Impact PP valve housing 2.0

Jump to latest Follow Reply
Did some more modifications to the 7mm valve housing, set the valve seat about 1mm deeper (I've ground a dedicated 10mm drill into a 90 degree angle with my drill bit grinder for the valve seat), and I also removed some more excessive material around the valve seat as well.

With this combo, I've hit 103 joules (76 ft/lbs) in 22 caliber with JSB Beasts, but I am looking for more. (nothing new here ;) )

I was happy to see that I got 294m/s with 34 grain beasts at 140 bar reg pressure, so the performance at low reg pressure is pretty decent. (95 joules or 70 ft/lbs)

1584584911_16597121035e72d8cf0394d6.28525698.jpg


1584584930_7545970075e72d8e26bb889.06157883.jpg


1584584944_5801035605e72d8f0c5b7c0.76689134.jpg

 
Upvote 0
Nice work. What alloy did you use for the housing? Could we have a look at your modified drill bit please?
Click to expand...

Thx, it's fun to do for sure, very rewarding work :)

To be honest, I am not 100% sure about the stock material, as I got it from a friend, but considering the way it machined (pretty easy) it is most likely Aisi304.

I will post a pic of the drill bit, but I am currently not at home. I've bought a drill bit grinder with collets 2 years ago, and it is very easy to adjust the angles with that grinder. Couldn't do without it. Same goes for my tool grinder (Deckel S0 clone) Good tools are half the work :)

 
Upvote 0
Fantastic work Gijs, have you tried it yet? (Probably not just asking) are you going to get a .35 setup?
Click to expand...

Thanks Nathan, yes, it works quite well, current "highscore" is 103 joules or 76ft/lbs in 22cal :)


I'm gonna make a new hammerspring as well in 1.5mm wire thickness. I've already made one, but the pitch could be slightly increased to create a bit of a longer.spring.

My current 1.5mm spring was bottoming out when cocked with still a bit room left on the HST slider, this also means that there is potential for even more speed😁

I'm gonna test this setup with 25 and 30 cal 700mm barrels as well in the future, and I have confidence that it is gonna be a real powerhouse in the larger calibers.

Because I have changed the position of the slots, I could also combine the power plenum with a extra added plenum through the manometer hole if needed :)
 
Upvote 0
Fantastic work Gijs, have you tried it yet? (Probably not just asking) are you going to get a .35 setup?
Click to expand...

Thanks Nathan, yes, it works quite well, current "highscore" is 103 joules or 76ft/lbs in 22cal :)


I'm gonna make a new hammerspring as well in 1.5mm wire thickness. I've already made one, but the pitch could be slightly increased to create a bit of a longer.spring.

My current 1.5mm spring was bottoming out when cocked with still a bit room left on the HST slider, this also means that there is potential for even more speed
1f601.svg


I'm gonna test this setup with 25 and 30 cal 700mm barrels as well in the future, and I have confidence that it is gonna be a real powerhouse in the larger calibers.

Because I have changed the position of the slots, I could also combine the power plenum with a extra added plenum through the manometer hole if needed :)
Click to expand...

Thats badass, if you ever want to sell a few put me on the list haha. I've managed 75 but needed a pretty high reg to get there. If you go .25 and .30 you'll see some big numbers im sure. 
 
Upvote 0
@Glem.Chally, Haha, sorry to disappoint you, it takes far too much time to make such parts on conventional machines, it would make things way too expensive. I purely do this for fun and as a hobby, and maybe to inspire other enthusiasts :)

@heavy-impact As promised, here are some pics of my reground drill to surface the valve seat.

I have a cheapo set of drills to grind into other profiles if needed, not gonna sacrifice my expensive 8% HSS-Co drills for that purpose😉

1584631257_14826066815e738dd9a77129.29817341.jpg
1584631258_15434788295e738ddab04412.85673856.jpg
1584631260_2032765885e738ddc03feb3.35401267.jpg
1584631261_15114139765e738ddd02ee26.34945995.jpg
1584631262_13687884815e738dde55d391.97648683.jpg

 
Upvote 0
I like your machine. I have a drill doctor 750 that I'm not very impressed with.

I use these diamond lapidary discs on a normal bench grinder for grinding tungsten but they would do well grinding tools with the proper fixture. The 600 grit disc that I use for 2% lanthanated tungsten is still like new after 7 years.
Click to expand...

Those grinding disc's look good, and they are even not too expensive too👍😊

With all due respect, but I'm not a fan of the drill doctor for precision work. Good enough for construction work, but not good enough for precision work, mainly due to the plastic chuck instead of collects, which have sometimes centering issues. 

For grinding d-bits etc. I use the machine below. I also have some diamond wheels for it to grind carbide end mills etc. 

I don't use them very often, but I can't do without them.

1584634813_5642228865e739bbd0bd307.41311157.jpg
1584634814_14256637985e739bbe230df9.24601282.jpg
1584634814_9969731675e739bbed6f3d7.29845906.jpg

 
Upvote 0
It's a Chinese clone of the Deckel S0, but it works fine for me.

It is called "U3 tool grinder" and you can find them in many different brands, most likely all from the same factory. 

If you want a very good one, I'd suggest to buy the Vertex variant from Taiwan. But the Chinese one works just fine for me, and it was a lot cheaper. 
 
  • Like
Reactions: heavy-impact
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu