terminal cup for 1-3/4 cutout?

[hkingman]

I'm refurbing some speakers from the early 80s, and need a replacement terminal cup for a 1-3/4 inch cut-out. The ones available currently all seem to require 1-7/8" holes.

Don't need anything fancy; spring clips would be fine...

Grateful for any help/suggestions!

thanks

-Henry

[planet10]

I found a set amoungst my stash. Post would be $9 air/$7 surface. cups are free.

dave

[Enzo]

Wow, free sure beats any prices you might find at Parts Express.

[ODougbo]

Very generous Dave.

Making holes bigger can be a problem, a small amount can be tougher then a large cut. There is a way to retro fit a hole; I’m sure plenty of thought of this, but here goes:

Make the hole size you want on a scrape piece, use foresight and place the hole so there is room for clamps and a router. Use a straight router bit – with bearing on top. See photo [the router is too deep, but did that for clarity]

Good news folks, new double bearing bit, top and bottom and slanted cutters to boot!

Awesome for speaker builders: Amana Flush Trim Double BB 3/4 DIA 47096

[Enzo]

However, it would be very simple to enlarge the hole for a square/rectangular terminal cup. A couple passes with a saber saw.

[ODougbo]

I did think about a larger and/or square cup, my post was more of how-to-do for enlarging “holes” in general. With ever going DIY speaker projects, occasionally a speaker hole just is a bit too small and that’s hard to fix. Also, comes in handy for retro fitting a new driver, when a larger size is needed.

There are ways to swap bearings on router bits and have similar results.

[hkingman]

Originally Posted by planet10

I found a set amoungst my stash. Post would be $9 air/$7 surface. cups are free.

dave

Dave, that is really generous of you! I write you off-line to arrange the details.

BTW, here's a thread with more details about the project:

Domus resto -- progress!

This forum is great!

-Henry

[hkingman]

Oh, and ODougbo, your shop looks cool! I'll bet you build a lot of great things there.

On occasion, I have rented a router from the local hardware store. However, I tend to explore other options first, because while I am generally pretty comfortable around power equipment, routers scare me. Anything faster than 30,000RPM just seems unnatural. Think of it -- 500 revs per *second*! Amazing.

Thank you for the tip, though! As I understand it, you're working on scrap material until you get the hole just right. Then, you're clamping the finished scrap over the actual item, and letting the bearing in the router run along the scrap. The hole is then transferred to the actual item. Clever! I would never have thought of that.

I considered getting out the 'ol half-round bastard file. Though it probably would have been pretty frustrating, given the 30-year-old hardwood I've got to work with. Thank goodness for generous Canadians ;-)

-Henry

[ODougbo]

Routers are fairly safe ~ as far as wood working tools go. They can always mounted under a table for some jobs. Replace base (or add onto) a arm, for a swinging hole cutter; there is gig out there for small sizes.

It’s nice to have three routers, laminate trimmer, mid size and large. If I had to pick one, I’d go for the smallest router I could find with a ½” chuck.
A few tips:
The better-quality bits are very nice (Amana, Freud, CMT), however the inexpensive ones do the job. The orange bit shown is a 2 for $5 special.
Safety tips:
I found this out the other day and I’ve been using routers…..well forever. The receiving shaft, where the bit slips into, can build up with dust, so over time, the bit will not go in as far/deep where it needs to be, so that should be checked and cleaned as needed.


Similar to above, make sure bit is all the way in!

Wear safety goggles.

*
The scrap wood idea~ I think that came to me when I cut a woofer hole just a bit too small. Comes in handy for swapping mids and tweeters also.

[hkingman]

Originally Posted by ODougbo

Similar to above, make sure bit is all the way in!

Heh. I shot a bit across the garage once. Which goes a long way toward explaining my fear of routers, I guess.

That, and the rental unit at the hardware store is enormous. A smaller one might be the ticket. I'll keep an eye on the pawn shops. The rental place doesn't rent bits, so I already have a growing collection of cheapie bits.

I'll bet those little palm-held laminate routers would be nice for veneer work on speakers .

Originally Posted by ODougbo

The scrap wood idea~ I think that came to me when I cut a woofer hole just a bit too small. Comes in handy for swapping mids and tweeters also.

Yeah, it's brilliant. When you have the cabinet, and need to find drivers, the cut-out size really limits your options. Being able to move up a bit in size would widen the field a lot.

In my case, if I had a 1-7/8 hole saw, I could just drill a perfect hole in some scrap, and use the router trick to transfer it to the case. You could of course just try to drill a hole with the hole-saw, but without the pilot bit, it's pretty tough to get it centered right, especially when removing so little material.

Thanks again,

-Henry