In need of some instruction

[Sabaharr]

I have been at this penturning for about 2 months now and reading this forum for over 6 months. I searched the archicves for my question and I either missed it or it isn't there. I read a lot about how great it is to turn between centers and drill on the lathe. There are several mentions of some additional equipment needed but I haven't seen anything about detailed set up. My biggest lack of understanding is how do you suspend a blank and bushings between centers without a mandrel to keep them aligned? What holds the blank in place for the drilling process? I have a chuck for my tailstock and a set of adjustable jaws to clamp on the bottom of a bowl. I use a JET midi lathe. Detailed info on these processes (better yet setup photos) or the link to the description that already exists, and computer challenged me can not find, would be appreciated. Thanks,
Stephen

 

[jkeithrussell]

For turning between centers, search for "mandrel-less". Here's a start.

http://www.penturners.org/forum/showthread.php?t=41743&highlight=mandrel-less

For drilling, you need a chuck/jaw system to hold the blank on the headstock and a jacob's chuck to hold the drill bit on the tailstock. Search "drill + lathe" and you should find some help.

 

[DurocShark]

I could have sworn I'd seen an article posted on this site, but I just went looking for it and had no luck.

 

[Sabaharr]

OK, I have figured out that to turn between centers it must require bushings that insert into the tubes and have 60° bevels on the other end. At least that's the only way I could figure it out to work. Now would someone confirm that for me? Since a picture is worth a 1000 words and I am not really getting any words would someone also kindly post a photo of a setup for drilling on the lathe? I inspect spacecraft at NASA so I think I can figure it out from a decent photo. Thanks to anyone that can solve this one for me'
Stephen

 

[DurocShark]

If you have 60° drive and live centers, you can use regular bushings too. Do you have the centers? If so just try it. It'll make sense then.

 

[Monty]

Stephen,
Check out this thread - http://www.penturners.org/forum/showthread.php?t=45557&highlight=lathe+drilling

On another note, I assume you work at the NASA Michoud facilities? My son is stationed with the Coast Guard there.

 

[JimB]

Stephen - you are right about the bushings. If you are doing slimlines you can't use the standard bushings. You need to order different ones. For other pens that have step bushings you insert those into the tube. Put a 60 degree dead center in the headstock and a 60 degree live center in the tailstock. Mount the blank with bushings between the centers and turn on your lathe.

I don't drill on the lathe but I believe what others do is mount the pin jaws on your scroll chuck (the one you use for bowls) and mount the blank. Put your jacobs (drill) chuck in the tailstock and put the drill bit in it. Turn on the lathe and use the hand wheel to advance the drill bit into the blank.

Hope that helps.

 

[Whaler]

Stephen
Here are a couple pictures of how I do it, hope they help.
The first shows the drilling
The second shows the 60* live and dead centers
The third shows the blank and bushings mounted

 

[Sabaharr]

Dick,
Thanks for the pics. They were just what the Dr. ordered. I actually have the accessories to drill with and gave it a shot. The jaws are round and hold a round blank well. Not so much with the square ones. I will have to get some different jaws I guess to do those.

Monte,
I use to work at Michoud. I was there for 4 years then about 7 years ago I transfered to Stennis Space Center in Mississippi. Its actually closer to home than Michoud. I heard that 160 people got pink slips today at Michoud. Glad I was already gone. We have so much work I have been putting in 50 to 70 hours a week. The contracts are pileing up through 2017 already, so there is some security here. At least as much as can be hoped for these days. Sure doesn't leave much time for turning though. Thanks for the help.

Stephen

 

[MikeMcM1956]

Stephen,
I'm going to give a shameless plug to johnnycnc, one of our members who makes the bushings for turning between centers. You can use normal bushings for most pens (except for slimlines), but you get a very small contact area between the edge of the bushing and the dead and live centers. Johnny's bushings are solid, with a 60 degree taper that gives full surface contact with the centers. His bushings are also made to much tighter tolerances than the ones that you get at the 'mass market' vendors. They're not cheap, but they are worth it. Start off with one or two types, and buy additional ones as you need them. Johnny also sells high quality 60 degree dead and live centers, along with other turning goodies you might need or want. Fair prices and great service.

His website is www.penturnersproducts.com, give it a look. If you drop him a PM, he will set you up to get an automatic discount every time you purchase....

Mike

 

[ldb2000]

Stephen , if the blanks you are trying to drill are perfectly square then the jaws shown will work fine but if the blanks are uneven or not perfectly square then you will have to either square them up or turn them round between centers like the ones shown in the second and third pictures first then drill them with the jaws you have . Just put a center mark on the ends of the blank ( I use one of those automatic center punches to make the mark (dimple)) then tighten the blank between the two centers , it may take a few turns of the handwheel on the tailstock until you get it tight enough for friction to keep it spinning while you turn it round .

 

[Whaler]

I will second Mike's comment. The bushings from johnnycnc are well worth the money.

 

[Sabaharr]

Yes guys, this is working great for me on the round blanks. That is what I was having trouble with. THe square ones I was easily doing with my machinest vise and drill press. I couldn't get the rounds ones straight until now. About 80% of the acrylic blanks I do are round already so this will help tremendously with them. I joined JohnnyCNC site and will be getting a few sets of his bushings for the pens I do most. Thanks for this much needed help. I hope I can one day pass on advise this much appreciated myself.
Stephen