why machining the groove wasn't an option? if i am not mistaken, unless the groove already touches the bottom, your ilustration would be correct, othervise you could simply remove some materials from the sides of the groove and it would fall deeper as e resoult untill it would actually touch the top of the rail, although it could also move side to side, it could have aded bonus of increasing the area of contact

You learned an important lesson that every machinist should know though: The more blue you put, the better the parts fit ;)

Man , you took way too long to post a new video , we missed u .. welcome back

I'm trying to learn to use metal working machines, too. I love having access to people with decades of experience and people as new to these tools as me. When folks like you demonstrate what you're trying, and include all your discoveries, mistakes, and successes it is a huge boon. Being able to observe mistakes I would have also certainly have made, processes I never would have thought of, or even things I know are wrong - it builds my skills and my confidence. If comments by other content creators are anything to go by, youtube can bring a lot of negative feedback. So, for what it's worth, I appreciate you and others who are willing to record, edit, and post content (a significant effort in itself) and put yourselves out there with what you've tried, wherever you are on your learning curves. Thanks!

With the caveat that I've never personally done any scraping - in the scraping videos I've watched (who would have thought my life would come to this?) they've always employed a cross-scraping pattern, whereas you appeared to be going at it from one direction only. A second pass at 90° to the first removes more material, and helps even-out the scraping marks, speeding things up and leading to a flatter surface. Keith Rucker is a master at this stuff.

Holy smokes, I am shocked by how poorly that thing is manufactured. Good on you for getting after it. Great video, and excellent work!

Thanks for bringing us along for the ride, sharing the good and the bad. Content producers like you infuse the rest of us with much needed knowledge without each of us having to learn the hard way.

G'day mate, I'm learning this process too, and one improvement I could suggest is that when you are bluing up the surfaces to scrape, use your indicator to map the top surface and bias your scraping to correct misalignment here. So if the back right corner is sitting low, then scrape more off the front left corner. Continue this effort until the piece is parallel to the bed, perpendicular to the prismatic ways (scraping the prismatic section unevenly will allow you to rotate the piece with respect to the work axis) and stable, then scrape down to an even contact surface. When you get to the saddle, remember the cutting forces will bend the saddle near the apron so it can rock. To counter this, get it perpendicular, parallel, stable and with even contact, then hollow out the middle 1/3 of the saddle prismatic section just a tiny fraction, so when the tool pressure pushes it down, it becomes flat in the middle and stays stable. Thanks for sharing your adventure and look forward to seeing the next video.

Please don't delay in making other videos on UKposts. Your videos are a great inspiration for me. Thanks!

Very much in agreement with going with the carbide scraper. I use carbide paint scraper blades too and for small hobby stuff like this, they are more than good enough. For a first go at it I think you did a great job.

Nice to see you posting again, Al. We missed you. Some nice "pimp my lathe" in this one. A joy to watch.

I found this really inspirational. I really liked to see exactly how difficult this process can be without all the mistakes cut out. Thanks!

Glad to see you back! So much fun to see how you tackle these projects.

I tend to find every wrong way of doing something before finally discovering the best/correct way of doing it but then i know how and why its done the way it is. I also then like to show others the way it should be done and can explain to them why its done a certain way. Thanks for your efforts and time showing us .

First of all, i have to say that all my "knowledge" on scraping also comes from UKposts videos. However i have two remarks. To me it looked like you always scraped in one direction. Typically i see people make two passes at 90 degrees from another. This should help to break up the contact pattern. The second point is the scraper geometry, I remember a video by " An engineers findings" about scraping steel. I think he added a heel to the scraper improved the performance in steel a lot

A couple of tips on scraping: I don't use a roller to spread the blue, I just smear it on with a finger (latex gloves of coarse) - especially for small parts like these prism and dovetail surfaces. First pass is usually too thick but if you rub that off and go again you can usually get a good pattern. Second tip (and this one really makes it easier!): Buy a tube of red artists oil paint. Smear a bit on your workpiece before your do a check with the bluing. Just smear on a bit, then wipe it off with a paper towel until all that is left is just a reddish tinge, then do your pass over the bluing. Those hard-to-see blue spots will pop out in living color!

