t use the compound, so I don’t need a scale. I think the slim glass scales could be fitted to the inner face of a cross slide. It probably wouldn’t interfere with the cross slide use, it would be hanging underneath the tool bit projection.



I'm terrified of hanging a scale right where my work is being done. But ya, that would work.


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## Tom Kitta (May 4, 2022)

Y axis behind cross slide, removes about 20mm or so of drilling capacity. X scale on the back side. Taper attachment would need to be designed to go around this somehow  or scale would need to be very low. 
On smaller lathe you will loose some capability with a DRO install, but DRO adds so much more that it is 100% worth it.


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## gerritv (May 4, 2022)

I think this thread has wandered off topic.

What was/is it that makes you think your lathe is not rigid? Are you hogging .25" cuts and it can't handle it? Are you trying to get a small lathe to behave like a bigger one? Are you upgrading the motor to provide the power to do deeper cuts?

By installing a Type A Multifix, you have added a 48mm lever from the cutter to the toolpost bolt. On a small compound that will add to your problems, not reduce them

A DRO won't help with rigidity

A bigger cutter holder likely won't do much either, esp with the 48mm overhang. Your compound mount to the cross slide will not deal with it. And you will promptly run out of tool height to centre of work.

If you take the time to watch what Tryally does with a Sherline and a 6 or 8mm diameter HSS cutter on a 0XA style tool post you will see that the additional expenses you are incurring are not necessary to get things done. Work with what the lathe can do, use sharp HSS tools

By way of comparison, this is the toolpost that Stefan was using on a 10x22 lathe, your A Type is bigger than that on a considerable smaller lathe.


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## Susquatch (May 4, 2022)

Tom Kitta said:


> removes about 20mm or so of drilling capacity. X scale on the back side.



It isn't the loss of travel that concerns me. I like to bump my tailstock against the saddle as a quasi tailstock stop. It allows me to vastly reduce the amount of cranking on the tailstock Quill between operations. I couldn't do that with a DRO in there. 



gerritv said:


> I think this thread has wandered off topic.



Ya, the DRO is off topic but it was being discussed by the OP as an alternative priority to improving rigidity. I think that makes it ok.


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## 140mower (May 4, 2022)

Susquatch said:


> It isn't the loss of travel that concerns me. I like to bump my tailstock against the saddle as a quasi tailstock stop. It allows me to vastly reduce the amount of cranking on the tailstock Quill between operations. I couldn't do that with a DRO in there.
> 
> 
> 
> Ya, the DRO is off topic but it was being discussed by the OP as an alternative priority to improving rigidity. I think that makes it ok.


While we are still off topic, could you drill and tap a hole in the face of the tailstock base and insert a bolt to act as a stop about a 1/16" before impact with the scales?
 Just a thought, might be like many of my other "good" ideas that don't get past the "cutting room floor"..


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## Dabbler (May 4, 2022)

Susquatch said:


> I couldn't do that with a DRO in there.





140mower said:


> insert a bolt to act as a stop about a 1/16" before impact with the scales?



It is alos common to bolt a shield on your cross slide that is rigid enugh to take the 'bump of the tailstock.  Either way, the tailstock 'bump' can be acomodated.  

-Why I never did this was the loss of drilling depth on my small lathe.  On my larger lathes, this is not a problem - so a DRO may well be in my future...


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## opensourcefan (May 4, 2022)

gerritv said:


> I think this thread has wandered off topic.


I'll be honest with you, I liked it's off topicness more than your post. You are writing from a sour negative point of view. Your comments aren't absolutes and the reality of each has more to be considered. You only offerd one line of neutral advice. Your DRO comment set me off and is indicative of your mindset when writing your post.

Re the Multifix lever, if you want to talk physics I'd be happy to engage, that is my training. The Principal Direction of Force in this situation lowers the 48mm moment that you eluded to.


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## gerritv (May 4, 2022)

How is my post sour? You go on about trying to make a lathe more rigid, and then segue into DRO. If you can't deal with the advice, based on experience with lathes from a Unimat to now a 1022 BTW, then you shouldn't ask.

I hope you enjoy the journey, not sure where it will take you though but I'm sure it will be interesting to follow.


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## opensourcefan (May 4, 2022)

gerritv said:


> How is my post sour? You go on about trying to make a lathe more rigid, and then segue into DRO. If you can't deal with the advice, based on experience with lathes from a Unimat to now a 1022 BTW, then you shouldn't ask.


