# Headstock Alignment Factory Provisions.



## opensourcefan (May 22, 2022)

So as a follow up to my 8x16 lathe headstock being out of alignment; I've come to the conclusion that I will need to recut the "V" on the headstock to allow room to move it without lifting up on the bed V. Right now if I shim it there's no room for the side to side movement and it lifts the headstock which in turn requires shimming in the rear to counteract the lift.

If I'm going to do some mods, I'm curious if I can build in a common method that some lathes incorporate for such adjustments. I just don't know what is used or what might fit on a smaller headstock.

I like the idea of putting it on a centering post that I can rotate about with some adjustment screws or something.

Anyone have any photos or ideas of what I can incorporate onto this?


----------



## Susquatch (May 22, 2022)

opensourcefan said:


> So as a follow up to my 8x16 lathe headstock being out of alignment; I've come to the conclusion that I will need to recut the "V" on the headstock to allow room to move it without lifting up on the bed V. Right now if I shim it there's no room for the side to side movement and it lifts the headstock which in turn requires shimming in the rear to counteract the lift.
> 
> If I'm going to do some mods, I'm curious if I can build in a common method that some lathes incorporate for such adjustments. I just don't know what is used or what might fit on a smaller headstock.
> 
> ...



Wow..... Thats a major undertaking that I'm not even sure I would trust.

The three methods I've seen most often are:

1. Shims in the right places
2. Bending the bed or frame with the levelling screws
3. Machining everything as close as possible in the first place (ie no adjustment practical).

If your lathe uses the first or second method, just have at it.

If your lathe uses the third method, which you have led me to believe is the case, I'd either give up and accept its limitations or I'd do a extensive analysis of the structure of the head and bed to see if I could find a way to do a bit of either 1 or 2 or both. Don't neglect the possibility of reverse bending by loosening or tightening existing screws

Can you take some closeup pictures of how the head and bed mate up?


----------



## opensourcefan (May 22, 2022)

How it currently attaches is quite simple so it's not that major really. The front bed V seats into a V channel in the headstock casting. That's it along with four through bolts into tapped holes in the bed. The rear bed way is just a flat mating surface.

Shims is what I am doing but it wasn't designed for it so there's no room for movement. Because it's a V, the only way to move is up while moving to the side. 

Option 3 is what I will try at first of course as this is how it was supposed to be. But I'm not holding out faith as attention to detail when building this thing didn't exist. 

I'm not going to just live with it, I *will* make it better. I'm not convinced that any lathe that suites my meager needs will be free from defects so I may as well tune this thing up. I like the size.


----------



## 140mower (May 22, 2022)

Have you tried running a fine stone over the surfaces and see if there's a small burr or something kicking it out of alignment?


----------



## opensourcefan (May 22, 2022)

140mower said:


> Have you tried running a fine stone over the surfaces and see if there's a small burr or something kicking it out of alignment?


No, Haven't pulled the head completely off yet.


----------



## 140mower (May 22, 2022)

I think I would start there, these offshore machines and attachments are kinda famous for leaving the factory a little rough around the edges. Stone, deburr, clean and reassemble and I suspect that you will be closer....


----------



## Susquatch (May 22, 2022)

opensourcefan said:


> Shims is what I am doing but it wasn't designed for it so there's no room for movement. Because it's a V, the only way to move is up while moving to the side.



Assuming I understand you, the head sits on the bed just like a tailstock does but without the ability to slide back and forth because it is bolted down.

If so, then the shim could be used like a saddle over the V thus imparting no side thrust - just vertical. It would also require a thicker shim on the flat to maintain even side-to-side lift. Or if you also need twist, perhaps deliberately different lifts.

Edit - I agree with what others added while I was writing my post. A light stoning is appropriate. Wouldn't that be nice to find a high spot that could be just stoned away?


----------



## opensourcefan (May 22, 2022)

Yep and yep. That is what led me into trying something else since that will be a lot of shimming leaving little contact with the ways unless the shims are full length. 

Thinking maybe an adjustable V grove in the headstock. 

