# MK Archry BETA risers: Things to consider



## kshet26 (Dec 20, 2010)

This doesn't necessarily mean the riser is warped. And the bolt holes themselves don't necessarily correspond to the center of the riser or the center of the limbs. And if you're using the limbs as a reference for the riser center, the limb dovetail can be off giving the appearance of warp (but that's why limb adjustment exists).

I have a Hoyt Horizon (painted) that has the top limb bolt hole tapped off-center. The riser has no twist and the the limbs align perfectly (and this is with junk T-Rex limbs). 

Did you try the winding stick trick to confirm?


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## aavaaz (Jan 11, 2018)

"And the bolt holes themselves don't necessarily correspond to the center of the riser or the center of the limbs"

They must and they should. Reason why MK recommends in their owners manual that one should go by the string bisecting the center of the holes. In my case, its the laser. 

"And if you're using the limbs as a reference for the riser center"

I am not. I have checked it with and without limbs. I am mounting the laser to the sight window which is supposed to be the flattest part of the riser. The laser bisects the bottom holes perfectly but is way off on the top holes. limbs and dovetails are not involved. Of course one could align the limbs on any riser, warped or not, due to the adjustable ilf, but that does not mean the riser is true. For clarification, I am only referring to the riser. The holes are off centered. then why does Mk recommend centering the string on the holes? Quite clear to me that they are banking on them to be true and in the absolute center. In the second replacement riser that Lancaster sent, the bottom ones are off.

Just for reference, I have 2 Uukha risers. Both are plumb straight, and the holes centers are spot on.

I don't have aluminum winding sticks but I did use two aluminum levels on either end making sure the worktable on which the riser was sitting was level.. sure enough the top was about 3/32" off.


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## Maggiemaebe (Jan 10, 2017)

kshet26 said:


> Did you try the winding stick trick to confirm?


Hey Keith. What's this trick you're referring to please? Haven't heard of it before. Thanks!


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## aavaaz (Jan 11, 2018)

This:

http://www.leevalley.com/en/wood/page.aspx?p=53276&

Fairly inaccurate for small variences compared to a laser.


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## kshet26 (Dec 20, 2010)

aavaaz said:


> I don't have aluminum winding sticks but I did use two aluminum levels on either end making sure the worktable on which the riser was sitting was level.. sure enough the top was about 3/32" off.


Good check! Sounds like you have a handle on the situation.



Maggiemaebe said:


> Hey Keith. What's this trick you're referring to please? Haven't heard of it before. Thanks!


It's the same trick as sticking arrows across the limb tips to check for twist. Chris probably has a video explaining it... but basically you lay a parallel arrow (aluminum or non-barreled carbon) across the limbs at each limb pocket. You then then compare the angles of each arrow to see if they're similar. A little crude, but serves as a sanity check. Wish I could find an example picture.


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## Bob Furman (May 16, 2012)

Here's a good writeup....

Please be patient....editing

https://www.dropbox.com/s/301kjzlbn...know about Recurve bow alignment !!!.pdf?dl=0


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## Seattlepop (Dec 8, 2003)

Apologies, not able to credit originator:


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## Maggiemaebe (Jan 10, 2017)

Perfect! Thanks everyone...I pictures' worth 1000...:darkbeer:


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## monterey (Feb 16, 2015)

Gillo makes a riser twist checker but I've never seen it for sale anywhere:
http://www.gilloarchery.it/riser_twist_cheker.html


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## Bob Furman (May 16, 2012)

monterey said:


> Gillo makes a riser twist checker but I've never seen it for sale anywhere:
> http://www.gilloarchery.it/riser_twist_cheker.html


If I recall, it was quite pricey.



Sent from my LM-Q710(FGN) using Tapatalk


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## bahboric (Aug 22, 2013)

I may be confused, but I don't see how any laser mounted on the sight window would measure the same thing as the winding sticks. Part of the problem is that I don't know what the laser mounted on the sight window is supposed to do, and maybe somebody could explain that to me. I could see it telling me if the limb bolts were equal distance from the plane of the sight window, but the winding sticks seem to be measuring whether the limb pockets are in the same plane. Am I missing something?


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## kshet26 (Dec 20, 2010)

bahboric said:


> I may be confused, but I don't see how any laser mounted on the sight window would measure the same thing as the winding sticks. Part of the problem is that I don't know what the laser mounted on the sight window is supposed to do, and maybe somebody could explain that to me. I could see it telling me if the limb bolts were equal distance from the plane of the sight window, but the winding sticks seem to be measuring whether the limb pockets are in the same plane. Am I missing something?


