chester conquest tailstock is sloppy, help required please!

[pmdevlin]

Dear all, just recently acquired a nice hardly used chester conquest, and am now starting the first small project (New at this !). I am using the tailstock with a 3mm bit to cut 12mm into some ally rod, but am struggling with the tailstock. When the nut is lose enough to allow the tailstock to freely slide, everything is sloppy, and the tailstock can move back and forwards 90 degrees to the bed, when the nut is tightened, the slop has gone, but I doubt its all lined up correctly. I have used a dead centre in the tail, and a pointy rod in the chuck, all lines up, no play in the head, and the start of the hole is centre, but the exit of the hole, only 12mm long, is off centre. The design of the tail sems to be "not that good" and pretty hit and miss. I removed the tail tonight, and was wondering if something is missing, like some sort of shim? There is only the retaining plate underneath. It has a hex bolt underneath, and two small screws at the rear, no idea what they are for, can anybody offer any advise, as I will be using the tail a lot, for thread cutting and hole cutting,
sorry it wa so long!, Thanks

[DMIOM]

Hi,

I don't know the "Conquest" but I'm not sure if we're using the same terminology - am confused by talk of using the tailstock for cutting threads etc.

The tailstock casting is normally never moved once you start the lathe turning under power. It is used, usually, to :
* hold a dead or rotating centre, to keep work centred when it is too long to be held solely in the chuck
* to hold certain types of tooling which are used exactly on-centre - e.g. drill bits
When drilling, or to keep a centre engaged, if you need to advance the 'tailstock' there is usually a handwheel to advance the tailstock quill after the main casting has been locked down.
The only time you might thread using the tailstock is using either a Coventry diehead, or a tap or die held in some form of chuck - but in all those cases, you would leave the tailstock locked to the bed/ways.  

Conventional thread cutting would normally be done with the tool mounted in a toolpost on top or cross slide.

The only adjustment normally need in-service on a tailstock is if you have had it previously offset laterally for taper turning (this may be your two small screws).

You may have a small twist to the bed - you need to get things all square (which is usually done by levelling, although not strictly necessary to be truly level, its one of the easiest ways to get it reasonably square). Try and turn a test bar and see that it isn't too tapered....

Dave

[Anzaniste]

I'm not quite sure of the orientation of the 90 degrees you refer to.

The act of tightening the tail stock down on the bed pulls it onto the V on the bed thus aligning and positioning the quill and therefore the chuck or what-have you. If , as you say, when the tail stock is tightened down the centre is where it should be then it is doing its job.

The reason for the drill  coming out of the bar stock off centre at the other end is down to drill sharpening. If the two flutes of the drill are not exactly equal  then the drill will wander off centre depending how deep the hole is.

[HS93]

welcome Paul, I think the problem he is having is when he tries to use the tail stock to hold a drill to make a hole in something held in the chuck, he is using a centre drill but finding the drill is wandering , also the tail stock does not seem to have a very good regester, and seems slopy on the bed , so when he tightens it up to use it to hold a dia nut for he is not shure if it is aligning properley, are they normally a slopy fit on the bed befor being tightend.
the lath he bought has had very little use and may need setting up, is there an ajustment at the head end, he is very new to the hobby ( like me) so it may be a set up problem unfortunatly I know very little about the lath so can not be of much use to him
I think it is also the same as the C3 from ARC

Peter

[Fergus OMore]

I'm somewhat unsure of the problem except to comment that the generic series of 7 X ***** Far Eastern lathes have not the best of tailstock fittings.
Actually, the net is full of comments about how to tackle the problem. I would suggest that our poster Googles ' Chester Conquest lathes' but moves on to various suggested web sites and joins at least one of the YahooGroups that has the '7 x 10, 12 14 or whatever lathe' as its main topic.
For what it worth, I have a little MJ189 which no one will have a clue-- but many of answers appear in the Unimat3 and 4  websites.

I DO know some of the equally ageing  writers who have addressed almost identical problems on these groups- and I would carefully follow their advice

[Stilldrillin]

Hi PM.

Welcome to the Collective. 

Like most others on here, I don't really understand your explanation. It's not easy, when you're new to machining! 

I have a Chester Conquest. Never had any tailstock problems..... Once I understood how to adjust it! 

Where are you? Is there anyone nearby who can help "hands on"?

David D

[andyf]

I'm not going to reply to your particular question, except to say that the tailstock should only be sloppy when you slide it up and down the bed to get it in the right place. When in use, it should be locked down to the lathe bed.

There is a good guide on the care and feeding of mini-lathes, written in English rather than Chinglish, here:
http://littlemachineshop.com/Info/MiniLatheUsersGuide.pdf .

