Mortise and Tenon questions...

[shilala]

I should say what I'm doing first, I'm planning a lingerie dresser and I'm figuring out how to make the dresser fronts parts (less the drawer fronts and drawers).

I can imagine how to make 3 sides of a tenon when I make parts. Being as I'd have to do a flip-over to do the last side, or go to the table saw, I think it'd be easier on me to just do all the tenons on the saw with a dado blade or break down and buy a tenon jig (http://www.amazon.com/Grizzly-H7583-Tenoning-Jig/dp/B000AJ7V1M/ref=pd_bxgy_hi_img_z).

The long pieces up the sides of the dresser front would receive the mortises, on the skinny side. In order to do the mortises on the shopbot I'd have to stand those pieces on their side and somehow get them in exactly the right position on the table. I can't imagine I can get the kind of precision I need.

That led me to thinking about getting a benchtop mortising machine (http://www.amazon.com/dp/B00006K00N/ref=pe_110380_26628870_pe_epc_dt1), or mortising attachment (http://www.amazon.com/DELTA-17-924-Mortising-Attachment-Chisel/dp/B0000223B4/ref=sr_1_5?ie=UTF8&qid=1352223413&sr=8-5&keywords=mortising+machine) for my drill press (http://www.amazon.com/Powermatic-PM2800-1792800-18-Inch-Variable/dp/B00169W89U/ref=sr_1_1?s=hi&ie=UTF8&qid=1352223512&sr=1-1&keywords=powermatic+2800).

What would your strategy be if you were in my position?
Mind ya, I'm not married to any of the ideas I threw out there. If I can make this all go with the stuff I have, I'd be thrilled. I just can't see it. I sure hope you guys can help. :)

[bobmoore]

Scott. Is this one piece or are you going into production with many pieces of the same design? Doing this for a one up on the shopbot would be inefficient unless you just want practice. Depending on your skills it would probably be fastest for one piece to just work the parts manually with table saw and drill press. Bob

[paul_z]

Scott,

If you value your time, definately take Bob's advice; However, if you want to use your bot take a look at this: http://www.flexiblestream.org/projec...al-wood-joints (http://www.flexiblestream.org/project/50-digital-wood-joints).

Paul Z

[srwtlc]

To echo the others, if it's just this one, use the table saw/dado blade and instead of the drill press, if you have a router table, use an upcut spiral cutter to do the mortises (assuming that your face frame is approx 0.75" thick, use a 0.25" cutter). Use some scrap to center the slot on the stock using the fence and mark the left and right edges of the bit on the table top. Mark your mortise locations on the front of your stock and drop down on the cutter at the left mark and push it to the right mark. I take 0.5" depth at a time. For face frames that may be enough. Make the tenons to fit at the table saw. Use glue/clamps and shoot some 0.25" crown staples in the back side.

If you want to do it on the bot, clamp the stiles in place and cut the mortises and make a jig like a dovetail jig to do the tenons over the edge of the table with parts clamped upright.

Use the bot to make the jig for clamping the stiles in place and it should be dead on.

[myxpykalix]

You ought to be able to make your tenons in about 5 seconds with the proper setup.
There was a video, asked about and posted not too long ago (sorry i don't remember who) of a guy who had a setup that held his stock in a vertical position with a air piston and he just went to town. Other will remember who and cite the link i hope.

You don't have to get that automated if it is a one off project. You can design a jig that will hold your stock in a vertical position and then just make a profile cut around the edges to the depth of your tenon, same thing with your mortise.

Here is a video of a vertical vise being cut and although there are no drawings to download you can see pretty easily how to design and build it yourself.
http://www.youtube.com/watch?v=Qzxub_SOsFI

[shilala]

This project does happen to be a one-off at this point, but I'm very likely to make others. I can't envision ever making more than a few, though.
I do plan to make a lot more pieces of furniture and wanted to form a plan of attack for mortises and tenons that I'll use on down the road.

Scott, it never even occurred to me to use my router table. My face frame will be 3/4" cherry. The top, bottom and base, I can block and screw all that.
I'm going to look at everything else you guys mentioned, as well. Any more thoughts would be greatly appreciated!!! :)

[garyc]

Scott...
Getting a holding jig to do tenons or mortises is not all that difficult. There are a good number of posts here on the forum where users have shown how they cut both the mortises and tenons. Tenons mostly vertical to enable 4 sided machining.

Here is a link to a jig I made some time back: http://www.shopbotblog.com/index.php/2008/08/dovetail-and-mortise-jig/

[Brian Harnett]

Here is my setup I do longer pieces in the other direction for mortising.

For tenons on long pieces I mortise the end on my table router and glue in a spline
http://i98.photobucket.com/albums/l249/brianharnett/Modified%20and%20Made%20Machines/IMG_2575.jpg
http://i98.photobucket.com/albums/l249/brianharnett/Modified%20and%20Made%20Machines/IMG_2577.jpg

A video of the process click on it to start.
http://i98.photobucket.com/albums/l249/brianharnett/Modified%20and%20Made%20Machines/th_chair.jpg (http://s98.photobucket.com/albums/l249/brianharnett/Modified%20and%20Made%20Machines/?action=view&current=chair.mp4)

[Simops]

Gary, Informative article!
I gather that a vertical vice only works on a gantry table style CNC. That is, can't do it on a Buddy?
Cheers

[myxpykalix]

Michael,
If you don't have the ability to hold your stock vertical you can certainly do them horizontal although you would still need to make a jig.

If you are going to cut tenons on square stock say 2"x2" then you would have one toolpath that does an "area clear" the size of one face of the four sides. As long as the part is jigged up so that it sits in the same place then just run that toolpath, rotate 90 degrees, repeat 4 times.

However if you have material that is 3"x1" then you would have 2 toolpaths. One area clear for the 3" side, cut it, rotate stock 180 degrees, repeat.
Then go to the area clear for the 1" side cut it, rotate stock 180 degrees, repeat. Let me know if you are still:confused: i'll draw a picture:D

[Simops]

Ok Jack....so I gather vertical hold can't be done with Buddy but work around is to do it horizontally over a few passes.....as long as you can assure it is re-positioned accurately. Mmmmm maybe stick with the table saw.

Thanks

Mike

[myxpykalix]

look at this drawing. This is what it would look like if you were looking at it from the Z. Here's the thing though. If you are doing a ton of these then i'd make a jig. If you are doing 4-8 it might be easier to do it on the tablesaw like you said.:eek:

[Simops]

Ta Jack.....do occasional furniture piece....not production....so will stick with traditional methods....

[shilala]

All great stuff. Thank You, Gentlemen!!! :)