Pardon if you’ve said so already, but have you measured just the backbone? Sounds like no.
Obviously if you are not willing to do this, you’re not learning anything about the CNC’s milling accuracy of the backbone.
- Thread starter Ziloooo
- Start date
Obviously if you are not willing to do this, you’re not learning anything about the CNC’s milling accuracy of the backbone.
for the wall height, no.....
the measure to the wall height for forend / backbone combined is just to verify: how the forend / backbone combined on the table can show different level measures from rear to front. If want to learn individually how backbone and forend are contributing to the combined diff, I agree with what you said.
wow 7 µm...
yeah, as long as they (KRG) say it's totally within their spec, I'm completely fine to live with that. But it can be better as you said.
Yes, of course. Here’s is my Bravo with the Arca rail screwed to the bottom.
I assume you understand that being threaded into the backbone does not obviate the need to take separate measurements if you’re interested in fine measurements?
Hold up, I guess it sounds like you do understand…
Au contraire mon frère, I own the folder and upgraded the forend to the aluminum Arca one.
The hallmark of what I’m calling autism on this forum has always been a combo of:
- OP has what seems to be a straightforward problem
- But OP actually has a masked anal question
- Markedly and weirdly friendly replies by OP to caustic comments
- OP seems to love debate more than actually figuring out solution to his problem (or in discovering if the problem matters IRL)
- OP’s intense desire to hear their opinion coming out of someone else’s mouth
- More friendly OP replies that disregard other’s evidence or expert’s opinions that contradict OP’s original belief
- OP seems to a lack of humor, banter, etc. He has a machine-like AI coldness about him.
- OP never (really) changes their opinion, or does so only after pages and pages of exhaustive debate
- OP often flies off onto tangential discussions (also anal)
- OP seems confused by hostility
- OP must have last word
But the poor fellows don’t understand the basic ground rules for how two normal adults interact when one asks for help and, crucially, how to accept the help given.
And then they get confused as to why they are constantly met with such hostility.
I have some empathy for you. But realize, if you are not an engineer or, especially in this context, a machinist, DO NOT engage in a debate as how you are right in their field of expertise.
Unless you like people making fun of you.
You might ask questions around the edges to gauge their actual level of knowledge or to potentially remind them of some crucial thing they forgot, but yeah. Go easy.
The overpowering need to debate in the face of superior knowledge, expertise, schooling etc combined with weird “upbeatness” is a dead giveaway to (what I’m coining) Autistic Forum Behavior.
#AFBisRealBros
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Based on how I would picture this part being made, it is clamped in a fixture to mill, probably a couple different ones.
The clamping pressure is more than likely introducing a twist which after unclamping is causing the twist in the part,
The cause could be, bad fixtures, inexperienced operators, after all in CNC all you do is push a button and the machine does the rest.
Wrong sequence of operations, or being the twist has zero effect on operation, who cares.
Based on your measurements if everything is + or - .010 it is a good part in a lot of manufacturing. From what I can see in your pictures I would have to say it is more than that.
The clamping pressure is more than likely introducing a twist which after unclamping is causing the twist in the part,
The cause could be, bad fixtures, inexperienced operators, after all in CNC all you do is push a button and the machine does the rest.
Wrong sequence of operations, or being the twist has zero effect on operation, who cares.
Based on your measurements if everything is + or - .010 it is a good part in a lot of manufacturing. From what I can see in your pictures I would have to say it is more than that.
Because if you manufacture something it needs to be done right. Making that right will require no additional cost. IMO the tooling to manufacture that was done cheaply instead of correctly, which causes every part to be off.
I would not be proud of that part and if it cost me a few dollars more todo it right that's what I would do.
Zero machine time, Zero material, zero labor, a few dollars more in tooling and probably not even that when it was built. Now it needs replaced. Might as well buy from China for half the cost if quality doesn't matter.
I can’t wait to see the threads some of these guys start when they put their money down on a “custom home” and see the fuckery that goes on in that industry…
you wrote a lot, I agree many of what you said.....
Answer you in two parts.
First part related to the topic:
Second part related to your life advice:
I think you summarize it pretty well, and I don't disagree with most of your points, except your statement regarding hostility.
I may accidentally miss it, but if you can find any of my reply hostile to a friendly comment that is to voluntarily educate me the knowledge about machining (extruding, cnc, tolerance), or to help measureing their own, or to give me the reference tolerance, or to discuss how should I measure it better. I intentionally ignore most of the trolling ones and until those few crowns start holding party in the thread. So far, in this thread, i think 30% provide direct knowledge / help, 60% provide neutral / objective comment (like those saying it's not functional), only few being hostile and satirized.
