Ravin / CP400 cable hack

4994 Views 44 Replies 9 Participants Last post by tpcollins, Dec 29, 2021

Jack Pine

Discussion Starter · Jan 7, 2020

3

Bought this dang wheelie crossbow used with a badly frayed and loose serving. Had to make a press for it before I could fix those issues. While I had it apart, I took 1 of those 4 pitiful little cables off to get specifications for making spares. Looks impossible for me to make anything that small, I have no idea how they do it; on a machine or something maybe,

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but I did find a way to replace those 4 cables with 2 longer ones. Still not perfected and tested yet but I think I'm on the right track.
The left side shows the factory cables and the right side is the single cable. I messed around with this about all day did everything wrong, so now I think I know enough to be dangerous or get it right.

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burky247365

· #2 · Jan 7, 2020

I really like what you are doing there , but with one single cable there is no way to tune out cam lean .
if that one long cable was 2 longer than stock cables that attach to the riser rather than loop through , you could then tune out cam lean . Just what i see .

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Jack Pine

Discussion Starter · #3 · Jan 7, 2020

Thats a good point. I thought about that too, even though I don't know anything about dang wheelie crossbows. I'm looking at a cam/wheel that according to measurement, is centered between the 2 limbs. Not being familiar with this stuff, I assume "cam lean" would be a condition where the cam would not run central/parallel with the gap in the limbs?
I also think that since the long cable is free floating and not attached, that as long as the limb deflection is at least close to each other, there doesn't seem to be a liklihood that the cam would be able to lean one way or the other. Looks like the only adjustment possible or needed is for length to line up between the timing marks.

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samt

· #4 · Jan 7, 2020

Make cable twice as long and with half as many strands. Serve it in the middle, then fold it. On layout, add additional 1/4" or so to account for the post when folded.

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burky247365

· #5 · Jan 7, 2020

Jack Pine said:
Thats a good point. I thought about that too, even though I don't know anything about dang wheelie crossbows. I'm looking at a cam/wheel that according to measurement, is centered between the 2 limbs. Not being familiar with this stuff, I assume "cam lean" would be a condition where the cam would not run central/parallel with the gap in the limbs?
I also think that since the long cable is free floating and not attached, that as long as the limb deflection is at least close to each other, there doesn't seem to be a liklihood that the cam would be able to lean one way or the other. Looks like the only adjustment possible or needed is for length to line up between the timing marks.

It might just work in a free float set up like you have there , the only way to tell is make the other side the same and check that the cams do not lean and stay parallel to the barrel when cocked .
I bet your set up is easier to tune timing and cam sync , can not believe they have not re routed those cables on there bows .

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Jack Pine

Discussion Starter · #6 · Jan 7, 2020

burky247365 said:
...the only way to tell is make the other side the same and check that the cams do not lean and stay parallel to the barrel when cocked...

OK got it.
I'll be working on this in my spare time until I either have something positive to report, or abandon it as unworkable.

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burky247365

· #7 · Jan 7, 2020

Jack Pine said:
OK got it.
I'll be working on this in my spare time until I either have something positive to report, or abandon it as unworkable.

Nothing ventured , nothing gained !!!!!

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Jack Pine

Discussion Starter · #8 · Jan 7, 2020

Learned from the mistakes I made yesterday, and today i made a cable that should work, have to make another in a day or so, and give them some hot tests.
One thing I hated about the little cables is, the end that attaches to the cam is not served! Made me nervous looking at those bare fibers, but got that fixed, and my new cable loops are served.

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Jack Pine

Discussion Starter · #9 · Jan 8, 2020

samt said:
Make cable twice as long and with half as many strands. Serve it in the middle, then fold it. On layout, add additional 1/4" or so to account for the post when folded.

Sent from my SM-T860 using Tapatalk

OK, I couldn't visualize what you were saying at first; duh!
Good idea, useful information I'll be able to use, but I really don't like those short little cables anyway, and especially the loop that attaches to the cam being un-served. In addition, if adjustment is needed, those things being so short and stiff, are hard to work with. This longer cable allows me to serve those bare loops, are easier to adjust, and I like that better than those puny little cables.

