Cheap/easy mech switch (if anyone cares in a world of regulated mods)

[Quigsworth]

To spare anyone my rational of going back to pure mechs in a world of 40, 50, even +100W chips I thought I'd jump right in with a photo essay if you will of how I overcame the problem to finding a high current, safe and reliable switch that at the same time didn't cost a fortune and wasn't as big as the mod itself....if you've tried looking on Ebay you'll know what I'm talking about...and no, this is not about grabbing a 10A SS vandal proof momentary (and that's it's off-shore rating, probably closer to 5A if you're lucky) to run my .25 duals and forever convince myself that what I've done isn't stupid...

If you've ever taken a look at a Reo Grand switch (below are some pics of my adaptations):



You'll see 2 methods, on the left I've added a copper stud, allowing me to "pair" the contacts (if you've ever set the points on an "70 car distributor you'll know what I'm talking about). It takes more space, a little more complex but affords you a more stable, larger positive contact area. On the right is closer to the Reo method, you simply mash the contact into the top of the batt. terminal and done. (I've used the actual Reo contact for this build as it's flexible enough to make it work.

As far as the "actuator" I went to an RC shop and bought brass matched rod/tube, the tube acts as a bering'd sleave that you can epoxy in place, the rod slides in it smooth as silk.



To stop the rod from sliding out I just drill a hole in it and tap a piece of wire in, or you can slot it and use a spring clip 6 of 1...

For the contact leafs I either use the Reo's orrr...pick up a high current DC relay from you local industrial electronics shop and start savaging,,,,



Those leafs are beryllium copper with silver plated contact points welded on (these particular leafs are rated at 25A DC!). The beryllium copper is springy which will force the switch open when you release the rod actuator.

You gone through all the effort to build your creation and you obviously have the skills, why not go the extra mile instead of just puking in some crappy switch you know is going to be dangerous and ultimately fail? You can adapt this method for top or side orientation (I just prefer top for pocket reasons)

Just trowing this out there for food for thought...

 

[TUS172]

Great ... I have a Reo and looked at the beryllium copper strip and delrin pieces that they installed. It is simple and quite adequate. I built a few bottom fed boxes and used one of the 48v 2amp rated dome switches in them. Built one for a friend and he says when he went to .3 ohms on his dripper the switch failed (replaced it). So I have since purchased a sheet of 3mm beryllium copper and delrin blocks to cut and shape to try and incoporate it into a decent design for use. I would like to put one to work for the OKR T10 and a DNA 30 as I have both on hand. Will use a battery sled though and wire to contacts.

 

[johndoe1027]

:bow: :iamsoooonotworthy:

Thank you for posting this Quigs. You. Are. The. Best.

I'm in the process of building my first basic "mech" box with a relatively hefty momentary push button but, after reading a handful of your posts, I will only use it to tide me over until I can build a box with a real mechanical switch like this.

I'm hoping to find some trades that use relays like this on a day to day basis that may have some laying around. Worst case I'll have to buy some but either way I truly appreciate you opening my eyes to this concept.

 

[Quigsworth]

:bow: :iamsoooonotworthy:

Thank you for posting this Quigs. You. Are. The. Best.

I'm in the process of building my first basic "mech" box with a relatively hefty momentary push button but, after reading a handful of your posts, I will only use it to tide me over until I can build a box with a real mechanical switch like this.

I'm hoping to find some trades that use relays like this on a day to day basis that may have some laying around. Worst case I'll have to buy some but either way I truly appreciate you opening my eyes to this concept.

Np, glad I could help...here's another example of one of the 25A contacts installed in a Grand I just rebuilt with a hybrid'd Magma with a custom marine brass center pin...



When I found that I was getting deeper and deeper into the sub ohm range I had to figure out a better way than just replace cooked switches (at $10+ a pop)...plus I was tired of the look of these big goofy looking knobs stuck on the side of my mods (or allocate a lot of space inside the mod if I wanted to sink it for a "flush" look)

I really have to give mad props to Rob at Reos Mods, I'm not saying he invented this method, peeps have been jamming conductor onto the tops of batts since they invented electricity...he just figured out a way to make it not just elegant and safe, but bullet proof reliable...I just amp'd it a bit bottom line is, as much as you want that nice SS momentary to work for you, they're just not engineered for what we demand of them (it's really not their fault ), 10A-15A in the electrical world is right on the edge of having to go to a control circuit solution (I'm an electrician btw)...typically these types of SS vandal proof momentary switches don't do the heavy lifting if they are switching any kind of meaningful load, the switch would be used to control the coil in a relay or contactor and it would switch the load, the current draw of a relay/contactor coil is quite low therefore there's no need to build them handle more than a couple amps (which is why there are so few high current models out there). All I did was pull the contact out of the relay and swapped out the relay coil with a manual push button...don't get me wrong, there are some good momentary switches out there ($$$) but even one with a 10A rating (and you'll also have to consider it's duty cycle) you have to do the math.

If you just go with a nominal 3.8v and your running .5 duals...add some nominal v drop and your close to what a good 10A rated switch can handle...then press it a couple hundred times...

