Not sure if I have the terminology right but it's the tube the piston slides back and forth in. The one that gets honed/deburred/cross-hatched in a tune.

My gun is at home so I can check tonight but if anybody has the inner diameter in in/mm I would appreciate it.

Thanks,

Casey

So pretty much what you buy at auto parts store, Harbor Freight etc?

I'm in touch with an outfit called Brush Research. They make products called Flex-Hone. I sent a rep some pics of the cross-hatching desired.

Regarding tuning in general, if anybody had favorite parts like screwdrivers, punches, drills, hones, sandpaper/emery cloth etc that they like to use in tunes let me know. I have no plans to make a business out of this but like the DIY approach. As much as I'd love a Paul Watts etc tune that's just too steep for me right now.

-Casey

Might give this a shot. Pasted below is the link to a brush-like product that should do the same kind of honing.

**Use or buy at your own risk - I've never used this product nor do I endorse it. Just providing the info**

Quote:

Thank you Casey,



Is it a straight bore or is it tapered?



Assuming it is a straight bore, that is a very straight forward application of the Flex-Hone tool and is typical of its uses.



Simply use a BC11818 Flex-Hone (1 1/8 180 grit silicon carbide).



See the product here:

http://www.brushresearch.com/brushes.php?c1=1



Thank you,



Grant Fowlie

Customer Service Manager

Brush Research Manufacturing Co., Inc.

4642 Floral Drive, Los Angeles, CA 90022

Phone: (323) 261-2193 x 707

Fax: (323) 268-6587

Email: GFowlie@brushresearch.com

www.brushresearch.com

That depends on what vintage 34 you have? If it is an earlier TO1 trigger it's ID is slightly larger than the current TO5 34s so a stock RWS seal is needed. If you have a current model 34 TO5 with the slightly smaller ID chamber, the large Apex seal will work good. I don't remember the exact ID numbers, maybe some else will chime in.

28mm then?

I use an impact screwdriver for the stock screws. Not so much for the impact, but for a bit that fits just right so I don't bugger the phillips head. Then I put it in my spring compressor which is a woodworkers bench with peg holes every 8 inches or so. A few light taps on the hammer on a Craftsman long punch (part of my full set - smaller ones are useful for the lever pins, etc) and the two pins holding the trigger are out (reverse is a few taps on the hammer once the holes are aligned - sometimes can push them in by hand, depends on how aligned. To get the piston out, need to take the cocking lever out of the slot in the piston. In my case, its a just pin on the cocking lever, the 34 may require more. The only other tool (besides hone and files if doing that deburr thing) are a thin blade screwdriver for prying the piston seal off and thumbs/fingers for putting the new seal on and determining if a debur job is in order and where......Don't forget Maccari heavy tar and moly.

You MUST use a hone that will go ALL THE WAY to the bottom of a BLIND HOLE! The last millimeter of the compression tube is the MOST important. If you use a brake cylinder hone you will have a transition at the bottom of the compression tube which will cause piston seal leaking and damage.
Don't do it at all if you don't know what you're doing.
Rob

http://www.SpringGunTunes.com

On all the drum brake wheel cylinder hones I've seen, the bracket that holds the stone prevents the stone from reaching the bottom of the hole. Disk brake caliper hones are made to go to the bottom of a blind hole.
Never use the beaded hones on airgun tubes.
Rob

http://www.SpringGunTunes.com

What's wrong with the beaded hone if it does essentially the same thing? Or does it not do the same thing?

And by blind hole I assume this means the hone is being inserted from the rear of the tube. The likelihood of me actually doing this is quite small but I guess I'm on a quest for knowledge at this point. Just like to know how it all works. A guy in town has a cheapie B3 he's selling - might be a good test mule for my tuning education

-Casey

The Flex-Hone has abrasive beads mounted on wires wrapped into a wire shaft and the beads are round (in other words a radius) which is incapable of reaching the extreme bottom-side of the cylinder.

A standard brake cylinder hone frequently has a base which the stone is attached to, which is larger than the stone, when you bottom-out the hone the contact point is the base and not the stone, which leaves a small portion unhoned.

A disk brake hone has a stone that runs the full length of the base allowing the stone to reach the very bottom of the cylinder.

Remember, when you hone a cylinder for an airgun you want the sides fully conditioned, it must be honed all the way to the bottom, you don't want an area of 1/8" to 1/4" left unhoned or performance will suffer as mentioned in an earlier post. Different hones for different purposes.

Hope this helps your understanding of the differences between hones and their capabilities and applications.

Gene

That's exactly correct. Great post.
Rob

http://www.SpringGunTunes.com

Rob,

The flex rod for my hone attaches to a the middle of each of the three stone assemblies. The individual stones protrude past their steel bases, so they can reach to the bottom of the cylinder. One needs to be careful that you don't dwell too long at the bottom as the edge of the stones could cut into the front of the cylinder, but that's just part of good technique to get the right crosshatch pattern.

This hone is as old as the hills as it hasn't been cost effective to hone a brake cylinder for years (I think I last did it on my 66 pontiac....)

Since the break hone mentioned above is ok for putting a cross hatch in the cylinder wall,
but is not able to remove any out-of-round or run out, tapper etc. often present in todays airguns.

Here what I like done to my guns when tuning.

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The machine pushes on the wedge to raise the stone up and down.
This type of mandrel uses one or more stones in a line.
As you can see only the last stone is being used to hone the tubes.
The others are not installed.
The shoe is the brass thing attached @180 deg. of the stone.
On the machine you can see a long mandrel set up to do HW medium size tubes (HW 95,57,50s,85,etc.)
Only one stone is on the very end of it.

Down in the bed of the tool is a sleeve you might notice.
That is a truing sleeve.
After every few passes it is used it to dress the stone with some grit and oil.
This keeps the stone true and straight.
On bad tubes the stone unevenly wears as it does more work on certain areas.
So it must be redressed often.
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The foot pedal on the machine is used to actuate the machine and push up the stone.
Each few passes one needs to squirt oil in the tube with a hose.
On most other applications one can leave a hose running on the part while it is honed, not possible here though.
A setting is used on the machine for amount of cutting pressure as well as amount of material to be removed.

You need to use a bore gauge to check often the tube measurements and amount of run out left to correct.

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KevinTK

But it may be cost prohibitive if you are paying for someone else to tune your gun.
Rob

Thank you for that info KevinTK

http://www.SpringGunTunes.com

Kev I'm sending my comp. tube to you for my next tune.