I have owned a Jet 1236 lathe for about 2 years and for the first time
today I tried to remove the spur center so I could install a Nova
chuck which I just purchased. The spur center refuses to budge. I have
pushed the drift rod as hard as I can, tapped it with a mallet and hit
it considerably harder than a tap with the mallet to no avail. I have
also put oil around the spur center and have the threaded index pin in
place but nothing seems to help. Any ideas?

Thanks,

Harry Sanders

Harry Sanders said:

I have owned a Jet 1236 lathe for about 2 years and for the first time
today I tried to remove the spur center so I could install a Nova
chuck which I just purchased. The spur center refuses to budge. I have
pushed the drift rod as hard as I can, tapped it with a mallet and hit
it considerably harder than a tap with the mallet to no avail. I have
also put oil around the spur center and have the threaded index pin in
place but nothing seems to help. Any ideas?

Get a plastic bag of ice and place on the spur center, wait a few
minutes, and whack the hell out of the drift rod. Heating the hub
would help as well, but be careful not to damage the
bearings/paint/etc. This will generally give you .001-.003" more
clearance for disassembly.

FWIW,

Greg G.

I have used a small pipe wrench on them. Just needed to break the "seal"
and it popped out! You can use a tape wrap around it to eliminate any teeth
marks from the wrench. That'll save your ice for better things! *G*

Leif
"Harry Sanders" wrote in message
om...
I have owned a Jet 1236 lathe for about 2 years and for the first time
today I tried to remove the spur center so I could install a Nova
chuck which I just purchased. The spur center refuses to budge. I have
pushed the drift rod as hard as I can, tapped it with a mallet and hit
it considerably harder than a tap with the mallet to no avail. I have
also put oil around the spur center and have the threaded index pin in
place but nothing seems to help. Any ideas?

Thanks,

Harry Sanders

"Leif Thorvaldson" wrote: I have used a small pipe wrench on them. Just
needed to break the "seal" (clip)
^^^^^^^^^^^^^
If you have someone to help you, I suggest using Leif's pipewrench approach
along with a big hammer on the knockout bar. The combination of torque and
impact should get it out easily, and maybe with less wrench marking.

On 30 Oct 2004 15:20:13 -0700, (Harry Sanders) wrote:

I have owned a Jet 1236 lathe for about 2 years and for the first time
today I tried to remove the spur center so I could install a Nova
chuck which I just purchased. The spur center refuses to budge. I have
pushed the drift rod as hard as I can, tapped it with a mallet and hit
it considerably harder than a tap with the mallet to no avail. I have
also put oil around the spur center and have the threaded index pin in
place but nothing seems to help. Any ideas?

Thanks,

Harry Sanders

turn something important on it.. the damn thing will decide to fall
out on it's own...



Want to cure Aids?
Give it a Dewalt part number and nobody will ever get it...

I have Jet Mini and had the same problem once. I couldn't get it out with
the drift rod either. My spur center has a hole through the side of it, so
what worked for me was popping out the spike in the tip of the spur center
(mine is just set in, not attached) and inserting a screwdriver or other
appropriately sized metal rod through the hole in the side of the spur
center. Lock the headstock with the indexing pin in your case. Now try to
twist the spur center out, the screwdriver will give you lots of leverage.

Hope that helps.

Andy



"Harry Sanders" wrote in message
om...
I have owned a Jet 1236 lathe for about 2 years and for the first time
today I tried to remove the spur center so I could install a Nova
chuck which I just purchased. The spur center refuses to budge. I have
pushed the drift rod as hard as I can, tapped it with a mallet and hit
it considerably harder than a tap with the mallet to no avail. I have
also put oil around the spur center and have the threaded index pin in
place but nothing seems to help. Any ideas?

Thanks,

Harry Sanders

get a 1X8 nut, cut it in half, put it on the threads of the spindle, put a
wrench on it so that the wrench holds the nut closed, and unscrew it - it
will push the spur out as you unscrew it.

(if you get desparate, I do sell nuts alone, but you ought to be able to
find one locally for a few $$)

www.home.labridge.com/~wnoble




"mac davis" wrote in message
...
On 30 Oct 2004 15:20:13 -0700, (Harry Sanders) wrote:

I have owned a Jet 1236 lathe for about 2 years and for the first time
today I tried to remove the spur center so I could install a Nova
chuck which I just purchased. The spur center refuses to budge. I have
pushed the drift rod as hard as I can, tapped it with a mallet and hit
it considerably harder than a tap with the mallet to no avail. I have
also put oil around the spur center and have the threaded index pin in
place but nothing seems to help. Any ideas?

Thanks,

Harry Sanders

turn something important on it.. the damn thing will decide to fall
out on it's own...



Want to cure Aids?
Give it a Dewalt part number and nobody will ever get it...

Puzzling. Another common problem I have so far escaped. Harry, are you
seating your work by rapping it into the center with the center mounted to
the lathe? I don't think that it's a good practice.

Best, in my experience, is to make cuts on the bandsaw or with a chisel to
seat the spurs, second best is to remove the center and use a few mallet
taps to split the piece ... I mean seat the spurs in their self-made
recesses.