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Jack Pine

Discussion Starter · #10 · Jan 8, 2020

2 easily made cables with served loops replacing 4 pitiful little cables impossible to make, difficult to adjust or install.

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canuckarcher

· #11 · Jan 8, 2020

Jack,just curious. What stops the cables from shifting where they are run through the riser?

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Jack Pine

Discussion Starter · #12 · Jan 8, 2020

canuckarcher said:
Jack,just curious. What stops the cables from shifting where they are run through the riser?

Not sure what specifically you mean? If adjusted for timing, it should stay unless more adjustment is needed due to cable stretch or other factors.
Just before he went to ATA, I talked to Dan Miller about this project to see what materials to use. Ordered some small diameter serving thread that I haven't got yet, don't know if he got to send it out before he left, but as soon as I get it, I plan to make a string and test everything.
Those cables run through the riser and I don't anticipate any shifting, but we'll see.

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canuckarcher

· #13 · Jan 8, 2020

Jack Pine said:
Not sure what specifically you mean? If adjusted for timing, it should stay unless more adjustment is needed due to cable stretch or other factors.
Just before he went to ATA, I talked to Dan Miller about this project to see what materials to use. Ordered some small diameter serving thread that I haven't got yet, don't know if he got to send it out before he left, but as soon as I get it, I plan to make a string and test everything.
Those cables run through the riser and I don't anticipate any shifting, but we'll see.

K,I just didn’t see a groove or anything to hold the cables in place where they run through the riser. I guess there must be a v or something there to keep them from shifting.
Shooting will tell the tale and your ability to make up and serve your own strings is a real bonus for this sort of testing for sure. Good luck on your r&d.....

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Jack Pine

Discussion Starter · #14 · Jan 8, 2020

canuckarcher said:
K,I just didn’t see a groove or anything to hold the cables in place where they run through the riser. I guess there must be a v or something there to keep them from shifting.
Shooting will tell the tale and your ability to make up and serve your own strings is a real bonus for this sort of testing for sure. Good luck on your r&d.....

Where the cables run through the riser is in a "valley", the pressure of the limbs should hold it there, I think... maybe.

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I was going to use the small holes you see there but they have kinda sharp edges but could be a future option.

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canuckarcher

· #15 · Jan 8, 2020

Jack Pine said:
Where the cables run through the riser is in a "valley", the pressure of the limbs should hold it there, I think... maybe. View attachment 162988
I was going to use the small holes you see there but they have kinda sharp edges but could be a future option.

Just a thought, but would a small clevice fit in the holes if they do shift? Just something else to think about. The clevice would be round so,no cutting your cable. Keep us posted please....I always like to see people’s improvements ....

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samt

· #16 · Jan 8, 2020

2

Or this from Firenock:

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robertyb

· #17 · Jan 8, 2020

I think you will be good to go where they are Cal. If not don't shoot your eye out.

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Jack Pine

Discussion Starter · #18 · Jan 8, 2020

samt said:
Or this from Firenock:

View attachment 162992 View attachment 162994

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I saw that, but don't know if that would bolt up to a cp400. Doesn't matter anyway, I think those are priced around $200 and that's not me, I'm a tightwad. That's why I built my own cp400 press, and all the string building equipment I use. Just call me Titus LOL.

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Jack Pine

Discussion Starter · #19 · Jan 8, 2020

canuckarcher said:
Just a thought, but would a small clevice fit in the holes if they do shift? Just something else to think about. The clevice would be round so,no cutting your cable. Keep us posted please....I always like to see people’s improvements ....

I don't think they will shift, I would think if there was danger of movement, the strings and cables would jump out of their tracks.

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Jack Pine

Discussion Starter · #20 · Jan 8, 2020

robertyb said:
I think you will be good to go where they are Cal. If not don't shoot your eye out.

I'll definitely be wearing my shooting glasses that day!

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