How to Adjust Flexispeed Lathe

Background:

After my inital optimism about the accuracy of my Flexispeed, I have realised that is not that good after all. I measured my piece of between-centres turning and realised that is tapered more that I had thought.

As I only have one centre, I then turned a point on a piece of brass in the chuck, then brought both centres up together to do a visual check of the alignment. The tailstock was off set, which I have now adjusted, but the tailstock is also lower than the headstock.

I now have ordered a new centre from Peatol: this is a parallel 1/2" shaft, so it should slide into the tailstock instead of the standard one so that I can check the alignment more accurately.

Next, I put a short stub of engineering grade nylon (about 1" diameter) into the 3 jaw chuck to turn a bush. After turning it down, it was clearly tapered, the taper being visible without measuring it.

Question:

I am aware that the headstock can be adjusted, as welll as the tailstock, but am reluctant to start fiddling too much. Can anyone advise me the best way to go about setting up this machine so that I can get it as accurate as is realistic for such a machine?

Regards,

James.

Hi
Are you sure the nylon was running true in your chuck before you started ?​

Alex,

I think that it was, but shall try again with a fresh length, making sure that it is as true as possible before I start.

Regards,

James.

Heroic measures but, assuming you have a bar that fits the head and tailstock, loosen the head and tailstock locking screws, fit the bar, tighten all and hope it gives a base to measure from ?
my tailstock was rather low due to wear.

Oh dear !Does this mean we have to re-classify the Flexspeed with the adept et al?

Neil

Posted by john carruthers on 07/08/2015 18:44:10:

John,

I have no suitable bar: would a length of bright mild steel be accurate enough or do I need to use something like silver steel? Did you shim your tailstock backup into line?

I hope not! With luck, it is just acombination of my ineptitude and the adjustable headstock and tailstock needing to be realigned after all this time.

Regards,

James.

.

Neil,

Given that the Flexispeed was the direct ancestor of the much-respected Cowells Lathe ... I do hope not.

Take this as your guide, James.

MichaelG.

Edited By Michael Gilligan on 07/08/2015 20:48:51

It was based on the Adept concept though.

A sort of missing link, Adept ---> X ---> Cowells

Neil

.

Here's the Logo for your Super Duper Mega Adept

MichaelG.

>>I have no suitable bar: would a length of bright mild steel be accurate enough or do I need to use something like silver steel? Did you shim your tailstock backup into line?<<

I imagine so, I used a roller from an old printer, it happened to be ground all over, straight and parallel. It was a good fit in the spindle bearings too.
Remove the spindle, fit the test bar, get it parallel to the bed, then set the tailstock to the head.
I shimmed my tailstock a few thou, just copper shim stock.

I would 2nd that - head stock first and tail stock 2nd. On both check the height of what ever you use as a test bar above the bed before checking the sides..Do 3 points on the height - each end and the centre and rotate the bar to check for bend in that. As I doubt that they left the castings lying around for a few years when these were made don't be surprised if the bed is a little warped.

I'd guess you have already checked that there isn't much play in the head stock bearings - any leads to a taper widening away from them as the work lifts when it's cut. The same cut also keeps removing material, much the same as when the work bends. The front bearing is very likely to be more worn than the rear.

John

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John C: Thank you for the detail. I shall look around for a suitable length of bar with which to do some tests. I have some shim brass around somewhere, and have used Coke can metal in the past for other types of shimming.

John W1: I have checked the bearings and they appear to be sound, without any discernible play in them. Thank you for the further detail on taking the measurements.

I confess to becoming somewhat frustrated as I really just want to be able to get on and use the lathe, not spend what seems like forever just seting it up to work. Still, once it is done and as accurate as I can get it, at least I can be reasonably sure that any future inaccuracies are a result of my workmanship, not the tooling.

Regards,

James.

Just an update for anyone vaguely interested.

I used a length of half-inch steel bar, secured in the headstock bearings, to check the alignment of the headstock. Just by looking down and sighting along the edge of the lathe bed, I could see that the headstock was about a yard out of alignment. Anyway, with some careful adjustment, I managed to get the DTI to read consistently along its length. I also shimmed the base of the tailstock to bring the height of the centres up to the same level.

Today, I put a length of nylon material (an old rolling pin) between centres and turned a collar at each end. To my great delight, to the best of my measuring ability, they were both the same diameter. I have since turned a short length in the chuck and it is turning parallel, something that it would not do beforehand.

What puzzles me is how my first attempt at turning between centres produced a bar that was anywhere near parallel, which it was.

Thank you for the advice to achieve this.

Regards,

James.

Edited By James Alford on 23/08/2015 21:36:58