Really just curious what options lathe manufacturers have used. I haven't been around enough to know, can't really find much documentation on headstock attachment out there.


----------



## Susquatch (May 22, 2022)

And one more add - don't forget to look at the head ways too. Lots of places for a burr or a tiny piece of metal (or other stuff) to hide.


----------



## Susquatch (May 22, 2022)

opensourcefan said:


> Yep and yep. That is what led me into trying something else since that will be a lot of shimming leaving little contact with the ways unless the shims are full length.
> 
> Thinking maybe an adjustable V grove in the headstock.
> 
> Really just curious what options lathe manufacturers have used. I haven't been around enough to know, can't really find much documentation on headstock attachment out there.



Can you remind me how much it is out and in which direction? You prolly said that already but I couldn't find it with a quick scan whereas you prolly have it burned into your brain.

A full length shim will tilt the head forward toward you or backward away from you but won't change its nod.


----------



## Susquatch (May 22, 2022)

opensourcefan said:


> Really just curious what options lathe manufacturers have used. I haven't been around enough to know, can't really find much documentation on headstock attachment out there.



Here is a quick summary of what I have seen:

Head bolted to the left side of the bed - what I have. 

Most common is Head sitting on the ways (prolly what you have). 

Head bolted down to a flat section beside the bed. 

Bottom half of head cast integral with the bed. 

One piece lower half head with the bed bolted to that. 

Prolly lots of other ways to do it, but that is what I have seen.


----------



## opensourcefan (May 23, 2022)

Susquatch said:


> Can you remind me how much it is out and in which direction? You prolly said that already but I couldn't find it with a quick scan whereas you prolly have it burned into your brain.
> 
> A full length shim will tilt the head forward toward you or backward away from you but won't change its nod.


It's approximately .005" over 3" in length. The end of a bar is closer to the operator. I've placed .004" of shims on the inside of the V way forcing it to twist away from the operator. That required 0.002" of shimming in the rear to bring it back to level.

It's about .002" runout now over 4" still towards the operator, however level is bang on.

If I was to use a full length shim it would need to be tapered.

I appreciate all the methods you provided, thank you.


----------



## Susquatch (May 23, 2022)

opensourcefan said:


> It's approximately .005" over 3" in length. The end of a bar is closer to the operator. I've placed .004" of shims on the inside of the V way forcing it to twist away from the operator. That required 0.002" of shimming in the rear to bring it back to level.
> 
> It's about .002" runout now over 4" still towards the operator, however level is bang on.
> 
> ...



Wow, 3am...... And I thought I was bad for that kind of thing!

Good morning to you when you read this!

I'm impressed with your results. You have managed to eliminate more than half the misalignment.

In so doing, I assume you have ascertained how much, where, does what. I also assume that your tie down bolts are tight when you do your measurements.

And of course, I assume you didn't find anything wrong with any of the ways. That's really too bad. I had really high hopes that a burr or a wayward chip at the factory was the source of all your problems. When @140mower suggested that possibility, my mind latched on to it. It just seemed so obvious that this is what happened. 5 thou over 3 inches is a LOT!

Since it is now level, but still pointing inward, it sounds like you will have to shim it in pairs from now on to avoid changing level - one at the front of the V-way on the left and the same size on the rear of the V-way on the right. The good news is that you won't be further stressing the head casting that much in doing so. I confess that I have been worried about that - again, 5 thou over 3" is a LOT!

But saying that also makes me wonder about your top & bottom gear box casting alignment. Is it possible that the top casting (which holds the spindle) is twisted inward relative to the bottom casting (which sits on the V-Ways)? I hope that isn't the case because they are often pinned to prevent that possibility.


----------



## Rauce (May 23, 2022)

As an extra check you could blue the headstock and see how well its contacts the flat surfaces and the V that it sits on. This would give you an idea of how well it is fitted right now. 

I'm not familiar with any lathes that have features for adjusting headstock alignment after it leaves the factory. What I've seen is some kind of feature that keys the headstock into a fixed alignment with the bed with the alignment set at the factory. 