And in my case, #24 kanthal at .3 on my Magmas...that's 12.6 amps...I'd be going through a lot of those switches and I'd be praying they fail in the open state and not weld closed (it's happened and it's scary)

I've got a couple builds for buddies on the bench atm and I was checking out ebay and found this 2 Pack Deltrol Controls 375P 3PDT 120VAC 30A Coil Relays | eBay

...pretty good deal when you consider that's 6 contacts that will out live the same value in momentary switches 10 fold (and I can maintain mine)...and as you can see in the above pics, in a much slimmer form factor.

 

[johndoe1027]

I love you Quigsworth.

I figured you were an electrician or, a master of everything you touch, or both. I have been a low-voltage tech for 10+ years now. I love making custom "black boxes" for my projects at work and now I have a new love. I'm moving forward with my "typical" box and the stainless momentary, for now (just to test an 8V box), but I will be on the fast track to make the next one with no wires. I will use your relay contact idea (again, thank you) and copper bus bars for the rest of the connections. It's gon be EPIC. All of the clouds!!!!

I have a lot of info to digest still but I am so excited about this. I have a Mutation X v2 RDA pre-ordered and I'm hopeful that it, on top of a dual 18650 series 'true' mech mod, will be my ultimate vape rig. For at least a few weeks... You know how it goes. ;-) Then I'll probably get into the bottom feed game and will have a whole new set of skills to learn. Hooray hobbies!

If you're ever in WNC, beers/food/E-juice is on me. For reals.

 

[rhelton]

That looks good

 

[rolf]

hi quigsworth !
that's not food for thought...that is a no brainer !!
the way to go for a unregulated mod . realy nice. just build a switch for a regulated mod and used a 22 caliber amo shell ..used of course..
with a spring from an pen .realy small works great for the purpose . have funn

 

[Quigsworth]

Rolf, you certainly don't need my help ...I seem to recall you're the "make your own molds out of foam and lay carbon fiber over it" guy...how's that mod working for you?...that was a nice build.

I still think about that mod...I have to do that one day

 

[rolf]

jes that's me
build a few mods since then so . allways trying new things . got to order more carbon fiber .
right now working on a bottom feeder with an plexyglass tank and a pump . want to see what all the hipe is all about !
so far I am not convinced and still prefere the ti fun ..just a stubbon kraut .
also making an atty out of junkbox parts for it . just having fun with some ideas . modding for ever!

 

[johndoe1027]

Hey Quigs, how would you set up a side switch? Would you have the leaf sticking up from the top of the battery and move it over to a contact from the 510? I can't figure out how to do it with a stationary battery post like you have in the pics.

 

[ayopassthat]

Thanks for the excellent idea. I bought 4 relays today for $7 on clearance at Radioshack. I got them out but I can't figure out how to remove the plastic piece holding them side by side. I can see it 's 2 pieces glued together but I am afraid to damage them. Again, thanks for the help. I couldn't find beryllium copper anywhere in my area and this works out very well

 

[cobalt327]

Slick 7 (slot car manufacturer) has silver contacts used in their controllers that are solidly made. They're available singly for around $5.00.

 

[Quigsworth]

Thanks for the excellent idea. I bought 4 relays today for $7 on clearance at Radioshack. I got them out but I can't figure out how to remove the plastic piece holding them side by side. I can see it 's 2 pieces glued together but I am afraid to damage them. Again, thanks for the help. I couldn't find beryllium copper anywhere in my area and this works out very well

They typically bond the contact leafs in like that...and the plastic used is typically very hard, and to your advantage, brittle. If you have a pair of sharp small side cutters like these,



the plastic will simply snap off and done.

 

[ayopassthat]

Thanks again, I was able to get them out with a little effort and I didn't damage a single one. I'm going to be making 20+ wood mods and I am looking to buy some raw beryllium copper rather than have to salvage each contact. All I have found are beryllium copper rods, they might work but a strip or pre-cut leafs would be ideal. Any idea on where to get these? I have searched high and low and the majority are links to custom made metalworks. If I knew of something else that used this size of contact I might be able to find replacements and use those...still no luck. If all else fails the ones from the relays will do.

edit: something like this might be what I end up buying

 

[Quigsworth]

Thanks again, I was able to get them out with a little effort and I didn't damage a single one. I'm going to be making 20+ wood mods and I am looking to buy some raw beryllium copper rather than have to salvage each contact. All I have found are beryllium copper rods, they might work but a strip or pre-cut leafs would be ideal. Any idea on where to get these? I have searched high and low and the majority are links to custom made metalworks. If I knew of something else that used this size of contact I might be able to find replacements and use those...still no luck. If all else fails the ones from the relays will do.

edit: something like this might be what I end up buying

Beryllium copper is tough to find, I ran into the same issue...for me, the local commercial electronics store is forever blowing out things, hence my first couple 25A DPDT relays...at a couple bucks a leaf I couldn't pass them up, especially with those big silver plated contact points

...that stuff you linked will work, a fellow ECF'er sent me some fingers off one of those RFI gaskets to try, only issue you may have with them is if you really need to bend/fold/mutilate...the stuff solders nice (make sure you quench with cold water to retain the spring) but on their own, they're pretty brittle, springy, but brittle...bend it too much it'll simply snap (forget about a nice tight hard bend), I found you can take some of the tempering out with a torch and let it slow cool...but again, no big silver contacts