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Posted: 6/30/2010 4:31:42 PM EDT
I just ordered one today. I have heard mixed reviews mostly good. Has anyone put one of these on. I know it is alot of work on the reciever. For the price I had to find out.
Link Posted: 7/2/2010 11:44:33 AM EDT

I'd like to retrofit a cheapo Century Bugly with one, lots of dremel work, anybody tried this?

BTW, I remember hearing somewhere recently that a big batch of surplus bulgy sidefolder stocks came through, and the price collapsed. Anybody know what I'm talking bout willis?
Link Posted: 7/14/2010 9:33:14 AM EDT
There has been alot of talk on other forums of the trunnion metal being too soft and not heat treated. I applaud Scott for getting these to market like he did, but just beaware the metal back there MAY be too soft.
Link Posted: 7/14/2010 3:37:55 PM EDT
I've also been debating on getting one, since I have a 5.45 saiga on order that I'd like to put a folder on (I want the US made poly folder, but I still need the trunnion, which seems to cost more than the set DPH has).
If the DPH trunnion is too soft, at worst I can use it for measurements and make a better one myself
Link Posted: 7/14/2010 3:55:18 PM EDT
The trunnions are soft and there is a guy on the AK forum who will properly heat treat the trunnion.
Link Posted: 7/14/2010 5:02:18 PM EDT
[Last Edit: 7/17/2010 11:13:01 AM EDT by iamg0ku]
Originally Posted By CajunX39:
The trunnions are soft and there is a guy on the AK forum who will properly heat treat the trunnion.


Thanks, that guy is me. I go by HobbyMachinist over there, here's a link to the thread where I "discovered" that I could heat treat these trunnion.
I've been fully heat treating bent flat receivers for a while now, and more recently I've been fabbing up whole parts and heat treating them with much success.




Here's the one I crushed. I should have stopped sooner, but I never in my life would have though the TRUNNION was collapsing.
That crushed trunnion was removed from the receiver, and a new Bulgy was installed.
I kept the trunnion lying around to remind me how I got screwed until I got a wild hair and tried to heat treat it. It worked very well surprisingly.

Now I'm heat treating them for people. If fact, my first 2 are tempering in the kiln right now. They took the hardening perfectly, and were between 55-60 rockwell.
I'll temper them down to about 35, and they will be good.

PM me if you're interested, or better yet, check me out at theakforum
Link Posted: 7/17/2010 2:36:57 PM EDT
Originally Posted By The_Mad_Axeman:
I've also been debating on getting one, since I have a 5.45 saiga on order that I'd like to put a folder on (I want the US made poly folder, but I still need the trunnion, which seems to cost more than the set DPH has).
If the DPH trunnion is too soft, at worst I can use it for measurements and make a better one myself


i need just the stock. wanna split it 60/40 ?
Link Posted: 7/18/2010 10:35:00 PM EDT
Those trunions don't need to be heat treated more than to withstand the carrier banging into them. Anything will buckle like that given enough pressure. Having said that, who wouldn't want a stronger part?
Link Posted: 7/19/2010 1:29:04 PM EDT
Originally Posted By uscombatdiver:
Those trunions don't need to be heat treated more than to withstand the carrier banging into them. Anything will buckle like that given enough pressure. Having said that, who wouldn't want a stronger part?


That may be true, but if the trunnion is actually softer than the rivet you are trying to set, I'd say that's a problem.
Link Posted: 7/19/2010 2:02:32 PM EDT
Originally Posted By uscombatdiver:
Those trunions don't need to be heat treated more than to withstand the carrier banging into them.

If the carrier is striking the stock block, something is wrong with the rifle. The rifle is designed so the carrier stops 3-5mm before it hits the stock block.
Link Posted: 7/20/2010 4:44:56 AM EDT
Originally Posted By iamg0ku:
Originally Posted By CajunX39:
The trunnions are soft and there is a guy on the AK forum who will properly heat treat the trunnion.


