Author Topic: B26 Cocking Plate (Shoe) Problems (Read 8234 times))

DMikeM · « **on:** August 04, 2011, 01:42:43 PM »

My B26 has broke 3 cocking plates (shoes) since I got it and I can't really figure it out. I got the last 2 replacements from Mike Melick (thanks Mike) but this time I ordered an R9/10 to see if maybe they are stronger. The only real changes I have made to my gun was debur and polish the usual places, replaced the spring to one for the Crosman Quest, converted .22 to .177 and chopped the barrel. Oh and I ruined the inner piston sleeve when I tried to install a vortek kit in it. I replaced that with a plastic one but it looks like it is chewed up some now. Could that be causing the issue?

Hey Mike you have any thoughts on this?

rsterne · « **Reply #1 on:** August 04, 2011, 04:16:27 PM »

Your problem is not uncommon.... and I have heard that even the original HW95s were prone to broken cocking shoes.... How bad is it when you clone a known problem along with the gun....

Does anyone know if the Weihrauch shoes were steel or aluminum like the ones in the B-26?.... I have heard that the shoe from an HW80 (Beeman R1) will fit, can anyone confirm that?.... It seems to me like some machinist should be making these on a CNC from Chrome-Moly and heat-treating them....

Bob

DMikeM · « **Reply #2 on:** August 04, 2011, 05:06:12 PM »

I don't think any of the shoes I had were aluminum. I keep looking at it and thinking how I can make them but stronger. But as I have no real machinist tools it's just not going to happen. If I had a lathe and mil I would be making all sorts of custom airgun gear. Pistons, custom cocking arms for the under/side lever guns. Custom scope mounts. The options are endless.

rsterne · « **Reply #3 on:** August 04, 2011, 08:02:57 PM »

I was told that the ones in a B-26 were aluminum, but that could be in error.... I guess I'll have to wait until mine breaks to find out....

Bob

mikeiniowa · « **Reply #4 on:** August 04, 2011, 10:32:18 PM »

B-26 shoes are steel, I only thing I can figure is breaking them would be slam cocking at the end of the stroke. The ones in my 26's have never broken and have thousands of shots on them...it's another airgun mystery... try the HW shoes, they seem to be much tougher...

DMikeM · « **Reply #5 on:** August 04, 2011, 10:56:53 PM »

thanks Mike I got one on the way. I don't think I cock it too hard but I will check myself when i get the new shoe.

rsterne · « **Reply #6 on:** August 04, 2011, 11:34:52 PM »

Mike, do you know if the HW80 shoe fits the B-26 and is it an improvement?.... I ask because I have seen them available somewhere....

Bob

shadow · « **Reply #7 on:** August 05, 2011, 10:31:24 AM »

The problem might be the "plastic piston liner" not giving enough support to the shoe during the cocking stroke and putting extra stress on it. I have several B26's and the shoe's have never failed and owned both for over 4 yrs. I have replaced a shoe for a customer and other repairs on B26's but the problem stemmed from a bad piston liner catching the shoe and damaging it. I also debure and polish the shoe's so that it glides through the cocking slot and on top of the liner. Ed

DMikeM · « **Reply #8 on:** August 05, 2011, 10:36:30 AM »

I have a metal liner from my B28 Vortek conversion. I will fit it to the B26 when the new shoe arrives and see how long it lasts. The last shoe was less than 300 shots.

mikeiniowa · « **Reply #9 on:** August 05, 2011, 12:06:04 PM »

also check that the piston isn't hitting the shoe when fired, different or softer seal could make it touch...

?

DMikeM · « **Reply #10 on:** August 05, 2011, 12:27:35 PM »

Would I just open up the back of the slot a little if it is and how would I know, just check it's resting place uncocked? I would assume too many washers/spacers in the head of the piston could cause that. I think I only have one up in there.
I Think my seal is the crossman quest seal. I also just realized it broke on fire not on cocking, cocked it fired then went to cock it again and it was broken. Will check the tolerances when I have it apart this weekend.

kestreltom · « **Reply #11 on:** August 06, 2011, 02:26:37 PM »

Hello Mike,
Sorry about your broken cocking shoe problem.

