Mandrel Saver questions

[Mike]

Reading posts on here for several hours the last couple days. Many tips and issues with mandrels and mandrel savers. I am happy with my mandrels and am getting excellent (IMHO) final results using them.

Sometimes when still square, the blanks will stop or squeal and I have to stop and tighten the knurled nut. My tools are sharp. Will the mandrel saver help this? Is there a mandrel saver that fits both the .250" and .290" shafts? Adapter?

I have not had a problem using the stock live center that came with my lathe, but today I found out I should be using a 60 degree center. Have not damaged the original, but I checked the Nova Live Center kit I bought and it came with one, so I am switching to that for now.

 

[Edgar]

A mandrel saver accomplished pretty much the same thing as tightening the knurled nut, but is easier & quicker to adjust & align.

A mandrel saver also works better with fixed length mandrels. You can slide it all the way down to the top bushing without having to stack up spacers or bushings to get to the threads for the nut. A shorter mandrel reduces the chance of bending it. It also gives more rigidity to the assembly than the point of a live center.

 

[MedWoodWorx]

Reading posts on here for several hours the last couple days. Many tips and issues with mandrels and mandrel savers. I am happy with my mandrels and am getting excellent (IMHO) final results using them.

Sometimes when still square, the blanks will stop or squeal and I have to stop and tighten the knurled nut. My tools are sharp. Will the mandrel saver help this? Is there a mandrel saver that fits both the .250" and .290" shafts? Adapter?

I have not had a problem using the stock live center that came with my lathe, but today I found out I should be using a 60 degree center. Have not damaged the original, but I checked the Nova Live Center kit I bought and it came with one, so I am switching to that for now.

I use a belt sander to make the edges a bit round before turning, it makes things easier for me. The only thing that a mandrel saver will save is the mandrel as the word implies: after some time tightening the nut, the mandrel will bent more and more thus the tubes will be less and less concentric.
However maybe you should try turning your blanks without one and save yourself money and time. Check out tbc ( turning between centers) in the library.

 

[leehljp]

I have not had a problem using the stock live center that came with my lathe, but today I found out I should be using a 60 degree center. Have not damaged the original, but I checked the Nova Live Center kit I bought and it came with one, so I am switching to that for now.

Initially using the stock live center, things go OK, but it doesn't take much time before the stock live center point balls up and OOR (Out of Round - as we say colloquially) rears its head. That point is not meant for a mandrel, period. That live center point is meant for wood. The mandrel has a 60° cup in which a 60° point is supposed to fit in snugly. Mandrels are made of metal (Of course) and as such requires a point made for metal - or the 60° point. IN a machinist's (metal) world, 60° is the standard point angle and therefore why the mandrel (metal) has a 60° cup.

You can use the original point, but it is only going to be a short while before the point balls up and throws the concentricity off.

 

[its_virgil]

I have 5 of the mandrel savers from PSI. No problems with any of them. I have one for each of the 4 mini lathes for the times I need all 4 lathes. The 5th one has the hole enlarged for the B mandrel. I have no experience with non PSI "mandrel savers".
Do a good turn daily!
Don

 

[AllanS]

Hey Mike - I'm also in Abq.
IMO the mandrel saver won't help with the stops. It just meant that I had to end up tightening up the tailstock. But I went with the mandrel saver in order to be able to turn without having to use spacers. Using a belt sander to get a head start on the turning by taking down the corners as @MedWoodWorx mentioned is a good tip that I use as well.

edit : for mandrel savers that fit drill shafts, you might want to look at this thread for @egnald's comments - but he steered me to a mandrel saver with a clamp collett

 

[Mike]

Thanks for the replies and advice. I am going to order the mandrel saver insert for my Nova live center from Wildaness Woods.
I have a fair amount invested in mandrels and bushings, not ready for TBC yet.

 

[Mike]

Wildaness woods is out of the mandrel saver insert for the Nova live center. I searched the web and don't see other options. Anyone know of another source?

I thought about finding a 1/4" ID bronze bushing and modifying it to fit the live center, but am not sure if it is worth the time.

 

[zorro9]

Hi Mike, just read your msg. I've ran into similar issue and noted the tool rest may be high or low depending on what tool your using.