I don't know the 'cheatsheet' or sth similar you mentioned. I'm not thinking that much especially communication between two adults. For me, a mutual respect should be the start of a conversation.
"your measure introduces error enough to make your validation failed, because ...." that's a friendly comment.
Still, don't get me wrong, I'm not here to debate, and the rest of your points are invaluable to me especially:
Answer you in two parts.
First part related to the topic:
That's not my intention, you see what i did is mostly to verify the machining error here. I'm not intended and do not have proper tool to make quantitative analysis tho. And I basically give up finding the root cause that, which part backbone or forend, at which point, is causing the issue becaue the current diff doesn't trouble me that much, as long as it's not the twist I initially suspected. I dislike the uneven bottom surface more.
I'm saying that is not to judge your ability to own. It's because you last reply
This is purely based on your assumption. If you go back to my original post, the first sentense is:
Second part related to your life advice:
I think you summarize it pretty well, and I don't disagree with most of your points, except your statement regarding hostility.
I may accidentally miss it, but if you can find any of my reply hostile to a friendly comment that is to voluntarily educate me the knowledge about machining (extruding, cnc, tolerance), or to help measureing their own, or to give me the reference tolerance, or to discuss how should I measure it better. I intentionally ignore most of the trolling ones and until those few crowns start holding party in the thread. So far, in this thread, i think 30% provide direct knowledge / help, 60% provide neutral / objective comment (like those saying it's not functional), only few being hostile and satirized.
I don't know the 'cheatsheet' or sth similar you mentioned. I'm not thinking that much especially communication between two adults. For me, a mutual respect should be the start of a conversation.
"your measure introduces error enough to make your validation failed, because ...." that's a friendly comment.
If you were I, would you like to
?
Still, don't get me wrong, I'm not here to debate, and the rest of your points are invaluable to me especially:
I do appreaciate.
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We have archived retard totality on this one.
But let me ask you this since you work in micrometers, would you say that you'd be able to achieve +-7 um or even easier +- .001" on a 10-12" AL part out of extruded stock over a run of maybe 20-50 units at a time?
Mind you a hollowed-out AL part that's threaded all over... without using grinding, or any kind of chemical milling or discharge milling.
The +- 7 um or scrap story was pretty neat.
How about say it in another way. Is this the best they can do at the current cost?
A few have mentioned KRG chooses function over quality (material wise, machining wise). I don't have a lot of chssis, but i know many of you have. Can anyone tell if the MDT, XLR, etc. hold the same tolerance for chassis at comparible price point?
Alert: this is just about, technically, the machining tolerance, not about if a loose tolerance on non-action mating area will impact any end result.
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Probably is. Last reply on this one
You're calling a company out on machine know-how because you don't like a non-critical fitment while actually having zero know-how yourself.
Then the twisting claim, which is a function of soft material removal with a rotating tool. Parts bow, flex and twist after milling, you live with that.
Clearance is built in so the tolerance is wider. The tolerance is wider because they want to make large runs of this part so you can afford it.
The dude that said that it would cost no money to make these parts absolutely straight in a hands-off production setting using extruded AL at the lowest cost possible is way off base. It would cost a lot more in time and material quality.
News flash, you aint getting prime cut usda choice aluminum in your gun AL parts. Bunch of wars out there, they are getting the choice stuff you are getting the stuff that's good enough, that no one will do any destructive or non-destructive testing, will not be validated by no lab ect.
KRG is probably looking at this shaking their head because is comical. You have already been told it's a cosmetic issue that will have no impact on function. Move on
Not sure, but Zilooo, are you by any chance outside of North America? And one further question is there any chance that you are using an AI bot that is being translated into English?
no i'm in CA but you might have realized English is not my native lang, so please bear with me if my grammar is crappy
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by how? i used to confuse myself on those 'yes/no' questions so i ususally answer the question in full lol
outside NA? no
using transbot? no
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I think you misunderstood that bit. I’m saying after the autist is insulted by a forum member, they unfailingly reply in a strangely upbeat and friendly manner.
I’m not saying you reacted in a hostile manner.
We can hold 20um on a 5 meter rail so 15 feet less than .001
.001 should be very doable in 12”s
When I run my bearing blocks I run 8-12 at a time on a bed that traverses 7 feet
We have machines that make aluminum drives to less than.001 in 6 feet
IMO for that part the tolerance is sloppy
What do you make? Linear bearings or something?
