Tailstock rebuild...with pics this time!

[websterz]

I had a half hour to play tonight so I started my tailstock rebuild. My biggest problem, aside from the wrench, has been alignment of the base to the ways. I think the biggest part of it is the plate they use for locking the tailstock down. Like so many other parts it's made out of butter. After disassembling the tailstock



I started by cleaning and bluing the base to see just how much contact I had with the ways.



Not much actual contact there so I got out the plate glass and 600 grit paper and lapped the base a bit.



That made a huge difference. I am not going for 100% contact as there are some pretty deep tooling marks there. This is plenty good for my needs.

Next I looked at the part that mates with the prismatic way and found a ridge running down the length of the part!



That required a bit of milling



to get it cleaned up and running true.



I lapped this section of the base and my picture didn't come out for some reason. Oh well...it fits MUCH better now!!

In anticipation of the next mod I removed the cheapie setscrew and drilled/tapped the main casting for 3 grade 8 8-32 buttonhead capscrews. This affords a proper grip on the base and should hold much better. I may add a couple to the front side as well to help keep it all level. By this time my phone battery died and being suppertime anyway I decided to call it a night. Tomorrow I am going to do the set-over adjustment mod and camlock mod so I don't need that dang wrench anymore. Part of the latter mod will be a much more substantial locking plate to eliminate my original alignment problem. Then, time permitting, I can get the tailstock adjusted in true and be ready for the next adventure. I will take a proper camera out with me so I can get better pics.

[bogstandard]

A man after my own heart W, get in there and fix it.

Bogs

[websterz]

A man after my own heart W, get in there and fix it.

Bogs

For quite a while I was afraid to do any modifications to my equipment. Some things you only get one stab at and you're up a creek if you blow it. I am over that irrational fear now. Aside from the electrical system I can make a replacement for just about any part I may destroy (I am a machinist after all!) so now I feel a bit more free to experiment. Turning these Chinese kits into precision machines is a very rewarding pursuit! 

[Brass_Machine]

Tres Bien. I have been inspired to check and tune mine. Good job.

Eric

[bogstandard]

W,

It is a major problem getting over the first hurdle and taking the plunge.

But the number of times I have seen people take on a stripdown and repair project, only to realise they need the machine, to make the part, to fix the machine they have stripped down in front of them. 

A little forwards planning does help, or mates not too far away, who can make the bits for you.


Bogs

[Brass_Machine]

...

A little forwards planning does help, or mates not too far away, who can make the bits for you.


Bogs

That's my problem... I don't have anyone that close. I want to change out the bearings in my lathe... but I know there is a spacer that needs to be turned down a little....

I will figure it out.

Eric

[websterz]

...

A little forwards planning does help, or mates not too far away, who can make the bits for you.


Bogs

That's my problem... I don't have anyone that close. I want to change out the bearings in my lathe... but I know there is a spacer that needs to be turned down a little....

I will figure it out.

Eric

I have turned many a part on the mill...but I have never milled on the lathe. Go figure. 

[bogstandard]

Eric,

but I know there is a spacer that needs to be turned down a little....

You have a mill, then face the end rather than turning it.

Bogs

[Darren]

...

A little forwards planning does help, or mates not too far away, who can make the bits for you.


Bogs

That's my problem... I don't have anyone that close. I want to change out the bearings in my lathe... but I know there is a spacer that needs to be turned down a little....

I will figure it out.

Eric

Eric, you can do this on the lathe, before or after you fit the bearings, you don't need another lathe 

[websterz]

Continuing on with the mods, here is one I have wanted to do for a long time...



My tailstock casting has a boss cast right into the side, that makes the mod just that much easier. Some castings require you to mill a flat. I drilled a half inch hole and installed a grade 8 1/2-13 capscrew and nut, shortened for clearance...





Then I drilled the bolt thru with a 5/16" bit, you can make out the thru hole in the last pic.

The cam is made out of a piece of half inch drill rod (silver steel) turned and threaded for a 5/16-18 Nylock nut. The lever is a piece of 3/16" drill rod press fit in place.





The actuating rod is another piece of 1/2" drill rod, tapped on one end for 5/16-18 and drilled thru with a 3/8" bit on the other. I milled flats on the cam end of the rod. The larger diameter hole in the cam end is for wiggle room when assembling...you'll need it.



The locking plate is milled from mild steel to fit between the ways and with plently of clearance below the bed so it moves without binding. The hole is 5/16", the slot is 1/2" to capture the bolt head. Doing it this way allows finer adjustment when tuning the cam. I turned the bolt one flat at a time until I got the cam just right. I will add a setscrew tomorrow to keep the bolt head from slipping out when I remove the tailstock.

That about sums up the camlock mod. Total working time about 4 hours of pure madmodder pleasure! Tomorrow I tackle the set-over adjustment mod. 

[bogstandard]

Very nice indeed W, and such a lot neater than a lot I have seen.

Just wait for the mad rush now, all the mini owners will be scrabbling for 1/2" bolts and nyloc nuts.


Bogs

[sbwhart]

That little Lathe will be a really nice Job when you've done with it



Nice work W

Stew

[Darren]

Nicely done, I bet the old system was a pain...

|Lucky for me mine was done at the factory, but your other mods I will look into....

[Stilldrillin]

These little lathes are only as good as you/ we can make `em. 

That one`s going to be a gem...... 

David D

[websterz]

Alrighty then...last mod for this part of the machine (for now anyway).

There is no reliable way to adjust the tailstock side-to-side for correcting taper. I don't count tapping and hoping as reliable. Little Machine Shop has a print available on their website:

http://littlemachineshop.com/Projects/TailstockAdjuster.php

Here is my modified tailstock:





I used 8-32 button head capscrews because I had them on hand. For the adjusting nut I took a spare 3/8" Allen (hex) wrench and lobbed an inch off the end of it. I annealed it by heating it red hot with the propane torch and letting it sit on a firebrick to cool while I finished the other bits. Once cool it was easy to drill and tap. I cut the groove with a parting tool. To the left of the adjusting nut you can see where I milled out the slot in the casting a bit and put in a heavy brass shim. That keeps my locking screws from buggering up the base. Pretty simple stuff, took about 2 hours. I also drilled through the side of my locking plate and added an 8-32 setscrew to hold the bolt head in place when I pull the tailstock.

[sbwhart]

That'll sort it out  nice fix

Stew