# First 3D-Printed Boy Scout?



## calinb

This one's "for a kid" (my daughter) and the one printing in the photo is for another kid (my nephew).  I CAD-ed up a solid model of Bill Hays' classic design. Simpleshot has a link to a 3D printable model of Joerg Sprave's Rambone, but I'm more of a side shooter/ergo kinda guy.

I'd like to post the CAD files on GrabCAD.com, because the site is not holophobic (irrationally fearful of weapons), like so much of the 3D printing "communitry," but I'll do whatever Bill wants me to do with my CAD files. Maybe he'll host them on Predator.com. Regardless of where the files are hosted, users should be advised to "build one for a kid," if they are used!


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## leon13

That looks great 
3d printing is really a fun thing 
Cheerio


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## e~shot

cool!


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## Bob Fionda

Great work this one.


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## JohnKrakatoa

nice man! Great colour choice too!


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## Imperial

i like the color. im a lil dense here, what is the material? plastic type?


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## calinb

Thanks for your replies, everyone!

The material is Oregon brand "Gatorline" trimmer (weed whacker) nylon line. It comes on large 5-lb spools in only one color--green! It prints great, but also might not be good for your health to print it in a living space area, because it may (or may not) give off toxic fumes. (Fumes from "non-3D printing" nylon materials have been claimed as a potential hazard but I've never seen actual evidence either way.) Still--best to not take a chance and avoid breathing any fumes when printing trimmer line. I also have some actual 3D printing nylon filament from Taulman 3D and 3ntr, which are claimed to print free of toxic out-gassing.

The Taulman nylon is white and can be dyed with ordinary Rit clothing dye. You can dye a spool of filament in two or more colors (the color changes every few inches along the filament). When printed, it gives an interesting zebra striped or tie-dye kind of effect. I think I might try it.

Nylon is very strong, but it shrinks a lot when cooling, which is limiting in both injection molded and 3D printed parts. Something like this slingshot must be printed with a honeycomb core, because a solid plastic part would shrink too much. My first one, above, is a shooter, but I'm changing the model to also print some strong and hidden plastic stiffeners internally. (Nylon is quite strong, but it tends to yield by bending rather than breaking.) One could easily add metal stiffeners too. Stiffeners would not be necessary when printing the more common PLA printing material, which is actually more brittle than I'd like, or ABS plastic. Some new types of PLA are not as brittle as normal PLA (or even quite flexible) and one I know about is at least as strong as ABS, without the cooling shrinkage and warping problems. I have some of this new technology PLA filament and also some polycarbonate, but haven't tried them yet. The polycarbonate requires very high temperatures (~300C desired) and I'm making some new Macor (high temp machinable ceramic) parts on my lathe to handle it.

I also have some Laywoo-D3 that I've never tried. (I'm kind of a nylon expert so I'm sticking with it for my first slingshots).

http://www.wired.com/2012/11/3d-printer-wood-filament/

I don't know if it will be strong enough for a slingshot, but printing one that looks like a real slingshot (wood) might be pretty cool too!

I'll post photos to this thread when I come up with something new. 



leon13 said:


> That looks great
> 3d printing is really a fun thing
> Cheerio





e~shot said:


> cool!





Bob Fionda said:


> Great work this one.





JohnKrakatoa said:


> nice man! Great colour choice too!





Imperial said:


> i like the color. im a lil dense here, what is the material? plastic type?


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## bigron

very very cool the shooter looks awesome :bowdown:


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## Chuck Daehler

Very nice and a complement to Bill Hays for designing the frame. Maybe send him one of your printed ones just as a "thank you"d for his collection.

Just wondering since I have zero experience with 3D printing, what's it cost for a slingshot like that in materials? Answer please/


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## calinb

bigron said:


> very very cool the shooter looks awesome :bowdown:


Thanks, bigron. That means a lot to me, coming from you!


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## calinb

Of course I'll answer any questions you might ask, Chuck. I've recently rediscovered the fun of slingshots (after using them as a tool to shoot pull lines over tree branches (in excess of 50' height, even) to prune them. I've learned a lot from reading your posts here and I'm happy to answer questions and contribute. I found that I could shoot round fishing weights much higher and more accurately than I could throw weights or weight bags.

