McM A5, Riser-fall..

netranger6

Gunny Sergeant
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Aug 15, 2009
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Vicoria, Texas
Guys, I know someone has a fix for this. It's really beginning to piss me off, having my riser fall in the middle of a breath. i have a McM A5 adjustable, integral, with 2 screw. What have you used beside brute strength, to keep the riser from collapsing over time? Rubber grommets, straws, chime in!

FYI. No, KMW can't retro-fit hardware.. Already went that route with a fail.
 
Re: McM A5, Riser-fall..

I've done a number of things.
First one was to divot the pillars where you normally tighten the set screws. I used a ball end mill, but you could do it just as easily with a drill bit.
Another option is to make a spacer for the cheekpiece, to keep it from collapsing. I used some delrin rectangular stock, cut to fit around the pillars and drilled for clearance.
 
Re: McM A5, Riser-fall..

WhiteDingo: Appreciate the advice man, but I don't have access to any machinery. If I did, I'd likely saw my arm off. Drill bit though, I do have that. So basically, drill at normal height so set screws....gotcha. Good idea, thanks!

Keith: I wonder if those would work? May have to take some measurements tomorrow.
 
Re: McM A5, Riser-fall..

In addition to the divots in the pillars, swap out the thumb screws for hex socket set screws.

Much easier to get adequate torque with the set screws than with the thumb screws...and they're flush or recessed instead of sticking out like the thumb screws.
 
Re: McM A5, Riser-fall..

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: netranger6</div><div class="ubbcode-body">WhiteDingo: Appreciate the advice man, but I don't have access to any machinery. If I did, I'd likely saw my arm off. Drill bit though, I do have that. So basically, drill at normal height so set screws....gotcha. Good idea, thanks!
</div></div>

Yup, just make a larger indent for your screws to bite in to. A small amount of loctite on the threads would also keep the screws from loosening in the field.
The Brain speaks truth. Cap screws or set screws in addition would make for a very secure setup. If you want to keep the thumb screws, you could swap them for a hex head type; I can generally get more torque than with the knurled ones.
 
Re: McM A5, Riser-fall..

Set the height with one screw in, with a pencil lead or finger nail polish brush (what ever) mark the post without screw in it

take a metal file, use the 1/8" edge and file a 1mm or so slot in the pillar

replace cheek piece and do the other hole same way

( i also replaced adj knobs with small headed hex screws )