Brake Cylinder hone Info for tuning

[gaisom]

Way back when I was rebuilding lots of 2 cycle motors I used a brake cylinder hone that had lots of little hone balls on the ends of wire to clean up the cylinders.

The reason I  liked to use it was that it would deburr and taper the exhaust and intake passage edges in the cylinders very nicely while honing the cylinder if you used it on a reversible drill.

I am thinking that it would do the same using it for the tuneup of an airgun.

Has anyone tried using one?

Think it was called a flex hone or something like that .   

After I posted this I found this link.

#http://www.brushresearch.com/brush-types.php?c1=4#

says I can't  post external links so I guess the copy/paste method will have to do.

Grant

[Scrambler82]

To me as an old time engine builder the ball hone works best in a cylinder that has little to no holes.

A Hone with a Stone OD within the specifications of the cylinder you are honing is best for the Air Motor Cylinder; it will give a smooth finish with any ball bouncing or catching on the cocking mechanism slot.

Chamfer the slots and holes before Honing the Cylinder with the flat stone hone.

Remember I am not an Air Rifle Rebuilder just a Motor Head.

[stonykill]

we called them dingleberry hones in the parts store I used to work at 

    Just a guess but I don't think they will work well on an AG .

[longhunter]

Flex hones won't work. They're too aggressive, and they don't get all the way to the bottom of the comp. tube. They'll leave a ridge just short of the end, and you definitely don't want that.

[gaisom]

didn't think about getting to the end of the cylinder.. I  can see thazt might be a problem.

[nced]

I had that issue when I first tried to use a brake hone to work an R9 receiver. This is what I ended up using for straightening R9 receivers that were "pinched" too much at the end plug area to install an oring sealed piston past the "restricted part" yet still maintain proper oring compression at the transfer port end.......

This was made by lathe turning a PVC pipe so it would slide into the R9 receiver after wrapping a layer or two of oiled silicon carbide "wet-or-dry" abrasive paper. When spun in the correct direction this long "hone" bridged all those dowel holes, punchouts, and the cocking shoe slot. It was tedious going however it does work well and I can "hone" all the way to the brazed in barrel pivot fork and clean up most of the "braze flash".

[gaisom]

Good to know. I am always thinking of bits and pieces i turned up years ago to use on the latest project.

Latest one is the "knee" on my roll out awning broke,  going to  use the rear suspension points off of a 20" boys full suspension bike to fix it.  Awning company wanted $127 for the replacement part. Time I get it done and painted most people won't see it and it might cost me $25 or so if I include labor.


Think outside what box?

[OleTomCat]

I had that issue when I first tried to use a brake hone to work an R9 receiver. This is what I ended up using for straightening R9 receivers that were "pinched" too much at the end plug area to install an oring sealed piston past the "restricted part" yet still maintain proper oring compression at the transfer port end.......

This was made by lathe turning a PVC pipe so it would slide into the R9 receiver after wrapping a layer or two of oiled silicon carbide "wet-or-dry" abrasive paper. When spun in the correct direction this long "hone" bridged all those dowel holes, punchouts, and the cocking shoe slot. It was tedious going however it does work well and I can "hone" all the way to the brazed in barrel pivot fork and clean up most of the "braze flash".

I use something very similar, mine is a slotted 1" wooden dowel, honing in this fashion from the very back of the compression chamber all the way to the transfer port helps to avoid egg shaped walls that occur a lot when people get to aggressive with flat stoned brake hones....

[my87csx481]

I had that issue when I first tried to use a brake hone to work an R9 receiver. This is what I ended up using for straightening R9 receivers that were "pinched" too much at the end plug area to install an oring sealed piston past the "restricted part" yet still maintain proper oring compression at the transfer port end.......
(placeholder for broken photobucket link....got an external link warning)
This was made by lathe turning a PVC pipe so it would slide into the R9 receiver after wrapping a layer or two of oiled silicon carbide "wet-or-dry" abrasive paper. When spun in the correct direction this long "hone" bridged all those dowel holes, punchouts, and the cocking shoe slot. It was tedious going however it does work well and I can "hone" all the way to the brazed in barrel pivot fork and clean up most of the "braze flash".

Sorry for the old thread revival.  Anyone have a picture of what nced posted?

I was thinking of using a flex hone, as they are available in many grits....but I can see how getting to the bottom could be a problem.

[PCPhack]

Yes, I have used a hone on steel air tubes, like on the Marauder, to help the hammer travel more smoothly. You need to then be sure to lightly oil it after the cleanup so that it won't rust, since honing will expose bare metal.

Like this one:

[nced]

I had that issue when I first tried to use a brake hone to work an R9 receiver. This is what I ended up using for straightening R9 receivers that were "pinched" too much at the end plug area to install an oring sealed piston past the "restricted part" yet still maintain proper oring compression at the transfer port end.......
(placeholder for broken photobucket link....got an external link warning)
This was made by lathe turning a PVC pipe so it would slide into the R9 receiver after wrapping a layer or two of oiled silicon carbide "wet-or-dry" abrasive paper. When spun in the correct direction this long "hone" bridged all those dowel holes, punchouts, and the cocking shoe slot. It was tedious going however it does work well and I can "hone" all the way to the brazed in barrel pivot fork and clean up most of the "braze flash".

Sorry for the old thread revival.  Anyone have a picture of what nced posted?

I was thinking of using a flex hone, as they are available in many grits....but I can see how getting to the bottom could be a problem.