Very nice and a complement to Bill Hays for designing the frame. Maybe send him one of your printed ones just as a "thank you"d for his collection.

Just wondering since I have zero experience with 3D printing, what's it cost for a slingshot like that in materials? Answer please/

Even with my new internal stiffeners, the material cost is only about 70 cents in trimmer line. I bought a couple of cases of official 3D printing nylon filament from Taulman3D on a special sale deal for about the same cost per pound as the trimmer line (~$10 per pound), but I save it for when I want to dye the plastic a special color (it's white and accepts any color of dye). Typically, one might pay $20 per pound or maybe even $30 for "specialty" and brand new 3D printer plastic filament technology. I plan to print some multicolor Taulman nylon slingshots after I get my CAD model as good as it can be with the internal stiffeners.

I also want to get it as good as it can be so others might be able to print it well. I'm waiting to hear from Bill. I know he's busy. Yes--I was thinking about sending him a printed copy to give to a kid himself. Now I think I'll send him two prints so he can keep one as a sample for himself.

At the risk of getting maybe a little bit off-topic, here's another example of what is possible. These AR-15 lowers are much stronger than most of what people have printed, because the ABS ones are glued and steel screwed together and the nylon ones are just screwed but both are plenty strong to stand up to this 12ga. shotgun equivalent kick:






Yeah--a printed slingshot can be plenty strong! It's all in how it's designed and printed. BTW, the end of the video is a little inside joke directed at the 3D printing "community." :rolling: Still, I prefer to mill such a part out of aluminum, because there's still a lot of work in making a 3D printed AR lower turn out acceptably strong, fit well enough, and work properly when fabbing it on a 3D printer. It's not like printing your family vacation photos on an inkjet, even though the media hype would have people believe that it is! I tell people that I found the 3D printing learning curve to be steeper than learning how to run a mill or a lathe. On the other hand, once a good model and process for something like a slingshot is developed, it's pretty easy for others to enjoy success with it.

In my PM to Bill Hays, I mentioned that I'd like to also CAD another version that uses his Predator Pro Titanium attachment clips. I think that, if he agrees that I should "go public" with the models, quite a few kids will get some free slingshots from 3D printing "makers" and maybe he'll sell a few bands sets and Predator Pro Titanium attachment clips. Also, I'd like to help some people in the 3D printing community discover the fun of shooting sports and, if Bill agrees, I'd like to post the files somewhere where they will attract their attention.

-Cal


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## Chuck Daehler

You've given me, us, a good bit of information in this fascinating field of 3D printing. I didn't know such things as trimmer filament could be used..we can get that here in bananaville..fluorescent colors as well. The shrink factor can be handled by scaling up the CAD drawing for nylon. Other filaments I doubt we can get here yet.

I was looking at some printers...for a hobby machine what would you recommend say under a grand?

It is very courteous of you albeit ethical to contact originators of designs for permission or business arrangement etc.. It could be a very mutually benefitting arrangement if agreeable to all parties. As printers come down in price I would assume they will be very common on table tops, shops, craft studios etc. and copy righted designs will be compromised. A laser scanner could also trim down software time to scan an object, transfer that scan to software and thence to a printer to duplicate it EXACTLY...minus shrink. As a former gold smith I can see huge applications in jewelry design potential and making silicone molds from a plastic original to mass produce an item in wax thence to lost wax casting such as I did 1000s of times.

I think your idea of adding metal stiffeners/cores to items, rules...no worries of it breaking and it controls lots of the shrink factor...I guess the printer will "go over" the core/stiffener and "read" the result as printed even tho it's metal added?

I'm really interested in this new tech. Printed ammo for that matter! Say, print 225 balls at once laid out in a block 15x15.

For your printer, how long did it take to print out this Boy Scout slingshot?

What printer do you have, what's the approx. cost?

thanks for answering all the questions, am sure you will be the 3D guru here!!!!

And thanks for contributing so much.