Thanks, that guy is me. I go by HobbyMachinist over there, here's a link to the thread where I "discovered" that I could heat treat these trunnion.
I've been fully heat treating bent flat receivers for a while now, and more recently I've been fabbing up whole parts and heat treating them with much success.

http://i285.photobucket.com/albums/ll66/Rube7979/CIMG1308.jpg
http://i285.photobucket.com/albums/ll66/Rube7979/CIMG1307.jpg

Here's the one I crushed. I should have stopped sooner, but I never in my life would have though the TRUNNION was collapsing.
That crushed trunnion was removed from the receiver, and a new Bulgy was installed.
I kept the trunnion lying around to remind me how I got screwed until I got a wild hair and tried to heat treat it. It worked very well surprisingly.


Thats going to happen if you don't back it correctly. Especially with side folder and under folder trunnions. I did that with a polish uderfolder once, easy fix though.
Link Posted: 7/20/2010 7:26:37 PM EDT
Originally Posted By ratfink57:
Thats going to happen if you don't back it correctly. Especially with side folder and under folder trunnions. I did that with a polish uderfolder once, easy fix though.


That's nonsence. I've built all sorts of different foling style ak's and NONE of the original military trunnions crushed like that.
Link Posted: 7/20/2010 7:40:08 PM EDT
Originally Posted By iamg0ku:
Originally Posted By ratfink57:
Thats going to happen if you don't back it correctly. Especially with side folder and under folder trunnions. I did that with a polish uderfolder once, easy fix though.


That's nonsence. I've built all sorts of different foling style ak's and NONE of the original military trunnions crushed like that.


I have seen plenty of underfolders and sidefolders flex much like that under stress of the press, fortunately none sustained the damage illustrated in the picture here. Fact of the matter is by hardening it without annealing it you increase the chance it will crack or split. It is safe to say that these trunions are safe in their "softer" state as millions are made that way in their countries of origin and no major problems have resulted. Having said that if you want a bullet proof trunion to go with your AK so be it. So many get things like titanium firing pins for indestructability and enhanced reliability so why not?
Link Posted: 7/20/2010 7:55:17 PM EDT
Originally Posted By iamg0ku:
Originally Posted By ratfink57:
Thats going to happen if you don't back it correctly. Especially with side folder and under folder trunnions. I did that with a polish uderfolder once, easy fix though.


That's nonsence. I've built all sorts of different foling style ak's and NONE of the original military trunnions crushed like that.


Yes and No, the first time i saw that photo, I didn't notice how bent it was. The Polish (original military) trunnion that bent on me only bent on one of the sides that protrudes forward for the front rivet. I didn't see the rear part in the photo this morning. Holy cow!

Link Posted: 7/20/2010 8:07:39 PM EDT
Originally Posted By uscombatdiver:
Originally Posted By iamg0ku:
Originally Posted By ratfink57:
Thats going to happen if you don't back it correctly. Especially with side folder and under folder trunnions. I did that with a polish uderfolder once, easy fix though.


That's nonsence. I've built all sorts of different foling style ak's and NONE of the original military trunnions crushed like that.


I have seen plenty of underfolders and sidefolders flex much like that under stress of the press, fortunately none sustained the damage illustrated in the picture here. Fact of the matter is by hardening it without annealing it you increase the chance it will crack or split. It is safe to say that these trunions are safe in their "softer" state as millions are made that way in their countries of origin and no major problems have resulted. Having said that if you want a bullet proof trunion to go with your AK so be it. So many get things like titanium firing pins for indestructability and enhanced reliability so why not?


You are wrong. Millions are not made that way. Except for the rivets, every single part on a military AK is hardened in some way. Even the barrel is work hardened through the hammer forging process. Every original trunnion you have ever held or seen was hardened. That's why you have seen them flex and return to their original shape.

And please, if you are going to talk to me about heat treating, at least get your terms right. You do not anneal after hardening, you temper. And that's exactly what I do.