If things haven't moved already, might I suggest you take care of cosmoline
("first time") and / or corrosion first by running some light oil or WD 40
into the area before you try to unseat with a rap, followed by a strap
wrench or pipe wrench. Even there, you want a sharp initial attempt, like
rapping the end of the handle smartly, not a slow torquing.


"Leif Thorvaldson" wrote in message
...
I have used a small pipe wrench on them. Just needed to break the "seal"
and it popped out! You can use a tape wrap around it to eliminate any
teeth
marks from the wrench. That'll save your ice for better things! *G*

Leif
"Harry Sanders" wrote in message
om...
I have owned a Jet 1236 lathe for about 2 years and for the first time
today I tried to remove the spur center so I could install a Nova
chuck which I just purchased. The spur center refuses to budge. I have
pushed the drift rod as hard as I can, tapped it with a mallet and hit
it considerably harder than a tap with the mallet to no avail. I have
also put oil around the spur center and have the threaded index pin in
place but nothing seems to help. Any ideas?

Thanks,

Harry Sanders

Harry,

If Mac's advice fails, try going barefoot at your lathe. NO DON'T.

Turn to Safety, Arch

Fortiter,


http://community.webtv.net/almcc/MacsMusings

At last! I finally got the spur center loose last night after several
days effort. Prior to last night I had tried several treatments with
penetrating oil (3-in-1 oil and WD40) along with a number of hard
whacks on the drift rod with a steel mallet. I had also tried putting
tape around the spur center and turning it with vice scripts to unlock
it. No luck here either.
It appeared that I was going to tear up the outer rim of the spur
center before it gave way.

Last night I started with a cooling-heating treatment using a hair
dryer to heat the spindle and a bag of ice around the spur center to
cool it. After about 10 minutes of this treatment, a hard hit on the
drift rod moved the spur center enough that the drift rod could no
longer reach the spur center but the spur center was still stuck. At
this point I tried the split nut approach. The nut did exert pressure
on the spur center but I had a problem with the nut spreading and
sliding up over the spur center. After the split nut treatment, I
searched and found a long steel rod to use in place of the drift rod
and one hard blow knocked the spur center out. I must admit I was
beginning to have some doubts if I was ever going to free this sucker
up.

Thanks to you guys for all the ideas. They were certainly a great help
in solving this problem.

Harry

Harry Sanders said:

At last! I finally got the spur center loose last night after several
days effort. Prior to last night I had tried several treatments with
penetrating oil (3-in-1 oil and WD40) along with a number of hard
whacks on the drift rod with a steel mallet. I had also tried putting
tape around the spur center and turning it with vice scripts to unlock
it. No luck here either.
It appeared that I was going to tear up the outer rim of the spur
center before it gave way.

Last night I started with a cooling-heating treatment using a hair
dryer to heat the spindle and a bag of ice around the spur center to
cool it. After about 10 minutes of this treatment, a hard hit on the
drift rod moved the spur center enough that the drift rod could no
longer reach the spur center but the spur center was still stuck. At
this point I tried the split nut approach. The nut did exert pressure
on the spur center but I had a problem with the nut spreading and
sliding up over the spur center. After the split nut treatment, I
searched and found a long steel rod to use in place of the drift rod
and one hard blow knocked the spur center out. I must admit I was
beginning to have some doubts if I was ever going to free this sucker
up.

Thanks to you guys for all the ideas. They were certainly a great help
in solving this problem.

Good that you got it out, I've never heard of one that was THAT
tight... Thermal expansion and contraction is a time honored method
of assembling and disassembling machinery parts. And the best part
is, no mangled, scored up parts to deal with from trying to force
something.

I guess Leif can save his ice for better things, like soaking his
battered hands from the pipe wrench... ;-)


Greg G.

Greg G. wrote in message
...
Harry Sanders said:

At last! I finally got the spur center loose last night after several
days effort. Prior to last night I had tried several treatments with
penetrating oil (3-in-1 oil and WD40) along with a number of hard
whacks on the drift rod with a steel mallet. I had also tried putting
tape around the spur center and turning it with vice scripts to unlock
it. No luck here either.
It appeared that I was going to tear up the outer rim of the spur
center before it gave way.

Last night I started with a cooling-heating treatment using a hair
dryer to heat the spindle and a bag of ice around the spur center to
cool it. After about 10 minutes of this treatment, a hard hit on the
drift rod moved the spur center enough that the drift rod could no
longer reach the spur center but the spur center was still stuck. At
this point I tried the split nut approach. The nut did exert pressure
on the spur center but I had a problem with the nut spreading and
sliding up over the spur center. After the split nut treatment, I
searched and found a long steel rod to use in place of the drift rod
and one hard blow knocked the spur center out. I must admit I was
beginning to have some doubts if I was ever going to free this sucker
up.

Thanks to you guys for all the ideas. They were certainly a great help
in solving this problem.

Good that you got it out, I've never heard of one that was THAT
tight... Thermal expansion and contraction is a time honored method
of assembling and disassembling machinery parts. And the best part
is, no mangled, scored up parts to deal with from trying to force
something.