No, you're not confused. As I alluded to, many things used as a reference for alignment have no bearing on, or relationship with 'proper' alignment. But they're convenient. Bolt holes, sight windows, flat spots on the riser, front stabilizer--to name a few.

I suspect that manufacturers accept returns on a fair percentage of risers and limbs that are perfectly straight. But because of how complex and deceptive the process it, they'd rather just go with 'the customer is always right' for cost and simplicity. The OP did some detailed checks and determined that the limb pockets were off, so that isn't the case here.


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## chrstphr (Nov 23, 2005)

MK would like to inspect both of these risers that according to you are warped. 

Are both risers at Lancaster?

Do you have the serial nimbers of the risers? What color were they? 

I pmed for your email address.


Chris


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## Vittorio (Jul 17, 2003)

monterey said:


> Gillo makes a riser twist checker but I've never seen it for sale anywhere:
> http://www.gilloarchery.it/riser_twist_cheker.html


If you really want one, you can get it from any of our dealers on special order only, 45 days delivery. Suggested retail price is 1200 Euro including Italian 22% VAT.

Surely not a consumer item, more suitable for pro shops, clubs, delears, distributors, manufacturers, than for individual archers. 

There are 2 parameters important for risers: parallelism of the limbs pockets at limbs contact points and strightness. If first one is OK, then 2nd one is not so important, provided tha the align system can mange the disalignement of the upper and lower limb pockets. 

How much OK is OK? The twist checker has a precision of > 0.02 mm on parallelism, so if a riser on it dos not shake at all, you can consider it better than 0.03 and almost perfect. Up to 0.1 mm, riser twisting does not give any real probelm in tuning and it is almost impossible to judge if riser is twisted at all , without the use of our tool. Our maximum level of acceptancein twisting is therefore 0.1 mm.

Temperature in anodizing has nothing to do with twisting or strightness problems, temperature is never high enough to influence the temper and the shape of the riser.

Problems only come from forging, forging milling, or milling. Forged risers are for sure less precise than milled one as average, but also milled risers if made with too many repositioning tools (using 3 axis machines and not cleaning set up tools continuously) ) are very often having troubles. Strightness can anyhow be adjusted if riser gets bent during milling, but for twisting no way, they have to be made good out of the machine.

Strightness standard tolerance in milling processes over 65 cm lenght is around +- 0.3 mm average. If riser has an excursion for alignement of +-1 mm from center, and parallelism tolerance is at 0.1 mm, you can stil get a perfect bow if (limbs are perfect and) strightness of riser is within 0.8 mm 

I have tested some cheap risers to be up to 1 mm twisted and >2 mm bent ... 

Of course, longer is the riser, more difficult is to contol its twisting and strightness .

Summarizing, usually you get what you pay for. But this is not a rule, as mistakes can happen in any production process.


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## Mark Talley (Aug 10, 2016)

Thanks for the wealth of information you bring. We definitely need a "Like" button!


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## chrstphr (Nov 23, 2005)

Vittorio said:


> riser twisting does not give any real probelm in tuning and it is almost* impossible* to judge if riser is twisted at all , without the use of our tool. But this is not a rule, as mistakes can happen in any production process.


I am suspect that the risers are truly warped. I find it odd that after 10 years for riser manufacture from MK, this is the first mention by anyone of a riser being warped. And he gets not one but two risers both warped. 

Now it could be possible in milling/ manufacturing that a batch is not correct. However MK Archery personally inspects every riser that goes out the door. 

I also find it interesting that he has returned at least one of the risers to Lancaster, but they have not contacted MK Korea to say they have a warped riser. it would seem that Lancaster has looked at the riser and find nothing wrong. 

MK Korea is contacting Lancaster. I have also pmed the OP to see if he returned both, has the serial numbers or if he still has one of the "warped" risers. 

I find it surprising he can measure the riser to such an extent to tell its warped. 


Chris


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## Mark Talley (Aug 10, 2016)

chrstphr said:


> I am suspect that the risers are truly warped. I find it odd that after 10 years for riser manufacture from MK, this is the first mention by anyone of a riser being warped. And he gets not one but two risers both warped.
> 
> Now it could be possible in milling/ manufacturing that a batch is not correct. However MK Archery personally inspects every riser that goes out the door.
> 
> ...


Curious to know how MK inspects their risers - optical comparator or similar?


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## chrstphr (Nov 23, 2005)

Mark Talley said:


> Curious to know how MK inspects their risers - optical comparator or similar?


they didnt say. They just said in their email that they inspect every riser before it leaves. Their english is not great, ( only one or two can even speak english at the factory), so i cant ask very detailed questions. But i would imagine since they know the milled specs and tolerances, they know how to check it after its finished.


