Small lathe Spindle Info.

[7HC]

Would be interesting to see if they sell! I think it's a waste to scrap them! I have quite a few that are the set screw type endmill holder. I think they will go for scrap. I might try to adapt a few to my quick change holder but I have quite a few of those, some never opened in sealed plastic bags. Maybe I box them up and sell them by the box on eBay!

Frank

I agree, don't scrap them, but offer them to the forum before they go on eBay.

M

 

[7HC]

Did some work on the 3/4" collet closer. Added cast iron back plate. All I need to do now is bore the locator hole and drill mounting holes. Plan to make an arbor and do it between centers do that it's in perfect aliment with the collet bore.
Is it better to tap the holes for the mounting screws or drill thru and use a nut? Total lenght of the closer is 2 3/8" including back plate.

Frank

If it's for a standard 7x mini lathe you could do either. The usual chuck mounting just uses the fastenings to secure it, the important part is the registration boss which requires requires a matching recess in the back of the chuck.
Regular chucks use threaded studs, but it's very fiddly getting the nuts onto them behind the backplate as there's so little space between the back of the spindle and the headstock.

It would probably be best to have loose bolts as it would be much easier to hold the nut while you spin the bolt, than it is trying to spin the nuts onto studs.

From an aesthetic point of view, using socket head cap screws in counterbored recesses would give an attractive and professional appearance, although of course that's just IMO .

M

 

[7HC]

......... I have quite a few that are the set screw type endmill holder.............. I might try to adapt a few to my quick change holder but I have quite a few of those, some never opened in sealed plastic bags.
Frank

Do you haver a pic of those?

M

 

[jumps4]

looks good so far frank, the closer is screwed into the backing plate right?
steve

 

[jumps4]

a good tight press fit should be fine the lathe this fits has no real power anyway
steve

 

[7HC]

That back flange is 7/16 thick I'm told the holes are 8mm. I can counterbore the holes though it wouldn't have much thickness. I can spotface the holes and use Button head Allen but then Button head has a smaller wrench opening. I as told the 3 hole pattern is better as some are not drilled for both. Don't matter to me I can do either. What about 5/16" easier to replace than 8mm.
Yes I know the registration hole is very important, that's why I plan to make an arbor and do it between centers.
Do you know how accurate the 55mm registration diameter is? Think 2.166 will work??
This one is for 3/4" max collet. Think I should make one with the 1"max collet closer? Or is that getting to big for that lathe?
Frank

AFAIK all the 7x use the three hole pattern; certainly all the chucks and faceplates that LMS sell for it do.

If you wait a bit I'll try a 5/16", but as I said it's just to secure the chuck, so a snug fit isn't necessary.
I'll also get you a measurement from the recess on the back of one of my chucks.

The spindle won't allow a 1" rod to pass through (I forget the actual clearance) but a 1" diameter workpiece is no problem for the lathe........my default chuck is a 5" independent 4 jaw. )

M

 

[7HC]

a good tight press fit should be fine the lathe this fits has no real power anyway
steve

Ouch! :nono:

It's no South Bend but it can get the job done, you just take smaller bites. )


M

 

[jumps4]

sorry I was not degrading the 7 lathe I have a sherline for a small cnc lathe and thats for threading bobbins i think.
but it also gets it done.
steve

 

[7HC]

Do you know how accurate the 55mm registration diameter is? Think 2.166 will work??
Frank

The register in the back of the 3" chuck that came with the lathe is 2.163, and the register on the faceplate from LMS is 2.1625.

2.166 will be a little sloppy I think. 2.163 looks to be the way to go, although I suppose you could offer the option of 2.160 and let the customer finish it to size.

M

 

[7HC]

Steve sent me a drawing of the spindle and it's showed the registration diameter is 55mm or 2.1653

Frank

I've seen the drawing and have no reason to doubt its authenticity.
However, these lathes are turned out by any number of manufacturers on the Pacific Rim so there's bound to be some variation.
I don't have another lathe to compare it to, but I can tell you that the faceplate and chuck are a snug fit on my spindle.

Maybe another member will come out of the closet and admit to being a 7x owner, and could take a measurement from theirs. :whistle:

Or why not let the customer finish the last few thou? After all, it's not like they don't have access to a lathe.:rofl:


M