Mandrel Help!! does my mandrel have a problem

[RyanNJ]

Here is a video of my mandrel at 500 rpm.
i have noticed that my pens are not completely round, they will match up to the band pretty well but part of the blank will be shallower almost as if the blank is an oval.

is the wobbling a problem? how do i correct it? where can i get a new rod for my mandrel?

this is the kit i was going to use for the beautiful pen contest but i want the parts to match up, if i am correct and my mandrel is bent it looks like i will not be able to make my pen


[URL=http://s284.photobucket.com/albums/ll24/LbIfisherman429/?action=view&current=2_5_10downloadjenbdaymasterbathetc1.flv]
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[RyanNJ]

Sorry for the bad video quality i thought they would be better... if needed i can try to take another picture

 

[ed4copies]

Ryan, video seems like a good idea, but without a tripod to control the movement, I think we are SOL!

IF you try again, leave the tool rest near the mandrel, so there is a "frame of reference" that will not move.

Sorry I can't be more help, yet.

 

[RyanNJ]

that was a cell phone video. i am going to take a video now with my camera and i will delete the others once i get it posted

 

[Mac]

If you lay a tool or screwdriver on the mandrel (not cutting edge, the back of tool some where along the shaft)with the lathe running you can tell somewhat, if it is round ,tool will not move if round or will not vibrate ,if out of round it will bob up and down or vibrate. I would try without bushings and brass first to see if it is the mandrel shaft itself ,then you can check bushings the same way, also the brass or you can get brave as I have done and turn ,with lite touch and not very much, the none pen end of bushing to see if it is the bushing itself. if round you should get a cut with your tool all around the bushing if it is out of round you wil get a cut on one side.
Hope this helps.

 

[RyanNJ]

ok. Mac i will go try that.

if it is indeed OOR where should i get the new mandrel and 60 degree livecenter

 

[Mac]

Is that a 60 degree live center or the one that came with the lathe???
All pen mandrels must mate with a 60 degree live center to match up with the 60 degree concave in the mandrels.

 

[RyanNJ]

that is what came with the lathe.
when i bought all of my pen stuff they said i did not need a different live center but from reading here it looks like i do.
where is the best place to get that?

 

[Mac]

that is what came with the lathe.
when i bought all of my pen stuff they said i did not need a different live center but from reading here it looks like i do.
where is the best place to get that?

When I started turning pens ,I bought a cheap mandrel around $10 bucks and did not know about the tailstock thing ,with the 60 degree live center. I messed up my mandrel shaft and my tailstock and several pens before I found this site. If you are on a buget ,I would buy one(60degree live center) from Grizzly that is what I have, BUT I have used mine pretty hard and it is starting to wear with a side to side motion ,I think the bearings are about to go. If you want a good live center and plan to make other stuff like bowls and pepper grinders, I would buy the oneway with the pen cone attachment. This is on my wish list. Craft Supply item#130-2200 and 130-3673. I know some turners that have this. and use it ,to its full potential. I also now have the adjustable mandrel .

 

[ed4copies]

Check "Landfill Lumber" (a member here), sometimes he has live centers (very reasonable)

 

[kennspens]

Penturnersproducts.com also has 60 degree centers for a reasonable price

 

[RyanNJ]

i will look into landfilllumber

where should i get the replacement mandrel rod?

 

[leehljp]

that is what came with the lathe.
when i bought all of my pen stuff they said i did not need a different live center but from reading here it looks like i do.
where is the best place to get that?

That is the rant that I have against commercial enterprises whose job is to "sell" what ever they have on hand - rather than to the real "need" of the customer. To some people, that is "good enough". A motto that I often go by: "Good" is the enemy of "Best".

Something that you might want to check on is TBC - Turning Between Centers, which is turning without a mandrel. It is different, uses less parts, and increases accuracy/precision in most cases. Normal bushings (except for slimline type of pens) will work but JohnnyCNC makes precision bushings, and bushings for TBC with slimlines also.

Hans (Hewunch) sells some great delrin bushings which greatly reduce CA sticking also.

If you check the commercially available bushings against John's, you will find a huge quality difference, especially in the "fit" department. His "pop" out, while the commercial bushings have a lot of slop in the fit. This alone contributes to difficult "fitting".

