Theoben Rapid Forum

Everything Technical About Rapid => Technical => Topic started by: Millingman on April 30, 2023, 10:20:59 AM

Title: Pellet probe experiment.
Post by: Millingman on April 30, 2023, 10:20:59 AM
Have any of you machining guys ever experimented making pellet probes from delrin or the harder plastic peek? I've tried delrin which seals very well onto the breach but doesn't last being a softer plastic. Peek apparently is much harder, more expensive to buy. Just a query.
Title: Re: Pellet probe experiment.
Post by: Andycoup on April 30, 2023, 11:56:23 AM
I have a .20 outer probe in peek, I havn't used it yet, but the fella I bought the cal change from said it works extremely well.
Title: Re: Pellet probe experiment.
Post by: Millingman on April 30, 2023, 12:42:48 PM
Thanks, I try making a couple and let you know👍
Title: Re: Pellet probe experiment.
Post by: Therapidman on April 30, 2023, 12:46:33 PM
I have a .22 probe made out of peek .. had thousands of shots and its still going strong
Title: Re: Pellet probe experiment.
Post by: Ca_Varminter on April 30, 2023, 02:28:53 PM
I was just out in my shop...
I was thinking about sleeving the front 1/4" of the outer probe!
I would turning down the outer diameter of the probe
Then press fit a piece of PEEK.
Turn it down and cut the Taper....
But still thinking about it....

Stuart
Title: Re: Pellet probe experiment.
Post by: Daztilley on April 30, 2023, 04:51:42 PM
Sounds like a good idea Stuart 👍
Title: Re: Pellet probe experiment.
Post by: KevG on April 30, 2023, 06:24:07 PM
done a few just for experiment sake
kevG
Title: Re: Pellet probe experiment.
Post by: Squinty on May 01, 2023, 06:03:29 AM
Put one in my FAC two weeks ago, all fine and dandy will see how it goes.

probe_edit_37145951597453.jpg




Title: Re: Pellet probe experiment.
Post by: Daztilley on May 01, 2023, 06:53:37 AM
Looks good and very well made - FAC will show if there's any blow by
Title: Re: Pellet probe experiment.
Post by: Squinty on May 01, 2023, 07:52:59 AM
Thanks ;)
There isn't blow by @ 140bar.


Title: Re: Pellet probe experiment.
Post by: Daztilley on May 01, 2023, 07:59:15 AM
Looks like it's a good upgrade then 👌
Title: Re: Pellet probe experiment.
Post by: Millingman on May 01, 2023, 09:40:32 AM
Agreed, looks like this is the way forward and easier to machine than stainless. Polyether ether ketone (peek) can be affected by over heating when machined might need coolant on the lathe but can be annealed etc.
Dr Bob get your lathe man on the job😂😂.
Title: Re: Pellet probe experiment.
Post by: Dave74 on May 01, 2023, 10:23:06 AM
I use peek probes in all my rapids, used a long time never had any problems with them
Title: Re: Pellet probe experiment.
Post by: Ca_Varminter on May 16, 2023, 09:59:16 PM
Well all of you Rabid Rapid members and KevG's Rabid Fox is to blame...
I lock myself into my Shop and fired up my Lathe..
With some 1/4" PEEK stock in hand, I started to cut things!

First turned down the diameter of my .22 outer probe to .188"
(https://photos.imageevent.com/scl_electronics/gun/ultimaterapid/websize/20230512_115528_1.jpg)
(https://photos.imageevent.com/scl_electronics/gun/ultimaterapid/websize/20230512_115812.jpg)
I also shorten it by .085"

Then a cut a piece of PEEK rod. Drilled and reamed as needed.
I pressed it on to to my Modified Outer Probe using my tailstock drill..
(https://photos.imageevent.com/scl_electronics/gun/ultimaterapid/websize/20230516_125854.jpg)

Turned down the PEEK insert to match the Diameter of the Outer Probe.
(https://photos.imageevent.com/scl_electronics/gun/ultimaterapid/websize/20230516_140300.jpg)

Now I cut the 20° taper into the end of the PEEK insert.
(https://photos.imageevent.com/scl_electronics/gun/ultimaterapid/websize/20230516_140744.jpg)

So after a bit of sweat... this what I came up with.....
(https://photos.imageevent.com/scl_electronics/gun/ultimaterapid/websize/20230516_141118.jpg)

Time to test now.....
Thanks Guys!!!
(https://photos.imageevent.com/scl_electronics/misc/mages/downapint.gif)(https://photos.imageevent.com/scl_electronics/misc/mages/downapint.gif)(https://photos.imageevent.com/scl_electronics/misc/mages/downapint.gif)

Stuart
Title: Re: Pellet probe experiment.
Post by: KevG on May 17, 2023, 10:44:40 AM
nice work that Stuart m8.
kevG
Title: Re: Pellet probe experiment.
Post by: Ca_Varminter on May 17, 2023, 02:28:27 PM
Thanks KevG....
I try.......
 :)  :)  :)  :)  :)  :)

Stuart
Title: Re: Pellet probe experiment.
Post by: Daztilley on May 17, 2023, 07:10:43 PM
That looks great Stuart 👍
Title: Re: Pellet probe experiment.
Post by: Ca_Varminter on May 17, 2023, 10:03:54 PM
Quote from: Daztilley on May 17, 2023, 07:10:43 PMThat looks great Stuart 👍
Thanks..... Like I told KevG..I Try....
But I don't have the Rabid Fox looking over my shoulder...
You know.. the Quality Control person!!!
 ;D  ;D  ;D  ;D  ;D

Stuart
Title: Re: Pellet probe experiment.
Post by: Joonoz on May 18, 2023, 06:17:54 PM
Theres a guy on another forum been making them for ages. I have all mine now in peek.

