Time to get better components, need suggestions

[godfreytoddanderson]

I have had problems with my last three pens. They all have a CA finish and I have been seeing patchy areas that are not glossy. The non-glossy areas cover about one third of the pen in random areas and the rest of the pen looks perfect.

After doing a lot of experimenting and testing I have come to the conclusion that it is my mandrel and live center that are causing this problem. I am using a Jet Mini lathe, the standard Woodcraft mandrel

http://www.woodcraft.com/family.aspx?familyid=3759

and a Little Machine Shop live center

http://www.littlemachineshop.com/products/product_view.php?ProductID=1189

My testing has shown that the mandrel is bent and the live center is wobbling. I've never really liked the live center because it is much noisier than the live center that I started with (the one that comes with the Jet Mini lathe which I know has the wrong angle on the tip).

So, here is my question. What do you think is the best mandrel (I'm ok with doing one half of the pen at a time if it fixes this problem) and what is the best live center. Price isn't really an issue here, whithin reason. What I mean by that is if I should have bought the heavy duty live center for twice the price its a small price to pay.

 

[its_virgil]

I know many penturners who use that live center with no complaints. I have two myself. My two make no noise. Maybe you received a defective one...it happens. Have you called LMS and complained?...maybe they'll take care of it. As far as the mandrel, I have mandrels from all suppliers and they seem to be pretty much identical. One solution (which I am considering) is to switch to Berea's larger mandrel(the B mandrel) and reaming all of my busings(from all three companies) to fit onto it.

You probably already know this, but overtightening the brass nut on the mandrel and overtightening the tail stock can both cause the blanks to bow and the manmdrel to bow respectively. If both are overtightened, then the runout problem is compounded.

I also use the Beall collett chuck to hold mandrels and think it is the best penturning tool I've ever purchased.

Do a good turn daily!
Don

Originally posted by godfreytoddanderson
<br />I have had problems with my last three pens. They all have a CA finish and I have been seeing patchy areas that are not glossy. The non-glossy areas cover about one third of the pen in random areas and the rest of the pen looks perfect.

After doing a lot of experimenting and testing I have come to the conclusion that it is my mandrel and live center that are causing this problem. I am using a Jet Mini lathe, the standard Woodcraft mandrel

http://www.woodcraft.com/family.aspx?familyid=3759

and a Little Machine Shop live center

http://www.littlemachineshop.com/products/product_view.php?ProductID=1189

My testing has shown that the mandrel is bent and the live center is wobbling. I've never really liked the live center because it is much noisier than the live center that I started with (the one that comes with the Jet Mini lathe which I know has the wrong angle on the tip).

So, here is my question. What do you think is the best mandrel (I'm ok with doing one half of the pen at a time if it fixes this problem) and what is the best live center. Price isn't really an issue here, whithin reason. What I mean by that is if I should have bought the heavy duty live center for twice the price its a small price to pay.

 

[Dario]

What Virgil said...but would like to add that the overtightening WILL ONLY bow the mandrel if the tubes were not (end) milled properly (assuming that the bushings are clean).

If the ends are not perfectly square, tightening will cause the camber on one side...thus the resulting bowed mandrel.

Hope this little tidbit helps.

 

[wayneis]

I don't use the brass nut because its large and kind of easy to over tighten. I just use a regular nut, its small and pretty hard to over tighten it. I also use the Beall collet chuck and agree with Don that its one of my best purchases right along with the blank drilling vice that I bought from Paul H.

Wayne

 

[godfreytoddanderson]

I always use a pen mill and only tighten the brass nut enough so that the blanks don't slip. I don't think that this is the issue.

I have had a piece of wood get between the lathe and the Morse taper on the mandrel and that caused a lot of vibration and wobble but I have been checking for that often and haven't had that problem again.

I will double check the live center and if I still see the problem I will call the Little Machine Shop about it. It really is a lot louder than any other item that I have tried that has a bearing. Its clearly all bearing noise.