I can see an industry unfolding here in Ecuador of making a desired original of plastic, accounting for shrink factor, making an RTV silicone mold of it (no shrink factor in that), using lost wax, casting bronze or brass parts...accounting for the shrink factor in metal casting as well (about 7% or so depending on the metal) in the original plastic model. Anything from the model train hobby industry (this gets seriously involved) to whatever part or casting one wants for further finishing/machining. hand gun grips custom made for one's hand based on a laser scan of a plasticine original squeezed by the client, zillions of applications. Note the NRA had in my avatar...can see applications in custom grips and plastic wear for fire arms, law enforcement (also part of my background) gadgets blabla...


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## Chuck Daehler

OK, it's raining, no shootin' today evidently. So. I am so curious about this 3D printer subject I decided to do some Google work.

Why 3D hasn't caught on as much as it could http://www.techrepublic.com/article/3d-printing-10-factors-still-holding-it-back/

Caveats http://gizmodo.com/why-3d-printing-is-overhyped-i-should-know-i-do-it-fo-508176750

An extensive link in all aspects http://www.3ders.org/3d-printing-basics.html

I read all three of these from beginning to end and now I've cooled off on 3D printing. The last link article says at least six months of learning curve, another article says three years to get really good...aside from learning the CAD program needed as well.

Humm...

Til 3D printing gets a bit more user friendly I think I'll wait a spell and have a couple M.I.s and bypass ops first.

Layering strength issues appear to affect model strength on the Z axis so making stuff that has to resist a lot of stress using plastics doesn't supersede injection molding. So don't worry guys who produce injected plastic SSs, your product line isn't obsolete by a long shot.

I'd want to see some strength break tests done using a digital scale pulling on that nice lime green slingshot to see how much it takes to break it AND after it's used say 5000 shots, another break test to see what it THEN takes to break it when the laywers bend and ply under band pull. I'm not being a sceptic, just thinking engineer's stuff here.

The value of 3D printing plastics is in prototyping as a precursor to mold making and likewise laser sintering of metal powder...possibly to make one of a kind aerospace, automotive/machine, NASA and JPL metal prototypes albeit functional items of limited number. Repairing UFOs and stuff so the aliens will shine favorably on us, right? Does a rubber like tree grow elsewhere in the universe? If not, how unlucky aliens would be without slingshots. Thimk about it. hehe, trade 'em a truck full of TBG for a time/warp drive.


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## Chuck Daehler

Possibly for super strength, use the 3D printer to make "scales" to laminate with epoxy and rivets if you wanna get fancy, over a core of micarta/G10, metal, wood etc. to make a glue together slingshot with little other work than making the core. Would this be handy for making custom colors glued to core de jour?

If you laser cut cores all the same exact dimensions for preciseness and laminated 3D scales over them...to make custom color combinations of core/scales...???...

Does the 3D printed nylon "stick" to stuff such as a core so that glue wouldn't be needed? Since nylon has a considerable shrink factor if it stuck to nylon hot, then cooled, would it self delaminate and pop off? These questions can't be answered likely now but food for experimentation perhaps.

Would the printer make a precise enough scale to not have to sand/work it to fit the metal or G10 core?

What would be the advantage to 3D printing scales when band sawing them would be much faster? So is this idea of mine about making scales on a printer, a moot point?


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## calinb

Chuck Daehler said:


> The shrink factor can be handled by scaling up the CAD drawing for nylon. Other filaments I doubt we can get here yet.


Yes--to some extent it can be handled that way. For something like a slingshot, the imprecision imposed by shrinkage is usually too small to make a difference in its function. For an AR lower, which has to interface with other parts, dimension "adjustments" become necessary.

One of the biggest challenges in 3D-printing with just about any plastic except PLA is the shrinking plastic causes stress and strain in the part as the new layers cool (which are supported by the cooler layers below). The strain causes the print to warp upwards (particularly at outside corners of the printed object). Eventually, the bond with the printer bed can fail. Though always undesirable, a little bit of warping might not cause any problems or significant separation of the part from the build surface, but it is something that 3D printer users are constantly battling and mitigating using a number of methods.

