Setting up the pen mandrel

[Stuart]

Finally had the opportunity to set up my pen mandrel with the taper in my new Jet mini. My question is - given how sharp the ?live? centre is, how do you get the free end of the mandrel to centre properly? On my GMC, that end is so blunt, it centred easily, but now on a decent lathe, that end shows a little eccentricity.

Secondly, and part of it, is there any danger of blunting the live centre by using it in the end of the pen mandrel? My GMC one is so blunt from years of pen-turning that I couldn't poke out an eye, but I'd like to keep the new lathe in a bit better condition.

Any advice appreciated (and any general pointers about the Jet Mini as well)

I like birthday presents :) and a second salvo tomorrow :D

[DJ’s Timber]

G'day Stuart

The angle on the live centre that comes with the Jet Mini is to steep, you need to either pop the centre out out and re point so that the cone itself picks up the mandrel not the point.

The easiest way out is to get another live centre that is suited to the mandrel and use the other one for when you are doing some spindle turning.

[jchappo]

I use a live centre with a cup. The point is short and doesn't bottom out in the dimple of the mandrel.

[lubbing5cherubs]

Gidday John, can you direct me in the direction so that i can see what you mean
bye Toni

[Skew ChiDAMN!!]

Secondly, and part of it, is there any danger of blunting the live centre by using it in the end of the pen mandrel? My GMC one is so blunt from years of pen-turning that I couldn't poke out an eye, but I'd like to keep the new lathe in a bit better condition.

Yes! They will cause the centre to wear eventually. Here's a pic of the cheap one I've used with my mandrel for the last two years or so. This was the right size originally, it's just a couple of years of use and abuse that's done the damage. [sigh] As it has been worn by my mandrels, it still centres perfectly for all that it looks like crud. If one of my mandrels had a different taper, I think it'd be a different story but fortunately all of mine are identical. [phew!]

My suggestion would be to buy a second one that's about the right angle... and use only that one with the mandrel.

(Oddly enough, my "damaged" tail-centre has proven very handy in other applications where a more conical one tends to split the wood. eg. turning lace bobbins. Go figure! :D)

[Penpal]

Stuart I find that live centre connection the worst way to do it,what I do is buy the live centre with a removable pointy bit and make a brass replacement centre with a 1/2 inch hole a snug fit for the end of the shaft and hold the blanks up to live centre with the spacers. Please see pic any questions I will help in explaining,this is the answer to stuffed up fixed live centres and holds the shaft better. On the other hand two things come to mind one your live centre pointed part can be a different entry angle to the hole in your shaft,two alignment ie centre of the headstock and centre of tailstock could be out,this you can check easily using a morse tapered point either end bring them together and lock the tail stock or use a thin strip of metal when you bring them together,if there is an error the thin strip will twist in that direction,if it is on centre will stay in place. I use a car feeler guage.
Peter

[Barry_White]

Stuart

When I ordered a pen mill and a 7mm drill from Gary Pye Woodworking he sent me a spare centre point which when you pop the live centre out of the morse taper you push the point out of the live centre with the pin with the knob on it.

Gary Pye told me to grind point off the spare one so it bears on the sides of the recess of the pen mandrel so that when you put the pressure on the tail stock the live centre will spin.

Hope that is clear as mud.

BTW I also have the Jet Mini and I would never had known the centre point popped out if Gary Pye hadn't told me.

[Touchwood]

how do you get the free end of the mandrel to centre properly?

Oh to have that problem, my birthday present Mini Jet has gone back already with a problem - not out of the box a month. I was concerned when I started using it how warm the wheel and head stock bits were getting.

When I enquired I got a sort of... "well love (in an almost suck air through teeth type way), friction creates heat ....., will get a bit hot, but if your worried bring it in and we'll take a look" type answer.

Anyway, played for a while, checked belts, decreased down ward pressure on motor etc but to not avail - so I took it back, complete with roughing gouge and wood so I could show them!!!

"Oh yes it is getting hot, the bearings must be stuffed!! Leave it and we'll fix it, but it won't be ready 'til mid January!!"

JD

[lubbing5cherubs]

JD no fun. you always get a dud with every make bummer you had to get it.
Skew that the one i Have. I did not know there was so many different one that why I began asking ot see what they meant
bye Toni

[tashammer]

JD it also sounds like you get a dud with whoever you get from the store - the "2 bricks Method of Seizing Attention" is quite good, i believe. The final method should only be tried under the direst of circumstances as there is no going back and saying things like "Would a band aid help?"; this is, of course the famous, "Bobbit Method of Attracting Attention". However, one has to say that you only have a short time to get your point across before they pass out, so rehearsal is strongly supported so that you get your timing right.

And a Happy Nude Beer to You and Yours

he cackled, layed an egg, looked confused. (Well it's 'mas, innit?).

[Skew ChiDAMN!!]

Skew that the one i Have. I did not know there was so many different one that why I began asking ot see what they meant

It's one of the cheapest available, but it's perfectly OK to support a pen mandrel. In the better centres the the spur in the middle can be removed and replaced with others. There's a whole heap of different types but, really, they all do the same thing.

[lubbing5cherubs]

Hey Jenny it got the poops with your for making it wait so now it making you wait :P
Toni :D

[Penpal]

Must admit if they did that to me for them walking with a limp as our Tassie friend advised how to use the two brick method would seem the least you could do for them.Sometimes sales exceed service.Remember in the 60s as a sparkie at the airport I was in the control tower and a RAAF light aircraft training plane was doing circuits and landings and the wind came up and created merry hell to control the plane.Next thing I heard was the trainee pilot requesting visual permission to land in a hurry,traffic controller said I can not see you with that the plane flopped down a big gust of wind flipped the plane onto the prop causing all sorts of excess noise etc and a muffled shout came over the intercom,now can you Swearing deleted see you dopey whatever.
Could be this person with no manners may be impressed with a visit from a friend or two big enough to be noticed and remembered by the big gust of wind and loud noises.Feel badly for you having the rough time,another suggestion get a brand new replacement or at the very least a loaner. Take care Peter

[tashammer]

It is quite sad that manners seems to have almost become extinct. I knew an old gentleman, alas, passed on now, who's manners were exquisite. It was delight just to stand and listen to him dealing with a customer. What a pity no-one videoed him. Bless Mr. Beauchamps where ever you are now.

[Stuart]

Well ladies and gentlemen, you have all convinced me that I was correct in thinking that I needed to pay attention to the tailstock for pen turning (as opposed to what I heard in the shop.)

Will look into this further. I had noticed that the centre pops off, so good to hear they are available as replacement parts.

I haven't checked the alignment between the head and tail as yet - on my to-do list. Didn't get to jump back on it today (Xmas) - I get a little more latitude on my birthday :D Did get to turn a nice pen in Mulga for my mum for Xmas - she was watching at the time, and didn't realise I was making her present :) Damn - that Mulga is bloody hard - got it smoking with the sandpaper, and the EEE!

[soundman]

I baught a different live centre when I baught my mandrel.

The supplied live centre has both its advantages and its limitations,
A plain standard cone type live centre is a good thing to have on hand, I use it most of the time.

cheers