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funkychicken
31st January 2008, 07:43 PM
See when I got a JET Lathe I thought this is going to be top quality!

It is, all except for one thing. As the title suggests, the centres don't line up.

Didn't really worry me until I tried to dill some pen blanks - the hole was very loose one end (where the drill entered.) I wondered why

Note: I was holding the blank in the pin jaws of my GWP chuck and my 7mm dowelling/brad point in my torquata drill chuck held in the tailstock.

The drill bit was not in the centre and so was rubbing against the side of the hole making it bigger.


So whaddoo I do now?? (not in reference to the drilling)


:~

Funky C

ss_11000
31st January 2008, 07:58 PM
can you take a photo of two centres next to each other ( tailstock bought right up to the headstock ) ?

jchappo
31st January 2008, 08:10 PM
As Stirlo said, align your headstock and tailstock like this...

66217

Now you can see what the problem is. Vertical misalignment can be corrected by adding shims under either the tailstock or headstock whichever is lower.

Calm
31st January 2008, 08:15 PM
66216[/ATTACH]

Picture wont open for me

jchappo
31st January 2008, 08:16 PM
Picture wont open for me

Having a bad night:((

Should open now

thefixer
31st January 2008, 08:21 PM
I have the same problem with my MC1100, But I have learned that if I turn the tailstock this way, twist it that way, lift my right foot off the ground three inches, poke my tongue out to the left and shut one eye then I can get it to align perfectly:rolleyes: Have drilled many pen blanks in this fashion and the inserts are always a nice snug fit from end to end. It is just a matter of getting to know your machines little quirks.


Cheers
Shorty

Sawdust Maker
31st January 2008, 08:36 PM
maybe you could use a drill press
but if you don't have access to one then you have to do the stand on one leg etc trick. Just make sure it's the correct leg :D

westpest
31st January 2008, 08:45 PM
Better yet buy a Vicmarc, when this occured on my new 175 Victor changed the lathe no questions asked...thats service

Calm
31st January 2008, 08:46 PM
maybe you could use a drill press
but if you don't have access to one then you have to do the stand on one leg etc trick. Just make sure it's the correct leg :D

My Hafco HF20HD has a lot of sideways movement in both the head and tailstock. I had the same problem drilling blanks and keeping the whole thing straight.

My thought was buy a cheap pedistal drill to do the drilling. Bought a GMC (only GMC thing ever) and when i got home and set it up i found it only drilled to a depth of 60mm so to do a pen blank i had to drill the first 60mm then wind the table up and finish the last bit then to get the drill out of the hole i had to wind the table back down. reaming the ends after the glue dried was the same process. Absolute PITA

Soon gave that up now i face east, stand on one leg, point my right arm due north, incline the head to 15 deg right and use the lathe again.

thefixer
31st January 2008, 09:05 PM
My Hafco HF20HD has a lot of sideways movement in both the head and tailstock. I had the same problem drilling blanks and keeping the whole thing straight.

My thought was buy a cheap pedistal drill to do the drilling. Bought a GMC (only GMC thing ever) and when i got home and set it up i found it only drilled to a depth of 60mm so to do a pen blank i had to drill the first 60mm then wind the table up and finish the last bit then to get the drill out of the hole i had to wind the table back down. reaming the ends after the glue dried was the same process. Absolute PITA

Soon gave that up now i face east, stand on one leg, point my right arm due north, incline the head to 15 deg right and use the lathe again.

Maybe you should have got a longer drill bit:D

funkychicken
31st January 2008, 09:31 PM
Okay...
Went to photo my lathe centres, camera died, came back in, realised I'd left the camera in the workshop, went back down, camera works, centres line up, I quickly drill a pen blank, same old story, camera's dead again

:~

Calm
31st January 2008, 09:38 PM
Okay...
Went to photo my lathe centres, camera died, came back in, realised I'd left the camera in the workshop, went back down, camera works, centres line up, I quickly drill a pen blank, same old story, camera's dead again

:~

If the centres line up check if the centre of the drill lines up with the drive spur.

Does the chuck wobble at all?

If the centres line up i can only think it may be a bent drill (centre wont line up with drive spur) or the wood in the chuck does not run true (wobbles). Others may have more suggestions.

Big Shed
31st January 2008, 09:48 PM
I have the same with my MC900, I now have the centres lining up perfectly when they touch.

