Need some assistance PLEASE

[CaliforniaRed]

I know this is a repeat topic but I am unable to find the topic using the search function. I must be using the wrong key words.

My pens are coming out oval. I have moved the head and tailstock together to check alignment and it looks perfect. I need additional help. I have the variable speed Jet mini.

If you have suggestions please suggest away. If you could point me to the previous topic that would be helpful also.

Thanks

 

[Fearless]

Here's one to start with Red.
I searched "oval"
I'm sure someone else will be along soon.


http://www.penturners.org/forum/topic.asp?ARCHIVE=true&TOPIC_ID=5775&SearchTerms=oval

Oh yeah. It's archived.

HTH

 

[rtjw]

A couple of things could be happening.

1. Your nut on the mandrel is too tight. Loosen it a little.

2. Your tailstock is not lined up straight. Adjustment is needed.

3. Your mandrel is too tight in the morse taper. Again loosening will help.

4. Your mandrel is bent. This would require either straightening it (very hard) or just buying another one.

 

[jeff]

Make sure both pieces of your morse taper are clean. A little piece of crud can throw you off. Also, see Russ Fairfield's excellent page on the topic.

http://www.woodturner-russ.com/Pen12a.html

 

[Rifleman1776]

Or using wrong mandrel. e.g. 7mm with 8 mm bushings.

 

[wdcav1952]

Originally posted by Rifleman
<br />Or using wrong mandrel. e.g. 7mm with 8 mm bushings.

Frank, I won't ask how you know that if you don't ask me how I know that! []

 

[lkorn]

Another possibility is that your tailstock is pressing too forcefully against the mandrel causing it to bow, thus causing your oval pens.

 

[woodscavenger]

If your blanks are not 90 degrees to the tube (which can happen very easily if you trim them by hand with a disc sander) then when you tighten the nut you will introduce a slight bend in the mandrel and so you will get and eccentric pen. Also if your tool is not sharp and you are pushing to hard to get a cut it will happen. Also some people don't really get that close to final dimensions with a skew or scraper and then use sandpaper to take it the rest of the way. If you do that then some woods will sand unevenly and create an oval shape.

 

[CaliforniaRed]

Thanks for all the replys.

<b>Fearless:</b> I searched oval but nothing came up. I never even saw the archive box until now. Thanks

<b>rtjw:</b> Don't think the nut on mandrel is to tight. Checked the alignment of the head and tailstock. Vertical is ok. Didn't think to check horizontal. Will check next. Had bent mandrel from when I had butter knives as my tools. Got a Tormek and fixed that problem.

<b>Jeff:</b> That is the link I was looking for. Went to the website but didn't know where to start to find that article. Thanks for the link.

<b>lkorn:</b> Thought about that but I usually only put enough pressure from the tailstock for it to just spin.

<b>woodscavenger:</b> This was the first time I used the miter saw to get 90 degrees on the tube. May have screwed something up there. The mandrel is brand new and checked for bends and found none.

Thanks again for all the input. That is why I am a member here. I will continue to take form the forum until such time as I have something of use to give back. I hope to be as helpful to others as you have been to me.

 

[knottyharry]

Chris,
One of the first videos that I watched, showed the person tightening the nut with a pair of pliers.
So monkey see, monkey do.
Only tighten the nut finger tight. A little over snug.
When you apply the chisel to the wood, if the blank spins, then stop and tighten the nut just a litle more.
And the tail stock, run it up close, and then turn the hand wheel till it touches the mandrel and the center starts to spin. You're not carrying any weight on the tip of the center. So all you want is for it to be holding the end of the mandrel.
And a light touch with the chisels, very sharp chisels.
Harry