RE: Need help on jointing a bed post

David Conley

Well-known member
Everyone,

I am interested in making a bed.  I drew up my plans for turned posts and a blanket roll.  The problem is that the bed of my lathe is 36 inch long and the post are 54 inches and the blanket roll is 57 ¼ inches long.  I am planning to spin the posts in two sections and the blanket roll in three sections.  I am planning on adjoining the sections together with a 2 inch long and 1 inch diameter tenon.  I have picked out the joint locations where I will have a 3 inch diameter cylinder for the mortise.

My questions are:
1) Does the mortise and tenon joint seem to be sized appropriately?
2) When and how do you drill out the mortise, before or after turning?  I have given it some though and here is some of my thinking.  I am really open for suggestions.

MORTISE BEFORE TURNING: I have thought about drilling the holes in the rough turning stock and then dry fitting a tenon plug into the mortise.  The tenon plug will also be turned so it will have a well defined center point for the lathe.  The tenon plug will also be only an inch longer then the mortise.  I think this method should accurately align the center points of the tenon and of the mortise.  Also, I will place the plug tenon end of the post on the non-drive side of the lathe.

MORTISE AFTER TURNING:  I am thinking that the drilling operation will require a little more precision to ensure the drill press table is perfectly vertical, the turning stock is perfectly vertical, and that the center is perfectly marked.  The one advantage is that the turned piece will be a cylinder and I can accurately align it to the drill press’ table.

OR A COMBINATION OF THE TWO:  In writing this, I am thinking that a combination maybe better.  The first operation is to turn the blank into a cylinder so that I can get the advantage of accurately aligning the piece in the drill press.  Next, I would drill the mortise, insert the tenon plug, and finish turning the piece. 

OR, am I just making a mountain out of a mole hill.  And that I should just pick one method and just do it. 

One advantage of being a hobbyist is that you have plenty of time to piddle.

Thanks for the information in advance,
David 
 
David:


  I would make the mortise first.  That way the mortise will be in the center no matter how the density of the wood  changes.  The other thing is to drill the mortise on the lathe.  Do not tighten the tail stock of the lathe until the drill bit has found its center--in other words, started the mortise.  Then tighen the tail stock.  There is an article in FWW on bed making,  around  issue #80 or so which shows the bedposts made in sections.  Good luck.

           
            Jim Vojcek
 
David,
Give some serious thought to making your lathe bed longer. That being said you can turn a #2 taper on a piece of wood and jam it into the headstock, then turn it down to your 1" tenon diameter. Now you can drive the sections from the mortise hole. You might want to make the tenons longer than 2", at least 3 maybe 4 inches would be better. Use a good hardwood for the tenon. Be sure to match up the wood grain before gluing.
Mike
 
David,

I turned my $500 Delta 36" lathe into an 8' lathe so I could turn my 7 1/2' posts in one peice. It cost me $60 at the steel yard and a little welding. I explained the process in deail on the old web site. I don't know if it is accessable yet, if not I could explain it again for you.

George Madok 
 
George,

I don't recall seeing the earlier material on your lathe.  I would like to learn about your method for extending your lathe bed and ask that you repost that information here if that can be done without causing you major inconvenience.  Thanks.

Kent Ryan
 
Everyone,

John Goyer called me on the phone and reminded me of a discussion at our Ohio River Valley Meeting about producing tenons on a lathe.  The tip was from Dick Kammerer. 

Dick told us it was a bear trying to remove “tenon plugs” because of all of the horizontal pressure applied by the head and tail stocks.  That pressure simply wedges the plug into the mortise.  Dick’s tip was to insert a quarter into the bottom of the mortise before you put in the tenon plug.  To remove the plug, you insert a wood/drywall screw down the center of the plug.  Once the point of the screw contacts the quarter, it will back the plug right out. 

I am not sure of all of the details on the plug.  But, I would probably pre-drill the inside part of the plug along the center axis with an oversized drill bit.  Thus when I am trying to remove the plug, I would only have to drill a short pilot hole and not have to worry about hitting the quarter, nor would I have to worry about the screw splitting the turned piece.  My final comment would be to use a metal slug out of an electrical box and not a quarter.

As far as my own situation, I think I will take the advice of several people of extending the bed of my lathe.  Luckily, one of my brother-in-law’s hobbies is welding.  He told me that he would make an extension for me.  If it works out and someone would like to see some picture, let me know and I’ll post some pictures.

Cheers,
David
 
David,
I like the idea of putting a quarter in the mortise. It is a neat method for removing the plugs and it gives you the added incentive of getting your quarter back! Good luck with your lathe extension. I have a powermatic 3520 that has a working length over the bed of about 32". I extended using wood and steel to over 109". I would suggest that you make it able to do at least 72" between centers. Somehow it is always an inch too short on the next job.
Mike
 
Kent I don't know how to get my original post from the old forum, so I will give you a new description.
The flat "ways" of my lathe (the part that the tail stock and tool rest slides on) are 4" high. I purchases 3 1/2" square steel tubing and 1/2" thick bar stock both about 5 feet long. Weld the 1/2" bar stock to the square tubing so it overhangs enough to allow the tail stock and tool rest hold downs to fit under the bar stock. I then measered the space between the delta lathe's "ways". Weld metal spacers to join the two lathe bed halves to match your "way" spacing. I mounted the lathe and my extension to  a 2 x 12 piece of lumber from home depot. I quickely put together a plywood base to go under the extension (using the original base for the lathe). I filled the plywood wox with 80# bags of concrete and bolted each end of the lathe to the wall. It is rock solid with no vibration when I turned the 4" thick, 8 foot long mahogany bed posts.

If any part of this expaination doesn't make sense let me know.

George
 
I would think about lengthening the pin to 2 1/2 ". Also cut a small groove down the pin. This will allow air and glue to excape as you glue it up. If you don't it would act like a piston and you could very easily crack the post which will mean early failure of your joint. I have also found it is a smart idea to drill a small pilot hole first. Then while you are drilling the hole in the lathe rotate the post to minimize your drill leading off. As far as the plug I just turn a pin with a shoulder and grab it with a pair of channel locks and twist it out. Sometimes it's not the length of your lathe but the material you have to work with.
 
Everybody,

It has been a little while, but I have completed the lathe bed extension.  (Too many other projects were in the way. )  

There are a couple of things that I would like to point out.  First, I have limited room in my basement, so I wanted an extension bed that I could easily remove and store.  Second, my brother-in-law made a really simple bed extension that other people maybe interested in.  It consist of two pieces of  3-in “C” channel for each side of the bed and four 2-in bars with mounting hole on each end. To build the bed, simply line up the “C” channels to match the width of my lathe’s slot.  Then, we lay the 2-in bars across the channel and weld the two together.  That’s it!  Quick and simple!!

(Post note: The welds are made with the C-channel upside down and the 2-in bars laying on top of the channel.  The welds are then made 90-deg to slot.  Again, easy!!)

As you can see in the picture below, I mounted the bed to a piece of hardwood and made a sawhorse for the outboard end.  I also added a tongue under the hardwood to bolt it to the original lathe leg.  In this, I was luckily that the original legs had a vertical hole in it that I could drill a hole through the tongue and then drop in a bolt.

Cheers,
David   

P.S. If the pictures are small, click on them to enlarge .
 

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