However, this is obviously not the case when I move the tailstock back in the drilling position, there is a fair bit of sideways movement between the tailstock and the bed.

So, I have resorted to drilling my pen blanks on the drill press, it is quicker anyway.

Still would like to get rid of that sideways movement in the tailstock though as it can be tricky to line it up correctly with the pen mandrel.

Maybe I should bid on that Vicmark VL300 on Ebay?

Nah, perhaps overkill for turning pens:o

funkychicken
31st January 2008, 10:21 PM
If the centres line up check if the centre of the drill lines up with the drive spur.

Does the chuck wobble at all?

If the centres line up i can only think it may be a bent drill (centre wont line up with drive spur) or the wood in the chuck does not run true (wobbles). Others may have more suggestions.


Nothing woobles, the centres (including the drill bit) line up, then don't, then do etc.

Don't have a drill press. Just want my lathe fixed.

nfld steve
31st January 2008, 10:36 PM
This might be a dumb reply:Is the blank in nice and true?In your chuck I mean?Is it spinning turu?
Also,what about putting your blank in the chuck,,then mark the center of the blank with something you can see when spinning,,,then bring up your tail stock,and before tightening it down,adjust it so the center,and drill line up,,,,then see what happens.
Also ,maybe a pen blank is not square and true,,you know,twisted aliitle like mine are,lol.
I think maybe the other guys had the answer with the face north,stand on your right leg,tap the tailstock 3 times with a piece of jarrah,while thinking of a nunber between 1 and 75,,and lol,,,what ever might work.
Actually,I have a similar problem with my Delta 14",,it's got a swiveling headstock,and,I can allign the points when the head and tail are brought up together,but what about when I move the tailstock back to do work?
I think it's also something I have to learn like the guys said,to get used to the machine.
If all else fails,call the company where you bought the lathe.You want to be happy with your machine.
All jokes aside,I wish you the best with it.I've never drilled a blank on the lathe yet,,some needle case,but no pen blanks.I should do that though because I bought a small drillpress,and it doesn't matter the size or the drill bit,it still only runs down 2",and that's not enough with my drilling jig+the lenght of the blank.So,drilling on the lathe sounds the best to me,I just have to practice.
Best of luck,Steve

nfld steve
31st January 2008, 10:40 PM
Oh,also ,maybe clean the Morse Tapers,and openings with something,could be fine rust,or packing grease or wax in there.
Steve
God I'm a genius this morning!!!lol.
(just have to apply this advice to my lathe now,:rolleyes:lolol)

ss_11000
31st January 2008, 10:43 PM
are you sure the drill chuck is running true?

funkychicken
31st January 2008, 10:45 PM
This might be a dumb reply:Is the blank in nice and true?In your chuck I mean?Is it spinning turu?
Also,what about putting your blank in the chuck,,then mark the center of the blank with something you can see when spinning,,,then bring up your tail stock,and before tightening it down,adjust it so the center,and drill line up,,,,then see what happens.
Also ,maybe a pen blank is not square and true,,you know,twisted aliitle like mine are,lol.
I think maybe the other guys had the answer with the face north,stand on your right leg,tap the tailstock 3 times with a piece of jarrah,while thinking of a nunber between 1 and 75,,and lol,,,what ever might work.
Actually,I have a similar problem with my Delta 14",,it's got a swiveling headstock,and,I can allign the points when the head and tail are brought up together,but what about when I move the tailstock back to do work?
I think it's also something I have to learn like the guys said,to get used to the machine.
If all else fails,call the company where you bought the lathe.You want to be happy with your machine.
All jokes aside,I wish you the best with it.I've never drilled a blank on the lathe yet,,some needle case,but no pen blanks.I should do that though because I bought a small drillpress,and it doesn't matter the size or the drill bit,it still only runs down 2",and that's not enough with my drilling jig+the lenght of the blank.So,drilling on the lathe sounds the best to me,I just have to practice.
Best of luck,Steve


Uhh how am I supposed to adjust the tailstock?


Don't think it's the MT either

Yes the drill chuck runs true...well it actually stays in the same spot :P

Calm
31st January 2008, 10:54 PM
are you sure the drill chuck is running true?

I am assuming you are holding a square pen blank in pin jaws and the drill in a chuck in the tailstock.

This means the blank is turning and the drill is not.

Try turning a blank round between centres, then holding in the chuck/pin jaws and see if it runs true.

