Safely open up a Disco gauge port assembly??

[ray1377]

And yes I know I have already read somewhere that you can replace it with one off a P-Rod and it will already be larger.
But I would like to modify the one I have and save the money.
Is there an easy, safe way to do this?
I don't want to risk the gauge blowing out of the air cylinder.
Thanks
Ray

[ray1377]

NT

[dmeguy]

If I remember right, I drilled mine offset, away from the gauge, to 3/16".

[rsterne]

You can use an end mill and offset the hole to the opposite side to the gauge port.... I used a countersink on both ends, then used an end mill (pretty sure it was 5/16", but 1/4" is the size of the valve inlet hole, so is big enough) offset into the space between the bottom of the gauge port hole and the O-ring groove on the opposite side.... I then blended the transition between the two with a Dremel.... Once I discovered that the PRod gauge port would work, I never did it any other way.... and it has about a 3/8" hole in it....

If you use the PRod gauge port, you have to use a 1/8" NPT male to female fitting as an extension for the gauge.... The original Disco gauge extension has straight threads on the male end, and seals with an O-ring in the gauge port.... The PRod uses 1/8" NPT tapered threads, and is sealed with Teflon tape.... The gauge is, of course, 1/8" NPT....

Bob

[ray1377]

You can use an end mill and offset the hole to the opposite side to the gauge port.... I used a countersink on both ends, then used an end mill (pretty sure it was 5/16", but 1/4" is the size of the valve inlet hole, so is big enough) offset into the space between the bottom of the gauge port hole and the O-ring groove on the opposite side.... I then blended the transition between the two with a Dremel.... Once I discovered that the PRod gauge port would work, I never did it any other way.... and it has about a 3/8" hole in it....

If you use the PRod gauge port, you have to use a 1/8" NPT male to female fitting as an extension for the gauge.... The original Disco gauge extension has straight threads on the male end, and seals with an O-ring in the gauge port.... The PRod uses 1/8" NPT tapered threads, and is sealed with Teflon tape.... The gauge is, of course, 1/8" NPT....

Bob

Thanks Dr. Bob!

Ray

[TF89]

I'm late to the game on this one and this is something I recently did.  I used a dremel and a 1/8" diamond bit to grind out the gauge hole.  I basically ground the offset to allow for a .250 hole when completed. 

The actual process was to grind the offset and then stepping up the hole using drill bits.  My memory is a little vague on what size drill bit I started with to true up the hole after using the dremel, could have been a 3/16th or 7/32 drill bit to start.  I ended up with a 1/4 hole and it worked great. 

As Bob mentioned, you will want to counter sink the ends and polish so that the air will flow better into and out of the hole.

Regardless, just figure how far the hole needs to be offset and start grinding, take your time and have fun.  I figured if I screwed it up I could just buy another one, there not that expensive.

Did you already try it and how it did it turn out?

Dave

[ray1377]

I'm late to the game on this one and this is something I recently did.  I used a dremel and a 1/8" diamond bit to grind out the gauge hole.  I basically ground the offset to allow for a .250 hole when completed. 

The actual process was to grind the offset and then stepping up the hole using drill bits.  My memory is a little vague on what size drill bit I started with to true up the hole after using the dremel, could have been a 3/16th or 7/32 drill bit to start.  I ended up with a 1/4 hole and it worked great. 

As Bob mentioned, you will want to counter sink the ends and polish so that the air will flow better into and out of the hole.

Regardless, just figure how far the hole needs to be offset and start grinding, take your time and have fun.  I figured if I screwed it up I could just buy another one, there not that expensive.

Did you already try it and how it did it turn out?

Dave

Yes, already did the deed.
I took a drill bit the same size as the stock disco gauge hole and drilled three more holes.
Imagine holding it with the actual air gauge port pointing down at 6 o'clock position.
Then I drill a hole at 9. 12 and 3 o'clock position and then used a dremel  tool to blend and smooth the three holes into the original center hole.
Worked pretty well for not having access to a milling machine or lathe I guess.
Haven't had a chance to see if there was any noticeable increase in FPE yet though.
Thanks
Ray

[BigBird]

The Prod gauge port was all sold out (people buying them up and selling them for 2x the price on ebay).  I drilled an adjacent hole to the middle hole and then used a bigger drill bit to drill between the two holes to connect them.  The two holes guided the larger drill bit down straight.  I used another drill and dremel bit to finish it off.  I did not countersink the ends because I didn't want to accidentally cut into the o ring channel.