IMG_20201117_182128672.jpg
Title: Re: Pellet probe experiment.
Post by: Millingman on May 18, 2023, 09:14:03 PM
Turned a few, they work well.

Title: Re: Pellet probe experiment.
Post by: KCE on May 19, 2023, 05:33:07 PM
What is the advantage of these?.

Regards kev.
Title: Re: Pellet probe experiment.
Post by: Ca_Varminter on May 19, 2023, 07:40:35 PM
I  am looking for a better seal... with less Lock-up pressure....
I did try this long ago.. but with Delrin(Acetal)
Not as durable as PEEK... It didn't hold up well....
So PEEK has been used many years by the Tuners over here...
Never got around to order some stock to try....
Well these guys on our site MADE me TRY!!!!!!

Time to pressurize the UL_Ti_Mate Rapid...
Let's see how it takes to 70 fpe...

 :o  :o  :o  :o  :o  :o  :o
Stuart
Title: Re: Pellet probe experiment.
Post by: KCE on May 19, 2023, 10:00:16 PM
kevG and the Rabid fox need a visit.

im sure he will know about this.

Regards kev.
Title: Re: Pellet probe experiment.
Post by: flyfisher on May 23, 2023, 02:44:17 PM
if any one is making these to sell I would like 3 in .177  please guys.
Title: Re: Pellet probe experiment.
Post by: Squinty on May 23, 2023, 05:10:16 PM
Thought about making one in 177 but there is only 0.8mm in the walls.
Less if sleeving the tip.
I made my .22 inners 3mm instead of 1/8- gains 0.1mm
Title: Re: Pellet probe experiment.
Post by: flyfisher on May 23, 2023, 07:18:27 PM
ah okay mate, thanks for the answer.
Title: Re: Pellet probe experiment.
Post by: rgc_swanseaARC on May 31, 2023, 09:20:15 AM
Anyone ever investigated cutting a groove in the end of the outer probe and sealing with an o ring. (70 or 90 shore for example)
That way, any leaks that appear over time, just change the o ring?
I am not in any way mechanically minded....my unfinished kit car can attest to that, but seems an inexpensive way to solve the leaking issue when it arises.

Kind Regards,
Rhys
Title: Re: Pellet probe experiment.
Post by: Squinty on May 31, 2023, 01:01:50 PM
Its been done ;)

Bucketboy machined o-ring grooves in metal probes  a few years ago.
Haven't got round to it myself although I have tried o-rings to overcome fine adjustment on an early R7 bolt.

However I do prefer the firmer lockdown with Belvilles, lost count of the times the cocking handle popped out of the gate bumping around the fields at night when I used an o-ring.




Title: Re: Pellet probe experiment.
Post by: Squinty on June 01, 2023, 03:05:08 PM
there you go..  just a quick trial on a bent outer.
Not a full groove in the face of the outer, imo it would need a 1mm o-ring supported on both sides.
O-ring sits on the inner under the spring, compresses into a radius.


IMG_20230601_160243.jpg
Title: Re: Pellet probe experiment.
Post by: angrybear on June 02, 2023, 01:03:23 PM
I think he meant a groove & O ring where the outer probe seals on the barrel breach, not to seal the inner probe.
Title: Re: Pellet probe experiment.
Post by: Millingman on June 02, 2023, 09:29:47 PM
That's an o ring setup on my Rotex Rm8 maybe that's what your trying to achieve.
My FX Dreamline has an o ring inside the brass breach for the probe to seal.
Title: Re: Pellet probe experiment.
Post by: Squinty on June 02, 2023, 09:54:56 PM
Quote from: angrybear on June 02, 2023, 01:03:23 PMI think he meant a groove & O ring where the outer probe seals on the barrel breach, not to seal the inner probe.

yeah.. crossed my mind after i posted

Quote from: Millingman on June 02, 2023, 09:29:47 PMThat's an o ring setup on my Rotex Rm8 maybe that's what your trying to achieve.
My FX Dreamline has an o ring inside the brass breach for the probe to seal.

like many the probe is also the air feed and goes further into the breech, the Rapid would be limited by the relatively short travel.
Title: Re: Pellet probe experiment.
Post by: KevG on June 03, 2023, 11:51:09 AM
never had a problem with the standard theoben or dr bobs probes my self
kevG
Title: Re: Pellet probe experiment.
Post by: PiL on June 04, 2023, 11:06:45 PM
I've got a peek probe on my .177 mk1. Dave from Doncaster who used to be on the old forum made it for me about 8 years ago and it's still going strong 👍
Title: Re: Pellet probe experiment.
Post by: Joonoz on June 05, 2023, 10:58:47 AM
Quote from: Squinty on June 01, 2023, 03:05:08 PMthere you go..  just a quick trial on a bent outer.
Not a full groove in the face of the outer, imo it would need a 1mm o-ring supported on both sides.
O-ring sits on the inner under the spring, compresses into a radius.


IMG_20230601_160243.jpg

When using PEEK on valves or pellet probes, if the hole is drilled to the correct size then the peek seals itself against the inner superbly. No orings etc required.