Salvo switch thread tapping. Need help?

[gav6280]

I've got a standard Salvo switch and need to tap a new hole for it in a cannister but cant find any thread data for the switch.

Anyone got any idea what size it is or even what size Drill and tap i need?

Cheers.

Edit found some:

Mounting Means:
Threaded Bushing —
11.89mm (.468²) dia.,
32 threads/inch.
Keyway —
1.73 x .89mmdeep
(.068 x .035² deep), provides
antirotation feature.

So still no idea what i need really...

 

[wes_wall]

Would love to help, but:

Nobody threads a keyed hole (on purpose.)
Most Salvos I have seen use a toggle switch and a boot.

Can you provide a picture?

 

[gav6280]

Forget the Keyway that is not needed in this case.

The thread is M12 x 0.75.

What size drill do i need? and any tips on how to do it as i have never cut a thread in anything before.

 

[wes_wall]

http://www.kasthurimmc.com/tap-drill-chart.html

If you are threading in aluminum, you'll want to get some tap cutting oil. I like tap-magic. If you are cutting in acetal or delrin, you will not need the lubricant. If the tap has a nice taper, you'll have to so something spectacularly stupid and gorilla like to mess it up.

You'll never need power, but you will need patience. Try to start out by hand, like you are actually trying to screw in a bolt. Then use the tap handle, or a suitable sized open end wrench. Screw it in about 1-2 revolutions, then back out. Clean your tap of the shavings. Screw it back in, this time going 1-2 more revolutions beyond the last resistance point. Keep doing this until you are all the way through. Keep cleaning your tap. If you feel very comfortable, try 3-4 revolutions, but in any case, you should not have to apply a superhuman amount of torque to get the job done.

If possible, try on a scrap piece first.

But seriously, it is still not clear to me why you need a threaded hole for a switch. (I will be happy to admit I am wrong here.) Usually the shaft of the switch is threaded, to accept a retaining nut, and to accommodate the boot. The hole is usually a through hole with a smooth bore. I would really like to see pictures as you go or when you finish or both.

Happy tapping.

 

[gav6280]

Switch : EATON|7546K40|Toggle Switch | Farnell United Kingdom

And Boot : http://uk.farnell.com/apm-hexseal/n1030/sealing-boot-toggle-15-32-x-32ns/dp/146843

 

[wes_wall]

Gav:

I am pretty sure you do not need to thread the hole....almost certain. I am certain you do not need a keyway. moreover, most companies recess the switch housing into the lid of the canister so it is not possible to screw in the switch. The recess also keeps the switch in position as you tighten it. After tightening it friction holds it in place.

All that said, and just to confuse you more, you should read this dissertation on switches for dive lights. (I did an effective job of convincing myself that toggle switches are not the best for dive lights.)

http://www.candlepowerforums.com/vb/showthread.php?t=228926

 

[gav6280]

Gav:
I am pretty sure you do not need to thread the hole....almost certain. I am certain you do not need a keyway. moreover, most companies recess the switch housing into the lid of the canister so it is not possible to screw in the switch. The recess also keeps the switch in position as you tighten it. After tightening it friction holds it in place.

All that said, and just to confuse you more, you should read this dissertation on switches for dive lights. (I did an effective job of convincing myself that toggle switches are not the best for dive lights.)

Well secretly i have always wanted to use a Piezo touch sensitive type, but despite asking in loads of forums and googling my but off i still have never been able to definitely figure out what it is that i would need to drive one.

Was going to get one of these: http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=0226104

So it looks like the toggle switch is staying for now.

Just assumed it need to be screwed in to stop it moving around to much and help in the waterproofing.

Also just seemed like the proper way to do it! No half measures or bodge ups on this one because its been in the making about 18 months now. I've put my heart, soul and a fair few $ into it.

Finished product should be 1500 Lumen, 6deg, 3 hours runtime, 100M+ depth rated.

 

[wes_wall]

Gav: there is a Yahoo forum that has lots of info on HID dive lights. Almost all of the information directly translates to LEDs. Sign up for that blog, and look for info on driving the piezoelectric switch.
I have successfully made reed switches from a schematic on that site. I built a printed circuit and encased the thing in epoxy. On the outside of the canister there is a trigger that moves the magnet. The trigger locks in place with a ball and detent. I even epoxied the magnet so it will not rust.
You should sign up for the HID forum for sure.

 

[gav6280]

Gav: there is a Yahoo forum that has lots of info on HID dive lights. Almost all of the information directly translates to LEDs. Sign up for that blog, and look for info on driving the piezoelectric switch.
I have successfully made reed switches from a schematic on that site. I built a printed circuit and encased the thing in epoxy. On the outside of the canister there is a trigger that moves the magnet. The trigger locks in place with a ball and detent. I even epoxied the magnet so it will not rust.
You should sign up for the HID forum for sure.

Thanks.

 

[gav6280]

Going to use this circuit and replace the switch in it with the RS piezo one and see what happens?