I've attached some screenshots from my software. You can see how the Boy Scout looks on the printer bed. Notice that I designed a "brim" into it which helps to keep the part stuck to the bed. It's easy to remove features like this later (cut or tear them away). Temporary "support" features for overhangs can be more work to remove. Another advantage of nylon is it "bridges" very well and doesn't needs as much support as most plastics. Most software can automatically add design features like these, but I often design my own features into my solid model of the part for optimum performance. You can see in the closeup of the fork that the brim is a few layers high and it is filleted. This makes it more effective, but only one piece of software can add a feature like this automatically (Kisslicer). However, Kisslicer doesn't do some other stuff. (You'll acquire a quiver of 3D-printing programs!)

You can also see the stiffeners I added in the cutaway view. These lines actually touch in the real part and make for a solid area of plastic. Technically, adding the "slits" to my solid model that produces this feature is not supported in 3D printing models (mesh models), because internal features like do not produce a "single shell" and properly "oriented" mesh, but you learn a few tricks in this business! 

One nice thing about nylon is the optimum setup doesn't require a heated bed or benefit from a heated "build chamber." Nylon probably bonds best to Garolite--a linen/cotton composite material. I bonded a thin sheet of machinable Garolite LE to the printer bed I use for nylon with contact cement. It must be bonded and squeezed to realize a very, very flat surface--say something like +/- 0.002 inches flat for the very best results. I would not recommend even trying to print on anything less flat than about +/- 0.010 inches and even then, adhesion with the bed would suffer a bit (and you'd get somewhat unevenly extruded first few printed layers).

I've had very good result also gluing cotton or linen painter's canvas to the build plate with Elmers or Wood glue. This method might even realize bonds as strong as the Garolite but the texture of the canvas is imparted to the printed part. It can be sanded away, if desired. I have also used a very flat poplar board as a build surface. Molten nylon sticks to other types of wood very well too. These kinds of materials should be available locally for you. These materials must be refreshed or replaced more frequently than the Garolite, which lasts a very long time before it must be resurfaced or replaced.



Chuck Daehler said:


> I was looking at some printers...for a hobby machine what would you recommend say under a grand?


In that price range, users like the CNCSeeMe Rostok and the Mendel90. Both are kits and I actually recommend assembling a kit anyway, because you will learn much that you will need to maintain and maximize your effectiveness with the machine. People that don't have the skills or aptitude and desire to put a kit together really should not be getting into 3D printing at this time (or probably not anytime in the next decade or so), IMHO! Also, there is a ton of flaky stuff out there that really doesn't work very well. One of the big names is Makerbot. They've had some problem with managing rapid business growth and the introduction of their Replicator 2 and don't really have a printer in your price range anyway (the one that is closest is very small). I mention them because they are clearly "anti-gun." Shapeways is also based in NYC and, true to the culture in NYC, even refused to even produce prototype parts for a plastic (toy-like) training gun that I developed with my business partner. (A little more on that later.) So I must snub both of these companies here!

http://seemecnc.com/products/rostock-max-complete-kit

http://reprap.org/wiki/Mendel90

The Mendel90 was designed by nophead and, though others may sell partial kits and parts, I think his kit is complete:

http://forums.reprap.org/read.php?94,196585

If you can spend a bit more, I highly recommend the Original Ultimaker. I've had mine for 2-1/2 years and it does everything the fancier-looking newer models can do (and maybe a bit more, actually). I am very happy that I got one of the "gold standards" in this hobby, because I've learned much of what's out there doesn't work very well. The UM is somewhat simpler to assemble than the SeeMeCNC Rostock Max or Mendel90, because no soldering is required. The Ultimaker customer support is probably as good as it gets too, though it's not perfect (this is an immature industry). The UM can print at 260C nozzle temps right out of the box and even a bit higher with a simple software tweak and maybe the addition of some nozzle heater block insulation to reduce convective transfer to the parts above it. For printing nylon, you REALLY want to be able to go to 260C and even a touch higher. I think the Rostok and Mendel90 will need "hot end" upgrades to achieve 260C without impacting hot end reliability and life.

https://ultimaker.com/en/products/ultimaker-original

All you would need to add to enable printing nylon is a suitable print surface (again, poplar or similar wood is very good) and some clamps to hold it to the printer bed (the low profile "paper clips" used to bind thick paper documents works well). Some people have printed on blue tape (as is done with PLA) and PVA glue, but I don't find this method to be ideal when printing nylon.