Chris


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## aavaaz (Jan 11, 2018)

Chris,
I have called MK in Korea. Lets just say their English is just as good as my Hangul. I have emailed them twice to no avail. The riser I have has 2 out of 4 holes drilled offset so the string is way off. I have used various precise methods to determine this, more so than anyone else would care to or have the knowledge to do so. Lancaster has also checked one of the risers that I returned and according to them ONE out of the 3 holes is "off". I have email correspondences with them on this with images. I have kept one of the riser as it was setup and test fired at Chua Vista. I would return it to MK under warranty if they ever bother to respond. Even if one assumes that the riser is not warped, should the mounting holes not be centered on a $1000 riser? All this when MK explicitly instructs in their owners manual that the string should bisect all four holes at the back, absolutely in the center. I don't want to get into the whole discussion of milling, machining and anodizing and I also understand that you represent the manufacturer and as such have motives to come to their defense. I don't and I also pay out of my pocket. I am not interested in any further discussion about this on this forum. Folks can do their do diligence themselves. Enough said.


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## aavaaz (Jan 11, 2018)

Vittorio said:


> If you really want one, you can get it from any of our dealers on special order only, 45 days delivery. Suggested retail price is 1200 Euro including Italian 22% VAT.
> 
> Surely not a consumer item, more suitable for pro shops, clubs, delears, distributors, manufacturers, than for individual archers.
> 
> ...


What he said. In this case, when the laser and the string are centered, the holes are a little over 1mm off. MK should not instruct the user to rely on the holes while setting up. Trust the Beiter gauges and a laser in combo. Having said that, the bow shoots phenomenally well with Uukha VX+ limbs and the riser is very responsive. Speaking of Uukha, I have 2 Uukha risers with xx and VX+ limbs. Absolutely dead center holes and all.


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## AR720 (Jun 28, 2016)

MK has changed their marketing strategy in the last few years to be more similar to the other big manufacturers (went from barely sponsoring anybody to handing out sponsorships; much more aggressive marketing). It's possible their production quality slipped in exchange for producing/selling more of their product.


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## Mark Talley (Aug 10, 2016)

AR720 said:


> MK has changed their marketing strategy in the last few years to be more similar to the other big manufacturers (went from barely sponsoring anybody to handing out sponsorships; much more aggressive marketing). It's possible their production quality slipped in exchange for producing/selling more of their product.


Virtually anything under the sun is possible - they may have tightened up their processes in the same period, bought new machinery that will hold tighter tolerances - the fact is you don't know. The answer to the only question is black or white: are the "warped by the anodizing process" (per the OP) risers within the manufacturer's specifications or not. How exact is exact? You measure anything closely enough and you will find it falls short of perfection. They're making risers, not grinding the contour of the Hubble lens. The OP called out MK for shoddy work and they have a right and an obligation to investigate the claims and respond appropriately. The OP put up $1,000 or thereabouts - any idea what MK has invested?


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## chrstphr (Nov 23, 2005)

I have given MK the email of the OP and told them to contact Lancaster for the other riser.

I am a better US contact for MK Korea than Lancaster Archery. For some reason, the factory will respond to me with a day. I order bows and limbs from them routinely and my turnaround time is much faster than Lancaster. There are quite a few who can post and atest to that. I also sell the entire MK product line while Lancaster only sells a few MK risers/ limbs. 

At MK there are only a few that can speak english. So there is a language barrier. 

I do represent MK to the US market. If you have a riser that is not right, i want to ensure you get a riser that is correct and that you are happy with. You should have a top of the line riser for the cost you paid. 

I have no hidden motive. If the riser is not warped, then i also want to clarify that or to clarify what the actual issue is.

MK is currently shut down for a week for holiday. But i have sent them all the relevant information. They will contact the OP and take it from there to get the risers back to check.



Chris


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## Scott_cr (Oct 22, 2015)

*MK Z User Manual*

Hey Chris,

Do you have a link or anywhere to get an electronic copy of the MK Z user manual? The links on their site are non-responsive...
thanks!
s.






chrstphr said:


> I have given MK the email of the OP and told them to contact Lancaster for the other riser.
> 
> I am a better US contact for MK Korea than Lancaster Archery. For some reason, the factory will respond to me with a day. I order bows and limbs from them routinely and my turnaround time is much faster than Lancaster. There are quite a few who can post and atest to that. I also sell the entire MK product line while Lancaster only sells a few MK risers/ limbs.
> 
> ...


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## chrstphr (Nov 23, 2005)

Let me check. I will pm you.


Chris


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