Link Posted: 7/21/2010 3:07:03 PM EDT
Originally Posted By iamg0ku:
Originally Posted By uscombatdiver:
Originally Posted By iamg0ku:
Originally Posted By ratfink57:
Thats going to happen if you don't back it correctly. Especially with side folder and under folder trunnions. I did that with a polish uderfolder once, easy fix though.


That's nonsence. I've built all sorts of different foling style ak's and NONE of the original military trunnions crushed like that.


I have seen plenty of underfolders and sidefolders flex much like that under stress of the press, fortunately none sustained the damage illustrated in the picture here. Fact of the matter is by hardening it without annealing it you increase the chance it will crack or split. It is safe to say that these trunions are safe in their "softer" state as millions are made that way in their countries of origin and no major problems have resulted. Having said that if you want a bullet proof trunion to go with your AK so be it. So many get things like titanium firing pins for indestructability and enhanced reliability so why not?


You are wrong. Millions are not made that way. Except for the rivets, every single part on a military AK is hardened in some way. Even the barrel is work hardened through the hammer forging process. Every original trunnion you have ever held or seen was hardened. That's why you have seen them flex and return to their original shape.

And please, if you are going to talk to me about heat treating, at least get your terms right. You do not anneal after hardening, you temper. And that's exactly what I do.




Sure I'm wrong and you are right and all these surplus trunions are crap compared to yours. Keep saying it and perhaps you'll actually believe and others with you. Doesn't change the fact that these surplus trunions are made to necessary spec and what you're proposing and selling (this is not the place to sell, but I guess that's besides the point) are nothing but unnecesssary work/cost.
Link Posted: 7/21/2010 3:53:10 PM EDT
Originally Posted By uscombatdiver:


Sure I'm wrong and you are right and all these surplus trunions are crap compared to yours. Keep saying it and perhaps you'll actually believe and others with you. Doesn't change the fact that these surplus trunions are made to necessary spec and what you're proposing and selling (this is not the place to sell, but I guess that's besides the point) are nothing but unnecesssary work/cost.


Apparently you don't even know what this thread is about. We aren't talking about surplus trunnions here. We are talking about the soft trunnions in the DPH stockset.

Maybe you would like to build your rifles out of airsoft parts, but some here are smarter than that. I'm done "discussing" this with you.
Link Posted: 7/22/2010 5:13:26 AM EDT
[Last Edit: 8/23/2010 4:43:17 PM EDT by dalesimpson]
Not only did he call DPH surplus, he called it SPEC

Someone got butt hurt, because they got called out for being an INTERNET COMMANDO............ So when do you stop and realize that you have NO clue about the issue at hand?





Image deleted. Let's try to play nice in the technical forums. - dalesimpson
Link Posted: 8/22/2010 6:02:53 AM EDT
Just chiming in. I received my DPH triangle folder kit, and because of this thread I decided to throw the trunion in the Rockwell tester at work. I got 10 RC, which isn't even a qualifiable reading in my opinion, but I don't have a point for B scale, as we only test in C. I would imagine that if the original military surplus trunions are forged and not heat treated in a separate process, they're around 35 RC. I'm going to heat treat mine, although I'm guessing what type of material the steel actually is, I'll start with treating it as if it were 4140 and go from there.
Link Posted: 8/24/2010 6:40:45 AM EDT
[Last Edit: 8/24/2010 6:41:02 AM EDT by JIMBEAM]
Originally Posted By iamg0ku:
Originally Posted By CajunX39:
The trunnions are soft and there is a guy on the AK forum who will properly heat treat the trunnion.


Thanks, that guy is me. I go by HobbyMachinist over there, here's a link to the thread where I "discovered" that I could heat treat these trunnion.
I've been fully heat treating bent flat receivers for a while now, and more recently I've been fabbing up whole parts and heat treating them with much success.

http://i285.photobucket.com/albums/ll66/Rube7979/CIMG1308.jpg
http://i285.photobucket.com/albums/ll66/Rube7979/CIMG1307.jpg

Here's the one I crushed. I should have stopped sooner, but I never in my life would have though the TRUNNION was collapsing.
That crushed trunnion was removed from the receiver, and a new Bulgy was installed.
I kept the trunnion lying around to remind me how I got screwed until I got a wild hair and tried to heat treat it. It worked very well surprisingly.

