The 75 Gr. Steel BH Adaptors

[dino]

Java Man,  
That is not the manufacture date.  4226-2 is 3R's part number for the computer system and catalog the other number is the warehouse bin location number.  It has nothing to do with who, when, or how they were manufactured.  These things on the internet spiral out of control sometimes.

 Dr. Ashby, have you contacted either Danny or Dale at 3R.  There is a lot of speculation going on here that maybe they could answer and if there is an issue maybe they need to know about it.  Just seems like the logical starting point if I had a problem with a product or noticed a flaw. dino

[GameGetter]

Has not happened since but about a year ago I had three 100gr adapters (from the same doz. pack) break the same way and had seen on the LW that someone else had the same problem with their 100gr,ers as well, at about the same time! I Think it was a steal issue.

[Dr. Ed Ashby]

Dean, I started this thread out merely to alert others, amd see if they had noticed the problem. These are the first 75 gr. adaptors I've done any testing with (and the 100 gr. ones too, for that matter). Wasn't sure if this was an isolated problem or a generalized problem. I think just emailing this thread to 3 rivers might give them an all-round heads up to what may be a problem.

Ed
TGMM Family of the Bow

[Java Man]

Dean,

Thanks for the correction.  

Gregg

[SlowBowinMO]

Dr. Ed, all the lot numbers we have here at Braveheart are similar but they do not match yours.     :confused:

[Jeff U]

One does not mean much but I recently had a 100 grain adapter fail as you describe.

I've had aluminum ones break before but never a steel one.  I've only used the 100 grain steel.

Arrow Axis ST 400 w/ 100 grain brass insert.  Steel 100 grain broadhead adapter with 135 grain glue on judo.  

It took quite a bit of abuse stump shooting around the yard.  

That is until I slapped it against my foot to knock off some dirt.  The judo went flying to lands unknown leaving the threaded shaft of the adapter still screwed into my brass insert.

[flightmedic]

i spoke with one of the reps for 3rivers yesterday, and we talked about the issue he was not concerned with the test results he claimed as far as they knew the 75 grains were not issue.and he had not heard of any complaints. he seems to think that" mr ashby test are a torture and are fine for whitetail and elk" just passing on the conversation

[Dr. Ed Ashby]

Interesting, since all the test shot failures happened on the bones of Georgia whitetails. Anything more than a whitetail rib becomes a torture test? Makes me wonder ...

Ed
TGMM Family of the Bow

[flightmedic]

i did some testing on my own today after using some of the 75 grain adapters, and glueing them to a magnus 2 blade broadhead, and shooting a carbon express arrow out of a striker stinger longbow 50#at 28inches. at aprox 10 yds i shot the attached broadhead/adapter into a sheet of drywall,5 times with no damage on the broadhead or adapters, then the same combo was shot into a 3/4 of pine 2 times with no damage to the broadhead but most importanly the adapter, i only stoped shooting because i didn't want to dig them out of the wood anymore.  

[Dr. Ed Ashby]

Steve, do those you're using appear to be the same as the ones I have; show in the photos? Is their cavity the same depth? If so, it's hard to account for the vast difference in performance, unless in the tempering. The ones I have will snap with what feels to be far less lateral pressure than it takes for me to bend a (solid, not hollow) aluminum adaptor. Did you try any angular impacts?

I did email this thread to the folks at 3 Rivers, but there has been no reply.

I'm really interested in finding out the what and why of the failures we've had (it's happened for Wesley, Dennis and I). I'm also interested in the seemingly vast differences in construction shown and described by the folks posting here; between the adaptors they have and those we have. If one version is out-performing the other, it would be good to know which is which, and by whom they are manufactured.

Ed
TGMM Family of the Bow

[BobW]

Ed,

The picture Mike Walker posted (page #2), and my head are the same model - these are "short" 75g steel.  Mine came from KustomKing.  They match the image in their on-line catalog.

BobW

[LKH]

Dr. Ashby, it sounds like 3 rivers is going to give you the "ignore till he shuts up treatment".   The last thing they want to do is admit their product may be faulty.

You need to restart this thread from time to time, not just recycle this one.  That will keep it current and I know I won't be buying any inserts or adapters till they answer.

[Dr. Ed Ashby]

Thanks Bob. Those Mike show have a significantly different shank profile that those I have, and it sounds as if they have a lot more metal thickness at the base of the taper's counter-bore.

I was trying the 75 grain adaptors out because I want to set up a lower mass Extreme FOC arrow for some testing from a 43# bow this year. I have some higher mass Extreme FOC's already set up for it, but also wanted to test some closer to threshold mass, but still with good structural integrity. Was planning on using the Modified Grizzly on the 75 grain adaptors, and a low mass/inch shaft. However, the ones I have certainly are not going to work.

Think I'll experiment with some like those Mike and you are using. It will save me having to shorten the 100 grain models. Got enough to do without that!

Ed
TGMM Family of the Bow

[Dr. Ed Ashby]

Larry,

I don't think these adaptors are necessarily a '3 Rivers brand'. They probably just buy them from some manufacturer and re-package them. They can't proof-test every product they carry. However, I hope they are concerned enough about their customers (and the animals they hunt) to investigate this potential problem product. I'm hoping that's what is taking them so long to reply; they're checking it out.

I lean towards this being an inherent design flaw with this particular adaptor; the counter-bored hole in the taper just doesn't leave enough metal thickness at the shank's attachment.

I don't have all my measuring equipment here, but think I can locate some to borrow. I'll do some precise measurements to post. Back in a bit.

Ed
TGMM Family of the Bow

[tradtusker]

interesting iv never had a problem with the 75gr adapters before and i use them on all my arrows to get 200grs up front with 125gr BH.
i will do some testing and measuring here and see what i come up with.

interestingly when i shot my 2 Water buffalo ( and did some testing with shoulder hits with both my recurve and compound) i had 4 of my 100gr brass inserts brake or bend, i was using the 125gr steel adapters, 1 of which also broke just in front of the thread. iv never used the brass inserts again for that reason.

i will look around and see if i have some of the damaged inserts(think i threw them away) and pics of the shots that may be of some use to you Ed

[Dr. Ed Ashby]

Thanks Andy, I would really appreciate that. Arrow integrity is so critical. I'm hoping that the Internal Footings will provide a significant boost in carbon shaft durability. First pre-production prototypes will get a workout this year. They're a different material than the IF's I developed and tested, for manufacturing reasons, but are also a 'single-unit', where mine were not. That is a big plus. Time will tell if and how well they work.

*****************
MEASUREMENTS
*****************
Ok, borrowed some vernier calipers from Harrold. He's a retired machinist/metal worker, so pretty good at precise measuring. Here are the dimensions we're measuring on the # Rivers 75 grain adaptors I have.

(1) 'Straight line' length of the taper (outside): 0.650"

(2) Depth of the counter-bored hole at the center (Check photo of broken shank, on page 1. The counter-bore has a conical termination): 0.671" (Note that the center of the counter-bored hole extends 0.021" beyond the taper - antually extending that far up into the metal of the shank.)

(3) Depth of the counter-bored hole at its edge: 0.640"

This means the calculated thickness of the metal holding the shank to to tapered portion of the adaptor is 0.010". That's ten one-thousands of an inch.

The "break-ring" showing on the shank(s) is so thin that neither Harold nor I could accurately measuring it with the vernier calipers; to verify the calculated thickness of attachment. However, we both did a visual comparison of the break-ring's width to some feeler guages, and both came up with 0.010". Appears to be an accurate measurement of the thickness of steel holding the adaptor's shank to its tapered portion. That is far, far too thin, by anyone's standards.

Ed
TGMM Family of the Bow

[BobW]

The "KustomKing" heads have 2mm (possibly 2.5) of material between the tip if the bore and the interface that butts to the shaft.

BobW

[Dr. Ed Ashby]

Bob,

For perspective: 2mm = 0.079". That's almost 8 times the metal thickness attachment of the adaptors I have here. 2.5mm = 0.098", or almost ten times greater. Big difference.  Think I still far prefer the heavier, solid adaptors.

I wish someone out there would consider making the lighter weight adaptors from something like titanium; lighter than steel, but stronger than steel.

Ed
TGMM Family of the Bow

[tradtusker]

sorry for bein slightly off topic.

well i found some of the old Buffalo arrows with the broken 100gr brass inserts. The two i have are both broken in the same place, just where the brass wall steps thinner to accept the thicker tang of the adapter above the thread, you will see both the adapters are broken here too      

The first pic shows both arrows with the broken brass inserts and back of adapters still inside the arrows.    

the second pic is the broken brass insert with the thread from the adapter still in it once i removed it from the arrow, with a good brass insert next to it for reference.
 

the last pic shows where they all seemed to brake and bend in relation the the adapter and insert.
 
 

hope it of some help to someone, i was not impressed by how many broke like this.
not everyone on is gonna be hunting buff with heavy gear,  but i'l try not to use them.

Ed have you ever seen this in your testing?

[tradtusker]

Just tested the 75gr adapters out of interest and they broke!and like Ed measured its a tiny amount of steel holding it on.
iv use them lots for hunting but this is a big design flaw, gonna be changing to 125gr adapters.