Chuck Daehler said:


> A laser scanner could also trim down software time to scan an object, transfer that scan to software and thence to a printer to duplicate it EXACTLY...minus shrink. As a former gold smith I can see huge applications in jewelry design potential and making silicone molds from a plastic original to mass produce an item in wax thence to lost wax casting such as I did 1000s of times.
> 
> I think your idea of adding metal stiffeners/cores to items, rules...no worries of it breaking and it controls lots of the shrink factor...I guess the printer will "go over" the core/stiffener and "read" the result as printed even tho it's metal added?


Yes--I've though about printing PLA as an "investment" material for loss casting directly! I plan to try a little bit of sand casting using printed models myself. I just have to find the time!

In general, the printer can't go over and embed other materials. It's best to place a cavity in the part and press or otherwise insert the stiffener after the part is printed. Unlike ABS and polycarbonate, printed nylon can't be glued or bonded well--it can only be welded or held together with hardware. Just about nothing sticks to it or reacts with it and it's self-lubricating too. Well--one adhesive I know about will bond to it acceptably well for some applications (rather weakly):

http://www.henkelna.com/product-search-1554.htm?nodeid=8797913579521

I'd prefer to screw two halves of a slingshot together, if necessary, using Plastite screws myself.



Chuck Daehler said:


> I'm really interested in this new tech. Printed ammo for that matter! Say, print 225 balls at once laid out in a block 15x15.
> 
> For your printer, how long did it take to print out this Boy Scout slingshot?


I'm very picky about aesthetics and appearance (plus nylon prints only relatively slowly) so it took about 8 hours. I just let it run overnight so why not go for a good appearance! I think the fastest I would try print it would be about 3-1/2 hours or so. With PLA, you could probably print one in a couple of hours, but conventional PLA is quite brittle and not as strong as nylon. In general, PLA is the fastest printing material, however.

You could print ammo very fast! Of course plastic results in light ammo that would not be good for hunting but it should work well on targets. I'll try it. What diameter do you think I should try?

I'll get back to you on the rest of the stuff soon. Gotta run for now. Oh yeah--I haven't even talked about software but I would not be into 3D printing if all I did was download models from the Internet. In Bananaland, it really makes sense to make your own parts or parts that people need. Real parts! Not just Garden Gnomes (my inside joke)! 

There are a ton of software options to consider too. If you will be fully designing your own parts (don't have to import someone else's solid models), not designing injection molded parts (like I did for my company), and will only print your parts rather than buy injection molds, I recommend getting the free (as in beer) CAD software DesignSpark Mechanical:

http://www.rs-online.com/designspark/electronics/eng/page/mechanical

It's based on SpaceClaim, which is a reliable and professional program. Personally, I like solid modelling programs that are more design history based rather than direct modelling oriented, but it's a personal preference. The gold standard in history-based solid modelling is SolidWorks ($$$). Space Claim is quickly becoming the gold standard in the direct modelling arena (also $$$ ) and I think it (and the free DesignSpark) are probably far less buggy than GeoMagic (formerly Alibre) and more capable than FreeCAD and other programs that are open source.

Yes--I did notice your hat. I just sold my half of this company to my business partner, but I did all the 3D printing prototypes and injection molded plastics design work for:

http://www.smartfirearms.us/

I didn't make much money in the startup but I DID learn a lot!

More later on your questions...including why I think it would actually make sense to ramp-up on 3D printing and design stuff in Bananaland!

-Cal


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## Bill Hays

Okay... that's pretty close to the coolest thing ever...

We'll definitely get something going.

For a long time I've been trying to do my small part to get and keep true artisans and real shooters interested and involved in slingshots... it's quite obvious we have another one in our midst!


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## Tentacle Toast

Nice...