Now I'm heat treating them for people. If fact, my first 2 are tempering in the kiln right now. They took the hardening perfectly, and were between 55-60 rockwell.
I'll temper them down to about 35, and they will be good.

PM me if you're interested, or better yet, check me out at theakforum



He heat treated mine. Quick turn around.
Link Posted: 8/24/2010 7:32:13 AM EDT
Originally Posted By Kuraki:
Just chiming in. I received my DPH triangle folder kit, and because of this thread I decided to throw the trunion in the Rockwell tester at work. I got 10 RC, which isn't even a qualifiable reading in my opinion, but I don't have a point for B scale, as we only test in C. I would imagine that if the original military surplus trunions are forged and not heat treated in a separate process, they're around 35 RC. I'm going to heat treat mine, although I'm guessing what type of material the steel actually is, I'll start with treating it as if it were 4140 and go from there.


Thanks for the Info!
Link Posted: 8/25/2010 3:18:37 PM EDT
[Last Edit: 8/25/2010 3:31:44 PM EDT by CKxx]
Can we get a link to the kit in question?

How is the quality of the other parts?

iamg0ku, can you PM me your contact info?

EDIT TO ADD: Does anyone know where I can find a real triangle folder assy.?
Link Posted: 8/25/2010 5:08:20 PM EDT
Originally Posted By CKxx:
Can we get a link to the kit in question?

How is the quality of the other parts?

iamg0ku, can you PM me your contact info?

EDIT TO ADD: Does anyone know where I can find a real triangle folder assy.?


The triangle folder is no longer on DPH's website. Either they're out of stock or they pulled them. I don't know which. The rest of the parts I would have trouble telling from original Bulgarian. I think it's a very well made reproduction. They just neglected to heat treat the trunion.
Link Posted: 8/28/2010 7:10:15 AM EDT
[Last Edit: 8/28/2010 7:11:58 AM EDT by Gunplumber]
What is the hardness of the factory trunion (C)? They are heat treated or there would be no point to prick-test them and I've never seen an AK part that wasn't. Based on having worked with them and hammered on them and drilled and welded and machined on them, I'd guess them to be mid to high 40s at least. Tempering down to 35 seems pretty low, just as leaving them at 55-60 would be way too high.
Link Posted: 8/28/2010 9:48:06 AM EDT
Originally Posted By Gunplumber:
What is the hardness of the factory trunion (C)? They are heat treated or there would be no point to prick-test them and I've never seen an AK part that wasn't. Based on having worked with them and hammered on them and drilled and welded and machined on them, I'd guess them to be mid to high 40s at least. Tempering down to 35 seems pretty low, just as leaving them at 55-60 would be way too high.


I don't know the value of a surplus trunion yet. I'm rebuilding a Tantal kit, and when I pull that trunion (it's going to be replaced with the DPH trunion) I will check it's hardness for comparison. I picked 35 RC as a hardness to shoot for basically because it's not a part that's containing pressure, it's tensile strength is relatively unimportant, and it doens't need to withstand a lot of impact. It just needs to stand up to the latching and unlatching of the stock without egging the hinge holes. I think 35 is enough for that, but if it comes out of temper at 45 I'm not going to draw it back again.
Link Posted: 8/28/2010 11:30:19 AM EDT
I'd be interested in your results. My assessment that it is relatively "harder" than 35 is based on the (entirely subjective) effort to machine them (cutting off tangs for pistols and ACE stocks) and the way a HSS or even a cobalt drill squeals when I'm drilling out a stubborn rivet and contact the side. It is hardly scientific. I no longer have convenient access to to a Rockwell tester.