LOL the parts. I make go inside CNC machines. the reason CNC machines are so accurate is because of the parts I make
45 years of experience speaking here 25 as a tool maker in the aircraft industry
The part is made sloppy whether it be too fast of production or poor tooling. Maybe it’s subbed out to China
Does it affect function? No. Its strictly cosmetic
And fast = money.
If KRG wanted linear guide straightness on the foreends they would have to charge linear guide manufacturing practices prices and pass the cost of linear guide caliber materials.
look up the price of LM guides, they cost less than he paid for that warped chassis and are far higher quality material , more accurate too.
Whiskey 3 chassis $969-1549
LM guide block $257 rail $225
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When you look at the hodge podge of patched together parts that KRG calls the W3, you start to realize why the backbone could be crooked and why KRG dummies up so quickly. I don't remember how much I paid for mine but it was well over $1k. Fortunately the guy that bought it has had good luck with it and loves it. Last I heard he put an ARCA forend on it and shoots it in his dungeon shooting range.
Yeah, i don't doubt there are some real cheap ones out there to make a little robot arm box car go from A to B...
Your concept of quality is how businesses go broke
"Right" is defined by design. Doing it "better" than that is a waste of time and money
This is like guys talking about how cheap AKs should be, and how anyone in the US should be able to make them for nickels if the soviets could do it. All without factoring in the monumental government funded manufacturing system that was created for the task.
CNC guy make parts for CNCs. Great. I’d love to see the retail on a whiskey3 held to his tolerances, made at MDT’s capacity. Don’t forget to amortize the cost of the tools/machines over their useful lives. And, let’s all remember that the tolerances in question are purely cosmetic.
CNC guy make parts for CNCs. Great. I’d love to see the retail on a whiskey3 held to his tolerances, made at MDT’s capacity. Don’t forget to amortize the cost of the tools/machines over their useful lives. And, let’s all remember that the tolerances in question are purely cosmetic.
I will give you an idea of the process for a bearing block,
High quality steel extruded into 16 foot lengths
extrusion then cut to length into 3" lengths
Machined to exact length
All holes drilled and tapped in raw material
raw material heat treated
after heat treat bearing grooves are ground
two mounting surfaces ground
washed
each block is hand fit to a specific rail for a predetermined pull weight
lasered with part number and company logo
assembled, bearings installed, end caps and seals
every block has documentation paper work tracing the entire process for QC/QA
High quality steel extruded into 16 foot lengths
extrusion then cut to length into 3" lengths
Machined to exact length
All holes drilled and tapped in raw material
raw material heat treated
after heat treat bearing grooves are ground
two mounting surfaces ground
washed
each block is hand fit to a specific rail for a predetermined pull weight
lasered with part number and company logo
assembled, bearings installed, end caps and seals
every block has documentation paper work tracing the entire process for QC/QA
I never mentioned pricing, I said with todays CNC that part is made sloppy.
see post #125 retail LM guides are cheaper than whiskey chassis so please tell me how we do that ? superior materials, smaller tolerances and cheaper retail. But I know nothing of what I speak.
google it for yourself LM guides are not that expensive
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@ironpony52 What chassis or stock do you like/are impressed with?
Might as well include the actions and barrels too.
Might as well include the actions and barrels too.
see post #125 and #131.
We build far more complex and tighter tolerances for less.
I do not do LRS i am only interested in this for the machining. I shoot a SIG Cross for my long range gun so I am shooting inferior equipment by comparison.
So the German made linear bearings i replaced in the grinding machine were like $3,000 for a set of two. Would they be better quality cause they are German and cost more?
Or did we get ripped off by the 200% markup?
Or did we get ripped off by the 200% markup?
$3000? Did you see the prices? That’s closer to 1000% markup.So the German made linear bearings i replaced in the grinding machine were like $3,000 for a set of two. Would they be better quality cause they are German and cost more?
Or did we get ripped off by the 200% markup?
And, until CNC guy has a chassis on the market that holds tighter tolerances in all of the non-critical areas while maintaining the same tolerances in the critical areas, all while keeping the retail price below that of this chassis, he’s just talking out of his ass.
I’m reminded of something that Ian McCallum (Forgotten Weapons) said regarding burgeoning gun designers. The gist is; he is often asked what advice he would give to aspiring gun designers. The advice is “sit down and rest until the feeling passes.” Everyone thinks they can do it better, faster, cheaper, etc. They are nearly universally incorrect.
A corollary to this is…
“How do you make a small fortune in the gun industry?”
“Start with a large fortune…”
Those percentages is pretty good behavior for this forum btw. It can get much worse. There's lots of good information on this forum but you need thick skin to survive here or do what you do, ignore the trolling. I don't suggest using the forum option of ignoring/blocking the trolls though because when they decide to be nice, they share good information and knowledge.