Years ago I tried "brake cylinder honing" on my Beeman R9s when HW used to do "manual honing" and the "honer" occasionally belled out the end of the receiver near the transfer port where pressure was highest. The "receiver belling" wasn't an issue with the thin edged parachute seals HW used at that time, however I started replacing the factory piston seals with home turned oring sealed piston caps I found that such "belling and receiver cross hatching" was detrimental.

The issue with brake cylinder hones for my purposes was that they didn't actually make the receiver straight or round, only cross hatched the surface, but if the cylinder hone was retracted from the compression area it would catch in the "cocking shoe slot" and get "messed up". Also. honing only in the compression area of the receiver tended to make the ID "fat" in relation to the rest of the receiver. Ther are also round hones made of abrasive balls attached to a shaft via wires. This could indeed bridge the cocking shoe slot so the complete receiver could be honed, however (again) all it did was to crosshatch the receiver without straightening or making the bore rounder than before honing......


My solution to these problems was to make a split lathe turned PVC mandrel with wrapped oiled "wet-or-dry" abrasive. The PVC was machined so that a wrap of oiled abrasive was a slip fit to the received. First I would slide a home made "gauge" through the receiver to determine if there were constrictions tight enough to affect the sealing of the .20 size orings I use.........

I don't attempt to remove the constrictions completely, only enough to allow my "gauge" to pass the restriction. Here is an example of a HW95 receiver restriction that was relieved.......


I've never used "honed receiver IDs" with my oring sealed piston caps. I did the "finish honing" with oiled 500 or 600 grit silicon carbide abrasive followed up was a buffing using 000 steel wool and a thorough stripping of petroleum based lubes before re-lubing with non-dieseling Krytox GPL205 grease. The last HW95 I bought a couple years ago also had a smooth receiver ID instead of the "cross hatch scratches" that were common with my Beeman R9s. Here is a pic of that HW95 receiver ID straight from disassembly and stripping of factory lubes prior to a Krytox application. Apparently when HW started using CNC machines they also stopped using "cross hatching patterns" in the HW95 receivers as this pic of my HW95 shows.............

[my87csx481]

Thank you for all the info.  VERY much appreciated.

If my plan is to use a standard style aftermarket piston seal, is there an advantage to having a cross hatch in the compression area of the receiver?

Or would it be best to simply clean up the burs, degrease and clean, grease (with Krytox), and call it good?

[Mark 611]

I have use the flex ball hone in my cocking slot part of the tube only!!!! but u want a fine grt and use oil, don't run it dry! I run the hone until I feel it not grabbing the burs or roughness then reverse and go the other way to clean up the other side, it doesn't take much to do this! u do not want to remove any more material then needed! I have also used the tri hone in the compression tube! it works if u trim off the excess metal under the stones! so the stones will reach the bottom of the tube! but as ED said this only to crosshatch the tube in this area, do not pull the stones into the cocking slot while running them u will destroy the stones!!!! the best way to do this is just have ur tube sunnen honed and be done with it!!!!

[nced]

I have use the flex ball hone in my cocking slot part of the tube only!!!! but u want a fine grt and use oil, don't run it dry! I run the hone until I feel it not grabbing the burs or roughness then reverse and go the other way to clean up the other side, it doesn't take much to do this! u do not want to remove any more material then needed! I have also used the tri hone in the compression tube! it works if u trim off the excess metal under the stones! so the stones will reach the bottom of the tube! but as ED said this only to crosshatch the tube in this area, do not pull the stones into the cocking slot while running them u will destroy the stones!!!! the best way to do this is just have ur tube sunnen honed and be done with it!!!!

Will Sunnen honing go all way to the "blind end" of a piston gun receiver where the critical "last 1/8" of compression takes place?

[Mark 611]

from what I could tell and see it looked like it went all the way to the end! I have had Rob Hawkins and Tom Gore both do a sunnen hone job on 2 different tubes so I don't know their methods on how they did it but it looked like both were complete to the end of the tube!

[nced]

from what I could tell and see it looked like it went all the way to the end! I have had Rob Hawkins and Tom Gore both do a sunnen hone job on 2 different tubes so I don't know their methods on how they did it but it looked like both were complete to the end of the tube!

Thanks for the feedback!

[TF89]

I have used the brake hone and that worked fairly well as long as the cylinder is round.  I had to remove some voids and true up a tube and to do that I used the PVC method.  PVC pipe inside PVC pipe for extra strength and then a drill bit epoxied in the end.  I didn't cut a slot because I wanted the shape to stay round and not take on the shape of the  tube.  I used spray adhesive to hold the sand paper on.  Since I was using honing oil I was able to remove the used cloth back sand paper fairly easily. 

Because my tube needed some serious work I started with 220 and worked it up to 600 grit.  This seemed to work quite well and I didn't have to worry about the the slot and since the honing surface was was 12" long (sheet of sandpaper width) I was able to true up the entire tube.  This particular gun was a cheap Chinese springer and if it didn't go well, oh well.  However in this case it worked beyond any expectation I had.

I've only tuned 3 spring guns, two with the brake hone and 1 using the PVC.  The brake hone works fine, however if I find myself doing it again, it will be with the PVC and cloth backed sandpaper.

I'm trying to remember, it seems that when I was done this tube  was about 2-3 thousandths larger in ID.  I wouldn't normally be that aggressive, however when I was done the new seal worked great. 

[Yogi]

Wow,

Don't size the seal, size the cylinder...

-Y

[Motorhead]

Wow,

Don't size the seal, size the cylinder...

-Y

NOT ... 

[TF89]

 I agree!! 

Normally the idea is to either cross hatch the cylinder or polish it without removing material or least not much.  In this case, in my opinion anyway, this tube needed some serious clean up. 

Worked far better than I could have hoped.