How would you do this?

[curtis rosche]

I'm working on a product for a class and have a question regarding the process for one of the steps.

You start with a 4'' x 4 3/8'' x 2'' block of oak.

Said block needs a recess 1'' deep 3'' long centered 1/2'' thick, 1/4'' away from the face, in the endgrain.


our current set up is a router table with a sled, you slide the block into a slot, the sled is moved from stop block to stop block till the cut is at full depth. a comment was made that this could possibly be unsafe, but I fail to see how as the wood cannot be thrown, and the user is not exposed to the cutter at all.

Use of multiple handheld routers was discussed, but a mention of failed accuracy was mentioned and more possible danger.

also the use of a mortise then a router was talked about.


any other methods that are missing? Any input on how to do it safely and quickly?


This process will need to be completed 51 times by a student who will not necessarily have strong experience with the equipment but will be taught before the use of it. Every single piece must be the same as they will be sold to the public.

[Ken Fitzgerald]

Curtis,

One alternate method would be to use a table saw with dado blade and miter gauge. Set the blade to the proper width, clamp the block to the miter gauge. Using the rip fence as a guide, rip the proper width and depth channel in the block and then fill in the ends with a square plug of the appropriate length.

[Mike Heidrick]

Horizontal slot mortiser or CNC router

[Peter Quinn]

Plunge router, bushing guide, template. Training. Or a CNC. My question for the router table is how do you set the bit height? Routing 1" deep into oak end grain will require small incremental steps with a 1/2" router bit. Do the corners need to end up square, or is the 1/2" diameter acceptable?

[Brian W Smith]

College textbooks have been written on jig/fixture design.....for those in the biz,it can be very entertaining reading.

Look at "old",Delta tenoning jigs.Not the new,lite weight models......theres a reason you want a lot of "heft" on certain fixturing.Understand "why",and you'll gain insight to your particular fixture.Good luck,be safe.

[Lee Schierer]

I would core out most of the recess with a Forstner bit and then use a router to remove the rest of the material in the corners. Hopefully you are not trying to route the full depth in one pass. That will put lots of pressure on the bit which may cause it to break. Also routing a blind hole leaves no place for the chips to go and chips need more space than solid wood which can also jam the router bit causing it to break or catch. Above all, I would insure that the block is held by mechanical means, not hands so that if there is a blowout that my hands are out of harms way. It only takes one bad area of grain twist for the router bit to grab and blow up the whole piece faster than you can blink.

[Ruhi Arslan]

Safest way for sure...

chiselmallet2-480x360.jpg

[Jeff Duncan]

For what your trying to do the slot mortiser would be the best bet! A slot mortiser could easily be setup to do that task safely and very quickly. With a router it's going to take a lot more thought. You'll need a way to either secure the stock in place and gradually move the router into it, or alternatively hold the router in place and move the stock into it. Either way is easier said than done once you factor in the need for safety and accuracy. Not sure exactly how your current jig is working in terms of depth adjustment? I'm guessing that's where the safety concern comes in?

Another possibility would be a milling machine if you had access to one. End mills work very good in hardwood end grain. Would be slower than a slot mortiser, but just as safe.

good luck,
JeffD

[Greg Hines, MD]

I would suggest you use a router, with incremental passes, and a sled. I would also recommend you start with an over-long piece, and cut your mortise on the end, then cross cut to final length after the fact, as that would be much safer. I would also (and have) incorporate toggle clamps or push clamps to hold it in place to your jig.

I have a Shopsmith type tool called a Smithy. It can handle router bits in the horizontal boring position with the correct collet. This allows me to make mortises for these sorts of things very easily with some stops clamped to the table.

Doc

[Peter Quinn]

Jeff beat me to it, but a Bridgeport with a DRO and possibly a power feed would be a real safe and accurate way to do this assuming you had access to one. An over arm router could also be effective.

[lowell holmes]

I would set up with a mortise jig like Mortise Pal or make one my self. The mortise would be cut with plunge cuts using a plunge router. No horizontal move of the router would be tolerated.

The mortise would then be cleaned up with a 1" Lie Nielsen bevel edged chisel. There are times that hand tools are quicker and much safer than power tools.

[curtis rosche]

I forgot to mention that it is in a production style setting and the operation must be completed in less than 4 minutes for each one.
The method that is going to be used is to predrill the endgrain with a 1/2'' bit then use the router table with a jig. worked very well with not having to push the wood down onto the bit.

the slot is part of a wooden "speaker" and is used to hold an iphone do redirect the sound.

Thanks for the input