[ajbarrell]

Dahui,

I remember reading in your website that you had problems with the alignment of your lathe's tailstock. Have you solved the alignment problem?

I recently took delivery of my new Tripower, and it's tailstock is significantly high also. High enough that I'm breaking drill bits.

Has anyone else seen this problem, or have a fix for it?

Tony

[handlewanker]

Hi Tony, if you've got a tailstock that you think is high then you've got a "refer to seller" situation.
Any work you do to correct it will void the warranty, and this is not just a simple adjustment here and there.
The height of the tailstock cannot be adjusted as opposed to the sideways adjustment used for taper turning etc.
The tailstock sits on a base that is closely fitted to the lathe bed, and the upper part of the tailstock is attached to the base by way of a raised vee and a flat across the base, to allow it to be moved across to set for taper turning or allignment.
If the barrel is "high" then the lathe is crap and poorly made, and requires serious remachining to bring the barrel bore to centre.
To check the amount of "high or low", mount a dial indicator on the chuck face and set it to rotate round the end of the tailstock barrel.
You now have two choices.
1- return the lathe to the seller as it's crap, or
2- machine the base to bring it down to the centre height.
If it is low, then you really have a problem which can only be cured partially by inserting packers between the upper and lower parts of the tailstock, definately not recommended.
There is no way to adjust a tailstock for this problem and if it's this bad then look at the rest of the lathe.
A last and long shot would be to mount a line bar in the chuck with an end support along the bed, and linebore the tailstock barrel bore true and have the tailstock barrel hard chromed and reground to the new diam.
This last method is probably your easiest way if the barrel is at most .030" high or low.
More than this could probably weaken the casting.
I would strongly suggest getting the "heap of sh##t" back to the supplier for exchange or refund.
Ian.

[S Lovette]

Tony,
Check the serial number stamped on you tailstock and the lathe ways. Make sure they match (check all of your parts). My Tri-power tailstock got switched with another machine and did not align. When I alerted JT we swapped assemblies for the correct ones and everything was OK. Fortunately my tailstock hadn't shipped with the other machine yet, so the exchange was quick.
If your parts are matched I strongly discourage you from trying to correct it by machining. You are unlikely to achieve satisfaction and may ruin the machine further. JT will be very responsive to correct the problem. He will not try to pass it off as OK until you say it is OK. Give him a chance and work with him. You will be satisfied.
Spencer

[ajbarrell]

Thanks Guys,

Spencer, good tip about the serial numbers--I'll check those first. Then, this weekend I'm going to verify that the lathe bed is level and true and if I still have the problem with the tailstock I'll give JT a call.
Tony

[handlewanker]

Hi Tony, good advice from Spencer.
Remachining on a new machine is usually a drastic measure and only to be attempted when ALL else fails.
Ian.

[dahui]

I just decided to remachine mine, however, I never checked the serial numbers. Where are they printed?

So far it seems find but I haven't been able to check it thoroughly yet. If you decide to machine it, just be sure you have a tool that can cut the little 45 degree raised part. I also found that it was about all my machine could handle in terms of the Y envelope but I do have the Eldorado so I don't know how that compares. I was about .013 high as far as I can measure.

Probably a better idea to get it swapped under warranty. Shoptask has always been very helpful with any issues I brought to them.

[ajbarrell]

I spent most of my shop time this weekend on the mill spindle and didn't really look at the tailstock as close as I wanted to. The mill spindle wouldn't accept a few of my R8 collets, so I removed the key inside the spindle and ground it down a couple thou. Now all my collets fit nicely, although I'm not sure if I have the bearing preload set correctly. It might be too tight, since the lower end of the spindle is getting pretty warm when it's running.

I did find that the tailstock gibs were way too loose. This caused the tailstock to rock back and the tool to raise--giving the appearance that the tailstock was too high. I tightened the gibs and locked the tailstock down tight and I think that it's close. Probably close enough.

Duahi, I'd have to say that's a gutsy move machining your machine's tailstock. Luckily, I think mine will be close enough that it will only take some light scraping.

Tony

[dahui]

Well, gutsy or stupid depending on how close I got it. I should get it tested out in the next couple of weeks. By eye it looks closer that it was before. I'll keep you posted and maybe we can all have a good laugh when I throw it in the trash.

[handlewanker]

Hi Dahui, if you are going to machine the base part of the tailstock assembly to drop the centreline of the spindle bore by .013", then you will have to mill the vee groove deeper and also the flat register further back, if that is how your tailstock is located.
There are two ways to achieve this, one is to mill it, if you have a mill big enough, and the other way is the tried and tested hand method, which I can assure you will give you 100% results, but requires carefull workmanship.
Make sure the tailstock upper half and lower half mating faces are clean with no paint or casting burrs.
Next ascertain the EXACT amount the tailstock is out, and that the tailstock BORE is parallel to the bed and not running uphill or down, done by checking from both ends in relation to the bed top face.
You should also check that the bore is in line with the centre of the bed and not running at an angle to it.
If you have this last fault it will play havoc when trying to turn parallel between centres or for drilling, all of which can be corrected by the application of a bit of common sense and carefull analysis.
To start off, mount a dial indicator on the 3 jaw chuck face and set the stylus to touch the OD of the barrel of the tailstock, just sticking out about 1/2", and rotate the chuck to swing the dial indicator stylus round the tailstock barrel, the tailstock being locked down onto the bed.
This will give you the amount the bore of the tailstock is out to the headstock centre line.
This method is also the most accurate way to reallign the tailstock for parallel turning.
Assuming you still have .013" high, remove the tailstock upper half.
The lower half of the tailstock must have metal removed from the Vee groove that the upper half locates into, and the flat face further back, NOT the bottom face that runs on the bed.
To achieve this metal removal, use an ANGLE GRINDER, (precision tool in the right hands), to lightly grind both the faces of the Vee groove and the flat
Don't dig the grinding wheel edge into the metal, but use the flat disc face at a shallow angle, and use a criss cross method, first making a number of light passes one way and then crossing the face in the opposite direction.
This will ensure that the metal is evenly removed.
Next lightly apply marking blue to the bottom of the tailstock body Vee and flat and then fit the two halves together and give a short back an forth rub to mark the fit between the two halves.
You will have a lot of high spots, shown by the blue being marked onto the bottom half.
Just lightly take off the bits marked with blue and keep repeating the process untill you get a more or less even marking pattern.
At this stage you will check the height again by the method outlined at the beginning, and also allignment in both horizontal and axial planes
If you carefully and lightly grind the faces, then the top half of the tailstock will progressively sink lower.
The important thing is to remove a SMALL amount of metal and CHECK your results. Then do it again, finally if you are capable a touch with a flat scraper is all you'll need to get the alignment 100%, which is better than the best machining methods.
The easiest way would have been to line bore the barrel bore, and have the tailstock barrel hard chromed and ground to the new diameter, takes less time and requires a lot less skill, and is standard practice in the machine tool rebuilding industry.
It also guarantees 100% horizontal and axial allignment in one operation.
I've been doing machine tool refitting for 40 years on and off as the occasion arises and this is just a breeze.
My biggest challenge was to refurbish a 10" swing lathe bed/saddle fit by hand, when the bed was worn from the middle of the bed to the chuck end by .013" and made any adjustment of the saddle impossible, but that's a long story and would bore most people.
Ian.