Two versions of the mini-lathe are in general circulation: the Seig and the Real Bull (I kid you not). Both are Chinese in origin, and the differences between them are very minor. Dealers like Chester UK add their own badges. The Little Machine Shop manual is written with the Seig in mind, but is equally applicable to the Real Bull (thoiugh yours will of course run on 230V, rather than 110V as in the US). The current Chester Conquest is from Real Bull.

Like Fergus, I recommend you join one of the Yahoo mini-lathe groups. The original one, "7x10 Minilathe", has largely degenerated into off-topic political ranting, but http://groups.yahoo.com/group/7x12minilathe/ is fairly tightly moderated.

As David D suggests, let us know where you are, in case there's someone nearby who can offer hands-on help.

Andy

[Anzaniste]

Another thought about the drill bit itself, did you start your hole off with a centre drill or did you go in with the drill straight away? If the latter is the case the point of the drill can wander before biting especially with a drill as small as 3mm. A parting off pip on the end of the bar stock can make this even worse.

[HS93]

he is using a centre drill

Peter

[pmdevlin]

thanks for all replies, Having read them back, I think my explanation needs clarifying!

so, I have been drilling 3mm holes into some ally bar, little project for a friend, its my first project, making some king pins for a large rc truck (big job for me!! ha ha). I used a centre cutter to start the hole, everything fine, then changed to what I thought was a good quality 3mm drill bit, slid the tailstock up, locked it in place, and used the handle to cut, nice and slow, and backing off to let swarf out. The entrance to the hole is fine, as I am just putting the drill bit tip into the centre hole, but after 12mm into the bar, (the lenght of the kingpins) the hole exits off centre.
When the tailstock is loose on the bed, there is movement noticeable back  and forward movement, if I hold the tail and push pull towareds and away from myself, this motion being at 90 degrees to the bed, the tail will move, so when being tightened I have doubts it is being pulled down to the bed centrally or square to the bed, as there is only a small plate under the tailstock securing it to the bed. As mentioned, there are two small screws at the back of the tailstock, no idea what they are. The lathe instructions are useless, no explanation at all regarding setting up anything!
I have joined the yahoo group, but got a bit lost as I couldnt find any sort of titles for topic threads, so was really hoping someone here would say they have such a lathe, experienced the same problems, and suggested a fix, and explained what the two screws where for, I have tightened and loosened, nothing seems to happen

[andyf]

As you tighten it down, the tailstock should be brought into line by the fit of the prism-shaped rib along the lathe bed into the V shaped channel on the underside of the tailstock.

The two little screws are, I think, to shuffle the top casting from side to side in relation to the bottom casting, for the purpose of turning tapers between centres. I don't do this, because of the difficulty of getting the tailstock back in line again afterwards.

None of this helps with your off-centre hole. Are you sure that the ally bar isn't so short that the chuck is holding it at an angle?

Andy

[Anzaniste]

How far off centre?

[andyf]

Just found this:
http://myweb.tiscali.co.uk/silkstone/minilathe/minilathe01.htm
which features a Chester Conquest.

Observations on the tailstock are 3/4 way down the page.

Andy

[Fergus OMore]

It's only a guess but your tailstock's fore and aft movement locks but it moves because your 'Two little screws' are not holding the top part of the tailstock casting  in one position. It is not only 'rocking about like a pea on a drum' but has a sideways shuffle.
I don't have a parts list but I would remove the tailstock and turn it over and see if it is loose- as I suspect.

Once this is corrected, you have to get the whole  thing in line with the mandrel.

It's not just  a Chinese lathe thing, most lathes have this facility.

F OM

[pmdevlin]

great link Andy, it seems this is a common problem, the run out is enough to visually see it, after only 12mm, have not measured it, but an estimate is up to 1mm. I can overcome it by not drilling any further than 10mm, it seems to be after that it runs out. The bar is long enough to go through the headstock, so I suspect its all about the tailstock set up. Took it off tonight, turned it over, and the hex bolt that permits the top half of the casting to move is tight, and there is also a sticker on the back with calibration marks on it , the two small screws still remain a mystery!

I think a lot more reading is in order to sort this, I had initially thought as the lathe is 2nd hand, something had been left off, like a shim or gib strip, but after studying the parts diagram apparently nothing is missing.

I might give chester an email to see what they can suggest!

many thanks to all

Paul

[loply]

The tailstock on my mini lathe, which is similar to yours, will set in a different position every time you lock it.

That's to say, if you get it aligned perfectly, move it a bit then lock it down again, it will be sitting differently.

This is because of the poor surface finish on the V on the underside of the tailstock and the small contact area between it and the V on the bed.

The solution, which I've yet to implement, will be to apply abrasive paper to the lathe bed with double sided tape and lap the tailstock to match until the surface is remotely flat and even.

[spuddevans]

The solution, which I've yet to implement, will be to apply abrasive paper to the lathe bed with double sided tape and lap the tailstock to match until the surface is remotely flat and even.

