Using a Roudover Bit on a Non-90-Degree Joint?

[David Carter]

I've got the sides and top/bottom extensions on the first of my DR250's, and I'm starting to think ahead to rounding off the edges. I've borrowed a router from a friend and purchased a 1/2" roundover bit.

I don't anticipate any problems rounding off the edges where the sides meet the top and bottom because they come together at a 90-degree angle. However, the angles are greater than 90 degrees where the back cover meets the top and bottom, and I don't see how you can do a good job of rounding those off with the router.

Am I missing something or do I just need to put the router down and use a sander for those two joints? What have the rest of you done on these joints?

[AntonZ]

Haven't done that myself, so this is my theoretical guess. 3 degree jig from scrapwood as wide as the router foot, making a horizontal surface that is perpendicular to the rear surface instead of 93 degrees (kinda similar to the technique described in the plans to route a tophat inlay).

[David Carter]

Haven't done that myself, so this is my theoretical guess. 3 degree jig from scrapwood as wide as the router foot, making a horizontal surface that is perpendicular to the rear surface instead of 93 degrees (kinda similar to the technique described in the plans to route a tophat inlay).

I thought about something like that, but then you'd just be rounding off the edge of the jig. What you're suggesting would work for the front edges of the top and bottom piece, but not for where they meet the back panel.

Thanks anyway...

[AntonZ]

Sorry Dave - I did not think straight. It's late here, it has been a long working day, that sort of thing.

The jig would actually need to be a lot narrower, less than half of router base is OK. It will not be very high either, shouldn't be because the roundover bit wouldn't go deep enough to get to the edge of the cab. And you only need 3 degree tilt anyway. Plunge the router almost all the way down and I would think you should be able to get to the edge.

[David Carter]

Sorry Dave - I did not think straight. It's late here, it has been a long working day, that sort of thing.

The jig would actually need to be a lot narrower, less than half of router base is OK. It will not be very high either, shouldn't be because the roundover bit wouldn't go deep enough to get to the edge of the cab. And you only need 3 degree tilt anyway. Plunge the router almost all the way down and I would think you should be able to get to the edge.

Thanks. That makes more sense.

Has anyone else actually used a roundover bit on the back of a DR cab? How did you do it?

[fender3x]

I just saw this. I had the same worry, but it turned out not to be a real problem.

Don't sweat the slight angle. You don't need a jig. Just run the router like you would on any of the other sides. The angle is too slight to matter. Same goes with corners. I used the metal ones rather than plastic, and worried a little that they would not fit tight due to the angle. But the corners fit tight and that was no problem either.

There may be some measureable difference, but I could neither see nor feel it.

[David Carter]

Don't sweat the slight angle. You don't need a jig. Just run the router like you would on any of the other sides. The angle is too slight to matter. Same goes with corners. I used the metal ones rather than plastic, and worried a little that they would not fit tight due to the angle. But the corners fit tight and that was no problem either.

Thanks. I'm glad you mentioned the corners also because I've got metal corners also, and I was worried that it would be an issue.

[Greenman]

I just saw this. I had the same worry, but it turned out not to be a real problem.

Don't sweat the slight angle. You don't need a jig. Just run the router like you would on any of the other sides. The angle is too slight to matter. Same goes with corners. I used the metal ones rather than plastic, and worried a little that they would not fit tight due to the angle. But the corners fit tight and that was no problem either.

There may be some measureable difference, but I could neither see nor feel it.

+1

Take gradual passes and watch the results of each pass and you will know when to stop.

[DJPhatman]

PRACTICE, PRACTICE, PRACTICE!

Practice on scrap wood first till you get a feel and a touch for running a router.

[Harley]

.... I was worried that it would be an issue.

You are worrying over nothing.

I use a 1/4" round off with a bottom bearing and just race around the edges like a mad bass-turd. Quick and done!!!

Use the plastic corners - they are much more user friendly for your cabs. If you don't know what to do with the metal ones you have, put them on the dog kennel - your mutt will think he's king.

[DAVID_L_PERRY]

Don't sweat the slight angle. You don't need a jig. Just run the router like you would on any of the other sides. The angle is too slight to matter..

+1 once more for clarity, no problem at all.

[David Carter]

Thanks for all the input, guys. I'm feeling much better. This being my first DR cab and my first attempt at using Duratex instead of carpet, I'm being somewhat paranoid about any imperfections that might show through once I'm finished. I appreciate your reassurance.

[fender3x]

I have not used carpet, but Duratex hides a lot. I used Radiata Pine ply for my DR, Virola ply on the horn sides. Both were grainier than the maple ply I used on my T39. You'd never know to look at them now.

[DaveK]

Duratex hides a lot

I didn't have the same luck. I found that I need to fill EVERY brad hole, etc., or they will show. Another troublesome area was the glue seam on butt joint corners. The PL air bubbles seem to suck the in Duratex and create a line. I run a putty knife loaded with Bondo over them and all is well.

[LelandCrooks]

Spray it.