Trilogy / Spyder Front block Thread Size

[KMDPB]

Hello,
Can anyone tell me the thread size of the front of a trilogy / spyder as I remember they have the same thread size. I remember seeing a post about it on here before but cant seem to find it again. I want to make a few spyder pump arms.
Thank you!

[Meleager7]

Palmers talks about the threads here

[Fubarius]

This is a case of metric and standard threads being very, very close to each other.

Trilogy front block is 3/4-16
Spyder LPC is a metric M19x1.5

But those two are in the vast majority of applications completely interchangeable.

For the technically minded folk, standard thread specs say outer thread size in inches and threads per inch, in this case 0.75" and 16 threads per inch.
Metric is outer thread size in millimeters and distance between threads. So 19mm and 1.5mm between threads.

So lets convert them to the same system. 19mm, divided by 25.4mm per inch gives you 0.74803". Pretty darn close. 1.5mm between thread is 0.059055" per thread, or divide 1 by that and you get 16.9333 threads per inch. So a tiny bit more fine, but still pretty close. Usually one of the two sets of threads is cut a bit deep anyways so everything just screws together just fine.

[ChoSanJuan]

I've got a Trilly adapter on my Spyder front block. Check out this month's marker competition for my closed bolt Spyder. They work.

[KMDPB]

This is a case of metric and standard threads being very, very close to each other.

Trilogy front block is 3/4-16
Spyder LPC is a metric M19x1.5

But those two are in the vast majority of applications completely interchangeable.

For the technically minded folk, standard thread specs say outer thread size in inches and threads per inch, in this case 0.75" and 16 threads per inch.
Metric is outer thread size in millimeters and distance between threads. So 19mm and 1.5mm between threads.

So lets convert them to the same system. 19mm, divided by 25.4mm per inch gives you 0.74803". Pretty darn close. 1.5mm between thread is 0.059055" per thread, or divide 1 by that and you get 16.9333 threads per inch. So a tiny bit more fine, but still pretty close. Usually one of the two sets of threads is cut a bit deep anyways so everything just screws together just fine.

Thank you very much!!!!

[Meleager7]

Knowing threads are so close, these get more interesting for a potential S’pump application!

[Jordan]

Knowing threads are so close, these get more interesting for a potential S’pump application!

See, I'd go the other way - use the PPS adapter to run an LPR and make some sort of pneu-mech or electro.

[Meleager7]

See, I'd go the other way - use the PPS adapter to run an LPR and make some sort of pneu-mech or electro.

a Pneu-Spyder!

[Magmoormaster]

So, what chosanjuan did.

This being the case though, why bother using the adapter? Just thread a Trilogy LPR straight into the spyder front block.

[ChoSanJuan]

I did it that way because I tapped my LPC to take the Rock... Trillys didn't exist when I did this in the early 2000s. But true, if you do some version of a Spocker, just get a Trilly LPR instead. If you are doing a straight up Spump, a Trilly kit will fit real nice.