Ohlsson & Rice: Kill Switch for Drillgine and other Tools

[CNew 404]

Did some investigating today in search of a replacement kill switch for one that is broken on one of my O&R tools.  I thought this might be helpful if anyone else is in need of a similar replacement.

 

The little red push button switch looks to be identical to the Switchcraft 951 from Switchcraft. They have a model “A”, “B”, and “C” and I think it is the “A” version. I have one on order and will confirm once I receive it. 

 

This photo is of a good working order switch on a Drillgine.

 

Clint

Edited March 28, 2019 by CNew
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[pmackellow 2,738]

Thats worth knowing, thanks !

 

[factory 487]

It does look similar, 951 is obsolete thanks to ROHS legislation, 951X is the unleaded replacement, 951X (A) has normally open contacts, 952X (B) has normally closed contacts (normally open is the most common type used for O&R's).

 

Full data-sheets & drawings here;

http://www.switchcraft.com/productsummary.aspx?Parent=971

 

Just be aware that the stop (or kill) switches/buttons vary a lot for the different tools, some have toggle switches too, and they usually have one contact directly connected to the casing (ground), I suspect the replacement won't.

 

For reference, my late production Drillgine has the standard brass strip version (presumably cheaper than adding the extra switch & wiring).

 

 

David

[CNew 404]

I ended up ordering the 951X “A” version. I’ll send some pics when it arrives.

[factory 487]

On 3/27/2019 at 10:59 PM, CNew said:

Did some investigating today in search of a replacement kill switch for one that is broken on one of my O&R tools.

 

Which O&R tool was the replacement switch for? you never said in the original post.

 

David

[CNew 404]

Oh, sorry - I stumbled onto a partial Drillgine the other day on a Craigslist post. It’s not in the greates of condition but I think I can still salvage what’s there for some spare parts.  The switch on it is broken and it made me curious enough to try to hunt down a replacement. I guess I probably don’t really need it but I thought if I could find the right one maybe it would come in handy some day, especially if I accidentally break a switch or find another O&R tool that needs one.  

 

I’ve also been thinking of maybe installing this type of switch on one of my display engines. This same type of switch is on my Orline Trimmer and it’s incorporated into the side of the blower housing. I kind of like the look and operation of this little switch instead of the little brass strip and I might come up with a way to use it as part of an engine display stand.  Speaking of display stands, I was a able to find a couple nice pieces at the local steel supply store that look like they would make nice semi-decorative bases for displaying these engines.  I’ll have to come up with a mounting bracket.  More fun projects for this Spring.

[CNew 404]

The Switchcraft 951X “A” switch arrived today. Looks almost identical to the original. It has one extra tab so I’ll have to figure out which tab to solder the wire that goes to the threaded post on the back side of the points.

[factory 487]

22 hours ago, CNew said:

Oh, sorry - I stumbled onto a partial Drillgine the other day on a Craigslist post. It’s not in the greatest of condition but I think I can still salvage what’s there for some spare parts.  The switch on it is broken and it made me curious enough to try to hunt down a replacement.

 

I’ve also been thinking of maybe installing this type of switch on one of my display engines. This same type of switch is on my Orline Trimmer and it’s incorporated into the side of the blower housing. I kind of like the look and operation of this little switch instead of the little brass strip and I might come up with a way to use it as part of an engine display stand.  Speaking of display stands, I was a able to find a couple nice pieces at the local steel supply store that look like they would make nice semi-decorative bases for displaying these engines.

 

Thanks for letting us know, looks like the original part no was A-3-3 for the button type switch.

Is you second Drillgine the same type or one of the other variants? I've only got the late AEP engined yellow Drillgine with the steel case.

 

Looks like you found some nice steel bases for your display stand, I look forward to seeing the completed project.

 

David

[CNew 404]

The parts Drillgine is an older type, before the AEP 13B engine.

[factory 487]

OK it sounds similar to your other one, is there much missing or damaged on it?

 

6 hours ago, CNew said:

It has one extra tab so I’ll have to figure out which tab to solder the wire that goes to the threaded post on the back side of the points.