By doing this the blank should be held better by the chuck and see if that makes it easier to drill straight.

Not sure if it will help but could be worth a try.

Sometimes when drilling i lock the tailstock and screw the drill into the wood by the tailstock thread and other times i push the tailstock instead of using the thread to do the drilling. When pushing i found by holding pressure on the lock handle it helps eliminate the "slop" in the tailstock to bed.

Skew ChiDAMN!!
31st January 2008, 11:15 PM
Also, try holding a round dowel in the pin-jaws. Bring up the tailstock until it almost touches, but not quite. Rotate the chuck slowly by hand.

No matter how you rotate the chuck, hopefully the tailstock will always point at the same general position on the end of the dowel. Even if it's out of alignment. ie. if it's low, it'll always point below the centreline of the dowel.

What's the point of this exercise? Well... if the end of the dowel wobbles around the tailstock centre, then you have another problem as well! 'Cos that means that, for some reason, your jaws aren't holding the blank squarely on it's axis.

eg. you haven't bolted them onto the right carriers or they're just "stuffed." Or, as an absolute worst case, the chuck itself is wobbling, but I'm assuming you've already checked that. [fingers Xed]

robyn2839
31st January 2008, 11:21 PM
have a good look at your chuck and check that it is not slightly out the live centre and the drive spur are exactly in line, the way to drill pens is to mark centre on the tailstock end bring drill up to centre then tighten your chuck, dont presume just because it is clamped in the chuck it is straight, i wouldn,t knock the lathe till you are sure ,it has always been spot on for me, bob

DJ’s Timber
31st January 2008, 11:26 PM
Try putting the drill chuck in the headstock end to see that the drill is actually centred in it.

robyn2839
31st January 2008, 11:36 PM
if the centres line up its not the lathe ,either the timber is slightly crooked in the chuck ,or the old adaptor nut problem ,it only has to be out a tiny bit to run out like that and is pretty hard to see just by looking at it .when i set chucks up i clamp something to the lathe then use a hacksaw blade or anything with a point clamp next to chuck at different places and turn by hand, bob

Okay...
Went to photo my lathe centres, camera died, came back in, realised I'd left the camera in the workshop, went back down, camera works, centres line up, I quickly drill a pen blank, same old story, camera's dead again

:~

robyn2839
31st January 2008, 11:40 PM
just got an idea, put the drill chuck in the headstock and spin to see if the drill chuck is straight,could be something

joe greiner
1st February 2008, 12:44 AM
Almost this exact same question is on a current thread on the AAW forum. Could it be due to global warming or phase of the moon?

Seriously, even on the best lathes, some slop is necessary in the tailstock positioning so that it can be moved; called "running clearance" in the mechanical professions. As blithely suggested, become acquainted with your lathe's quirks and adjust to them, with shims if needed. Another factor to consider is the nature of drilling into non-uniform material such as timber: The drill tends to follow the path of least resistance along or across the grain; this is often not exactly where you want it. Just need to accommodate it; then it's called "assembly clearance."

Joe

ss_11000
1st February 2008, 07:34 AM
This means the blank is turning and the drill is not.

.
'my bad' i didnt write what i meant clearly:-. what i meant was is the drill bit centered:cool:. i have noi idea why i wrote if it was running true?:?

Calm
1st February 2008, 08:01 AM
i have noi idea why i wrote if it was running true?:?

Stirlo at your age your having this problem. Dont worry about it, it only gets worse as you get older:D:D:D

wheelinround
1st February 2008, 09:16 AM
FC your not the first person to have this problem with a JET I think it was Amos who had similar from Melb no idea what his results were.

Noted that no one mentioned checking the bed of the lathe for distortion as in arching from one end to the other or using winding sticks to make sure it's level.

I got the digital dial gauge out to check mine and found it depended on how I tightened down the tailstock slightest movement sideways puts it out minute :doh:

OGYT
1st February 2008, 10:21 AM
FC, when I first bought the little Vicmarc, I checked to see if it lined up properly. It was off just slightly to one side. Decided it was the 2x board I had it mounted on. I put a thin washer under one of the tail end legs and the opposite side front end leg, and when I tightened it down it was spot on!
When you check for alignment, look at it from directly above, and directly to the side. It'll possibly tell you whether it's alignment or bed twist.
Another thing. If the insert isn't in all the way, the chuck will have runout.
Al

nfld steve
1st February 2008, 10:48 AM
Uhh how am I supposed to adjust the tailstock?


Don't think it's the MT either

Yes the drill chuck runs true...well it actually stays in the same spot :P

What I meant by that was,on my lathes,I got 3,the tailstock has alittle slop from side to side in it,,in them,and I just tried and I can lock them down alittle to one side or the other.On mine,there is alittle play in the tailstocks.
They need this of course so they can slide back and forth the bed,,,alittle play,but I wonder does yours have more play in the tailstock.
I was thinking of trying to attach a thin strip of neoprene or something on each side of my tailstock,underneath where it meets the lathe bed.If it ever becomes necessary.
Just a thought,,,that's it for my thoughts though,lol.
Good luck,Steve.

Big Shed
1st February 2008, 11:08 AM
FC, I asked a similar question a little while ago.

In case you haven't read that thread, have a look here (http://woodworkforums.com/showthread.php?t=64602&highlight=drilling+pen+blank), some of the ansswers might help you as well.

funkychicken
1st February 2008, 10:38 PM
are you sure the drill chuck is running true?


Try putting the drill chuck in the headstock end to see that the drill is actually centred in it.

I checked and the drill chuck is slightly out of centre, the end of the drill wobbles about a mm or so.

But see the start of the hole is the problem, where the drill bit comes out of the blank it's a good fit. :?


Pics are attached..couldn't focus on the centres (darn camera):~


Funky C


Oh and Bob, apart from this little thing, it's an awesome lathe!

ss_11000
1st February 2008, 10:59 PM
easy. put something thin under the headstock.

eg. paper

robyn2839
1st February 2008, 10:59 PM
on the four bolts that hold the headstock to the bed loosen them and under them pack a thin peice of paper then tighten, (about as thick as a school exercise book cover)
and see how that goes,add more if needed till same height as tailstock, if the drill is 1mm out of centre it will make the hole 2mm bigger , then wobbling will make the hole even bigger. might have to send the drill chuck back if its out of centre
........bob...........

OGYT
2nd February 2008, 03:32 AM
FunkyC, is that pic taken from above? Or from the side?
If it's taken from the side, Stirlo and Bob are right on target.
If it's taken from above, it's probably bed twist.

joe greiner
2nd February 2008, 04:46 AM
If it's taken from above, it's probably bed twist.

Mebbe. But could also be side slop in the bed channel.

Joe

pitbull
2nd February 2008, 06:00 AM
I have the same problem with my MC1100, But I have learned that if I turn the tailstock this way, twist it that way, lift my right foot off the ground three inches, poke my tongue out to the left and shut one eye then I can get it to align perfectly:rolleyes: Have drilled many pen blanks in this fashion and the inserts are always a nice snug fit from end to end. It is just a matter of getting to know your machines little quirks.


Cheers
Shorty

Mines a different make of lathe but using your instructions worked perfectly, thanks Shorty. :U

wheelinround
2nd February 2008, 07:27 AM
I checked and the drill chuck is slightly out of centre, the end of the drill wobbles about a mm or so.

But see the start of the hole is the problem, where the drill bit comes out of the blank it's a good fit. :?


Pics are attached..couldn't focus on the centres (darn camera):~


Funky C


Oh and Bob, apart from this little thing, it's an awesome lathe!


FC did you take that photo with the tailstock clamped down or loose :?

Hickory
2nd February 2008, 01:07 PM
Are you sure it is the center that doesn't align? I have a chuck and it is mounted on a MS shaft, but the problem is it is mounted on the end of a long screw thread with a MT. Put the long lengh and distance from the MT to the chuck plus the bit, by the time it gets to the work a micron can be multiplied by angle of the dangle to produce failure. I am going to get a short shaft chuck MT gismo to eliminate this long reach problem. could this be your problem, not the lathe but the attachments.

Big Shed
2nd February 2008, 01:46 PM
Just to muddy the waters further, I have been playing around with my MC900 lathe. I have a drive centre similar to the above picture, as well as a live centre the same as in the photo.

When I put my adjustable pen mandrel in the headstock and spin it without bringing the drive in the tail stock up to it, it runs quite true. However when I bring the tail stock up to fit in to the little dimple on the end of the pen mandrel shaft, I get quite a wobble. I am not applying any undue pressure with the tail stock.

On further examination I find that the little pointed centre in the live centre does not run true!