Gday, as far as I’m aware scraping is an art form and the only way to learn is to have a go, it’s enjoyable to learn new things mate, great job I say, cheers

You asked for tips so 😅 When you're inking the brayer, it seems like you're keeping it in contact with the glass and rolling it back and forth. When you do that, the same place on the roller sees the same thick and thin spots on the glass over and over. If you lift up the brayer between rolls, it should get to a thin even layer much more quickly. Really admire your willingness to go for it on this project! Thanks for posting it

thanks for sharing your journey and adventures

This is so good! Is so rare to see this part of the learning process with such polished and well presented video. im happy I stumbled across this

So glad to see you back with a new video. You have been missed. Thank you for a very informative, interesting and inspirational video. 👏👏👍😎

YES, I was waiting for this for months

Great to see a new video from you. Always enjoyed your mini lathe content

Other youtuber's who show scraping technique seem to recommend a much thinner scraper bar that has more 'flex' in it. One simply made a Sandvik-style scraper using 4mm stock bar. It's a pleasure watching you work.

Always nice to see new content from you. Thank you

I commend you for putting so much time and effort into this lathe. Going to be an expensive mini lathe after you calculate in the hours😮 Then again learning new skills is also very valuable. You might want to check if the top and bottom of the casting are in the same plane, its easy to mess up the planes. Measure, measure and measure. Also try and get that cross hatch pattern.

Great video! I have learned so much watching you work on this import lathe. I have one also and I'm experiencing many of the problem you have shown. Your vids have helped me to know what to check and how to go about fixing the problems with this lathe. Thank you so much.

You are doing great, glad to see you are back. Really enjoy and learn from your videos.

Thank you for this. Lots to do but now it makes sense where to begin.

Always look foward to your videos

Great job mate, really enjoy your videos, therapudic watching you work through and learn as you go. Cheers mate

If you intend to shim the headstock, it might be worth beaing in mind that it doesn't need to slide. Hence it only needs to be solidly bedded and to be aligned with the tailstock. Also, learning from your experience with clamping the shims to the tailstock, you might consider placing the headstock/epoxy/shim package on the ways and using the weight of the headstock to provide the clamping force while the epoxy cures. Or not using epoxy at all..

nice to see you back! 👍

I have found that my lathe is made in a similar way and am looking forward to your project and finding away to correct it. I have used sharpie to blacken a surface and rubbing it to a mating surface rubs off the sharpie. Thanks for sharing.

Great documentation of your learning adventure. Yes it is as simple as removing the high spots and checking. Keep in mind you can speed up the roughing phase by filing sanding honing and grinding, then go to finishing with the scraper. You have already made a huge improvement in the tailstock, the headstock will be less alien to you. Best of all, you have control over your equipment, and your understanding will pay off in the long run, cheers!

Hooray! Thanks for posting again!!!

Oh man we all have to go through the process so you are doing great just keep at it you will get there

As for your statement about a band saw, I used a portaband set in a vertical holder that mounts in vise, I mounted a small plate to act as a table to cut on

My first scraper was a flat file, the ground as mentioned. First scraped a piece of aluminium and I'd recommend it to practice. Even with the alu my scraper went blunt quite fast. Now I bought a Sandvik tip, used for hours and remained sharp, separates visible amount of cast iron

For some reason I have a sweet spot for “improving sub standard mechanical devices”. Your video editing, voice over, approach to the task at hand…in the top tier in my opinion. 👍 About the bench grinder, I would love to see how you made the diamond wheel adapter as well as your approach to some upgraded grinding rests. No pressure 😊 Thanks once more for great content.

Very well made video. Thanks 🙏 learned a lot. I have a 7 x 10 central machinery, mini lathe. Having so much fun. I think I might try some scraping. 😊

Really enjoyed watching that video. Thank you for making it.

excellent work on this. your mistakes really add character to your machine and great content to your video. Keep it up, looking forward to the headstock

Nice video. Will have to do the same to mine someday and daresay have similar experience levels - so thank you very much for sharing your experiences.

Very nice. I enjoyed every minute of it.

Great work by the master👍

Thank you for sharing. Have a great day and stay safe.🙂🙂

So thrilled to see a new video from you🎉🎉🎉. As bad as it is, id be tempted to just make a new one, but fixing it is a good project too.

HI Well Done. I hand scraped the bed of an Atlas Press Company lathe into alignment with a surface plate using much the same methods you are learning to use. The lathe then gave many years of good use where the saddle could not be adjusted at the head stock end without freezing tight at the tail stock end before i did the scraping.

