AirArms CD and HW Rekord Trigger Units Interchangeability

[robs5230]

Following a thread on another forum I've been receiving PMs about the above which I couldn't fully answer via PM as I can only post pictures on open forum --- so here goes.

Both units have there locating pins at exactly the same spacing, this is no surprise at I'm told Ken Turner used to build the Mach one triggers for Venom which the CD is closely based on, note that the standard Weihrauch blade sits @ 10mm forward of TX's :-



CD into Weihrauch

Now for this I used a TX rod in a custom made rotating piston in my 77 :-

image.jpg


To get the CD in you have to relieve the back block with a Dremmel to get clearance for the cassette rivets and widen the slot a little :-

image.jpg



There you go, to get the safety to work on the CD triggered 77 I had to take a touch off the top sear.

So to answer your question, Rob, to put a CD into an Old School 85 you'd need an 85 piston fitted with a TX rod (you could shorten the stroke at this point) and simply relieve the back block to take the CD unit.




All the best Mick

Nice one Mick thanks.
Did you relieve the HW rear block with hand tools ? Could you give / do you have details of measurements needed or is it a case of just trial and error until the CD fits ?
2 major problems now..
Firstly getting the piston altered to have a TX latch rod and secondly getting hold of the quite elusive CD trigger unit.

[Mach 1.5]

Both units have there locating pins at exactly the same spacing, this is no surprise at I'm told Ken Turner used to build the Mach one triggers for Venom which the CD is closely based on,

As above. Ken Turner did not build the Mach 1 triggers. The company he worked for made the parts for them following venom contacting them to produce the parts which were then sent to Ivan and Dave to build. The CD is trigger in the MK1 tx200's is a copy of the Mach 1 trigger.
Mach 1.5

[FPoole]

Both units have there locating pins at exactly the same spacing, this is no surprise at I'm told Ken Turner used to build the Mach one triggers for Venom which the CD is closely based on,

As above. Ken Turner did not build the Mach 1 triggers. The company he worked for made the parts for them following venom contacting them to produce the parts which were then sent to Ivan and Dave to build. The CD is trigger in the MK1 tx200's is a copy of the Mach 1 trigger.
Mach 1.5

There are 2 versions of the AA/CD unit for the MarkI's as well. The early ones were screwed together instead of the rivets, like we now have. The sears also look a little different as well as the trigger blade. I have a CD unit that uses the screws, but it has the current blade. I wish I could find the earlier blade, but it works just fine. I modified a blade to change the screw angles and it made a positive, but very slight difference for the better.

[MartynB]

This is a very interesting thread as I asked a similar question about changing the trigger mechanism in a FWB Sport and decided it wasn't worth the hassle

[T 20]

Both units have there locating pins at exactly the same spacing, this is no surprise at I'm told Ken Turner used to build the Mach one triggers for Venom which the CD is closely based on,

As above. Ken Turner did not build the Mach 1 triggers. The company he worked for made the parts for them following venom contacting them to produce the parts which were then sent to Ivan and Dave to build. The CD is trigger in the MK1 tx200's is a copy of the Mach 1 trigger.
Mach 1.5

Cheers Paul, I'm always happy to be corrected by someone more knowledgeable than me.

BTW, I'm loving that old school HW50 I bought off you.




All the best Mick

[T 20]

Nice one Mick thanks.
Did you relieve the HW rear block with hand tools ? Could you give / do you have details of measurements needed or is it a case of just trial and error until the CD fits ?
2 major problems now..
Firstly getting the piston altered to have a TX latch rod and secondly getting hold of the quite elusive CD trigger unit.

Hi Rob

I just pushed the CD into the back block until the rivets touched, then I lined the cassette up with the pin holes and marked where to relieve for the rivets.
To line the cassette fore and aft, I put pins in the cassette and back block, then with the back block upside down on a flat surface I lined them up with a set square.
I relieved for the pins and slightly opened out the slot using a dremmel and a decent flat file --- a bit time consuming but easy enough to do.

One thing I forgot to mention in my opening post was the fact that the TX piston rod is a bigger OD to the Weihrauch piston rod, so you have to open the spring guide and back block hole IDs to match.

To get your piston altered I'd try NickG as he makes his own pistons and rods, for the CD it's a matter of waiting for a second hand one to come up, or you could try Julian Bond for a new one.




All the best Mick

[robs5230]

Hi Rob

I just pushed the CD into the back block until the rivets touched, then I lined the cassette up with the pin holes and marked where to relieve for the rivets.
To line the cassette fore and aft, I put pins in the cassette and back block, then with the back block upside down on a flat surface I lined them up with a set square.
I relieved for the pins and slightly opened out the slot using a dremmel and a decent flat file --- a bit time consuming but easy enough to do.

One thing I forgot to mention in my opening post was the fact that the TX piston rod is a bigger OD to the Weihrauch piston rod, so you have to open the spring guide and back block hole IDs to match.

To get your piston altered I'd try NickG as he makes his own pistons and rods, for the CD it's a matter of waiting for a second hand one to come up, or you could try Julian Bond for a new one.




All the best Mick

Cheers for the clarification Mick. At the minute I'm not up for buying a new CD unit but will persist in trying to find a used one.