I also dropped a rifle minus the stock and it dented the rear tang hole. Attempting to bend it back caused it to snap off - behavior I'd expect of something at least RC 45, not something as low as 35.

But notthing beats real numbers.
Link Posted: 8/28/2010 12:04:15 PM EDT
[Last Edit: 8/28/2010 12:04:49 PM EDT by Kuraki]
Originally Posted By Gunplumber:
I'd be interested in your results. My assessment that it is relatively "harder" than 35 is based on the (entirely subjective) effort to machine them (cutting off tangs for pistols and ACE stocks) and the way a HSS or even a cobalt drill squeals when I'm drilling out a stubborn rivet and contact the side. It is hardly scientific. I no longer have convenient access to to a Rockwell tester.

I also dropped a rifle minus the stock and it dented the rear tang hole. Attempting to bend it back caused it to snap off - behavior I'd expect of something at least RC 45, not something as low as 35.

But notthing beats real numbers.


I'm heading over to the other building to heat treat the DPH trunion now. I will hopefully remove the other trunion tonight and test it tomorrow. I'm still curious as to why they disappeared from DPH's website. I'd like to order another kit.
Link Posted: 8/28/2010 1:59:53 PM EDT
Well, my attempt at heat treat failed. I'm 99% positive this DPH trunion is an MIM part with little to no carbon content. 1600F for 30 minutes, quench in oil, yielded no change in RC value. I question anyone's claim about hardening these parts, unless they're case hardening them with Kasenit or something similar.

For posterity:

After quenching


In the Wilson


Reading
Link Posted: 8/28/2010 2:40:54 PM EDT
Originally Posted By Kuraki:
Well, my attempt at heat treat failed. I'm 99% positive this DPH trunion is an MIM part with little to no carbon content. 1600F for 30 minutes, quench in oil, yielded no change in RC value. I question anyone's claim about hardening these parts, unless they're case hardening them with Kasenit or something similar.

For posterity:

After quenching
http://i305.photobucket.com/albums/nn203/kuraki556/4ebe022d.jpg

In the Wilson
http://i305.photobucket.com/albums/nn203/kuraki556/0dc36f95.jpg

Reading
http://i305.photobucket.com/albums/nn203/kuraki556/3e609e62.jpg


How can YOU question someones method of heat treating, when you baked yours for 30 min @ 1600F.....???.... Your correct about one thing, your attempt was a failure.
Link Posted: 8/28/2010 3:04:27 PM EDT
Originally Posted By Kuraki:
Well, my attempt at heat treat failed. I'm 99% positive this DPH trunion is an MIM part with little to no carbon content. 1600F for 30 minutes, quench in oil, yielded no change in RC value. I question anyone's claim about hardening these parts, unless they're case hardening them with Kasenit or something similar.

For posterity:

After quenching
http://i305.photobucket.com/albums/nn203/kuraki556/4ebe022d.jpg

In the Wilson
http://i305.photobucket.com/albums/nn203/kuraki556/0dc36f95.jpg

Reading
http://i305.photobucket.com/albums/nn203/kuraki556/3e609e62.jpg


It's a shame your attempt failed. I can't imagine why you would leave the part in the kiln for 30 minutes at 1600F though. Such thin metal would bleed off all it's carbon very quickly in such an environment. I'm sure that you have ruined your trunnion with poor technique. Maybe you can buy one of the new ones that turbothis is making over on theakforum.

I've done about 20 of these trunnions for people now, and I can assure you that they can be through hardened with the proper technique.


Link Posted: 8/28/2010 3:13:40 PM EDT


It's a shame your attempt failed. I can't imagine why you would leave the part in the kiln for 30 minutes at 1600F though. Such thin metal would bleed off all it's carbon very quickly in such an environment. I'm sure that you have ruined your trunnion with poor technique. Maybe you can buy one of the new ones that turbothis is making over on theakforum.

I've done about 20 of these trunnions for people now, and I can assure you that they can be through hardened with the proper technique.