I still have the scrapers made by my father in the 195o's and 60's which he used to scrape bearings and brake drums (dint ask the process but it did not involve a lathe and wont pass health and safety. These were made by grinding off the teeth bach to a smooth surface from old files. I have flat, tapered and half round taper. They hold their edge pretty well still.

Had to scrape mine in the same way. I actually shaped a regular file and used it to scrape with. Amazing how bad off these are. but its like they say, they are truly a kit.

Great video, thanks for sharing. I also had issues with my mini lathe tailstock, which I largely solved by re-making the base. I used your logic, in that if it went horribly wrong, I still had the old base (which would have still been better that none!). Indeed, I STILL have the old base! My replacement has served me well, but I can't drop the old one in the scrap bin -I might need a bit of cast iron at some point 👍 🇬🇧

Yes please, make the video about adapting your grinder for carbide i think that's interesting and would be very helpfull, i already have the carbide paint scrapers in my shopping cart to make some test also and learn to scrape since i'm making the tapered gibs carriage mod. Thanks for the tips very appreciated :)

Lovely to see a video from you drop. If you haven't come across it: The channel "An Engineer's Findings" has a video called "Hand scraping carbon steel: carbide insert geometry" about the difficulties of scraping mild steel vs the usual cast iron used in tools. As I understand it "Turcite" is the material of choice for resurfacing ways, but I imagine mild steel is a lot easier to come by and cheaper for experimenting on. (I'm sure you're aware of Keith Rucker's rebuild of his machine with it). These minelathes seem ideal to see how far you can take it using whatever methods are convenient at hand.

Yep, you should consider anything coming out of China as a kit. Usually about 90% done and requiring a bit of fitting. I have been playing with one of those very cheap X-Y tables, I paid 89 buck for it. I have now scraped and lapped it to the point where it moves smoothly. I also replaced the bearings that drive the axis, going to roller bearings from the lumpy ball ones that it came with. My next video on this will be about how square the two axis are to each other, now that I have it into a condition where it actually moves. I also have one of these mini lathes, it's tail stock was even worse on fitting the ways. I had bought that from Vevor and got them to give me a $200 discount. I then went and bought a new tailstock from "The Little Machine Shop" company for $100 that fits much better. Still, in the end I will be doing the same job that is being done here, refitting or remaking the tailstock and other components.

=O new video~~!! Thanks n_n

Shoutout to the Chinese bloke who messed this up… if it wasn’t for them we wouldn’t have had this excellent video!

What !? A new video from a very small lathe ! I'd be damn ! Welcome back ! Love your videos !

So just listening to your learning process, I think you have a great method for learning new skills. I'm not a machinist. I just watch a lot of youtube videos and am fixing up an old Atlas lathe. So I really don't have much experience, but I think the right fix for this mismatch is to machine the lathe bed. If you could just machine that forward 45 deg angle on the bed, both the tail stock and head stock would set lower, bringing the back flat section into line. It would also move both of them back, get a larger surface area for all contact areas, and it looks like the contact should be moved farther back so there is a larger surface on the flat part of the ways also.

Nice work! It will definitely help me in order to improve my lathe, I have the same model.

I am about to tackle the same problem on my big lathe's tailstock, on which I'm just finishing a major refurbishment, but in my case the remaining height discrepancy between prism and flat way is a tiny fraction of yours. In my case it's remaining after my machining both surfaces to correct the alignment of the barrel bore with the turning axis, and honing the bore -- both of which were spectacularly successful. (I had to build a rigid hone for the purpose, very accurately guided) The Schlesinger toolroom lathe (toughest grade) limit for parallelism (10b) is 0.01mm in 100mm in the horizontal plane (twice that in the vertical), which it was far outside: I've managed to get it down to 0.002mm. I've given a bit of thought to how best to proceed with my height mismatch (a separate issue) -- I've pretty much decided I need to teach myself how to scrape properly -- but I'll ponder yours and see if I can offer anything worthwhile.

My attempt to tailstock issue was to mill deeper v groove. Did the same to the carriage. Still more work to do, but promising.

Great to see another video on the mini lathe. Have you ever watched any of Keith Ruckers videos on scraping.