There are epoxy type products that are specifically designed for this type of application. One would rough mill the female V in the headstock to get clearance for alignment, set it in position and then inject epoxy to fill the space. Release agent would be on the bed so the epoxy bond to the headstock side only.


----------



## Rauce (May 23, 2022)

Here is a link to the application manual from Devitt Machinery in the US. They are a distributor for epoxies used in Machine building and re-building. 



			http://manuals.chudov.com/Moglice-Epoxy-Application-Handbook.pdf
		


For a static alignment application the product I think you want is DWH 310 FL ("has steel fillers and is often used to produce bearing seats, align
ball screws, align columns to beds, locate hardened seats in identical pallets, etc"). If you contact them I'm sure they will discuss your application and guide you through what products you would need.


----------



## Susquatch (May 23, 2022)

Rauce said:


> As an extra check you could blue the headstock and see how well its contacts the flat surfaces and the V that it sits on. This would give you an idea of how well it is fitted right now.
> 
> I'm not familiar with any lathes that have features for adjusting headstock alignment after it leaves the factory. What I've seen is some kind of feature that keys the headstock into a fixed alignment with the bed with the alignment set at the factory.
> 
> There are epoxy type products that are specifically designed for this type of application. One would rough mill the female V in the headstock to get clearance for alignment, set it in position and then inject epoxy to fill the space. Release agent would be on the bed so the epoxy bond to the headstock side only.



The beauty of an epoxy "shim" is that it can be full length so stressing the head casting is not an issue. 

The downside is the challenge of trying to get it right the first time. Not confident that this is within the skill sets of mere mortals like most of us.


----------



## whydontu (May 23, 2022)

I would think the epoxy would be relatively easy to do. Shim to suit, crazy glue the shims to keep them in place, squoosh in epoxy and tighten down the clamp bolts to extrude the excess epoxy. Scrape of the excess, some masking tape to hold the epoxy in place until it cures.


----------



## opensourcefan (May 23, 2022)

Susquatch said:


> I confess that I have been worried about that - again, 5 thou over 3" is a LOT!


Yes, I noticed it when I was trying to make a close tolerance but short part. Brutal, never expected that.


Rauce said:


> There are epoxy type products that are specifically designed for this type of application.


That is a great idea. That's about 99% prep and 1% squeeze. Making sure everything is perfect prior to void filling. I do like the idea of it creating a larger seating surface though.


----------



## opensourcefan (May 23, 2022)

On a side note, how sufficient would 4 bolts mating two flat surfaces be for a headstock? No V seating or anything else, just two surfaces stuck together with 4 bolts in slightly oversized holes holding it together.


----------



## opensourcefan (May 23, 2022)

Susquatch said:


> Wow, 3am...... And I thought I was bad for that kind of thing!


Lol, sorry if I woke you. Good morning to all. My shift working has never coincided with normal people.


----------



## RobinHood (May 23, 2022)

opensourcefan said:


> On a side note, how sufficient would 4 bolts mating two flat surfaces be for a headstock? No V seating or anything else, just two surfaces stuck together with 4 bolts in slightly oversized holes holding it together.


Well, on my 10 hp, 19” swing CMT lathe there are 6 bolts, one pin to swivel about, and an adjusting block at the very left end under the HS holding things in alignment.

I would think on a lathe your size four bolts, a pin and the adjuster should be strong enough to secure the HS to the bed.

My guess is you are thinking of machining the V off the bed and just bolt the HS to it (properly aligned)?


----------



## opensourcefan (May 23, 2022)

RobinHood said:


> Well, on my 10 hp, 19” swing CMT lathe there are 6 bolts, one pin to swivel about, and an adjusting block at the very left end under the HS holding things in alignment.
> 
> I would think on a lathe your size four bolts, a pin and the adjuster should be strong enough to secure the HS to the bed.
> 
> My guess is you are thinking of machining the V off the bed and just bolt the HS to it (properly aligned)?


Thank you.

