rounding over the edge of the teardrop

[Tom&Shelly]

So I'm ready to put a rounded edge on our hatch, and will later do the teardrop. Seems like a silly question, but I've not found the answer anywhere else:

Which way should I hold the router? My intuition is to put the plate against the side and have the bearing run along the roof, but I can't find any examples online where folks have done it this way. Seems like it will take some strength (or at least stamina) and concentration to keep the plate flat against the wall.

The alternative, of course, is to put the plate against the roof and bearing against the wall, but when the roof curves, it would be difficult to keep the bit perpendicular to the surface.

So I'm thinking the first solution is the correct one. I've also figured out I have to go from right to left, as the cutting will be done with the underside of the bit.

My intention is to use a 3/8" radius round over bit, and to make several passes, "lowering" the bit about 1/8" each time.

Comments? Safety concerns?

Thanks!

Tom

[tony.latham]

In a sense, I've done it both ways. From the side to trim the wall aluminum and again from the top to hash off any stray roof aluminum.

I would suggest you run the router over the edge on both surfaces --unpowered-- to feel which one has more control. I'm guessing it's from the top.

If it were me, I would do it in one pass (seriously). Geeeez, what could go wrong?

But tell me which one you went with. I'll be doing the same down the road. I'm trying to get the other wall done. I just cut off the hatch end and it came out fine.

Tony

[dhbret]

The safest way for the wood, but also the hardest physically is to allow the bearing to follow the curved surface (the roof) and router base on the flat surface (the wall). Is insures that base is always flat, not rocking if it were to follow the roof. Taking controlled deeper cuts is the way to go to eliminate any blowout. Been doing custom woodworking for over 40 years so I hope this explanation helps. I also teach Router 101 at the local Woodcraft.
Bret

[twisted lines]

1 Day late!
I trimmed the overhang on my top yesterday, and wen't left to right

[troubleScottie]

You might want to add a Universal Router Base to your router.

It greatly increases the surface area of the router plate making easier to stay in contact with the surface you are gliding over.

[KTM_Guy]

That is where a small router or laminate trimer comes in handy. I would run it with the base on the top first pass then another pass with the base on the wall.

Todd

[Tom&Shelly]

The safest way for the wood, but also the hardest physically is to allow the bearing to follow the curved surface (the roof) and router base on the flat surface (the wall). Is insures that base is always flat, not rocking if it were to follow the roof. Taking controlled deeper cuts is the way to go to eliminate any blowout. Been doing custom woodworking for over 40 years so I hope this explanation helps. I also teach Router 101 at the local Woodcraft.
Bret

Thank you everyone for your comments!

Bret, your description matches my intuition, plus, you're teaching at least one more class in routing than I've ever taken.

Probably should have mentioned in my first post, but I already routed the outer skin on the hatch flat using the router and bottom bearing template bit, with the plate horizontal. Worked okay with that bit, but the plate could, of course, rock. I'm worried that would distort the shape of the cut with the round over bit.

For the hatch, another option is to tip it on its side, which I may do. I tried holding the router with the plate vertical (cutter horizontal) and found I want to hold the motor to support the weight. Still, I let the plate tip slightly if I wasn't very careful. Nice thing about a bottom bearing bit is that I don't think that will cut in too deeply if I inadvertently let the plate tip--I'll just have to go back over it.

For the cabin, of course, I won't have the option of tipping it on its side, and with my Benroy shape, I have a few feet in front, where I'll have to hold the router sideways either way.

Have some non-tear drop related commitments today and tomorrow, but I'll be back at it on Sunday, and will report back what I tried and results.

Thank you again, everyone!

Tom

[Tom&Shelly]

OK, did it the way Bret suggested and it came out fine!



I could have probably done it in one pass, but did it in three for each edge. The most comfortable for me was to cradle the motor with my right hand while my left held the left handle.

Sure left a mess! The router blew a lot of the dust up and onto my head. I should have worn an old hat!



A lot of the "dust" is actually fiberglass and epoxy cut into pieces sort of like shredded cheese. Normally I sweep the dust outside (we live on woodland) and let the wind and elements recycle it, but with the plastic and glass in this, I swept it into the garbage.

Thanks again everyone, for your advice!

Tom

[DWT77]

OK, did it the way Bret suggested and it came out fine!



I could have probably done it in one pass, but did it in three for each edge. The most comfortable for me was to cradle the motor with my right hand while my left held the left handle.

Sure left a mess! The router blew a lot of the dust up and onto my head. I should have worn an old hat!



A lot of the "dust" is actually fiberglass and epoxy cut into pieces sort of like shredded cheese. Normally I sweep the dust outside (we live on woodland) and let the wind and elements recycle it, but with the plastic and glass in this, I swept it into the garbage.

Thanks again everyone, for your advice!

Tom

[dhbret]

You have successfully passed Router 101 Up next is Bandsaw Basics. See you next class.
Bret