Lathe/Mandrel assistance

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Ardy

Ardy

Member
Joined
Jan 11, 2013
Messages
9
Location
Oliver, BC , Canada
I bought a Mastercraft lathe about a yr ago. It worked great for about 10 months then developed (not sure of the correct term) a vibration in the mandrel that made it pretty much impossible to turn anything. Tried a new mandrel in it, same thing. Took it in for warranty repair they said nothing was wrong with it but because they had it for two months, I bought another Mastercraft lathe (stupid me) it worked great for 3 months now it's developing the same thing. My husband (former auto mechanic) took the first lathe apart and replaced the shaft and bearings in the headstock. The original shaft had wear on it and he said one of the bearings was noisy.... but when we ran it up again, same problem. There's not much else in there.. and the motor purrs along so what the heck is the problem?? Any idea's?
 
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Do the centers of the tail stock and head stock line up? What are you using in the tail stock? Could the dimple in the end of your mandrel be getting out of center? Does the vibration only occur when using the mandrel?
 
If I were you I would save my money and get a better quality lathe. My wife works for Canadian Tire and those lathes will not stand up to use they were intended for. I know people are on a limited budget but in Canada the General lathes are more like the Jet they have in the US. There are a few people out west that have the Jet and I think they got them in the US as there are no Jet dealers out west.

Lin
 
I had a similar issue on my powermatic. What had happened to me was the tail stock wore a grove in the end. Of course I did not see the grove. So it would not line up with the mandrel end some times, and then shimmy when I was cutting. When it lined up it worked fine. I also bought another mandrel thinking i had bent it. Two solutions I found were as follows. My friend Karl at the local WC told me to take a diamond file, (I have a flat plate type) and re- true my tail stock which I did. Simply left it in the lathe and turned it by hand took 5 min or so. This was nice to have a tail stock to use and save $50.00-$100.00 instead of buying a new one. The best thing I found to do is buy the tail stock the PSI sells we're the end of the mandrel goes into a hole in the mandrel. Do not use the nut to tighten the tail stock. leave it off. When you bring the tail stock up the tail stock pushes on the end pen bushing. It works very well. Good to run grand kids are here.
 
Tom T said:
I had a similar issue on my powermatic. What had happened to me was the tail stock wore a grove in the end. Of course I did not see the grove. So it would not line up with the mandrel end some times, and then shimmy when I was cutting. When it lined up it worked fine. I also bought another mandrel thinking i had bent it. Two solutions I found were as follows. My friend Karl at the local WC told me to take a diamond file, (I have a flat plate type) and re- true my tail stock which I did. Simply left it in the lathe and turned it by hand took 5 min or so. This was nice to have a tail stock to use and save $50.00-$100.00 instead of buying a new one. The best thing I found to do is buy the tail stock the PSI sells we're the end of the mandrel goes into a hole in the mandrel. Do not use the nut to tighten the tail stock. leave it off. When you bring the tail stock up the tail stock pushes on the end pen bushing. It works very well. Good to run grand kids are here.
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I use #1 Mt mandrel and mandrel saver from Penn State. Will check on alignment on the 1st lathe but know that the 2nd lathe is very true as I use it daily.
 
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lorbay said:
If I were you I would save my money and get a better quality lathe. My wife works for Canadian Tire and those lathes will not stand up to use they were intended for. I know people are on a limited budget but in Canada the General lathes are more like the Jet they have in the US. There are a few people out west that have the Jet and I think they got them in the US as there are no Jet dealers out west.

Lin
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I would now agree with you that the Canadian Tire lathes are (searching for acceptable word) poor. They start out good but 200 pens later not so good.

I am looking for a new lathe, but it needs to be light enough for me to lift it in and out of a storage locker in the community workshop pretty much daily. I can handle about 40 lbs (medium sized retired woman). Am wondering about The Apprentice 812 from Craft supply. Any idea if this is good lathe?
 
Have you cleaned out the Morse tapers in your lathe spindle and tailstock? Maybe you have some gunk in there that is keeping your mandrel / mandrel saver from seating properly.

