Another newbie question

[Stuart Smith 5Participant @stuartsmith5]

John

Before I bought my mini lathe, I was advised to buy the book ‘The mini lathe’ by Neil Wyatt (editor of Model Engineers’ Workshop magazine and moderator on this forum) . I found it very useful as a complete beginner.

**LINK**

It would be particularly useful for you since he has the cl300 lathe and shows how to carry out adjustments including the tail stock.

Stuart

[John Almond 2Participant @johnalmond2]

Hi Stuart.

I have indeed bought the book, im looking at it now.

[Andy_GParticipant @andy_g]

Posted by John Almond 2 on 17/12/2020 11:24:37:

…, it all seems to move around a bit before the bolt grips then has I tighten the bolt it moves away from me and ends up in that position.

any thoughts?

It shouldn't move around as you tighten the bolt (a very small amount of movement may be unavoidable).

The most obvious thing to check is that there isn't a lump of swarf or dirt stuck between the tailstock and the bed – Slide the tailstock off and clean the bed and mating surfaces carefully.

Also check for any damage or 'bruises'.

I couldn't see this mentioned above – apologies if I missed it. There's no point performing any alignment until the position is repeatable.

[JasonBModerator @jasonb]

Have a look to see in the bright area arrowed is making contact with the flat part of the bed as that would stop the Vee faces from mating

[John Almond 2Participant @johnalmond2]

Thank you for all the suggestions chaps.

I will check the above advice and take a photo regarding the V faces mating.

Regards.

John

[SillyOldDufferModerator @sillyoldduffer]

In line with Jason's suggestion, is this part of the 'V' ok?

Might be a trick of the light.

However, try testing the 'V' and other bearing surfaces for straightness with the edge of a steel-rule, a sheet of cardboard to stop glare escaping over the top and a bright torch. Lay the rule edgeways along the suspect surface and shine the light on the reverse side, looking for light escaping underneath. The flat running edge can be inspected by holding the rule and tail-stock up against a window or strip light, but a shield and torch help seeing if anything is amiss in the 'V'. I'm wondering if the V is misshapen, and can't sit evenly on the bed prism.

Another way of highlighting poor fit is to lightly smear the V with Engineering Blue and press the tail-stock into position against the bed. The greasy Blue film is displaced from the high contact points and ideally there aren't any! Practice first: engineering blue isn't that easy to use. Once diagnosis is certain, high-spots can be removed with abrasive or a scraper. Don't rush to remove metal – ask advice first. (Didn't go well last time I tried…)

Dave

[John Almond 2Participant @johnalmond2]

Try again, I got a post ready and was ready to send then went back to add another photo and my post had gone so here we go again………

photo below is the grip plate finger tight.

this one spanner tight.

here is the gripper plate, it looks a bit bent, dont you agree?

and here is the tail stock sitting on the bed

ummm, not sure it should be like that

[John Almond 2Participant @johnalmond2]

A couple more.

on the one just above , that is finger tight, when I used the spanner , it move to the right of the work but kept central………..ish.

[Dr. MC BlackParticipant @dr-mcblack73214]

From the photographs, it looks as if the top part of the tailstock can slide transversely across the part that slides along the bed.

Does it need some adjustment there?

MC

[JasonBModerator @jasonb]

That is what I said first of all, Adjust so it lines up.

Narrow edge of that clamp should be at the front, see parts diagram

Edited By JasonB on 18/12/2020 12:20:07

[Howard LewisParticipant @howardlewis46836]

Maybe, this problem is why the last owner got rid of the machine.

The first essential has to be getting the base to locate properly on the bedways.

If the Vee in the base is not sitting firmly on the Vee of the bed, the reason for that needs to be found. The bruise is a good starting point. There needs to be a slight clearance between the base and the bed, to allow for when the clamp is tightened.

It may have no effect, but the clamp is not symmetrical, so may contribute to sideways movement when tightened. Have not checked my mini to see if fitting the clamp "wrong way round" is either possible, or will produce lateral movement.

As already advised, remove any obvious damage marks and then use engineer's blue to check for a fit, without the clamp, and then when clamped..

Bear in mind that it is possible that the Tailstock body may be offset so far from the base that tightening the clamp, with an excess displacement may be a contributory factor to the movement.

As an aside, I was given a Tailstock with a lever lock, instead of the screw type clamp. It was WAY off centre (5mm ) on my machine. Stripping it showed that the abutments for the lateral grubscrews looked to have been "machined" with an angle grinder. Milling both faces flat, and taking more off one than the other allowed the Tailstock to be aligned, although one side then required a longer grubscrew.

As always, detailed examination will reveal the cause of the problem.

Howard

[John Almond 2Participant @johnalmond2]

Again, thanks for the replies to probably dumb newbie questions.

trying to upload new photo to my album but keep getting this .

sorry, the page you have requested cannot be displayed at this time, please try again later.

Anyway, I found a photo of the clamp plate from elsewhere and it does not look like the one I got.

[Howard LewisParticipant @howardlewis46836]

If you are unhappy about the clamp plate, you could always make a replacement. It only requires a piece of steel, a little more rigid that the original, and a short piece of M10 studding.

Having said that the present one should be able to provide sufficient clamping force to lock the Tailstock.

It might be an idea to separate the base and body, and concentrate on the base before starting to investigate the body. The hole in the base looks large enough to cope with sideways movement of the body.

It could even be that the clearance holes in the Base and the Tailstock body do not coincide properly!

As I found, some of the workmanship may be rather rough, rather even approaching precise!

Maybe the capscrew underneath is too tight, or that the surface on which it seats is rough. It needs to be tight enough to prevent clearance between base and body, and yet allow the two capscrews to pull/push the body across the base, without any movement in other planes. Which prompts a question about the condition of the mating surfaces of the base and body.

A strip down and thorough clean and tidy up of the parts may improve matters..

Carry on reporting your findings. They may benefit some other owner

Howard

[Dr. MC BlackParticipant @dr-mcblack73214]

If you decide to make a new clamp plate, I suggest that you try to obtain some High Tensile Studding. The studding sold by one chain had very mixed reviews on their website.

If studding isn't available, you could use a High Tensile bolt or machine screw through a thicker plate plate.

If you tell us your approximate location, there may be another member nearby who could help.

Good luck

MC

[John Almond 2Participant @johnalmond2]

Again, cheers lads for the suggestions and advice, its all very welcome.

MC, I live in the Wigan area.

I decided to knock together a replacement grip and low and behold, success.

I will now make something else with a bit more beef and slightly thicker threaded bar.

Heres how the temp gripper looks.

I just super glued it on at the bottom so it wouldn't turn when nipping up the top nut, but it seems to be working ok.

[Howard LewisParticipant @howardlewis46836]

Again, a little careful fettling changes the sow's ear into silk!

Good that you have found a cure.

Haven't checked, but think that the thread for the clamp is M10, based on my memory of the size of spanner needed for the nut.

Howard

[Dr. MC BlackParticipant @dr-mcblack73214]

The screw at the end of the top part of the Tailstock (Part No. 199 on the Parts Diagram to which Jason B referred) looks to have a rather mangled slot in your most recent photograph.

If it was me, I would replace that screw with a Cap Screw so it can be tightened with an Allan Key.

Some years ago, I purchased a Selection Packs of Cap Screws, Nuts, Washers, Spring washers, Wing Nuts, et hoc genus omne – so there's a very good chance that I will have what I need when I need it.

You may like to consider doing the same.

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