Yep, my thought was cutting an inch and some off the bottom of the head stock effectively creating a base with the head on top. Adding a rotational pin and an adjustment as you mentioned would also be added. If I slightly enlarge the holes on the base then I should be able to have the space to adjust. Now I haven't done any measuring or anything to see if I have the thickness to pull that plan off.


----------



## 140mower (May 23, 2022)

opensourcefan said:


> Lol, sorry if I woke you. Good morning to all. My shift working has never coincided with normal people.


I'm thinking that if you came here looking for normal people......
 I never did well with shift work, I find it hard enough getting the required rest without messing with my sleep schedule. 
I'm liking the idea of shimming and epoxy that way you can scrape a little bit out of the way at either end if needed for clearance.  I'm glad my old South Bends haven't given me that kind of grief.


----------



## gerritv (May 23, 2022)

opensourcefan said:


> Thank you.
> 
> Yep, my thought was cutting an inch and some off the bottom of the head stock effectively creating a base with the head on top. Adding a rotational pin and an adjustment as you mentioned would also be added. If I slightly enlarge the holes on the base then I should be able to have the space to adjust. Now I haven't done any measuring or anything to see if I have the thickness to pull that plan off.


you'll lose a lot of rigidity that way, it is unlikely there is that much meat on your casting.
The mistake made during manufacture seems to be that the V in the head stock is too close a fit to the V on the bed. If you open up the V in headstock then you get some wiggle room without redesigning the whole thing?

Unless of course you want a swiveling headstock ala Unimat DB200 and Sherline. Then I would take the V off the base and add a pivot.

Gerrit


----------



## Rauce (May 23, 2022)

I would think the v is actually meant to be contact with the headstock. The problem would be that the female V in the headstock is not aligned with the spindle. Presumably the V in the bed is straight along it’s length.


----------



## opensourcefan (May 23, 2022)

Rauce said:


> I would think the v is actually meant to be contact with the headstock. The problem would be that the female V in the headstock is not aligned with the spindle. Presumably the V in the bed is straight along it’s length.


Yep, that's exactly what I think the issue is. The seller stated that they never have this issue, true or not,they don't have a mechanism for adjustment really so I imagine they're relying on the V to seat and align. 

Taking that into account, I'm sure many have seen my machine is very green. However when I look close I can see red in some spots, blue maybe as well if my memory serves. They're doing nothing more that grabbing pre manufactured parts and slapping together a different machine with some added fluff or tweaks.


----------



## Susquatch (May 23, 2022)

opensourcefan said:


> Thank you.
> 
> Yep, my thought was cutting an inch and some off the bottom of the head stock effectively creating a base with the head on top. Adding a rotational pin and an adjustment as you mentioned would also be added. If I slightly enlarge the holes on the base then I should be able to have the space to adjust. Now I haven't done any measuring or anything to see if I have the thickness to pull that plan off.



I'm not on that page. In my view all machines are a compromise of competing goals. If you cut anything off your bed you will sacrifice rigidity and vibration. They are too important to give away in order to achieve an improvement in axial alignment. What good is perfect alignment if you can't cut soft butter...... (gross eggageration of course).

I suspect your bed ways are fine (or at least close enough for all intents and purposes) for the size of your lathe. And assuming there is nothing between the head and the bed that is throwing off the alignment (have you removed the head and looked yet?) then I'd wager that the bottom of the head is prolly good too. It's just too difficult to accept a major flaw like that happened. If there is nothing on the ways, my guess is that the top half of the head is misaligned from the bottom half causing the spindle to point where it shouldn't.

Whether or not that exists, and if it cannot be fixed directly, I would much prefer to shim the ways as you have already done. Just finish the job. You can then go for a full repair with full length epoxy bedding if you want. But I do like what others have said about shimming, bedding, and then finish bedding without the shims.

I doubt very much that you will ever need to do this again. Therefore not much point in trying to design in any future adjustability.

It will be a lathe to love when you are done.


----------



## opensourcefan (May 24, 2022)

Susquatch said:


> If you cut anything off your bed you will sacrifice rigidity and vibration.