Will this not result in the tailstock being lower than it should be?

Tim

[Fergus OMore]

It could also make a smallish problem into a bigger one. There is no guarantee that someone armed with abrasive paper on sticky tape is going to tip the poppet completely out of alignment.

Frankly, I would build up the bottom of the tailstock with a decent metal filled bodge and clamp it onto a greased bit of the levelled lathe bed but with the tailstock poppet fully extended as parallel as possible- maybe checking with a sprit level. At least, no damage will ensue but it will give some indication of what the underneath of the tailstock base casting should be if it had been machined properly. At least, there will ONE reference line created. Again, it will get somewhere to give an informed opinion for others to take up.

It sounds quite bonkers but this is almost exactly what a professional does with something like Moglice. Incidentally, Myford lathe had a worn saddle and this  was built up with Turcite.

[Stilldrillin]

Abrasive on the flanks of the bed V, will make the tailstock V wider. 

Not what you want.......   

David D

[Anzaniste]

Turn a piece of bar between centres. If it is tapered then your tail stock is is off centre. Doing that test will confirm things one way or another.
The fact that your hole does not appear to be off centre when you have only drilled 10 mm but is off centre when you drill 12 mm is quite mysterious. How are you defining off center by measurement or visually?

[Fergus OMore]

Take a No3 MT centre- insert in spindle
Take No2 MT centre- insert in tailstock
Take a razor blade and bring tailstock almost touching the spindle centre. Lock down the tailstock.
Bring poppet up to hold the razor blade which will be upright or lean one way or other
Report findings, please

[pmdevlin]

really appreciate all the suggestions chaps, I was banned from "playing" tonight as family duties where backing up, so could not do any tests

How are you defining off center by measurement or visually?

I I use one of those funny "find the centre of a bar" tool things, like a small square, the hole is off centre at 12mm, when turned down back to 10mm, its ok, certainly within tolerance, this was repeated twice with different jobs, so in my mind the drill bit in the tailstock is not cutting square, and the further I go into the bar, the more pronounced the off centre cut becomes?, I tried yesterday to cut further, in excess of 15mm as a test,  but it started to sound horrible so I backed out thinking I might break something

The tailstock on my mini lathe, which is similar to yours, will set in a different position every time you lock it.

If thats what happens, then I suppose I am stuck really, without any serious modifications that I feel are beyond my skill set unfortunately, googling does produce a lot of posts about this problem, but very little to remedy it, I keep seeing a cam lock conversion, but assume that is just a quick convenient way of locking the tailstock?

Take a No3 MT centre- insert in spindle
Take No2 MT centre- insert in tailstock
Take a razor blade and bring tailstock almost touching the spindle centre. Lock down the tailstock.
Bring poppet up to hold the razor blade which will be upright or lean one way or other
Report findings, please

now the very embarrasing reply, whats a poppet, and whats MT? Sorry to be so stupid!! I understand what it will achieve, the razor balde should be all square when the centres are touching? any deviation will show which way the tailstock is favouring, can youtube videos, and/or pics be uploaded? I could provide evidence of what is going on,

many thanks!

[Fergus OMore]

MT is Morse Taper which is  tapered shank to be found on a variety of things such as drill holders, centers and collets.
A poppet is the round bar that can be driven backwards and forwards in the tail stock body. Don't get me wrong but these are generalisations in common use.

I'm glad that you have understood about the alignment of centers with nothing more than a thin blade ie a razor  or a Stanley blade.
What does trouble me is why things go wrong- part way through a drilling- or are you being let down by not knowing the correct wording.
I can assure you that you are not alone and you will persevere- as we all have done.

Might I suggest that many things cannot be taught from a 'correspondence course' and that you try to find a helper locally?
The most important thing is that people will try to point you in the direction.

[Stilldrillin]

Never before, heard the quill, or ram being called a "poppet"!  

Learn something new, every day...... 

David D

[loply]

Abrasive on the flanks of the bed V, will make the tailstock V wider. 

Not what you want.......   

David D

On the contrary, it's precisely what you want.

It's well documented that tailstocks on cheap lathes are almost always delivered high, sometimes really high, mine for instance was 0.3mm high until recently.

By sticking abrasive paper to both the V and the opposite (flat) side of the bed you will abrade both sides of the tailstock evenly.

This will enlarge the V on the tailstock thereby increasing surface contact, lower the tailstock to the correct height, and at the same time rectify the awful factory finish which leaves very little contact and wavey critical surfaces.

With care you will preserve the relevant angles and grind out a new and flat set of surfaces for the tailstock to sit on.

If it ends up too low, which I think is unlikely, shims would have to be inserted between the tailstock base and body as per any other tailstock raising situation.

Cheers,
Rich