Thank you for the information. I will use this to repair my lathe, sir. thank you..🇮🇩

I had the same problem and solved it by making my own base for the tailstock. I have not finalized the machining of the shoulders as I have to do something similar for the headstock. and of course the saddle will require something similar. The only thing that will not change is the bed.

scraping is an art in it self, well done... Thanks for taking the time to make the video and share it.... you got a new subscriber.....

Yes the adapter looks very interesting

Two thing's:- (1)As far as cutting or scraping a metal piece of any type of metal goes make sure that the metal of your hand tool/any drill bit is of a harder rigid material than your subject/workpiece. In this detail, carbide work tools, blades, and drill bits are the most preferable and the most bang for your money as they last a long time, and the fewer times you need to make any adjustment to your tools and drill bits the better. But there are times when your workpiece metal/materials are too soft for your carbide tools so, in that case, you have to work with a tool that has a tier higher hardness than your work metal or closest to it for example:- workpiece metal hardness is tier3/4 than your working tool metal hardness needs to be tier4/5 and so on. If I am correct the carbide tools hardness typically is between tier7-10 so you will be good to go on most projects. (2)Widening the groove in the x-axis and make sure it's all the way through the whole length of the groove in the y-axis while leaving the depth in the z-axis the same as you could have used your blue ink you have applied it on the face of the groove & sliding place piece while having them aligned with each other and having them clamped in the right spot and getting an ink impression on a thick paper or cardboard you could have figured out how much you need to mill the width of the V-groove equally on both sides overall and get the exact milling of the metal from the workpiece just right. The way you did it is for when your V-groove is flush with the track but your opposite quanter support section has too much play in the Z-axis and needs extra material to support it so it can be leveled with your track to speak off.

I was apprenticed as a machine tool fitter and was lucky enough to have worked on all manner of machine tools. The best by far were British and German. Makes like Herbert, Asquith, Wickman, Jones & Shipman, So-and-so etc etc. Having seen these Chinese made lathes and milling machines and tried to use them, I am appalled at the quality. It makes me sad that nearly all of our machine tool industry has gone and people buy this rubbish. All of the old engineering colleges have gone that used to have good makes of lathes like Colchester, Harrison and so on. These old makes are still around as in used condition, but after 50 years or so are still far more accurate than the rubbish made in China today. Colchester lathes had a motto on all their machines which read "the world turns on Colchester lathes".

Dont forget the clamping of the tailstock might cause deflection. I think its a good place to stop on that part, the significant wobble is gone.

As kokodin5895 says, remachining the V groove will solve all the problems. I have a similar lathe with the same problems, they all have as far as I can see. The V groove is 92 degrees so an end cutter on the mill will fit right to the top of the V without touching tho opposite side, I made a 44 degree wedge support to set the part at the right angle for machining. The tailstock was done first, I needed to widen the V groove by 1.4mm so I took 1mm off the side nearest the center of the lathe bed and 0.4mm off the outer face, it fitted fine with no discernable rock but lowered the tailstock by about 1.5mm so the top part had to be shimmed to get it back on center. A month or so later I tackled the saddle and headstock in the same afternoon, much the same set up but far harder to hold and very light cuts had to be taken. I cut the same 1mm from the far edge and 0.4mm form the front hoping that they would all line up as before when refitted. They fitted well but the down side was that the front saddle gib was now bottoming out on its screws so the gib seat had to be skimmed a suitable amount. Another downside was a visible crack inside the rear of the headstock, it only went part way through the casting but made me very careful when tightening the screws during refitting. Also the screw holes for the apron had to be drifted 1mm or so towards the front to stop the half nuts bending the lead screw when engaged as the saddle now sits a little rearwards of its previous position, it was lower as well but the leadscrew bearings had enough adjustment to allow for this. I still needed thin shims between the tailstock and its base to get the height right but I expected that. The outcome was all 3 items are now sitting square on the bed with no rock, machining is now much more positive with less vibration and squealing, all I have to do now is improve the awful gibs in the cross slide and compound as they are just not solid enough, even when locked with the gib locks I added at the same time as I cut the Vs. I would say that as a rule its best to fix the problem rather than try to get round it, I considered shims at first but decided to go "the engineer's route" and machine everything to fit, after all it only has to be done once. My lathe came from Vevor and I complained about the fit of the tailstock, they offered me a £20 refund, I pointed out that this would not fix it and they upped it to £40, I looked at their website and pointed out that a replacement tailstock was £121 and accepted a refund for that amount. As it happens a new one would not help as they looked axectly the same, it might have been some work with a steep learning curve, I am a relative newcomer to machining, but the problem is solved and I am £121 better off. Your videos are very instructive and entertaining and I have watched them all, how about a sub series Adventures With A Very Small Mill as your's is definitely in that category. Keep posting the videos.