I have a little experience with this since I made a custom piston for my B26 with a machined travel slot for the shoe that does not go all the way through the piston skirt wall. I had to shave a little off the bottom of my shoe to make it fit so it slides nicely in the slot. There is about 15 thousandths clearance between the end of the slot and the shoe when the piston is in the resting, un-cocked state.

If you could post of photo of the broken shoe it would help.

Make sure that the end of the slot in the piston leaves some clearance for the shoe when it is in the un-cocked state, you don't want the end of the piston slot to contact the shoe at all when the rifle is fired.

Check to make sure that the shoe is not catching on a burr in the piston slot. Also make sure that the fit is not too tight. Since the shoe is long enough to span several coils of the spring, I don't think that the plastic liner can cause a foulup unless the plastic is badly torn up.

btw - I took my modified B26 (custom piston, vortek spring, RcnMo trigger, match grade barrel, etc.) with me to visit family in Cleveland, Ohio. I checked the velocities with my Chrony and was surprised to see that I only gained about 25 fps. I normally shoot in Albuquerque, at 5000 ft. and I was expecting more velocity at 700 ft. Home = 775 fps w/ 7.9 CPH , Cleveland = 800 fps " " "

best,
Tom

DMikeM · « **Reply #12 on:** August 06, 2011, 02:59:42 PM »

Tom thanks for the info, I will look for these issues. My FPS at 7,000 FASL is 720 with CPL and 725 with RWS SD.

DMikeM · « **Reply #13 on:** August 06, 2011, 05:01:05 PM »

Here are some pictures of that cocking shoe.

kestreltom · « **Reply #14 on:** August 06, 2011, 08:47:43 PM »

Mike,

Those look like tension failures... Does that seem correct?

I will take a good look at my B26 tonight and think about this.

Tom

kestreltom · « **Reply #15 on:** August 07, 2011, 01:41:45 AM »

Hey Mike,

Take a look at this and see what you think...

https://picasaweb.google.com/lh/photo/DZ4EaBuy7Bw1asYY2ZhrNnA9VXibv_x-BMSRYMQV8kw?feat=directlink

Tom

DMikeM · « **Reply #16 on:** August 12, 2011, 01:09:01 PM »

Ok got the replacement shoe from Pyramyd (Got an R9 one). I really didn't think it was going to fit because it is much thicker and punched out of steel instead of cast. I decided to do a full tear down since this was the second gun I had tuned myself. Found the piston to be dragging a little and the piston shield was tore to shreds. I had made it from a aluminum can. So I made a new one from a soda pop bottle. Honed the tube again and found a piston seal that looked about the same. Chucked up the piston and seal in the drill and sanded until it fit right and put it all back together. The shoe was very snug but did fit well. Cocking the gun is better than it has ever been and I gained 40 fps on the tune up. It also shoots better overall. Now instead of 720 with CPLs its 760, but it did pull off a couple 780s. Maybe it will break in and give me some more.

D14Jeff · « **Reply #17 on:** February 12, 2013, 06:53:11 AM »

does the Xisico B26/B26-2 still have issues with the "cocking shoe" breaking ?

TOM aka critter99 · « **Reply #18 on:** February 12, 2013, 07:17:37 AM »

Would the new style HW95 shoe fit??
http://vortekproducts.com/ourstore/Seals-Tuning-Parts?product_id=141

http://vortekproducts.com/ourstore/image/cache/data/20121123_141215-500x500.jpg

mikeiniowa · « **Reply #19 on:** February 12, 2013, 12:40:06 PM »

out of all the B-26's I have sold only a very few had this problem, most were home tune jobs...i have the steel piston liners on hand, the aluminium one might be part of the problem...

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B26 Cocking Plate (Shoe) Problems

Author Topic: B26 Cocking Plate (Shoe) Problems (Read 8234 times))

kestreltom

kestreltom

kestreltom