I didn't bleed off any measurable amount of carbon in tool wrap. I've seen no data as to your process, perhaps you explain it completely in the other forum, I am not going to register to find out. I'm simply posting the process I attempted, and the opinion I formed through it. I don't believe there's enough carbon in this part to be hardened in any way that doesn't introduce carbon, such as case hardening.

People are pefectly free to cast my opinion to the side. I'm simply sharing what I found.
Link Posted: 8/28/2010 3:15:23 PM EDT
Definetly sounds like Kuraki has all of the equipment. Sucks that he baked the HELL out of his trunnion.
Link Posted: 8/28/2010 4:03:55 PM EDT
Originally Posted By Gunplumber:
What is the hardness of the factory trunion (C)? They are heat treated or there would be no point to prick-test them and I've never seen an AK part that wasn't. Based on having worked with them and hammered on them and drilled and welded and machined on them, I'd guess them to be mid to high 40s at least. Tempering down to 35 seems pretty low, just as leaving them at 55-60 would be way too high.


Even factory parts can vary quite a bit in their hardness. For instance, I've run across a Bulgarian 74 front trunnion that was so hard that it ground cobalt drill bits to powder when attempting to drill the hole for the front latch pin. I had to use a carbide endmill to complete that trunnion.

The issue with these DPH trunnions is that they are so soft that they are crushing under the force of setting the long rivet. Therefore the solution is to make them hard enough to withstand that force without making them so brittle that they develop stress cracks and shatter in case the BC hits the trunnion repeatedly or the rifle is dropped.
When I experimented with the trunnion that I had, I made videos showing the difference in the original part vs parts with my heat treatment. The results were clear. The heat treated parts were much stronger than the original. The heat treated parts resisted crushing, could withstand being bent, and the grain structure of the steel was tighter than the unheattreated part.

video #1
video #2

Now I don't have access to a rockwell tester, so I can't give an exact finished HRC# for my parts. What I can say is that a 60HCR file scratches the hardened part and a 55HRC file will not. This puts the as quenched hardness between 55 and 60HRC. Additionally, a 40HRC testing file can barely scratch the tempered part. Therefore I can say that my parts are between 35 and 40HRC. I'd bet that they are about 38, but I can't say for sure. Additionally, I can say that each one of my parts goes through the exact same heat treatment. I harden each part individually to avoid problems with hot spots in my kiln and uneven heating between the parts.

Based on my research, 35-40HRC will give the best strength to hardness ratio for this type of steel. I believe that 40-45HRC will be a tad brittle. Personally I wouldn't want my parts breaking from a simple drop to the floor. If you notice in my second video, I was able to crush my tempered part a little bit under extreme force. I think this is a good thing because the alternative is the part shattering which would obviously render it useless. The bottom line is I've done at least 20 of these for people now, and I've had nothing but good things said about them.

Link Posted: 9/5/2010 4:29:01 PM EDT
amazing how far we've come in just a few months.

i remember when i got a 3-day ban because DPH got all pissy that I was one of the first to out these as cheap chinese pot-metal knock-offs that don't line up to receivers intended for actual military parts. took my review personally and the fact i stood by my statement, even after everyone sang scott's praises. he may be an excellent guy who stands behind what he sells, etc. doesn't change the fact that the third-world eastern nation he hired the work out to wasn't up to the task of making a quality part.

at least it's good to see other people with the same knowledge. just unfortunate they had to spend their own money to learn.
Link Posted: 9/8/2010 6:03:12 AM EDT
Link Posted: 9/9/2010 10:40:03 AM EDT
With respect, when I was asked for pictures to back up my claims, I happily provided detaile photos of how poorly they fit. The photos were promptly edited out of my posts and my account was locked, the email citing some random ee thread in which I had never posted. When the fourth email requesting more information regarding exactly what infraction I'd committed went unanswered, it became very clear that factual information wih photographi proof holds less pull than vendor status.

Have a great day, and I'll refrain from visiting this thread or any on the subject in the future. At least the photos are still available elsewhere.
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