For the last finish you could use valve grinding paste, the high spots would grind down first and should make for a nice contact with the bed. But it may be difficult to keep it consistent on the whole length and not make the rail uneven...

I used reversed sandpaper on the bed groove, then moved the tail stock base plate and head over it to lower it end fit the groove. Parts are soft metal.

Hack saws are ok 🤠 Great video and I’m glad you included mistake footage as well. I’m not sure scraping the tailstock is worth it when the lathe bed is not scraped. But I suppose if you can’t precision grind the tailstock then scraping is the next best thing. I watched a fellow scraping the beds on a planner and it took him for ever. Man I can see him in my mind doing it but his name doesn’t come to me……. Kieth Rucker! (Google knew). I’m sure you have come across him by now. Also this is not a surface that is used in motion. It’s moved into position then clamped solid. Fantastic practice though.

For a cast iron, you need negative rake, and you controll depth of the cut by downward pressure on the scraper. And rake angle is important, depending on the type of the iron. 5 to max 8 degrees. Thin the blade so you can reach tight spots. Its just angle on the edge that counts. blade itself can be tappered or whatewer. For a mild steel, you need to grind positive rake, but also need to grind a "heel" (like on engraving tools), and you control depth of cut by changing the angle. Steel can be scraped very nice that way. Check An Engineer's Findings clip about it. For polishing the edge.. just make block of some realy hard wood like locust, hornbeam or similar, with 95 degree angle. Notch that edge for about 1-2mm. Flat brass stock and diamond paste... Put the insert on one edge of wood block, brass stock on another and you will get a guide for your 5 degree rake. Remember.. carbide do not like to be grind or honed away from the edge. It is so hard that it will microchip the edge. Change dirrection of scraping for 90 degrees on every pass, so you avoid chatter.

Always scrape next pass crosshatch to previous, it will give you a better surface. If you need to peel off more material use just double passes with crosshatching directions. Use red oil based paint it's more contrast on metal.

Nice work! Im going through the same modifcation. How will you align the the headstock to the tailstock? Are you planing to mod the tailstock for adjustment? You could use self lubricating bearing brass for the sadle shims.

Keith Rucker at Vintage Machinery is one of the best sources on scraping on UKposts. Search him up and you will find many videos. Just watching this, I suggest cross hatching the scrapes. Scrape at an angle and then go back with the opposite angle to make Xs. Good work on your first attempt!

Perfect 👍

On my little import lathe the headstock was misaligned with the bed by about .006" over 13" toward the operator and .010 vertically away from the bed. I scraped it in to get the horizontal error easily corrected by torturing a few inch pounds more on the screws on the V and shimmed the rear of the V and flat with shim stock. Once I could easily repeat perfect alignment by removing the headstock and replacing it several times, I waxed the bed and screws then put a layer of jb weld onto the bottom of the casting, put the headstock back on the bed, tightened everything down back into alignment, cleaned up the excess squeeze out and waited 24 hours for the epoxy to cure. (Same as bedding a rifle stock) The headstock now has 100% contact to the bed and is aligned to the bed to within .0003" both horizontal and vertically. Alignment was done with an mt3 test bar and 4" machinist level.

i have the same problem with my vevor 7x14 lathes tail stock but ive not noticed it with my carriage but rigidity is a issue, i thought i had pinned it down to my cross slide an have been collecting material to attempt to make a solid mounted tool post but havent gotten around to it but after seeing this i think im going to tar mine down a little further an see if this is an issue with mien as well. makes sense if they use the same process to make the carriage as the tail stock they would both come out bad but ive only noticed it with my tailstock cause it was obvious even to me never touching a lathe b4 that it was wrong its time i tear into it i guess. i got a mini mill also so i have the tools to do the work i just dont have the know how yet. i got them both around the same time an the mill has been great, way better build quality over the lathe, not the same brands so that could be part of it, mills from wen its the 33013 an the lathe was the 7x14 with all metal gears an suppose to be upgraded motor from vevor but im not sure what the standard motor is but if i had it to do over knowing what i know now about the machine i would have save a couple 100 bux more an got a bigger machine all together.

Hello Alistair, An interesting video, thank you. I was wondering if you measure how parallel to the ways the top surface of the piece you scraped was. Take care. Paul,,

estou impressionado com a quantidade de coisas que aprendi

Hi! . There was one guy from UK that made a PPT how he made "epoxy way shims" making a composite out of bronze + graphite + ptfe powders and epoxy making in tokind of "boots" for each sliding surface.

I have a question. Wouldn't it be faster, and perhaps with a better result, to use fine sandpaper? Place the paper on the bed of the lathe, fix it with clamps. Attach the tailstock and move it slightly and let it grind?

Not going to claim I'm an expert on this or anything. But I think there's a problem with your procedure on this one. Basically, as you scrape away material on the shims you're rotating the casting about the angled ways like a fulcrum. So until you're getting flat contact on the shims, the contact points on the other two surface would be changing as you're scraping the shims. As well, you're also essentially moving the fulcrum at the same time by scraping all three points, so you'd have to move relatively more material from the shim to see any difference. To me it would make the most sense to only scrape the shims until you were getting pretty even contact along it's length, and then start scraping all 3 surfaces to bring it down evenly.

A few things... Go in alternating directions when scraping... You cant just approach the material from one side, you have to cross your scraping marks, kinda like how you sand stuff, you do it from one direction and the next pass is from another angle across the prior one... It prevents you from making furrows or grooves in the surface, and results in points, rather than streaks of contact... You are getting nowhere apparently most likely as a result of working on that exact combination of V+flat ways, as any level of angular change or change in fit in the V groove instantly tweaks the flat way contact... Scraping is an art, and reading and understanding the printing and relying on other checking methods is quite tricky, as you have to know what influences what, and how stuff will interact with ways in perfect situation, and how any deviation from perfect fit will change the picture that the printing shows... I would most definitely try and mill out the V groove a bit before the job, its not so flimsy as to be unable to be milled down 40thou or 1mm... That would have deepened the contact area, and could have allowed you to fix the fit of that section tremendously, allowing you to merely focus on scraping of the flat sections until you get a perfect fit on that side... Also, for a proper intro to scraping, go to Gtsw Stefan`s channel and watch his work, and go to Robin Renzetti`s channel and watch his work in that area... They are invaluable as a source if you want to start scraping and between them, you will get enough tips and directions that if you ever have any questions, it will be the result of forgetting what they said and will return you to rewatch their videos as i have multiple times... All the best! Steuss

It turned out pretty good, but I think I would have tried gluing some diamond sandpaper to the ways. Your scraping seems to have worked out fine though, and you can't beat success.

The hard part is getting the center of the tailstock to align with the axis of the spindle in the headstock, while at the same time being parallel with it.

Expecting more videos

Its a bit late now but I use a thick tipped Sharpie marker in blue for my layout work.

Can you stick some adhesive backed sharpening film to the bed surfaces and prism and just lapp the carriage against it?

Findings of an Engineer has some tips on scraping steel. The negative rake is for cast iron because it's brittle. Positive rake for steel but grind a heel so you don't dig in too far. Scrape for bearing on the tail stock, like the other guy said. A HSS scraper should last for several passes on such a tiny area.

When using a hacksaw, it is best to make long, fast strokes. And positioning yourself so your arm naturally moves in a straight line can improve the cut too. You will be amazed how fast and clean your cuts are after a little experimentation. Manual hand tools are extremely powerful and make less mess when proper technique is used.

I am no machinist of any kind I was thinking you could tape emery paper to the bed of the lathe and sand the edges flat it would take off the high spots. Cheers

I'm sure it's already been mentioned but... Grinding the groove doesn't involve grinding it deeper. You just have to grind it wider. You could grind all of it off of the outside edge so the flat would move over the way more also.

At the same time would it not be easier to remanufacture the base plate? With the time invested in the project?

I'd recommend using turcite it would prevent wear on the bed of the lathe.

this sheet stuff called turcite seems to be pretty popular with some, it might, if you do something like this in future, be a better choice.

I don't know why but I thought you had done this 3~4 years ago? For cast iron, an old vented brake disc should be more than enough to cut 'sheets' to shim headstock? (I'm sure you will find a use for the surplus) Although if you wanted thicker, a solid disc will probably be around 10mm thick.