I'm assuming you're somewhat new to firearms (or at least building/assembling from components) due that desire of wanting to measure everything and because you didn't know what exactly you should be measuring. Measuring everything is one of those things you'll grow out of.
Anyways, despite the wall height difference (cosmetic), the W3 Arca forend is most likely NOT twisted (functional). Arca wouldn't function well if it was. Function matters significantly more over cosmetics for many on the forum. Example - Are the holes aligned well enough so you can actually bolt pieces together, is there threading on holes that should be threaded, is the Arca rail function is straight and correct width, so on and so forth. Does the chassis do what it should do from a functional perspective? Anything else and you get opinions, especially when it comes to things that fall under the cosmetics category.
Based on the follow up questions of wanting measurements from others or trying to get opinions on acceptable manufacturing tolerances on other brands' chassis (something we don't know because again, manufacturer's secret), a lot of people are suspecting that the wall height difference is bothering you a great deal.
It ultimately boils down to this - no one knows the exact specifications that are within acceptable manufacturing range so asking people to measure their examples of their W3 chassis still wouldn't answer your question because the specifications are a manufacturer's secret. Put in another way, if someone gave you the measurements on their forend, how do you know theirs isn't the one that is out of spec and yours is perfectly within spec? You wouldn't. You might like their numbers better because it appears better but it doesn't necessarily make it technically right.
So...
You're better off just selling off the forend or entire chassis as it's likely you've already decided that your particular product is unacceptable to you for the price you paid. People are not likely to be able to convince you that it's fine. Selling the chassis or forend because it left a bad taste in your mouth is also fine. You don't have to keep things you don't like. You may not get all your money back, but mentally you'll be in a better place and that'll be worth more than the amount of money you lose selling it off.
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This is why we keep getting more stupid expensive shit rather than more affordable function forward shit. All these people buying plastic and Aluminum guns because they think they look cool..
i can't agree more and you spoke out almost everything in my mind.
still want to give my W3 a chance to be on the range to decide if i really love it that much.......
i think the hodge podge of patched (lol) you mentioned is their modular design, can't say it's good or bad for now, especially for rigidity.
something I really wish they can impove: leaving some holes on the forend so the user don't need to remove 8 screws on the forend to expose the backbone to install the spigot.
1) I never said I could do it cheaper
2) I never said it would not function
3) I never said faster
4) I did say I could do it for the same time/cost better
4) In my first post I said it would operate fine strictly cosmetic
5) The part for a CNC machined part is crap.
It is very obvious that people are posting on a subject that they have very little or no knowledge about. The fix for that could be as simple as slowing the run time down 3 minutes.. After some more thought last night I would say the operator is not taking the time to fixture the material properly. I have seen that issue before with new guys. Literally for 5 extra seconds it could be done right.
2) I never said it would not function
3) I never said faster
4) I did say I could do it for the same time/cost better
4) In my first post I said it would operate fine strictly cosmetic
5) The part for a CNC machined part is crap.
It is very obvious that people are posting on a subject that they have very little or no knowledge about. The fix for that could be as simple as slowing the run time down 3 minutes.. After some more thought last night I would say the operator is not taking the time to fixture the material properly. I have seen that issue before with new guys. Literally for 5 extra seconds it could be done right.
So the German made linear bearings i replaced in the grinding machine were like $3,000 for a set of two. Would they be better quality cause they are German and cost more?
Or did we get ripped off by the 200% markup?
I can not say without knowing other factors. Was that installed or just 2 blocks? It could of been one of ours as we have plants in Germany.
Were they one off to replace an obsolete part ? Being a grinder I would say you were in a very tight tolerance part, possibly 0-4UM.
I don't care. You're comparing apples to oranges.
Tell me you don't know how to make money in manufacturing without telling me you don't know how to make money in manufacturing.
Companies never release the specs and drawings of what they without an NDA for two reasons. Competitive advantage is clearly the first one.
The second reason are the OP and Mr precision linear guide. The first one knows nothing and the second one thinks he knows enough to judge everything.
If the average person such as the original poster, who admittedly knows very little about machining buys as a precision stock chassis assembles it and notices it twist the part is a piece of crap
These parts are extrusions. They are a shaped tube. In raw form (4m long pieces) they are called billets.
So machined parts from billets... is correct. However the backbone is mostly shaped. All it gets is a few drill holes, tapped, and a magazine cutout. Oh, and recoil lug slot. It would be 2mins at most to make.
Now id like to hand the conversation back to the screeching autistics.
Keep doubling down on how little you know about making money in the mfg business.
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