What advice did you provide? Use a smaller tool post and that a DRO won't help rigidity? Experience is one thing, being able to convey it in a useful manner is another.


gerritv said:


> I hope you enjoy the journey, not sure where it will take you though but I'm sure it will be interesting to follow.


You see, you just can't help it. Such a rude comment and we don't even know each other.


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## Tom Kitta (May 4, 2022)

Dabbler said:


> It is alos common to bolt a shield on your cross slide that is rigid enugh to take the 'bump of the tailstock.  Either way, the tailstock 'bump' can be acomodated.
> 
> -Why I never did this was the loss of drilling depth on my small lathe.  On my larger lathes, this is not a problem - so a DRO may well be in my future...



I have two bolts in there for that purpose. Do not want to slam the tailstock into DRO accidentally and shields are huge and would take like extra 20mm or more.

Actually I just checked and I lost ZERO drilling capacity for drills over around 1/4" . The tailstock tube normally extends over an inch and then there is the chuck body plus drill length. Unless using very short drill such as center drill my tailstock will not bump into bolts protecting DRO before it bumps into the work piece. 

Dabbler, you may do measuring on your lathe as well, use say 3/8 drill bit and see whatever you can touch work with say tailstock tube fully retracted and with say 20mm spare - if yes, DRO for most drills will not have effect on drilling ability.

Besides, how deep do you plan to drill with smaller drills. My tailstock tube extends just over 3". 

DRO would be more of an issue installed this way on large lathe - but on the large lathe there is space elsewhere for it - so no issue.


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## Susquatch (May 4, 2022)

140mower said:


> While we are still off topic, could you drill and tap a hole in the face of the tailstock base and insert a bolt to act as a stop about a 1/16" before impact with the scales?
> Just a thought, might be like many of my other "good" ideas that don't get past the "cutting room floor"..



Actually, I like it. But I'm thinking a bumper on the cross slide might serve the same purpose and protect the scale even better because it can be better located. Only the loss of repeatability would stop me.

I like how one good idea leads to another.


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## Susquatch (May 4, 2022)

Dabbler said:


> It is alos common to bolt a shield on your cross slide that is rigid enugh to take the 'bump of the tailstock.  Either way, the tailstock 'bump' can be acomodated.
> 
> -Why I never did this was the loss of drilling depth on my small lathe.  On my larger lathes, this is not a problem - so a DRO may well be in my future...



I could NEVER put a scale in there without a shield. So I think you may be onto something there. Like the bumper as an off shoot of @140mower 's suggestion, I think that a separate but robust shield is yet another step forward!

Edit - English sucks. By separate I mean not attached to the DRO scale in any way. By robust I mean can handle bumping with the tailstock.


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## Dabbler (May 4, 2022)

Tom Kitta said:


> Dabbler, you may do measuring on your lathe as well,



I like your lateral thinking, but you have missed my point.

The way I work, with the drilling I do, from #40 all the way to 1",  I could find all kind of work-arounds to allow the DRO and shield, bit I choose to have full drilling capacity instead of having a DRO.

Yes I can buy long series drills,  Yes I could buy a longer chuck arbor combination, but to me it just isn't worth it.  I really do not like stick-out, on the work or on the quill.  It increases flexibility (vibration) and magnifies inaccuracies in the lathe chuck or the tailstock chuck.  I keep everything as compact as possible.

On my bigger lathes, well, that is another matter:  longer quill reach, better access to the chuck because of longer overhang on the tailstock.  easy-peasy.

After all, we are talkng about rigidity here as the *primary* focus...


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## whydontu (May 4, 2022)

Being the rule follower that I am, I started a new thread called "Lathe Rigidity Testing Segue To DRO" with photos that demonstrate my solutions to most of the DRO, crosslide, tool post questions raised in this thread. I didn't add anything about rigidity, since my BB B2227L CX708 has one aspect that quite a bit different than most of the smaller lathes - the bed is quite solid, no arches on the front of the bed. Flat cast iron from top to bottom over the full length of the bed. Lots of beefy ribs between the front and back. Fiddly to install because I have to make sure the bench surface is flat everywhere, not just at the mounting points.


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## Dabbler (May 4, 2022)

@whydontu I love your lathe!  it seems very well built...


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## Susquatch (May 4, 2022)

whydontu said:


> Being the rule follower that I am, I started a new thread called "Lathe Rigidity Testing Segue To DRO" with photos that demonstrate my solutions to most of the DRO, crosslide, tool post questions raised in this thread.



What rule? 

See you there!


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