0% receivers

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Vonz90
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Re: 0% receivers

Post by Vonz90 »

Netpackrat wrote: Tue Jan 25, 2022 12:02 am
Vonz90 wrote: Thu Jan 20, 2022 3:07 pm
blackeagle603 wrote: Wed Jan 19, 2022 5:44 pm Would heat treating be helpful?
I don't do aero stuff so maybe the aero guys can chime in, but at least in the part of the engineering word I live in, I have never seen a need for heat treatment of anything aluminum that I have designed. There are some alloys that can theoretically be heat treated, but it is not common.
Some of the most common alloys are heat treated. Say you make something out of 6061T6, the "T6" is the temper designation. It comes from the mill with all the heat treatment it will ever need (or benefit from). If you ever get your hands on a piece of 6061T0, you will be able to tell the difference, especially in thin sections. In aviation we're usually working with 2024. The normal way it is supplied is in some form of T3 or T4 temper, which again is the heat treated state (with some minor differences between the two and other designations besides). Occasionally we will need to make a repair part with some significant forming operations which would result in cracking if done to material in the T3/T4 condition. In those cases, it's common to start with T0 material, do the forming operations, and then have the part sent out for heat treat. The T0 material is very soft and wouldn't be useful for much, aviation or otherwise.

Other alloys are not heat treatable, and reach their full temper through work hardening. These are common in marine environments for example (5083/5086, 5052), and sometimes in aviation for non-structural parts (tanks, fairings, etc... Generally 3003 or 5052). The door, bonnet, and boot lid skins of my MGA are made of 5052. Part of the panel beater's art is to arrive at or near the desired hardness at the end of forming operations, since the only heat treating process available with such alloys is annealing. Depending on what you are making, and how severe the forming operations, you might need to anneal several times before the part is completed. You don't want to have to anneal again as you are just finishing because then the part will not have its full possible temper, but if you don't anneal enough you could get a crack somewhere in the process.
blackeagle603 wrote: Mon Jan 24, 2022 8:45 pm Yeah, only time (in my sphere) I've seen aluminum heat treated was after welding.
The reason for that, is if you started with something like 6061T6, after welding you might have something closer to T2. That might be strong enough depending on the application, but if heat treating is specified, the purpose is to restore the temper that the material originally had prior to welding. Some alloys (such as 2024) are not generally considered weldable.
This is true, and I should have been more clear in my wording, but I was referring to heat treatment after machining.

I suppose heat treatment after welding makes sense, but if (or one of the engineers working for me) ever designed an assembly requiring welding aluminum, I would think again and do something else.
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Netpackrat
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Re: 0% receivers

Post by Netpackrat »

Vonz90 wrote: Tue Jan 25, 2022 2:43 am
Netpackrat wrote: Tue Jan 25, 2022 12:02 am
blackeagle603 wrote: Mon Jan 24, 2022 8:45 pm Yeah, only time (in my sphere) I've seen aluminum heat treated was after welding.
The reason for that, is if you started with something like 6061T6, after welding you might have something closer to T2. That might be strong enough depending on the application, but if heat treating is specified, the purpose is to restore the temper that the material originally had prior to welding. Some alloys (such as 2024) are not generally considered weldable.
This is true, and I should have been more clear in my wording, but I was referring to heat treatment after machining.

I suppose heat treatment after welding makes sense, but if (or one of the engineers working for me) ever designed an assembly requiring welding aluminum, I would think again and do something else.
As far as that goes, the welded aluminum structures I am most familiar with are either welded together from non heat treatable alloys, or they were designed with welding in mind, such that the strength reduction in the heat affected zone would have been accounted for in design.
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Vonz90
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Re: 0% receivers

Post by Vonz90 »

Netpackrat wrote: Tue Jan 25, 2022 4:14 am
Vonz90 wrote: Tue Jan 25, 2022 2:43 am
Netpackrat wrote: Tue Jan 25, 2022 12:02 am

The reason for that, is if you started with something like 6061T6, after welding you might have something closer to T2. That might be strong enough depending on the application, but if heat treating is specified, the purpose is to restore the temper that the material originally had prior to welding. Some alloys (such as 2024) are not generally considered weldable.
This is true, and I should have been more clear in my wording, but I was referring to heat treatment after machining.

I suppose heat treatment after welding makes sense, but if (or one of the engineers working for me) ever designed an assembly requiring welding aluminum, I would think again and do something else.
As far as that goes, the welded aluminum structures I am most familiar with are either welded together from non heat treatable alloys, or they were designed with welding in mind, such that the strength reduction in the heat affected zone would have been accounted for in design.
This is nothing against welded aluminum or the strength of it if done right. It is that welding aluminum is a pain in the ass for volume production, especially if you are not set up for it. At the point I found it necessary I would just pay for some tooling so we could do something else.
Last edited by Vonz90 on Wed Mar 23, 2022 2:54 pm, edited 1 time in total.
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Netpackrat
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Re: 0% receivers

Post by Netpackrat »

HTRN wrote: Wed Jan 19, 2022 5:52 am If you're considering them disposable, just print a lower using a fdm printer and high strength filament, like polycarbonate or nylon. If you're going to consider lowers disposable, might as well use something cheaper than a 3k dollar gg.
Some necro to touch on the subject of FDM printers now that I am getting a little bit of firsthand knowledge. I recently purchased and assembled a Prusa I3 MK3S+ FDM printer from a kit. The first thing I did with it was to use it to print a set of spare parts for itself, and since then I have been using it mostly for shop gadgets, tool organizers and that type of stuff. First observation, and I kind of knew this going into it, is they are SLOOOOOOW..... That's not all bad, since you can pretty much let it run in the background while you do something else, but there's a reason why guys who are 3d printing parts commercially have rooms full of dozens of them going 24/7. At the Prusa factory in Prague, they have over 600 of them printing parts for their product line (plus hundreds more on the development side), and they always have an order backlog. Although I think a lot of that is due to difficulty in sourcing the parts they don't make in-house.