 

[altaciii]

Or Johnnycnc, he has all the tools you may need, and some suggestions at no cost. His website :

http://penturnersproducts.com/

 

[RyanNJ]

I have toyed around with the between centers thing but i want to get my moneys worth out of what i have, i bought all the bushings for the kits i use. i think what i am going to do is turn 1 blank at a time when i order/ get a new mandrel and live center.

how much am i look at to turn between centers? and what do i need

 

[Mac]

For the one that I messed up I went back to woodcraft cause that is where I bought the orginal.
On the 60 degree live centers you have to remember that I turn alot of different things and I will need a better center than some. I don't want to buy one every year. And don't know about any other than I mentioned. If you need a piece of equipment and get a recommendation from others make sure that their use is the same as yours!

 

[ed4copies]

Ryan,

This mandrel will work well

http://www.pennstateind.com/store/PKM-FLC.html

It allows you to turn one half of the pen, at a time. You MAY be able to get it through "www.woodnwhimsies.com" or "www.woodturningz.com" at a slightly lower price and better customer service.

I have a few of these, they work for me.

Yes, I have turned "mandrel-less" as well, it's nice, but I stick with the mandrel 90% of the time.


YMMV

 

[RyanNJ]

that is the mandrel i am using now so all i need to do is buy the replacement rod correct?

 

[Mac]

If it is bent or the concave is messed up . Woodnwhimsies carries replacement rods for that one and is cheaper than pen state and better service.

 

[RyanNJ]

ok i think that is the way i am going to go.

 

[leehljp]

how much am i look at to turn between centers? and what do i need

1. Dead Center - # 1 Or #2 MT depending on your lathe $10 - $13 plus shipping.

2. For Slimlines special bushings $12/$13 plus shipping.

3. Normal bushings can be used in most cases on TBC, but they are not as precision made.

While most people think that custom bushings that JohnnyCNC and Hewunch make are too expensive - they are worth it.

IF a person really wants to step up their precision finish AND extend the life of bushings - use calipers to determine the size, not the bushings. Even with Johns and Hans, they will get sanded and will have a chisel touch them over time. The OD of the bushings will be reduced to the point that they can be used to accurately determine the size of the blank. AT that point, a new set of bushing will be needed. For the most part, bushings are regarded as "consumables". BUT with determining the sizing by calipers instead of the bushings, it does not matter if the bushings are reduced in size at the neck from sanding or chisel bumps.

 

[RyanNJ]

it looks like the bushings are anywhere from 11-$25 per kit is this true

 

[jeffnreno]

TBC Bushings

it looks like the bushings are anywhere from 11-$25 per kit is this true

That is true - But you will not believe the difference - These bushings are made to much more exact tollerances

 

[johnnycnc]

it looks like the bushings are anywhere from 11-$25 per kit is this true

Yep. And if you try just one set, you will be in jeopardy of being spoiled.
Expensive? All depends on how you look at it, and what you are after in this game.
Add up the cost of replacement mandrels, replacements for chewed up live centers, and the cost of made in Taiwan bushings,
plus the possible aggravation factor when your barrels are off center to your kit parts.
I'll brag on my product, and say it may well be one of the biggest improvements you make to your pen turning, if you are looking for better results.

 

[keithkarl2007]

Even with a 60 degree live centre, if you apply too much pressure on the tailstcok you'll still bend the mandrel slightly.

 

[RyanNJ]

Yep. And if you try just one set, you will be in jeopardy of being spoiled.
Expensive? All depends on how you look at it, and what you are after in this game.
Add up the cost of replacement mandrels, replacements for chewed up live centers, and the cost of made in Taiwan bushings,
plus the possible aggravation factor when your barrels are off center to your kit parts.
I'll brag on my product, and say it may well be one of the biggest improvements you make to your pen turning, if you are looking for better results.

so i would want the steel bushings or delrin?

 

[johnnycnc]

so i would want the steel bushings or delrin?