That be crazy, I know I'm up to being crazy but I wouldn't do that. I meant cut an inch off the bottom of the headstock casting. Leaving two flat surfaces which one will receive a pin etc. I'd only lose an 1/8" but like I said not sure if it'll be possible.

Edit: oops, it's 3am again...


----------



## Susquatch (May 24, 2022)

opensourcefan said:


> That be crazy, I know I'm up to being crazy but I wouldn't do that. I meant cut an inch off the bottom of the headstock casting. Leaving two flat surfaces which one will receive a pin etc. I'd only lose an 1/8" but like I said not sure if it'll be possible.
> 
> Edit: oops, it's 3am again...



Do you actually sleep? 

I would not cut anything off the bottom of the head either. Same reason. The lathe is only as good as it's weakest link. 

If universal adjustability was that important it would be built into every lathe on the market. 

I think it's only on the bigger ones because it's so difficult to align them any other way and their size makes it easier to get out of alignment. 

Anyway, my point is that once yours is aligned you will prolly never touch it again. Why go to so much trouble to facilitate something you won't ever use again? If it were mine, I'd just align it, and be done with it.


----------



## Darren (May 24, 2022)

I would be asking for a new head casting, or looking into reboring the bearing bores. You will surely have geartrain alignment issues if the spindle is that far out of alignment. Maybe not a huge issue for a hobby lathe, but something to consider if you want it to be right.


----------



## cuslog (May 24, 2022)

Darren said:


> I would be asking for a new head casting, or looking into reboring the bearing bores. You will surely have geartrain alignment issues if the spindle is that far out of alignment. Maybe not a huge issue for a hobby lathe, but something to consider if you want it to be right.


Son worked several years for a major oil field C0., built their own drill rigs etc. They used to buy offshore pumps, blow off preventers etc. Job one was to strip them apart, re-bore all the bores and replace all bearings. Major castings / forgings were what they really bought them for, most of the bores / bearings were wonky in one way or another. Still worked out cheaper than buying North American or Euro.


----------



## opensourcefan (May 24, 2022)

Susquatch said:


> Anyway, my point is that once yours is aligned you will prolly never touch it again. Why go to so much trouble to facilitate something you won't ever use again? If it were mine, I'd just align it, and be done with it.


Yes, I most likely will end up at that after I exhaust all my mental dreams and plans and get to actual work


----------



## PeterT (May 24, 2022)

It would be useful to see some pics of your headstock & underside V-groove as well as the lathe bed footprint it resides on. Or maybe snip of the shop manual if it shows this detail?
I cant visualize a scenario where the HS V-groove is milled straight but the spindle is bored at angle. I mean anything is possible but one would think they have reliable fixturing for this important stuff.

If its 'only' the V-groove that is the culprit, that might not be that onerous of a job. But first things first. I can think of a few things that might assist jigging to ensure alignment success. And epoxy selection is another topic.


----------



## opensourcefan (May 24, 2022)

PeterT said:


> It would be useful to see some pics [snip]











The front third is over top of the gearbox. The 4 bolts go into the bed casting. I don't have any of the underside yet but the first plan is to remove, inspect,clean and inspect again, reassemble, test. If it doesn't magically fix itself then I'm gonna have fun. 

I'm going to install a stepper motor onto some gears so I can remotely turn the head in any direction. Kidding, that was for @Susquatch


----------



## PeterT (May 24, 2022)

So the manual infers 2 Vee slots, at least as drawn on the chuck side. But your picture shows a Vee slot on operator side & rectangular clearance slot on other side? Does that rectangle run right across the headstock? Do you have a pic of the lathe area where HS is bolted to?


----------



## PeterT (May 24, 2022)

If the HS were to be remedially rotated slightly so the spindle was corrected parallel to ways, is there any metal to metal drive train connection to gears below? Or is it just a rubber belt from those up to the spindle? (ie. wondering about secondary misalignment once HS is shifted).