 

The original switch will have one tag directly connected to the threaded part (the engine case is the return connection for it), the new switch has insulation in-between as indicated below.

 

 

You will need to use both of the tags on the new switch, solder an insulated wire to one tag to go to the points, solder a bare wire to the other tag (the one nearest the case would be best) & wrap it around the threaded part of the switch before attaching it to the casing.

Of course if you have a suitable sized tag washer similar to the one in the picture below you could use that instead.

 

 

David

[CNew 404]

Thank you David - I would not have been able to figure that out on my own, electrical stuff is not my strong suit!  I’m pretty sure I’m tracking with your guidance for the insulated and bare wires with regard to the two tags. When I finally get around to installing one of these new switches I’ll be sure to send a picture before I actually put it on the tool.

 

Clint

[Wallfish 698]

If the switch comes apart, you can just remove that insulation ring which David pointed the green arrow to.

The switch body appears to be isolated from those tabs and by removing that insulation ring you are just connecting the tab to the switch body. The switch body will connect to ground when it's installed on the handle and therefore ground the the wire when the the button is pressed which connects those 2 contacts.

Either way you do it will work fine.

[CNew 404]

John, 

   Another great option. I’ll fiddle with the switch and see if the isolation ring is easy to remove, seems like it would be possible. That would definitely simplify things a bit more.

 

Clint

[factory 487]

1 hour ago, Wallfish said:

If the switch comes apart

 

If it's anything like this late 60's Switchcraft push switch then you will find that it's pressed together (see arrow) & cannot be taken apart without destroying it.

 

 

This is what I meant by wrapping a bare wire around the threaded part of the switch to connect a tag to the switch body (demonstrated with a push switch from my electronics spares & a bit of scrap wire), obviously solder the tag on your switch and don't solder the wrapped part unless you want a melted plunger.

 

 

David

[CNew 404]

David, 

   That’s very helpful, thank you for the photo of the wire on the tag!  You e got me curious now, I’ll have to go look at this switch and see if it’s all one piece like the one you show.

 

Clint

[CNew 404]

I took a close look at th new switch and it doesn’t look like it comes apart so removing the insulating ring is probably not an option.

[factory 487]

Option C;

 

I had a thought while I was at work, you may be able to swap the plunger.

The spring clip can be carefully removed (hopefully it doesn't end up on a low earth orbit), getting the spring back on is a little trickier, but I've just successfully tried it with that larger Switchcraft push switch I found yesterday.

 

I would try it on an old one that doesn't matter first.

 

 

David

 

P.S. A similar spring clip is used on the O&R engine PTO shaft.

[CNew 404]

Great idea David. I’ll take a closer look this evening to see how the plunger is attached. I don’t recall seeing a little ring clip but I’ll see if it has one or something similar.

 

Clint

[factory 487]

It is hard to tell if it has the same type of clip from your picture, I took my picture with the switch pressed to make it more obvious how the parts are held together.

 

David

[CNew 404]

David,

   As usual you are spot-on, there is indeed a small clip holding the plunger in place. Switch plungers might be the easy way for a fix!

 

Thanks,

Clint

[Wallfish 698]

That appears to be a nut which holds the tabs and isolators all together.

 

[CNew 404]

John,

   That’s what I thought at first too but after closer inspection it is basically a very thin crimped metal retainer. It might be possible to gently lift the four little tabs that are folded over and crimped.  I wish I had a couple spares to play with just in case it messes it up. I may scout eBay for some used ones to tinker with.

 

Clint

Edited April 1, 2019 by CNew
Typo

[Wallfish 698]

I'd just go with David's idea. It only needs to ground the points.

I know those handles are a tight fit so less wires is helpful but not if you got a ruin the switch

[factory 487]

The data-sheet describes everything in detail, the crimped bushing will probably break if you try to undo the crimped part.

The "button retaining ring" is the part I took off on my larger switch.

 

http://www.switchcraft.com/Drawings/951x_961x_cd.pdf

 

David

[CNew 404]

I think I’m going to try the retaining ring approach first to just swap the plunger.

 

Thanks David!