Thanks for all of the suggestions. Could one of you post the model number or a link to the Beall collet chuck for me?

Todd

 

[mrcook4570]

Originally posted by godfreytoddanderson
<br />I have had problems with my last three pens. They all have a CA finish and I have been seeing patchy areas that are not glossy. The non-glossy areas cover about one third of the pen in random areas and the rest of the pen looks perfect.

Is it possible that you are not getting a very thick build up of CA and are just sanding through it?

 

[godfreytoddanderson]

Stan,

I think you are right that I am sanding through the CA. I've done some spot sanding by hand in the dull areas with a high grit micro mesh and the dust that I get is tan rather than white. I'm hoping it is because of the wobble though. I never used to have this problem and I haven't changed anything.

How many coats of CA do you guys usually put on? I've been doing a couple coats of thin for sealing and then four or five coats of thick.

Todd

 

[jodoidg]

Todd
Sounds like your putting plenty of CA on, are you using BLO with the CA? Too much BLO will cause ghosting or cloudy areas to randomly appear. I’ve also had problems with old CA. Hard to say if your not running true or, having finishing trouble?
John

 

[godfreytoddanderson]

John,

I don't use BLO as part of the CA finishing process (tried it and had the problems that you mentioned) but I did use an extrememly small amount on the current project to make the grain pop out more (Thuya burl in this case). Could that small amount cause this? Since I put the BLO on the raw wood I have redone the entire process three times trying to fix this.

I was worried about old CA so I opened brand new bottles for this current pen.

Todd

 

[Paul Russell]

I have the slightly better live center from Little Machine Shop. I love it and it is solid. Absolutely no wear at the tip in over 2 years service.

http://www.littlemachineshop.com/products/product_view.php?ProductID=1592

 

[jodoidg]

Todd,
No, that little BLO should not hurt anything. I have read on here and it has happened to me that every once in a while you get a blank that just gives you fits trying to finish [!]. My only other thought might be the blank is not completely dry? You may want to sand it down “again†and put in the rack for a couple of weeks. This way you can turn something else that won’t give you fits and come back to it at latter time.
Good Luck
John

 

[Pipes]

I use the adjustable Mandrel from Woodcraft and have a couple of Bereas all work fine and the 2 live centers I got from LMS work pefect NO noise at all the piece a JUNK I first had from sears was worn out in 1 week !!! about 15 pens ! I would call LMS and talk to them as that live center is IMO as good as any pen turnner can get and needs mine is still pefect after about a 100 pens or so ! Can't even tell its been used really just IMHO here for what thats worth !!






http://affordablepipes.com/

 

[godfreytoddanderson]

Ok, thanks everyone for the advice. I will call the LMS today and talk with them. One way or another I will replace my live center, look into the Beall collet chuck and I will probably replcace my mandrel if I can't straighten it.

Todd

 

[godfreytoddanderson]

I borrowed my grandfather's old dial gauge from my dad and measured my mandrel. It is 5.5 thousandths out in the middle. I'll try truing up the mandrel, turn the blanks to round and retry the finish.

 

[godfreytoddanderson]

Ok, I trued up the mandrel so it is out less than one thousandth of an inch in the middle. Then I started with a brand new blank that I have had for almost a year so I know it is completely dry. I turned it and did my standard finish process. I can see that most of the problem is gone. Now I have what looks like dull patchy areas over the denser parts of the wood. Mainly over the eyes and tighter grain areas.

I figured that the softer areas must have been reduced more during turning or sanding leaving high spots. I resharpened my skew and returned and barely sanded at all this time with the same results. This is getting really frustrating! Any ideas on where to go from here?

Todd

 

[gerryr]

Originally posted by godfreytoddanderson
<br />

Could one of you post the model number or a link to the Beall collet chuck for me?

Todd

I don't think anyone gave you the link for the Beall collet chuck.
http://www.woodchipshome.com/mm5/merchant.mvc?Screen=PROD&Store_Code=WC&Product_Code=CCBEALL&Category_Code=CHU