----------



## opensourcefan (May 24, 2022)

PeterT said:


> If the HS were to be remedially rotated slightly so the spindle was corrected parallel to ways, is there any metal to metal drive train connection to gears below? Or is it just a rubber belt from those up to the spindle? (ie. wondering about secondary misalignment once HS is shifted).


Just a belt to the spindle pulley. The gear train is on it's own arm (seen hanging off to the right) which can be rotated and adjusted to suite. No worries after the fact.


----------



## opensourcefan (May 24, 2022)

PeterT said:


> So the manual infers 2 Vee slots, at least as drawn on the chuck side. But your picture shows a Vee slot on operator side & rectangular clearance slot on other side?


Oh the manuals for these lathes can't be trusted. The clearance slot goes all the way, only a single V as a seat. No pic of the bed sans headstock yet.


----------



## PeterT (May 24, 2022)

Is this red stuff some kind of adhesive or just primer poking through?


----------



## opensourcefan (May 24, 2022)

Just the décor from the previously painted stripes on the bed channels before the manufacturer covered over them in their own green.


----------



## Susquatch (May 25, 2022)

Thanks for the photos. Answers many questions in my mind. The main one being that the top half is separate from the bottom half. So it is not rotated VS the bottom - or perhaps it would be better to say that it doesn't matter if it is because the top half is directly sitting on the ways.

I still think it's best to just get on with aligning it.  As @PeterT implied and as others have already mentioned, not all epoxies are born equal. They sell special epoxies just for this application.

For the record, I don't like that red goo coming out of the one V-Way. If some of that is between the bed and the head, it could explain everything. Ie the machine was setup properly, then sent for painting, then reassembled and shipped. But nobody checked for stuff where it doesn't belong.

I repeat what I said before. You have to take the two halves apart and check them thoroughly for dirt, goop, metal chips, and interference. 

I love your stepper idea...  LOL!


----------



## Rauce (May 25, 2022)

Susquatch said:


> You have to take the two halves apart and check them thoroughly for dirt, goop, metal chips, and interference.


Yup, and for good measure blue check it! That will be the final word on how the headstock is contacting the ways.


----------



## PeterT (May 25, 2022)

I guess more data to come, but I'm wondering out loud why the front rectangular slot under HS could not also be similarly backfilled with epoxy same time the altered HS Vee groove has been pasted with something 'thin' like Moglice. The larger rectangular backfill would probably require a more thixotropic, slow cure epoxy blend (upscale version of JB weld). But as-is the clearance slot doesn't appear to be doing much of anything, so grouting it at same time could provide another support register for increased HS rigidity? But OTOH maybe making the joint 'too' permanent has downsides. I've only seen a few videos on Moglice installation, none on removal/rebuilding the alignment. Cant imagine it would be easy to pop off without some planned jacking screws or similar.


----------



## Susquatch (May 25, 2022)

PeterT said:


> I guess more data to come, but I'm wondering out loud why the front rectangular slot under HS could not also be similarly backfilled with epoxy same time the altered HS Vee groove has been pasted with something 'thin' like Moglice. The larger rectangular backfill would probably require a more thixotropic, slow cure epoxy blend (upscale version of JB weld). But as-is the clearance slot doesn't appear to be doing much of anything, so grouting it at same time could provide another support register for increased HS rigidity? But OTOH maybe making the joint 'too' permanent has downsides. I've only seen a few videos on Moglice installation, none on removal/rebuilding the alignment. Cant imagine it would be easy to pop off without some planned jacking screws or similar.



I'll have to re-read the thread. For some reason I had the idea that there was a typical V-way and flat-way Combo on this machine. 

If so, there is no reason that I know of why they can't be used with an appropriate epoxy and release agent such that future separation is not an issue.


----------



## opensourcefan (May 25, 2022)

Susquatch said:


> I'll have to re-read the thread. For some reason I had the idea that there was a typical V-way and flat-way Combo on this machine.


Yes that is correct. Front is V, rear is flat because what might have once been a V has been cut out to clear the rear bed V.


----------