Second, printing the high strength materials can be difficult. Not even in the same league as the poly or nylon that HTRN mentioned, I have some stuff that I want to run in ABS. While my printer is capable of running all of those materials, it is printing in "hard mode" and I am probably going to have to use an enclosure to get the ABS parts to print accurately. Also one of the parts I designed (that came close to filling the print volume), when I loaded it in the slicer (CAM software that generates gcode for 3d printers), said it was going to be a 2-1/2 day print, pretty much no matter how I sliced it. I went back in and redesigned it for more efficient material use and better printability, and the best I was able to do was get it down to under 2 days.

Something like the FGC-9 that was designed to be made using no manufactured gun parts, you would be looking at weeks of printing just for the plastic parts. Probably worth doing if you have no access to guns at all, but equipping even a small squad is going to take a lot of print time. They specified PLA because just about any printer can do it (doesn't strictly require a heated bed though it is better with one). PETG is probably a better choice because while it is a little trickier to print with, it's much easier than nylon, poly, etc and still has decent strength and temperature resistance. Either way, if you want it to be an option, the time to fire up the printer is not the night before you think the boogaloo is going to kick off.

Speaking of the FGC-9, I took a glance at some of the drawings, and the word that almost immediately came to mind, was clownshoes. At least compared to what a guy with a reasonably well equipped home shop could produce if he put his mind to it. I am glad that the design is out there, so that people who DON'T have access to a reasonably well equipped shop can still defend themselves (or fight tyranny). I will stand by what I said above WRT this overall type of arm, as applied specifically to the FGC-9. Will get the job done if decently well built, but it definitely should be thought of as a stopgap tool to be used until better can be acquired. In that regard it's an order of magnitude better than something like the WWII Liberator pistol... If the intended use case for one of those went sideways on the user, he could pretty much count on getting dead. With the FGC-9 it would be possible to fight your way out of a tight spot.
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HTRN
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Re: 0% receivers

Post by HTRN »

Netpackrat wrote: Wed Mar 23, 2022 1:30 am First observation, and I kind of knew this going into it, is they are SLOOOOOOW..... That's not all bad, since you can pretty much let it run in the background while you do something else, but there's a reason why guys who are 3d printing parts commercially have rooms full of dozens of them going 24/7. At the Prusa factory in Prague, they have over 600 of them printing parts for their product line (plus hundreds more on the development side), and they always have an order backlog. Although I think a lot of that is due to difficulty in sourcing the parts they don't make in-house.
Well yeah. When my employer bought their First FDM printer, a BigRep Studio, it was to bring the convoluted Ductwork for the Verizon project. Each one took 8 plus hours to print, and that was on a commercial FDM machine who's price was, at the time, somewhere around $50 grand.
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Netpackrat
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Re: 0% receivers

Post by Netpackrat »

I kind of want one of these:

https://www.youtube.com/watch?v=0E0dM0ZdpRE
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Cobar
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Re: 0% receivers

Post by Cobar »

These guys do quite a few videos on more interesting materials. Vision Miner Youtube

Been looking for an excuse to spend the money to enclose the ender I have and build a Voron. With prices the way they are I have a hard time spending any money I don't absolutely have to though.
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HTRN
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Re: 0% receivers

Post by HTRN »

Netpackrat wrote: Wed Mar 23, 2022 10:54 am I kind of want one of these:

https://www.youtube.com/watch?v=0E0dM0ZdpRE
Hurm...

Very interesting - Formbot has kit options up to a 350mm cube.. that's over a cubic foot...
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blackeagle603
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Re: 0% receivers

Post by blackeagle603 »

Anyone making multi-head units for paralleling buildup?
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Netpackrat
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Re: 0% receivers

Post by Netpackrat »

HTRN wrote: Wed Mar 23, 2022 2:57 pm
Netpackrat wrote: Wed Mar 23, 2022 10:54 am I kind of want one of these:

https://www.youtube.com/watch?v=0E0dM0ZdpRE
Hurm...

Very interesting - Formbot has kit options up to a 350mm cube.. that's over a cubic foot...
The LDO Motors kit is supposed to be better. Supposedly pre-orders for the next batch will open later this month for the 300mm version, a little later for the 350.

https://www.printedsolid.com/products/l ... 0882401365

I may go for a Voron later, but I am going to work up to it by building a Bear Mod version of the Prusa first, with a taller than stock Z axis. Doing it as a scratch build rather than breaking my new Prusa. Looked at simply buying one of the clone kits and extending the Z, but some of the clone components are not so good.
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