 

[Mike]

Thanks for the reply, I am not a seasoned turner, have had my lathe 10 plus years, but have very time little using it. I am now discovering some of the pitfalls but having a mostly fun and satisfying time turning. Final products are turning out nice, but some frustration getting there.
I was turning a handle for a pigtail flipper last night from a 2" square stick of maple. The wood is so hard the drive center does not easily penetrate the end enough not to slip and is also potentially a little dangerous. I drilled a hole in the end about 1/4" deep with a spade bit. The hole in the center from the point of the bit is too large for the spur point, so it does not stay centered. I just centered it and drove it in with a mallet and got the handle finished. Turned out nice.
I will search for better way to ensure stock is centered and secure.

Wildaness Woods now has the mandrel saver insert for the Nova live center. I ordered it and it has shipped. I found plans for a small sled for the bandsaw to hold the blanks while cutting off the corners. I am going to build one of those, possibly today.

 

[Mike]

I ordered the mandrel saver insert for my Nova chuck from Frank at Wildaness Woods about 3 weeks ago. The website said it was in stock. I still have not received it and no correspondence other than the order received email. I left a message at the phone number on the site and sent an email. I am worried he is ill or something. Anyone know Frank? Is this typical behavior?

Thanks,
Mike

 

[Smokey S]

Hey Mike, you can get a center drill to start the inset bevel in the end of your work. This is what is used in a regular machine shop to create a divit for a center. And oh yes, I have been understanding routinely the frustrations of getting there. Mostly with my own criticism. Just saying.........Smokey

 

[Mike]

All,

I had Rick H. fabricate the mandrel saver insert for my Nova live center. I believe it was the first one he has done. It turned out really nice and fits my mandrel perfectly. I also ordered a tool rest post and a couple rests and the offset sanding jig with the new offset mount. Very nice work, can't wait to use these on my next pen. First I am going to attempt a 2" sphere my wife wants for a decoration. Probably use the tool rest first.

I am still worried about Frank at Wildaness Woods. He has not sent me the part I ordered from him or replied to an email or phone call. I hope he is OK. His website is still up.

Thanks,
Mike

 

[David350]

Mike, one of the things I do with my mandrel saver is that on a 2 barrel pen like a cigar, I turn the barrels one at a time. When I was turning with both barrels on the lathe at the same time, I would get a significant amount of "chatter" especially with the "acrylic" blanks. When I switched to a single barrel at a time, this issue went away. Once I have turned the second barrel, I put the first barrel on and proceed with the sanding / finish / polishing, CA application, etc.

At first I really hated the single barrel process as I thought it was going to waste a lot of time and I stubbornly stuck to trying to turn with both blanks on the mandrel / lathe at the same time. Once I switched to the single blank system above, it was so much easier to turn and I had better results. Additionally, one is much less likely to bend the mandrel, especially using a mandrel saver (I use the PSI system). I was kicking myself for not switching my process earlier and I think it actually goes faster now that I don't have to worry about the chatter and I get a better turned finish. Good luck!

 

[Mike]

Thanks for the input. I will be turning a few pens this week, I will try both ways. The mandrel saver insert Rick made should have almost no runout. ID is only .001 bigger than mandrel. His work is very nice.

 

[Mike]

I got the mandrel saver insert from Rick H and turned a few pens using it. I actually bent my mandrel shaft because I over-tightened the tail stock trying to stop the stopping. I ordered a new mandrel shaft and a second mandrel and I am going to try David's advice and turn 1 barrel at a time using mandrel saver. I will use one for the mandrels for finishing both tubes at once.
And just so we are clear, I am not saying Rick's mandrel saver was the cause, it is very nicely done and I just over tightened the tail stock.
The tool rests and bland squaring jig are also very nice.

Mike

 

[MedWoodWorx]

..actually bent my mandrel shaft because I over-tightened the tail stock trying to stop the stopping.

I find that grinding the edges of the wood blanks at the belt sander helps a lot with stopping. Cheers

 

[Mike]

I find that grinding the edges of the wood blanks at the belt sander helps a lot with stopping. Cheers

Yes, I was trying to avoid that step. Probably should stop being lazy......
I made a small sled for my bandsaw. I should make one of the jigs I have seen on here for cutting the corners off blanks now that I have it.

Thanks for the reply.
Mike