Spinning the live centre by hand and comparing it to a fixed reference point I find that the centre point wobbles by at least 1-1.5mm! Whilst this doesn't explain why I wasn't getting good results with drilling pen blanks, it certainly explains why I get non-concentric ends on my turned pen blanks!

Might be time to get a new live centre.

rsser
2nd February 2008, 02:21 PM
Yeah, the points on live centres can get bent.

And as posted, you can get crud in your tailstock MT.

You can get crud build up on the bed faces of your tailstock.

And wear on the quill.

Big Shed
2nd February 2008, 02:30 PM
Not helped by the fact that these particular live centres are not solid, but have a removable point.

funkychicken
2nd February 2008, 04:04 PM
FunkyC, is that pic taken from above? Or from the side?
If it's taken from the side, Stirlo and Bob are right on target.
If it's taken from above, it's probably bed twist.

It's taken from above, from the side they line up goodly.



FC did you take that photo with the tailstock clamped down or loose :?

Clamped down.


I've tried to move the headstock sideways but because of the way it's made it only moves back and forth (like the tailstock)



Should I get a replacement??


Funky C

Mulgabill
2nd February 2008, 07:59 PM
FC, I am not sure that I followed this thread correctly,:? but could the Tailstock quill be out of true???

TTIT
3rd February 2008, 12:11 AM
.......MC900 lathe. ................... On further examination I find that the little pointed centre in the live centre does not run true!................... Might be time to get a new live centre.Had the same problem with my MC900 live centre - turned out to be the bearing had shifted on the MT shaft. Used to just give it a tap in the right spot with a mallet and it was all good - until next time :~:~:~. Ditch it and get another centre - quick :;

funkychicken
3rd February 2008, 09:45 PM
FC, I am not sure that I followed this thread correctly,:? but could the Tailstock quill be out of true???


Uhh, I hope not

weisyboy
3rd February 2008, 10:47 PM
wile you have the centers together like theat give each one a spin by hand (indervidualy)and see if they run true or if they wobble.:2tsup:

this will tell you if one is bent or worn.

OGYT
4th February 2008, 03:00 PM
Since the photo was taken from above, try putting a washer under 'near' headstock leg, and/or the 'offside' tailstock leg, and then tighten them back down. That's what I did to my little vic, and it solved the problem. The thickness of the washers (both of them in my case) allowed the bed to twist just enough to remove the alignment problem.

wheelinround
4th February 2008, 03:15 PM
how old is this lathe if new take it back

check dimensions of the tailstock casting and slide area make sure its clean underneath

funkychicken
4th February 2008, 05:06 PM
wile you have the centers together like theat give each one a spin by hand (indervidualy)and see if they run true or if they wobble.:2tsup:

this will tell you if one is bent or worn.


Both centres run true


The lathe was bought by bob (robyn2839) used once, then sold to me - I've used it a fair bit so I dunno if it's returnable:?

DJ’s Timber
4th February 2008, 05:48 PM
Have you checked to see if the bed is flat? Take the tail stock off completely and put some winding sticks (http://www.leevalley.com/wood/page.aspx?c=3&p=53276&cat=1,41182) on to see if it's flat, might have twisted it if you've bolted it down. Check the bottom of the tail stock to see that there is no crud stuck to it or a bit of casting isn't lifting it.

robyn2839
4th February 2008, 10:20 PM
the thing that amazed me when i purchased this lathe was the fact thatthe centres were that exact that the two points actually stuck into each other ,which i was amazed by ,so possibly it could be bolted down causing a slight twist,sounds possible. bob

funkychicken
5th February 2008, 05:13 PM
The lathe isn't bolted down

:?

weisyboy
5th February 2008, 05:25 PM
what not blolted down?

whats keeping it from falling off the bench?

petersemple
5th February 2008, 05:39 PM
I'm guessing it's bolted to the stand, but the stand isn't bolted to the floor - in which case that's similar to my setup. From memory the Jet stand is similar to my MC900 stand. If that's the case then if you have added extra bracing or a few snadbags for weight in the stand, which I know a lot do, then that could have altered things a bit.

peter

funkychicken
5th February 2008, 05:41 PM
what not blolted down?

whats keeping it from falling off the bench?


The fact that it weighs 45kg and it's little rubber booties:p

I was gonna bolt it down until I realised it'll probably need to be moved soon and I don't have any roof screws.

