mickyd's Woodworking Projects

[mickyd]

I'll say one thing, Mike, you sure don't shy away from the testy jobs. Cutting sliding dovetails that fit has always been a challenge for me. I get it done but I create a lot of scrap as I do the job. It usually takes me about three test fits before I am satisfied. This being a "precision measuring device" necessitates a really good, sliding fit and there is no material for a start over..

This will be a tool that you use frequently and given your propensity for detail I am sure that it will be a fine instrument that any one us would be proud to have in our tool kit.

I'm using a digital caliper reading to .001". (sorry shipwright.....just had to do it...) Shooting for a .500" wide groove in my .750" thick stock, centered so I have .125" material on each side. I'm using a 3/8" straight bit so I have to make a pass, rotate the part 180° and make a second pass. I practiced on some scrap wood last night and after adjusting the table router fence to a smidgen over .125", I made a short cut. The cut resulted in about .138" so I put 4 sheets of paper between the stock and the fence as a shim and ran it through again. Hit .126" so I'll try a full pass tonight. If all goes well, it will be that dimension over the entire length. I'll flip the part 180°, run it through, and what I get is what I get. I have featherboards pressing the stock over it's entire length so we'll see how it goes. I'll use the similar process (paper shims and all) for the tongue, making it slightly under whatever the groove comes out as. I'll shoot for a tight vs. loose fit. Can always sand or file vs. trying to pack that sawdust back inside.

And P.S. ....I can't make any scrap unless I want to take a trip to the hardwood store.....

[shipwright]

Mike, a good way to check how grain is going to react to the cut (ie: chip out etc.) is to run a cut with the bit only about 1/2 way up. This will preview for you what to expect in the final pass. If chipping is a real problem, as with some woods and grain orientations it can be, you can cut at highest speed in a series of thin cuts, raising the bit (a bit) each time. In some cases doing this in "climb cut" mode works best.
Climb cutting is OK if:
1) You are prepared for the direction from which the force will be applied and are appropriately braced for it.
2) You advance in thin cuts
3) You (and your fingers) have good position and control of the piece.

Advancing in thin cuts is also an excellent way to build confidence with a router as any mistakes will have diminished bad concequences both for you and your workpiece.

.....and Dusty is right. Never run anything between the fence and the bit. It can have much the same effect as pulling a trigger, but without the aiming features.

Paul M

[SDSSmith]

Roger. Capisce.

This is the piece that I'll be free hand 1/4" rounding tonight. It's 3" x 6". I'll be doing the entire inside of the "L". Having never free handed, I'll clamp it in a hardwood hand screw. I'll feel more comfortable that way.
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Photo on the left.....As I come down from the top of the "L", the grain isn't quite running in the right direction but I guess that's life?? I'm obviously going to have grain direction change as I come around the radius where it will start to cut cross grain.....over 90°'s worth even.I assume no biggie since this had to happen all the time when routing??

IMO, I route across the end grain first then if I get a little chip out the long grain cut normally removes it. When dealing with long grain cuts that include funny grains that cause chipout, I will carefully make a climbing cut in those areas of the piece. In your situation the with 1/4" roundover bit, I would not hesitate to do a climb cut if necessary. Okay, shoot me now.

[shipwright]

Hey, Mike fill yer boots with the caliper but don't think that's what's giving you the precision. That's what your paper shims are doing. Good idea! You are progressing at lightning speed. My point is that you could achieve the same end by cutting one piece (the groove or the tail) first and then with a series of shimmed increments, trial fitting in between, slowly bring the other to exactly where you want it. All this without even knowing to the 1/2 inch how wide it is.

I assume both ways will work but I admit I've never tried the measuring one.

One caution: Don't get carried away with precision fit here. Remember it is wood and not all that dimensionally stable especially when you talk in 1/1000ths of inches. A sliding dovetail that is a little loose will tighten straight and true when you try to force the pieces away from each other (as I assume the locking screw does... admit I didn't check back to first post on this) but a tight one just won't budge if it swells.

Edit: OK, I looked back and that's not how the lock works, but the advice still works.

Good Work Mike !!
Paul M

[mickyd]

I feel like I am going on my first date!!! Part of me is very anxious to get home and give the routing a try yet another part of me is petrified!!! SDSSmith and shipwright.....I understand your advise though.

I'll make sure to have a faceshield, safety glasses, cup, and chest protector on. Pinkies will be well out of the way for sure.

[JPG]

Mike, a good way to check how grain is going to react to the cut (ie: chip out etc.) is to run a cut with the bit only about 1/2 way up. This will preview for you what to expect in the final pass. If chipping is a real problem, as with some woods and grain orientations it can be, you can cut at highest speed in a series of thin cuts, raising the bit (a bit) each time. In some cases doing this in "climb cut" mode works best.
Climb cutting is OK if:
1) You are prepared for the direction from which the force will be applied and are appropriately braced for it.
2) You advance in thin cuts
3) You (and your fingers) have good position and control of the piece.

Advancing in thin cuts is also an excellent way to build confidence with a router as any mistakes will have diminished bad concequences both for you and your workpiece.

.....and Dusty is right. Never run anything between the fence and the bit. It can have much the same effect as pulling a trigger, but without the aiming features.

Paul M

I agree with Paul and Rob iff you adhere to the red print above. I would not recommend it to a 'novice', but I think you ARE aware of the 'issues'!

[reible]

For me I see a big issue that has not been addressed... how are you going to start he cut? If you attempt to start at a corner it is likely the bit will catch and the part will will go flying..... You need a place to start that is not a corner.

I'm hoping someone has mentioned that a starting pin or safety pin is also need to do the start. Without both of these we are going to have to be so lucky.......

To be honest I don't even want to think about this...

Ed

[JPG]

For me I see a big issue that has not been addressed... how are you going to start he cut? If you attempt to start at a corner it is likely the bit will catch and the part will will go flying..... You need a place to start that is not a corner.

I'm hoping someone has mentioned that a starting pin or safety pin is also need to do the start. Without both of these we are going to have to be so lucky.......

To be honest I don't even want to think about this...

Ed

That inside corner worries me also. This would be a good project for 'hand' work.

[shipwright]

IMHO neither of the concerns mentioned above will be much of a problem with a 1/4" bit set only 1/2 way up. A starting pin is a good idea but with this little bit exposure I don't see a problem. In fact it may catch just enough to use as a starting pin practice session. You wouldn't want to go experimenting with a starting pin for the first time with a full cut on a bigger bit.

IMHO

Paul M

[mbcabinetmaker]

I have just had time to catch up on this. I agree with shipwright about the practice session with the starting pin. Just make sure you have a firm grip, rest on the pin and ease into the cutter. Once you make contact with the bearing forget the pin until you are ready to remove the piece from the cutter. Just reverse the starting procedure. I have not seen you router set up. Does your pin screw in place? I once had one of the tapered ones to vibrate loose on a shaper. That was some fun!!:eek: