1/4" Adapter for Screw Driver Panel Mount Air Vairables

The 1/4" dia. spacers in the adapter kit will either be hard nylon or metal, depending on what is in stock.

Here is a little adapter for the small screw driver panel mount air variables. This little adapter kit turns a screw driver type panel mount air variables into a air variable with a 1/4" shaft.I will try and take you thru it step by step as how I do it. you can follow along with the photos.


Small bastard type file.

Dremmell tool is nice but not needed if you not have.

Small plastic hammer or use your big hammer if all you have.

Step 1

Take screw driver air variable and take the small bastard file and pass over all the edges of the hex type head on from of air variable. Make 1 or 2 passes to start with. Next, take the big round collar in adapter kit and see if it will push down on the hex head of air variable you just filed the edges a little with bastard file. You want it to be snug, not lose and if it looks like it might fit, take the small hammer and tap it down about half way on the small hex shaft on air variable.If it looks like it will not fit..then take off and file just a little more on the edges of the hex head of the air variable and then the big collar should fit. ( Note: do not over file the hex head )

I would also advise to take a small burr tool on dremell tool and rough up the surface inside the big collar.

Look at all the photos..they say a photo is worth a 1000 words!

Step 2

Locate the round 1/4" spacer in adapter kit..( note: will be either metal or nylon ) and also the 4-40 metal screw and the small hex nut.

Take and thread the 1/4" 4-40 screw thru spacer and into the small hex nut, and make sure the nut it tight on bottom of spacer with 4-40 machine screw threaded thru it. Next take your dremmell tool or file, and rough up the little hex nut on the sides and also on the end. Do not file the edges on the little hex nut.


Take the spacer with the machine screw threaded thru it with the small hex nut on end and see if it will fit in the big round collar on the air variable. If it does not, take a small file and file the edges on the small hex nut..( one pass on each edge should be enough ) and then it should fit.


Take the small air variable and stand up or support in a vertical position and see if u can make it level. Then the next step is to mix a small amount of epoxy and make sure you mix it good. Next take some of the mixed epoxy ( The end of a match works good for this ) and fill the big collar full of epoxy. Next take the spacer with the machine screw thru it and the small hex nut on end and fit into the big collar with the epoxy in it. Make sure the spacer is vertical or straight up and down.

Now just let it dry for 24 hours and then the air variable is ready to use...do not worry about any epoxy that may run out of bottom of big collar on air variable. See photo no. 11 and it explains what to do there.

I recommend also before you use the air variable that a small amount of 3 in 1 oil or other light oil be used on the shaft that goes thur the ceramic part of air variable, this will make the shaft turn smooth.

There you go..about all there is to it. Enjoy and have fun and take the time to look at all the photos and just take your time and you will have a nice air variable you can use with a 1/4" shaft so you can use a knob to turn it and not have to use a screw driver!

If by chance You get a little of the epoxy on your fingers do not worry about it...it will come off...the epoxy is not like super glue!



Photo no. 1 shows the adapter parts kit.

Photo No. 2 is example of the air variable used in instructions. This photo shows just the stock air variable with no work done yet.


Photo no. 3 shows air variable with big collar on hex head of air variable


Photo no. 4 shows the 1/4" spacer with 4-40 threaded machine screw and small hex nut.


Photo no. 5 shows the 1/4" adapter kit on air variable


Photo no. 6 shows the recommended epoxy adhesive to use. I do not recommend using super glue..You can, but it will not make for a very strong bond. The 2 part epoxy is the best and the type that has about 30 minutes working time is what I use. You should let dry for a least 24 hours be for using the air variable.

You only need a small amount and just follow the directions on the package of epoxy. You can get at ACE HARDWARE or other hardward stores...I like the 2 part the best.


This photo shows dremel tool with round sanding disc.


PHOTO NO. 8 Shows Dremel tool with burr tool.


Photo no. 9 shows one way to mount the small air variable vertical and photo no. 9 shows air variable with just big collar.


Photo no. 10 shows spacer with machine screw and nut mounted in big collar on air variable.


Photo no. 11 shows spacer with a set of vise grips on the shaft. If by chance some of the glue goes down into the part of air variable that turns, do not worry about it..Just take the vise grips and rock back and forth and turning the shaft and it will break lose. It does not take much to do this. I would wait for at least 24 hours after you have applied the epoxy before doing this.

One other note of interest..There are some screw driver type air variables this adapter kit will not work on, look at photo of the screw driver air variable here. If the ones You have do not look like one in photo or the nut arangment on cap is a lot different, then this adapter kit probably not work.