Peter, I made my own bench for it


Interesting note: When I stick the pen mandrel in the lathe with the tailstock not brought up it doesn't spin true

weisyboy
5th February 2008, 06:31 PM
pen mandrel easly bend a large temp change can cause this or a bump be a nother tool or by being dropped.

funkychicken
5th February 2008, 06:48 PM
It's a brand new mandrel so it should not have anything wrong with it

ss_11000
5th February 2008, 06:49 PM
carl - pen mandrells mainly bend due to too much pressure being put on them by the tailstock. but you are right, dropping them or knocking them can cause it to.

weisyboy
5th February 2008, 07:03 PM
are you sure the MT's are fitting properly.

try mounting the blank losely in the chuck and mounting the chuck on the lathe. bring the tailstock with the drill up to the blank and line it up with center of blank and tighten chuck. this should get it as close as possable to lined up.:2tsup:

DJ’s Timber
5th February 2008, 07:13 PM
Have you check to see if the bed is flat by using some winding sticks? We can keep sprouting hints and tips at you, but unless you give us some more feedback on what you have done to check the problem, we can't really say much.

As I said in a previous post, have you done these and if so, what was the result?


Have you checked to see if the bed is flat? Take the tail stock off completely and put some winding sticks (http://www.leevalley.com/wood/page.aspx?c=3&p=53276&cat=1,41182) on to see if it's flat, might have twisted it if you've bolted it down. Check the bottom of the tail stock to see that there is no crud stuck to it or a bit of casting isn't lifting it.

weisyboy
5th February 2008, 07:19 PM
the dril bit might be bent.:?

funkychicken
5th February 2008, 07:28 PM
I'll try all you're ideas now...

funkychicken
5th February 2008, 10:22 PM
Tested for twist in the bed - none
Tried Carls idea - no dice

I tested to see how well the tailstock fitted on the bed and it has some wiggle. So If I wiggle it one way and lock it, the centres almost very nearly line up but if I wobble it the other way then the centres are nowhere near close.

The pen mandrel wobbled alot without the tailstock brought up but when I brought the tailstock up it stopped wobbling (like it should)

robyn2839
5th February 2008, 10:53 PM
The pen mandrel wobbled alot without the tailstock brought up but when I brought the tailstock up it stopped wobbling (like it should)quote

the mandrell should run true even before the tailstock is bought in

weisyboy
6th February 2008, 08:33 AM
if the mandrel i wobeling tehn rollit along a flat serfice to check for bends if it is straight then your problem it the hedstock being out of line/bent.

wheelinround
6th February 2008, 09:08 AM
FC measure the underside of the tailstock slides base front and rear both sides check for square of the slide ridge even measure the bit in the middle front and rear here in could be the problem.
If you can wiggle the base and get a closer line up the machining may have been a bummer.

boysie39
6th February 2008, 10:14 AM
Hello all, I am reading all the posts to try and make up for the the years I've missed all you nice Aussie people, and I mean that ,ask me brother if I'm a liar.Great forum we have one in Ireland and I signed in a year ago and it's still on the page as the last to sign in .Iwonder why anyway about this lining up lark, If you slacken off the headstock a little with the chuck on and bring up the tail stock with a live center in it ,enter the live center into the chuck and gently tighten the chuck after tightening the tailstock of course it will ease the two into alinement then tighten up your headstock anb Bobs your uncle.
I got told off on an US forum for having too long of paragraphs with out full stops and commas. I hope its not the same here. By the way if that system doesent work blame Andy Lodge a UK turning pro, If it does it was all me own idea.
Thanks to all for a lot of late nights but wonderful enjoyment and Ideas that keep this old fool active and looking forward to tomorrow to try something else out. Slan Leat and Regards Boysie.:U:roll:

petersemple
6th February 2008, 03:32 PM
if the mandrel i wobeling tehn rollit along a flat serfice to check for bends if it is straight then your problem it the hedstock being out of line/bent.

I check suspect mandrels on the lathe. Bring up the tailstock. With nothing on the mandrel bring up a pencil to the centre of it gradually with the pencil resting on the toolrest. turn off the lathe. The pencil mark should go all the way araound or nearly all the way. If the mark is only on part of the mandrel then a bit of pressure on the high spot (the part with the pencil mark) hould straighten it a bit then test it again.

