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Discussion Starter · #1 ·
I took my TT trigger out of the Dagger, and opened it up to see what makes it tick. What I discovered was the outer edges of the string slots are machined square as you can see in the 2nd pic.

When the string is cocked, it’s guided into the string slots, and has to hit the front of the safety at the rear of the housing. This sets off a chain of events - this action moves the safety rearward and puts it on “safe”. This also moves the sear and allows the claws to move up and lock into position and hold the string behind it.

The issue is two fold - first the string has to go all the way back and there’s only about a 1/16” difference between the front of the safety and the back of the housing (last pic). While pulling the cocking rope back against the 220# limbs, and with the hooks on the outside of the rail, there’s little chance to keep from pulling the string past the front of the safety and wrapping around the outer edges at the back of the string slots as noted awhile back by Tnmnts.

I’m not capable of stopping my pull within that 1/16” margin so the string is going to whack the back of the slot and the cocking force will continue to pull the string around those outer slot edges. I do have a RSD cocker that I could use to stop any over travel from cocking, but I’d rather use the cocking rope.

So I’ve ordered some Mitchel’s 1/8” wide abrasive tape and I hope I can round off those outer slot edges on both sides slightly.

My latch edges are rounded and really smooth so they’re not doing any harm to the serving. It would be interesting to see if anyone that has a TT trigger is experiencing the same fraying issue.


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I had the same problem with the TriggerTech trigger in my Excalibur bows! I used my Dremel and polished the edge off of the housing. I also put a small patch of mole hair at those points on both side of the trigger housing. No more cutting the serving! Good luck!


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Discussion Starter · #3 ·
I had the same problem with the TriggerTech trigger in my Excalibur bows! I used my Dremel and polished the edge off of the housing. I also put a small patch of mole hair at those points on both side of the trigger housing. No more cutting the serving! Good luck!
I thought about that but all the Dremyl tools I have would cut a concave edge on the outside and I want a rounded over convex edge. If I could find a metal cutting 1/4” - 5/16” diameter ogee bit with a 3/16” pilot, that would work perfect.

I’ll see how the abrasive strip works first.
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I would try shortening up my cocking rope a bunch before I did anything else. You shouldn't be reaching to your arm pits to cock your bow. You can always let the rope back out if that does not do it.
 

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My rope cocker is very short. Anymore and I’ll be cocking the bow by hand! The trigger just needs that last part of the pull to engage the fork! This is the 3rd replacement so I figured it’s a small engineering overlook!


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Discussion Starter · #6 ·
I would try shortening up my cocking rope a bunch before I did anything else. You shouldn't be reaching to your arm pits to cock your bow. You can always let the rope back out if that does not do it.
All my cocking ropes are as short as I can get them, I do have Vendettas on all 3 that I have to manipulate the cord around to get to the cocking groove on 2 of them.

The issue with the handles in my armpits is mainly with the Deathstalker, the Ventilator with the short sled isn’t as bad. The short 10” stroke on the Dagger is a piece of cake plus the cams roll over (relax) around the last inch or so. Problem is you have to smack the front part of the TT safety pretty good to actuate the sear setting the latch and by then your at the back of the housing.

I thought I had explained that earlier - my bad.
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When I do trigger work, that edges is always address and I round that edge off with a pen knife or a small screw driver and use a Trump sharpie to color the raw aluminum. Abrasives will leave a rough edge.
Still, something is up when you have to drive that string into the end of the string slot to cock the trigger unit. That's not right.
 

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Discussion Starter · #8 ·
Still, something is up when you have to drive that string into the end of the string slot to cock the trigger unit. That's not right.
I agree Boo, but this is what I’m stuck with. When I look at a TT trigger for an Excalibur, the part that the string hits to set the latch sticks way out in front of the end of the string slot, and it looks like the the claws trip downward when set.

In the 1st pic, (from TT website and looks exactly like mine) the string first goes past the ADF in front, passes over the claws which drop down and out of the way, and then when the string hits the front (back) end of the safety - that moves the sear and locks the claws upwards. The string slot is about .190”, so by comparison the front of the safety extends barely a 1/16” in front of the end of the slot and needs a good whack to set it. :confused:

I forgot to include a pic of the claws but they are rounded off rather generous and is smooth as can be - 2nd pic. When I get done with it, it will not be fraying my serving like it has been. I think I’ll drop an email to TT and ask the what were they thinking putting the latching mechanism so close to the end on the string slots.