The steel are good for turning, sanding..whatever.
Delrin are primarily for finishing, but some people are coming up with other crazy uses for them, too!:biggrin:

 

[leehljp]

Yep. And if you try just one set, you will be in jeopardy of being spoiled.
Expensive? All depends on how you look at it, and what you are after in this game.
Add up the cost of replacement mandrels, replacements for chewed up live centers, and the cost of made in Taiwan bushings,
plus the possible aggravation factor when your barrels are off center to your kit parts.
I'll brag on my product, and say it may well be one of the biggest improvements you make to your pen turning, if you are looking for better results.

I will say the same thing. And I don't get anything compensation or ask for it either for intentionally mentioning John's quality work! I get rewarded by not having problems with his bushings that I had with commercial bushings.

My spending on bushings went down once I got one set of his for each pen model that I use - plus I don't have to replace mandrels anymore.

AS Dizzy Dean used to say: "If you did it, it ain't braggin!" :biggrin:

 

[RyanNJ]

i am getting mostly everything to go TBC if i decide to go that way but i am going to hold off on the bushing for now. i just wish that i could get the TBC bushings are a madrel through the same person

 

[johnnycnc]

i am getting mostly everything to go TBC if i decide to go that way but i am going to hold off on the bushing for now. i just wish that i could get the TBC bushings are a madrel through the same person

PM me, and I can make that happen, if you are sincere.

 

[ed4copies]

You can't beat John's quality, if that's the direction you choose to go!!!

 

[RyanNJ]

That is what I am leaning towards but I need to hold off for a little while before i take the plunge

 

[RyanNJ]

ARGGGHHH!!!!!!!

I am beyond frustrated.
i bought a drill chuck and new mandrel rod.
when i put the drill chuck in the bit does not spin perfect.
and the brand new mandrel rod is wobbling. I give up. what i am i doing wrong????

 

[leehljp]

ARGGGHHH!!!!!!!

I am beyond frustrated.
i bought a drill chuck and new mandrel rod.
when i put the drill chuck in the bit does not spin perfect.
and the brand new mandrel rod is wobbling. I give up. what i am i doing wrong????

Do you mean that you mounted the drill chuck on the lathe? IF this is what you mean then here is a possibility: some tapers are extra long and do not seat well in the head stock of some lathes. I experienced this on my Rikon. I had to grind some edges off of the MT on the back end of the taper. Since then, no problem.

Not your problem - but it is similar: On the tail stock, some people want to turn the rear handle to the point that the MTaper is fully recessed to the back. This does not work on the tail stock as the full recess is intended to unseat the morse taper.

IF you are talking about a DP, then that is another situation altogether.

 

[leestoresund]

Mandrel problem

JR Beall has a video where he straightens a mandrel by hitting it with a hammer and measuring the correction with a micrometer, you know, one of those used to set alignment on your saw, or set up the blades on your jointer.

May be on youtube.

Lee

 

[RyanNJ]

Do you mean that you mounted the drill chuck on the lathe? IF this is what you mean then here is a possibility: some tapers are extra long and do not seat well in the head stock of some lathes. I experienced this on my Rikon. I had to grind some edges off of the MT on the back end of the taper. Since then, no problem.

Not your problem - but it is similar: On the tail stock, some people want to turn the rear handle to the point that the MTaper is fully recessed to the back. This does not work on the tail stock as the full recess is intended to unseat the morse taper.

IF you are talking about a DP, then that is another situation altogether.

drill chuck mounted on the lathe.
that and my mandrel wobble.

I am to the point that if there is anyone in my area that makes pens i want to visit them to see how they do it or have then visit me to see what i am doing wrong.

 

[timcbs]

You may want to try turning between centers, it is like night and day deference but you would need to buy new bushings, once you try it you will wonder why you ever used a mandrel, check with member Jonnycnc he sales all that stuff.

 

[timcbs]

Here is a link to the video http://www.youtube.com/watch?v=_c--nfxh8og

 

[RyanNJ]

You may want to try turning between centers, it is like night and day deference but you would need to buy new bushings, once you try it you will wonder why you ever used a mandrel, check with member Jonnycnc he sales all that stuff.

I have been toying around with that idea.

but if my drill chuck and mandrel are not turning right i have little faith that TBC will do anything different.

The $150 i would need to spend on bushings is something i am also apprehensive about