Ed
 
Have you tried getting rid of the mandrel entirely for a test and turning something between centers to see if the problem is there when you do?

If it is then it could be wear in the taper of the head, tail stock, or in the live center bearing. (you could probably get an indicator of this by any scuff marking on the polish of the mandrel tapers, there should be none).

Basically, the live center and the dead center (in the headstock) should show absolutely zero play (movement) when fully inserted if you try as hard as you can to make them wiggle (with the tailstock locked down so it can't wiggle - it shouldn't be able to either). The points of the dead and live center should show absolutely no movement around their center point either when viewed from the end as they are turning (make sure the alignment is near perfect then move them to almost touching and rotate one then the other and observe it under magnification).

If you have a drill chuck that will fit your headstock then put a piece of long piece known perfectly straight rod in it (drill rod works fine but any good quality cold roll round bar should work) and rotate it slowly. If anything is off alignment with the axis you will see wobble on the end, if in alignment it should run true with no wobble).

Vibration in a rotating part always leads me to suspect bearing or shaft wear first, and less common causes second.
 
If the vibrations are only when using a mandrel then I suspect you are using the cup centre in the tail stock that came with the lathe, the point of which has worn and doesn't hold the tip of the mandrel properly anymore. Are you using the point of the cup centre or a live centre with the 60 degree cone?
 
Ardy said:
lorbay said:
If I were you I would save my money and get a better quality lathe. My wife works for Canadian Tire and those lathes will not stand up to use they were intended for. I know people are on a limited budget but in Canada the General lathes are more like the Jet they have in the US. There are a few people out west that have the Jet and I think they got them in the US as there are no Jet dealers out west.

Lin
Click to expand...
I would now agree with you that the Canadian Tire lathes are (searching for acceptable word) poor. They start out good but 200 pens later not so good.

I am looking for a new lathe, but it needs to be light enough for me to lift it in and out of a storage locker in the community workshop pretty much daily. I can handle about 40 lbs (medium sized retired woman). Am wondering about The Apprentice 812 from Craft supply. Any idea if this is good lathe?
Click to expand...

I would say that the 812 is more of the same as what you have now. Have you seen the new Nova Comet. It's a little more money but I have heard good things from the people that have them on hear. They have them up at the KMS in Kelowna

Lin
 
lorbay said:
Ardy said:
lorbay said:
If I were you I would save my money and get a better quality lathe. My wife works for Canadian Tire and those lathes will not stand up to use they were intended for. I know people are on a limited budget but in Canada the General lathes are more like the Jet they have in the US. There are a few people out west that have the Jet and I think they got them in the US as there are no Jet dealers out west.

Lin
Click to expand...
I would now agree with you that the Canadian Tire lathes are (searching for acceptable word) poor. They start out good but 200 pens later not so good.

I am looking for a new lathe, but it needs to be light enough for me to lift it in and out of a storage locker in the community workshop pretty much daily. I can handle about 40 lbs (medium sized retired woman). Am wondering about The Apprentice 812 from Craft supply. Any idea if this is good lathe?
Click to expand...

I would say that the 812 is more of the same as what you have now. Have you seen the new Nova Comet. It's a little more money but I have heard good things from the people that have them on hear. They have them up at the KMS in Kelowna

Lin
Click to expand...

Never heard of it but will investigate. Thanks for the tip.
 
Ardy, I think Frank has the right idea. Put a dead center in the head stock, 60 degree live center in the tail stock (forget the mandrel saver). Bring the two together. If they line up, the lathe is good. Get you some bushings to turn between centers, you won't have any more problems. Unless the lathe realy is that bad!
 
Curly said:
If the vibrations are only when using a mandrel then I suspect you are using the cup centre in the tail stock that came with the lathe, the point of which has worn and doesn't hold the tip of the mandrel properly anymore. Are you using the point of the cup centre or a live centre with the 60 degree cone?
Click to expand...

Same thoughts here. The live center that comes with the lathes does not have a point to match the center in the end of the mandrel. Before I got a 60 degree live center (one made for metal lathes) I filed the point on the one so not so 'pointy'. Then it will sit in the mandrel taper better and not be just running on the point in the bottom of the center.
 
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