Peter

weisyboy
6th February 2008, 04:20 PM
I check suspect mandrels on the lathe. Bring up the tailstock. With nothing on the mandrel bring up a pencil to the centre of it gradually with the pencil resting on the toolrest. turn off the lathe. The pencil mark should go all the way araound or nearly all the way. If the mark is only on part of the mandrel then a bit of pressure on the high spot (the part with the pencil mark) hould straighten it a bit then test it again.

Peter

this would be the way to do it but he is trying to see if it is the mandrel or the lathe so doing it in the late would not work out.

weisyboy
6th February 2008, 04:25 PM
I got told off on an US forum for having too long of paragraphs with out full stops and commas. I hope its not the same here.

na mate this is an ausie forum we (most of us) dont caer how long ya paragraph is and as for punctuation just forget about it we dont need a full stop or commer to tell us were to take a breath just tpe what ya want to say and we will understand it don matter if ya use proper gramma either and as for spelling well that dont worrie me as i cant spell anyhows im pretty sure you will fit in here no matter how you chose to type your mesages all were interested in is good woodowrking and good mates and yes this is a great for and has been the cause of manny late nights late starts and long breaks.

killerbeast
6th February 2008, 04:49 PM
na mate this is an ausie forum we (most of us) dont caer how long ya paragraph is and as for punctuation just forget about it we dont need a full stop or commer to tell us were to take a breath just tpe what ya want to say and we will understand it don matter if ya use proper gramma either and as for spelling well that dont worrie me as i cant spell anyhows im pretty sure you will fit in here no matter how you chose to type your mesages all were interested in is good woodowrking and good mates and yes this is a great for and has been the cause of manny late nights late starts and long breaks.

I couldent agree more. Im from Denmark and cant even spell in danish. But the guys and galls here are nice all the same :-)

funkychicken
6th February 2008, 09:35 PM
FC measure the underside of the tailstock slides base front and rear both sides check for square of the slide ridge even measure the bit in the middle front and rear here in could be the problem.
If you can wiggle the base and get a closer line up the machining may have been a bummer.


Uhh do you mean "measure the underside of the tailstock" ?

If so then I understand

wheelinround
7th February 2008, 08:01 AM
Uhh do you mean "measure the underside of the tailstock" ?

If so then I understand

:2tsup: Yes FChttp://www.woodworkforums.com/attachment.php?attachmentid=66345

looking at your last photo taken from above why not also check the vertical of the tailstock use a square and measure or visual and see if it doesn't lean to one side.

hughie
7th February 2008, 08:28 PM
:2tsup: Yes FChttp://www.woodworkforums.com/attachment.php?attachmentid=66345



looking at your last photo taken from above why not also check the vertical of the tailstock use a square and measure or visual and see if it doesn't lean to one side.


I'd say that you have fundamental problem relating to the machining. This is not easy to fix, unless you got a tame engineer around somewhere.

How serious is this for you? I know drilling out the pens on a ped. drill probably is not the ideal way to go. But it would alleviate the problem.
The rest can be taken care of, as a wood lathe is mainly free hand turning and any such problems can taken as you go along.

My chiwanese MC1100 has all sorts of dud machining aspects including a wonky tailstock. That not only is the wrong height but will swing a couple mm's side to side :U The headstock before I did some serious mods swung around like a weather cock and so on. But it still turns out a good bowl and or spindle or two. But then I must admit I dont turn pens.

funkychicken
7th February 2008, 11:07 PM
I'm pretty sure the MT and the small spindley bit of the pen mandrel are both straight...or maybe they don't screw into each other true...


The tailstock sits on the bed nice and flat.


Should the pen mandrel wobble at all? Even with pressure on it from the tailstock?

wheelinround
8th February 2008, 05:38 AM
FC the pen mandrel will wobble due to the misallignment and if you have as Stirlo said put to much tension on it.

The tailstock may sit flat but is it square up right/vertical and centred- square underside along the length of the slide area

Are the two machine surfaces underside the same depth and are they the same width from edge to inner edge.