The 3rd pic is my Ventilator trigger - that’s the way to set the claws imo. And the rear edges of the Scorpyd string slots are rounded on the outside. :)

Still would like to hear from others besides BigBowMan that have TT triggers to see if they have similar issues.

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Discussion Starter · #9 ·
As Yogi Berra would say “You can observe a lot just by watching (or looking)”.

I was looking at my Ventilator and noticed the string rides “on the rail” all the way back into the trigger. So I dropped the TT back into the Dagger’s rail and the string rides on top of the rail all the way back too! :eek:

However, when looking from the right side - 1st pic, there’s bosses on the TT housing that drops into notches in the rail, and I noticed a bevel in back of those notches to facilitate dropping the trigger into place. When I ran my finger across that notch, I thought that’s not very good.

But I looked at the left side - 2nd pic, and that rear bevel stuck out like a sore thumb. When I ran my finger across it, it made me realize that it was more likely the cause of the fraying on the left side. And my serving fraying aligns exactly with the outer corner of the rail.

Another factor is the top edge of those bosses are rounded at the top much more than the top corners of the shooting rail. This creates a natural “catch” against the string when the string rides along the rail. I might try putting a release agent on the TT housing and bosses, assemble it, and then top a spot of epoxy into that notch in an effort to minimize that bump.

But somewhere between this issue and the squared top edges and rear of the string slots is causing the problem. Or I could say to hell with it and just reserve the string every year. :confused:

It would be interesting what other Mission owners with TT triggers see on their crossbows.


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If that was a question BBM probably not. Most of the TTs do not have rough latches. If it does fray either send it back to TT to fix or do it yourself. I am guessing yours is for an Excal.
 

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Tp,
That was a good find of yours to determine sharp edges were the issue with serving fraying.

I spent most of my working life involved in manufacturing as some level. During that time I learned the importance of removing sharp edges. Unfortunately some in manufacturing fell to recognize this or they want to cut cost at expense of quality. Quality should be second behind safety in importance.

And yes I have found sharp edges on crossbows that were allowed and caused damage.
 

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Discussion Starter · #14 ·
Tim,
My DS 420 is 5/8" to the inside edge of the hole.
Wow, your cams must really be advanced. I’ll see where mine end up after I get my string and cable set form Marty.
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Discussion Starter · #17 ·
BBM - it looks like your claws and the back stop that sets them is one piece like my Ventilator. And it looks like you don’t have those bosses that stick out from the housing. On what crossbow is this TT on? Thanks.


I just got a brand new TriggerTech Trigger and have to polish the fork and round the edges!






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Discussion Starter · #19 ·
It’s for my Excalibur Matrix 355.
Thanks BBM, I had seen how different those are online. I got to thinking last night that the culprit could be those dang alignment bosses the drop down into the rail sides. Although the front gap is not as severe as the back, I can still feel the edge of the rail corner sticking out proud in front of the rounded bosses.

When I cock the Dagger, the string travels backwards over these corners at a couple miles per hour. But when shot, the 330 fps translates to 225 mph - that can’t be good hitting the front corner edges that stick out on the rail. If I really examine my serving, the left side has fraying but even the right side shows some evidence of the serving being disrupted.

I’m still going to round off the outer string slot edges, but somehow I’ll have to figure out how smooth out that transition when the string travels over the larger radius on the housing bosses and against the sharper corners on the rail. Short of sanding the rail’s leading edges in front of the trigger bosses, I’m not sure what else will work.
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Discussion Starter · #20 ·
They say a picture is with a thousand words (actually a video in this case). I do believe the sharp edges on the strings slots and having to go all the way back to cock the Dagger isn’t helping the serving any.

I know there is some string down pressure on the rail, so I took a drill bit the same diameter of my serving and dragged it slowly across the “locator bosses” on the sides of the TT housing. These notches are large enough to trap the serving as it goes along that section and even make a clicking sound.

Even at high speed it would seem that the notches are going to catch the serving as it goes whizzing by especially in the front one. This can’t be good on the serving. :confused:

The only solution I can think of at the moment would be to cover that section from the back of the string slots to past the front notch with some adhesive aluminum foil tape. I might have to replace it once in a while but that sounds easier than reserving. I use to have some that the furnace people left one time but that is all gone. I’ll have to go to Lowe’s.

 
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