I guess Leif can save his ice for better things, like soaking his
battered hands from the pipe wrench... ;-)


Greg G.

Hey! Come on now guys! If I had realized that you were still having
problems with the sucker, I had a couple of other aces up my sleeve. First,
though! Did you try the pipe wrench? You mentioned visegrips, but they
wouldn't be strong enough. All you needed was a an 18 or 24 inch pipe
wrench and a ten to twenty foot length (*G*) of galvanized pipe to slip
over the handle of the wrench and you could have rotated your shop and
perhaps the world. I forgot to mention that I now use an old bicycle inner
tube to protect the spur drive collar instead of tape. The rubber really
grips it.

Now to the causes and conditions of the matter. What caused such a stubborn
issue in the first place? I read on this newsgroup that this type of
sticking is due to not keeping the morse taper clean. Since that time, I
have had no problem with sticking drive centers. Get a metal gun bore
cleaner brush and some solvent and clean that puppy up. Both sides: head
stock and tail stock and also the drive centers themselves!

Leif

Leif Thorvaldson said:


Hey! Come on now guys! If I had realized that you were still having
problems with the sucker, I had a couple of other aces up my sleeve.

Just revving you up... ;-)

But seriously, I heat connecting rod bores with a hot plate and cool
piston pins with cryo freeze to assemble engines with non-floating
piston pins. Works great and is more accurate than using a 20 ton
hydraulic press - I get no scoring of the pins or bores. Works for
anything that has an interference fit. No force, just finesse.

I also wonder why it was so tight. Once the thing moved at all, it
should have just popped out. I wonder if there was extensive rust or
corrosion in there. A tapered MT joint should not have been that
difficult to remove.

You are right about keeping the Morse tapers clean, however. It not
only makes them easier to remove, but makes them less subject to
slipping.

FWIW,

Greg G.

Comments for Leif - No, I never did try a pipe wrench. Perhaps that
would have been better. Certainly the bicycle inner tube would have
offered much more protection that the tape I used.

As to why I had such a bad sticking problem, the spur center came
installed in the lathe and had never been removed in 2 years. I used
to tap the wood gently onto the spur center with a mallet (I think
this is recommended in the Jet manual). Perhaps this was the culprit.
In any case, I won't do that anymore. In the future I will keep a nut
on the spindle when using the spur center to assist in removal.

Hey! Come on now guys! If I had realized that you were still having
problems with the sucker, I had a couple of other aces up my sleeve. First,
though! Did you try the pipe wrench? You mentioned visegrips, but they
wouldn't be strong enough. All you needed was a an 18 or 24 inch pipe
wrench and a ten to twenty foot length (*G*) of galvanized pipe to slip
over the handle of the wrench and you could have rotated your shop and
perhaps the world. I forgot to mention that I now use an old bicycle inner
tube to protect the spur drive collar instead of tape. The rubber really
grips it.

Now to the causes and conditions of the matter. What caused such a stubborn
issue in the first place? I read on this newsgroup that this type of
sticking is due to not keeping the morse taper clean. Since that time, I
have had no problem with sticking drive centers. Get a metal gun bore
cleaner brush and some solvent and clean that puppy up. Both sides: head
stock and tail stock and also the drive centers themselves!

Leif

Good plan. Might have been some cosmoline in there, too.

"Harry Sanders" wrote in message
om...

As to why I had such a bad sticking problem, the spur center came
installed in the lathe and had never been removed in 2 years. I used
to tap the wood gently onto the spur center with a mallet (I think
this is recommended in the Jet manual). Perhaps this was the culprit.
In any case, I won't do that anymore. In the future I will keep a nut
on the spindle when using the spur center to assist in removal.

Hi Greg

Yes I was wondering about the same thing, unless the straight end on the
taper and the hole through the spindle somehow have a interference,
which should not be that way, but it is not impossible of course, many
times the knock out bars are made out of steel and they will flare the
ends off the tapers if hit enough times, and if the size of these are to
close they could give you trouble, to prevent the flaring I use a brass
bar, it was hollowed and I filled that up with lead, works like a charm.
The fitting of parts that have to spin true by heating one part and
warming the other is a favorite way for me as well, rather than welding
with all the problems of uneven shrinking etc., I machine just under
size and cool the one by placing in the freezer for a few Hours and then
heat the other part on the stove or in the oven or with a torch whatever
is the best way, then have every thing set up and ready and then do it
quick and right. Made a couple of #5 mt with flanges that way, just
shrunk on and there have been some big and heavy chunks of wood spun on
them, never budge.

Have fun and take care
Leo Van Der Loo

http://homepage.mac.com/l.vanderloo/PhotoAlbum18.html

Greg wrote:
I also wonder why it was so tight. Once the thing moved at all, it
should have just popped out. I wonder if there was extensive rust or
corrosion in there. A tapered MT joint should not have been that
difficult to remove.

You are right about keeping the Morse tapers clean, however. It not
only makes them easier to remove, but makes them less subject to
slipping.