If I can get to the lathe and take photo's today of what I mean I will.

funkychicken
8th February 2008, 08:46 PM
The mandrel wobbles even with very light pressure on it.

robyn2839
8th February 2008, 09:00 PM
i would wait till you have your get together ,and perhaps you can have this problem sorted out by someone who actually sees the problem,we can all offer different ideas ,but to see it in the flesh will help enormously and should be able to be sorted out.bob

funkychicken
8th February 2008, 10:30 PM
i would wait till you have your get together ,and perhaps you can have this problem sorted out by someone who actually sees the problem,we can all offer different ideas ,but to see it in the flesh will help enormously and should be able to be sorted out.bob


I'd have to agree with you there


Meanwhile I have another problem....My chuck is stuck on the lathe...

ss_11000
10th February 2008, 08:14 PM
Meanwhile I have another problem....My chuck is stuck on the lathe...
:rofl:

i had the same problem once

i just stick my knock out bar in the jaws and the spanner around the insert and twist them in opposite directions.:2tsup:

funkychicken
10th February 2008, 10:20 PM
:rofl:

i had the same problem once

i just stick my knock out bar in the jaws and the spanner around the insert and twist them in opposite directions.:2tsup:


See I kinda deformed the end of the knock out bar doing that...

But now my chuck is free, I used a 600mm shifter to shift it:D


And meanwhile the lathe has developed a tika-tika-tika etc.. noise when it's spinning.:~


I took the whole thing apart, only thing I found out was that someone had placed two bits of cardboard under the front points of the headstock. Bob??

wheelinround
11th February 2008, 09:30 AM
See I kinda deformed the end of the knock out bar doing that...

But now my chuck is free, I used a 600mm shifter to shift it:D


And meanwhile the lathe has developed a tika-tika-tika etc.. noise when it's spinning.:~


I took the whole thing apart, only thing I found out was that someone had placed two bits of cardboard under the front points of the headstock. Bob??

Tika-Tika-Tika noise I have had when I have over tensioned the belts FC slacken off a bit and it goes away.

Now lest hope the cardboard sorts out the alignment problem FC.

funkychicken
11th February 2008, 06:40 PM
Mooooo noise I have had when I have over tensioned the belts FC slacken off a bit and it goes away.

Now lest hope the cardboard sorts out the alignment problem FC.


I kinda removed the cardboard *innocent whistle smilie*

But the problem is that it needs to move sideways not upways:~


I fixed the Tika-Tika-Tika noise! There's a little trench in the spindle and a little thing goes into it to make sure the pulley spins when the spindle does and is tightened by a little grub screw..I tightened the screw, the sound stopped.

I must say that the spndle ( I removed it from the lathe) just screams quality and solidness

robyn2839
11th February 2008, 09:58 PM
See I kinda deformed the end of the knock out bar doing that...

But now my chuck is free, I used a 600mm shifter to shift it:D


And meanwhile the lathe has developed a tika-tika-tika etc.. noise when it's spinning.:~


I took the whole thing apart, only thing I found out was that someone had placed two bits of cardboard under the front points of the headstock. Bob?? no not bob if you found cardboard packed under the headstock i would be ringing jet up and asking why and i would not do too much pulling apart till you contact them. bob

robyn2839
11th February 2008, 10:00 PM
:rofl:

i had the same problem once

i just stick my knock out bar in the jaws and the spanner around the insert and twist them in opposite directions.:2tsup: why dont you take the chuck and insert off together?why would you seperate them?????

ss_11000
11th February 2008, 10:12 PM
why dont you take the chuck and insert off together?why would you seperate them?????

sorry..i meant to say put the spanner around the spindle ( the bit that insert rests against ), not insert.:-

funkychicken
11th February 2008, 10:22 PM
no not bob if you found cardboard packed under the headstock i would be ringing jet up and asking why and i would not do too much pulling apart till you contact them. bob


I put it all back together no worries...which is quite unusual for me:p

I'll give them a ring tomorrow...Colin wouldn't have fiddled with it would he have... no...


Should I call Jet Aus or US I'm pretty sure it's US made

robyn2839
12th February 2008, 05:22 AM
it came in an unopened box with warranty, bob

funkychicken
12th February 2008, 10:13 PM
I stuck the mandrel in the drill chuck it done spin good like. hardly no vibration what.

But when I put the tailstock up to it it didn't vibrate at all... but I'm pretty sure it was bending it. The tailstock point didn't enterthe mandrel sockety bit centred.

I dunno if this'll mess with any finished pens

funkychicken
21st February 2008, 10:37 PM
I had a brianwave:D


I know some tame machinists so I'll be able to do some machining - so much for snappy wordplay:doh:

I'm thinking I'll take a teensy bit off the base of the tailstock so that it'll sit at the right height and I'll put bearings on it that'll run against the in-side of the bed. So it'll move forward but not sideways.

Waddya think?