john, what kind of bit is used to mill .25 recesses in a piston for buttoning?
i will use a vertical drill press but obviously can't use a drill bit. my problem is that JM old school buttons on the open end of the piston shear off because this is a high stress area. the oned on the front near the se3al are fine probably because the seal aleviates some of the forces on the buttons.
my plan is to use the old school buttons but cut a shallow recess for them. the HW piston on the 50s is not very hard metal so i think i can cut them with the drill press.

watta ya think?

He has what he calls starter bits. they are tapered and won,t actually grab like a drill bit would. I,ll try to ask him tonight for the name.They make a nice divot in the piston. You could probably ask Rayburn for advice on this also, He knows more about machine work than anyone else I know.

what kind of bit?

its called an "end mill". it has a .25 shaft and cutting head. will fit in a drill press chuck. i will have to be careful since it don't want to damage the
piston. i am only cutting line .015" deep. just enough to grab the button and give it something to grab onto.

You can't plunge with an end mill with more that two flutes. You'll have to pilot drill your holes first. If you plan on doing this on a drill press...Don't. You'll just screw up a good piston. JMO.
Rob

educate the ignorant(me!)...why can't a drill press be used?...thanx. ignorance can be cured with education...

I guess if you had a good enough drill press you could do it. What you want to do is find the crest of the piston and put it directly under the tool. The work also needs to be secured so it doesn't move. You'll need to pilot drill the hole to the proper depth without drilling through the piston skirt. And, you'll need to drop your end mill to the proper depth within a few thousands of an inch. You'll need to be able to change tools without the piston moving. And you'll need to be able to indicate the position of the buttons at 120 degrees apart. I just don't know how you can do this (properly) without a vertical mill, good vise and index table.
You'll also need a lathe to trim down the buttons to the proper diameter. The piston must also be positioned in the lathe chuck so there is zero runout of the piston. And that's after you measure the diameter and runout of the compression tube.
Instead of doing a sloppy mill job, why not just use Maccari's "Jim's Old School Buttons"?
Rob

i did use jm old school buttons. they have held fine on the end of the piston with the seal but not on the skirt. the skirt must take more stress because the buttons came off. maybe i did not prepare the surface properly. i will try again.

Most people think super glue sets up within seconds. It doesn't. It takes 24 hours for it to cure completely. The surface and the buttons must be carefully prepared as well. There is a method to the madness.
Rob

I agree with Rob on this one.

I have used the OS buttons with good success too. I use Locktite Super glue no problems. I prefer to hand sand the buttons to fit each has its own needs I have found. I like to get a 220 grit paper wet and feather sand it to fit right. It takes time wetting, sanding, drying, lubing and try in the tube. I like to round down the edges of the buttons so the contact is in the middle this way they don't come off and ride smooth. You can see the contact parts when doing it this way and adjust each button to fit per your needs. Any real drag and you will drop FPS though. I always do buttons first then the seal as I do not want the drag of the seal interfering with my feel of the buttons as the seal drag is much more than buttons will ever have or need. The fit can be difficult on many guns as the tube variances are terrible at times in the area the buttons ride in. There can be bulges, taper run out in the range of 0.010" or so in this area. The compression tube is better than the cutout area as far as I have seen.

I need to hone a compression chamber on a R7 right now as there are 0.003"+ high spots near the welds of the front bracket. After this is resolved I can size a wasp seal to go.

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Remember to degrease with rubbing alcohol and glue the brown side down, i.e. sanding the purple colored side.