AirArms CD and HW Rekord Trigger Units Interchangeability

[T 20]

Hi mate, I contacted Steve about a TX blade a while back but I’ve since left the company that I emailed from so I’ll be struggling to get an answer.
The adjustment screws in the TX blade when fitted to a Rekord unit, offer the whole unit a load more adjustability. I’ve got one on a HW95 and it’s lovely.

Hi Craig

You just reminded me that I'd brought a couple of trigger blades into the house to look at. :-

image.jpg

Without measuring, the TX blade looks to have a bigger pivot pin hole, but I suppose the hole in the cassette can be reamed out to match a TX pin.



All the best Mick

[PhatMan]

Mick,

Many thanks for this most useful post

Have fun & a good weekend

Best regards

Russ

[T 20]

Mick,

Many thanks for this most useful post

Have fun & a good weekend

Best regards

Russ

I'm glad you're finding it useful, Russ.

I suppose I better briefly include the Walther LGU and LGV pistons in this thread as my .22" TX is shortstroked by simply fitting a Walther LGV piston in it, which works perfectly with the bog standard CD trigger unit.

So in theory the TX trigger and back block could be used in both the LGU and LGV with a little alteration to the stock --- as far as I know no one has tried this conversion yet ?




All the best Mick

[Shed tuner]

So in theory the TX trigger and back block could be used in both the LGU and LGV with a little alteration to the stock --- as far as I know no one has tried this conversion yet ?

As the trigger is the only real weak link in the LGV, it would be an interesting one... trouble is the casing / arrangement is very different, so not sure it'd transalate...

As an aside, you can drop a CD top sear into a Rekord too and it works just fine with the TX style mushroom ended piston rod.

[T 20]

As an aside, you can drop a CD top sear into a Rekord too and it works just fine with the TX style mushroom ended piston rod.

The only problem with that is the fact that no one seems to sell CD top Sears, Jon.

I've looked at Knibbs, Chambers and Julian Bond, and none of them even show a part number for the top sear.

[Shed tuner]

The only problem with that is the fact that no one seems to sell CD top Sears, Jon.

I've looked at Knibbs, Chambers and Julian Bond, and none of them even show a part number for the top sear.

Nah, you are right, it's a real pain. However I just picked up bunch of CD trigger parts from the bay - trouble is there were actually enough bits to make a whole trigger, so having done so, I'm still short a top sear

[Artfull-Bodger]

Hi Craig

You just reminded me that I'd brought a couple of trigger blades into the house to look at. :-

image.jpg

Without measuring, the TX blade looks to have a bigger pivot pin hole, but I suppose the hole in the cassette can be reamed out to match a TX pin.



All the best Mick

I find fitting a brass rod into the hole and then re drilling for pin size is a better option, the smaller the pin diameter the lower the friction.

[T 20]

the smaller the pin diameter the lower the friction.

Ah, unfortunately it doesn't work like that.

You would expect the smaller surface area of the smaller pin to give a lower frictional loss but that's not the case.

The standard formula for working out the coefficient of friction does not include surface area :-

image.png

U = the coefficient of friction between the two materials.

image.png

[Artfull-Bodger]

Ah, unfortunately it doesn't work like that.

You would expect the smaller surface area of the smaller pin to give a lower frictional loss but that's not the case.

The standard formula for working out the coefficient of friction does not include surface area :-

image.png

U = the coefficient of friction between the two materials.

image.png

Oh yes, I recall trying to comprehend why wider tyres gave more grip on our race car when this one was trotted out by a college student at Prescott, according to the theory we should see the same level of adhesion and less drag by using narrower tyres, therefore faster, never worked like that though.

It could simply be less surface imperfections in the bore or on the pin in the smaller bore leads to less fouling, whatever the cause I have found smaller pins to be beneficial.

[T 20]

Oh yes, I recall trying to comprehend why wider tyres gave more grip on our race car when this one was trotted out by a college student at Prescott, according to the theory we should see the same level of adhesion and less drag by using narrower tyres, therefore faster, never worked like that though.

It could simply be less surface imperfections in the bore or on the pin in the smaller bore leads to less fouling, whatever the cause I have found smaller pins to be beneficial.

The other good question is why don't formula one cars use pushbike brakes to save weight.

[Artfull-Bodger]

The other good question is why don't formula one cars use pushbike brakes to save weight.

Indeed!