Modifying the minilathe - episode 6 - headstock alignment 

Thanks for watching.

Glad you are enjoying the series. Thanks for watching.

Yes and No. The steel bar I bolted it too reduced deflection significantly. Just not enough. Look that the bed cross section of a Schaublin 70 watch lathe in comparison to see what a stiff bed in a lathe this size looks like.

Thanks for watching. I'll be addressing this in the next video.

Glad to assist.

@@RotarySMP i have an older 1.2 meter, clapped out lathe. Most likely made by sieg some 25 odd years ago that im thinking about giving som love. So im glued to these episodes.

@@claeswikberg8958 Get stuck into it. I am sure you can improve it.

NZ only went metric in 1970, so my Dad always used imperial. Plus I became a aircraft mechanic, and planes are still largely imperial. I am pretty comfortable in both systems. Do you watch Cutting edge engineering? His banana rulers are classic.

Glad you enjoyed it. I think my editing got a fair bit better in the year since I made that video.

That will have little effect if you run the moment of inertia calcs on that bed section.

I'll get into the reinforcement plan on the next video. Thanks for watching.

Do you mean the old set up with the toothed pulley directly onto the spindle? That was an HTD 5 pulley which I got from Mädler.de. I bored it out to fit the spindle.

I didn't bother. Epoxy alone has a very low youngs modulus, so it does very little for stiffness. The whole machine is a bit of a wet noodle, so it would take a lot of redesign to significantly stiffen it up. Better to start with a stiffer machine.

Thanks for the encouragement.

Your welcome Nico.

I really need to make a smaller hand scraper. At the latest when starting the cross slide ways.

I agree. This was my only machine for years, and it is pretty impressive what you can get done, despite the shoddy quality and light construction. Must say that twisting it +/- 0.002" just with the hands surprised me though.

@@RotarySMP me too that's quite a feat of strength...on your part lol. I'd love a big hefty lathe but I just haven't got the room in my shed nor the desire to take on the task of getting such a heavy thing through the door etc

With big lathe/mill, you can cut with about anything. On those wobbly mini machines, you need super sharp HSS tools with very positive cutting angle to get any precision. Otherwise the machine gets just twisted out of alignment.

One of the benefits of working with these little machines is that when you use a 'proper' lathe (even a relatively small one) you really appreciate the rigidity in a way that ABOM never would!

@@RotarySMP I was very surprised just how weak the bed is as well. Really needs to be bolted down to something flat and rigid, maybe scrape in the surface of a chunky steel I beam?

Nice one. Only 34 more videos to go :)

NZ only went metric in the early 1970's. My Dad always talked in imperial, and gave me some of his measuring equipment, whereas I have bought metric, so I have a mix. I am an aircraft mechanic, and most aircraft, and jet engines are still made with imperial sizes and fasteners, so my apprenticeship was done in imperial. I mostly work in metric, but probably have a better "feel" for tolerances with imperial, and I really like that Verdict "tenths" indicator.

Thanks. I would bolt it down.

Thanks.

Kind words, but misplaced. I am not skilled, I just play one on the internet. What you see is the magic of editing :)

Wow, I got it as a birthday present a few years ago. I believe you can find a scanned pdf of Connelly online though.

I burnt out the DC motor years ago as well.

Glad to see im not the only one

Fitted a 1 hp 3 ph to mine and now i have to be careful not to snap the bed i half !

@@ianbertenshaw4350 Mine ended up with a 3/4hp 3ph and VFD.

thanks for watching. I used it years ago. Really it is just a test bar with the entire center portion relieved so it is only two rings. Easier to make, and good enough for head stock alignment, but tells you little about wear in the bed.

Thanks for your quick reply. The method you describe is not Rollie;s Dad’s Method (RDM). Your method I believe is widely used to align the tail stock with the spindle axis. The earliest reference I found to RDM is:- people.ne.mediaone.net/wasser/NEMES/RDMLatheAlignment.html The method requires a test bar that must be round along its length but does not require to be accurate for, straightness, uniform diameter, it does not need to be mounted accurately in the chuck, nor does the chuck need to be in alignment. No metal removal is involved. DTI measurements are required at the chuck end and the tail stock end along with some simple calculations to establish run out between the spindle axis and the ways although measurements at a few intermediate positions can indicate if the ways are straight. I believe the method provides ready answers for new lathe owners fundamental questions ie are the ways straight and is the headstock aligned to them. Again thanks for your patience.@@RotarySMP

Thanks for watching. Concrete is not very stable (but probably fine in this application). Epoxy granite would be better, but all that sort of thing really would exceed the scope of this project. I'll address this in the next video.

@@RotarySMP epoxy granite is amazing stuff, but it's not super cheap so you tend to save in the amount. Concrete is fine, but of course only if the amount is high enough. Thanks for the reply. Btw, are you planning on a cnc conversion or keeping it manual?

@@MF175mp It is. I made some E/G and tested it on the CNCZone endless M/G thread. Got about 40Gpa Youngs modulus. I did make a Head support for a Deckel FP0 from it, but then they project got terminated by buying a MAHO.

I doubt the mix of units is holding back views. When you are running a home shop on a budget you invariably end up with a mixture of imperial and metric measuring devices, at least in the Uk, so you have to be somewhat proficient st both. I greatly prefer the metric system though.

I generally work in metric these day, but the Verdict is such a nice DTI, that it made sense to use it for this part of the project. With relative dimensions like this it really doesn't matter. You start with 30 and have to get to 2. Thanks for watching.

Why not?

What an odd question. If something is inherently flawed but can still be improved by some work, why not do it?

Thanks for watching. A great question, I ask myself every time lay a finger on this project. I talked about my motivation to do this in the first episode. A combination of: 1/ it is there and unused 2/ it would be handy for cutting threads 3/ I want to move from understanding the theory of scraping and machine tool refurbishment to actually doing it, and this is a nice small project for learning 4/ It seemed well suite to make videos for entertaining you.

Think of it this way, it may be a turd but it is going to be one of the best turds around. That's called pride of ownership.😍