What Is In My Spindle???

[TommyD]

Thanks for your service.

My job is teaching people, much like you, how manual machining works at a community/tech college. I have taught guys, and gals, in our small amount of time together, to SAFELY use lathes, Bridgeports and the surface grinder as well as how precision tools are used. These guys and gals are in programs to become Engineers to, hopefully, support the growing amount of work coming back to the USA.

 

[bbutcher]

Hey guys my name is Jason. I believe this is only my second post because I like to comb through the forum to try to figure my problems out but im at a dead end. My lathe is a atlas 10f. in the pics there is what I assumed after much research, was a spindle sleeve. I used a large dowel through the spindle and a mallet to attempt to loosen it but I didn't budge and I didn't want to use much force because I was scared of damaging the spindle. you would be amazed at how many pics of these lathes dont show the spindle very well and none of the hundreds I have looked through seem to have the exact same thing that is neither a #3 taper or and #2 taper. it wont hold a #3 and of course a #2 is way way loose. please tell me what this is and how to remove so I can try turning between centers. thanks guys.

I have an old Atlas 10 inch lathe, and mine has a spindle sleeve with a 3MT taper that fits the spindle. The sleeve is designed to take 3AT collets, and I have a set in sizes from 1/8 through 1/2 inch along with a drawbar. There is also another part of the set that is important, called a "thread protector", just a steel ring threaded on the inside to 1 1/2-8 TPI. This thread protector is supposed to be screwed onto the spindle before inserting the spindle sleeve, and then you can just unscrew the thread protector to remove the sleeve. When I forgot to install the thread protector one time, I had to use a 3/4 diameter rod and a hammer to remove the sleeve. It did take some pounding to get it out. If you do not have the thread protector, I suggest making one, from about 2 1/2 OD X 3/4 thick steel. The exact size is not critical, but it needs to be threaded to fit onto the spindle, and have a couple of holes for a spanner wrench to push the spindle sleeve out.

Bob

 

[bbutcher]

If you are missing the collets that can be a problem since 3AT collets can be hard to find. Another option is to use an ER collet chuck with a 3MT taper. These are easy to find on ebay, and you can get various sizes including ER16, ER20, ER32, and even ER40. The cost goes up with the size, but so does the maximum size stock you can hold. For example with the ER40 collet chuck you can purchase a set of 25 collets from 2mm to 26 mm inside diameter. These have a clamping range of 1mm, so you can hold any size stock from about 0.040" to a little over 1" diameter. Collets are also available in English sizes, but usually come in 1/16th inch increments, so they will not fit every possible diameter stock, since they still have a 1mm clamping range. Another consideration is the chuck uses a drawbar, usually 1/2 inch diameter to secure it in the spindle. This prevents long stock (3/4 dia and smaller) from extending all the way through the spindle. If that is a problem, I submitted a design to the Yahoo Atlas_Craftsman users group
https://groups.yahoo.com/neo/groups/atlas_craftsman/conversations/messages
for an ER collet chuck that has a 3MT taper and incorporates a nut with two different pitch threads (1 1/2-8 and 1 1/2-10) to secure the collet chuck with the spindle thread. You need to join that group to get access to the files, but you will find lots of good stuff there. Look for ER40 collet chuck for Atlas 10-12.pdf in the Drawings, Atlas or Craftsman Machine Parts section of files. This concept could be adapted to other size collets of course. It will be a good project in machining, and does require cutting a couple of accurate tapers and some threads. I recommend purchasing the collets and a nut for the chuck since the nut has special machining to grip the collets. It is also possible to purchase a 5C collet chuck with a 1 1/2-8 thread, and then you can use 5C collets. The chuck can be quite pricey, but 5C collets are nice since they can be purchased in a wide range of sizes up to 1 1/6th inch as well as Hex and square shapes. 5C collets do not have a very large clamping range however so you will need lots of them to fit all sizes possible, and the chuck may not run as concentric since it screws onto the spindle outside with some room for run-out.

Bob

 

[jason30809]

just signed up for the yahoo group thanks for the advice

 

[Tozguy]

For spindles that have a threaded nose check out the Beall chuck. It is an ER32 size and the chuck screws onto the spindle. It allows holding of long work because of the through hole. I have one on my Christmas list. I asked Santa to google Beall Tool.