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## calinb

That's a good choice in article, Chuck. I agree with nearly everything stated. As I mentioned, it took me longer to learn how to run a 3D printer than it took me to learn how to run a mill or a lathe--and I'm a tech/computer guy (20 years at Intel--mostly running CAD design tools), "wrench savvy," and I already knew how to run those machine tools fairly well. It took me about 6 months to achieve decent proficiency on one of the best hobby 3D printers around!

I agree that 3D printing is way over-hyped and Cody Wilson represents the pinnacle of it. He attracted a bunch of attention and misled people about the capabilities WRT guns--at least for most people. It's worth watching this video too:






Granted, Barnacles did not use the best material, CAD model, or techniques for printing his AR15 lower receiver--one can do far better than he did (as demonstrated in my link above) but his conclusions are very truthful. Most parts fail pretty quickly, at least. There isn't much of a fatigue life factor in most 3D printed parts.

Like I said in my post above, "3D printing isn't like printing your family vacation photos on an inkjet!" However, for those who have mastered it, it is wonderful! I always try to bring useful, turn-key designs (and all the support information) to anything I release to the world to print. If you had my instructions and CAD models for printing and AR15 lower in ABS and followed the process exactly, you'd end up with a much better result than the one that generated all the hype from Cody Wilson. Of course it uses metal screws to mitigate the reduced Z-axis layer strength too. As long as nylon is printed hot, it has far, far less of this problem. The problem is most 3D printers don't handle 265C temps and so the recommended settings from the manufacturers are usually too cold and weaker parts are the result. Geesh--even some ABS needs 260C! (And faster prints required higher temps, because the filament has less time to melt.)

If those article gave you the impression that 3D printing is not for you, it is probably an accurate impression! SLA printers are outrageously expensive (and their resin too) and bring their own set of problems. Same with laser 3D scanners.

Most people don't know how to print fully strong parts. Though FFF/FDM printed parts will always have a "grain weakness," due to the printed layers, I've done a bunch of empirical destructive testing of printed parts and the strength can be quite impressive, IF the part is designed well and printed optimally.

I've CAD-ed up windshield wiper transmission end bearings, valves for my pressure washer, reflex sight mounts and other gun accessories, and replacement parts for a number of mechanical devices (mostly in nylon). Having a 3D printer enabled me to prototype complex parts for my business and NEVER have to redo an expensive injection mold, which is a pretty common expense in product development. This is why I say such capabilities would be useful where you live, but the article was correct. 3D printer usefulness is low, until you climb the CAD learning curve, because most of the (perhaps millions?) of models posted to the Internet are probably not going to be something you'll want to print (unless you like garden gnomes, toys, and trinkets  ).

The problem with my Boy Scout slingshot project is it actually takes longer to make the CAD model than to simply make one slingshot by hand from wood or PET, HDPE, G10, or whatever. But that's just for ONE! The benefit of 3D printing and CAD is, once you have a good design and model, you can make subsequent copies quickly, easily and economically.

This is why I did the Boy Scout model--and Bill Hays' encouragement to "give one to a kid." Using my model and instructions, 3D printer owners should have a high success rate.



Chuck Daehler said:


> OK, it's raining, no shootin' today evidently. So. I am so curious about this 3D printer subject I decided to do some Google work.
> 
> Why 3D hasn't caught on as much as it could http://www.techrepublic.com/article/3d-printing-10-factors-still-holding-it-back/
> 
> Caveats http://gizmodo.com/why-3d-printing-is-overhyped-i-should-know-i-do-it-fo-508176750
> 
> An extensive link in all aspects http://www.3ders.org/3d-printing-basics.html
> 
> I read all three of these from beginning to end and now I've cooled off on 3D printing. The last link article says at least six months of learning curve, another article says three years to get really good...aside from learning the CAD program needed as well.


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## calinb

>Possibly for super strength, use the 3D printer to make "scales" to laminate with epoxy and rivets if you wanna get fancy,

>over a core of micarta/G10, metal, wood etc. to make >a glue together slingshot with little other work than making the core. Would this be

>handy for making custom colors glued to core de jour?

>Does the 3D printed nylon "stick" to stuff such as a core so that glue wouldn't be needed? Since nylon has a considerable shrink factor

>if it stuck to nylon hot, then cooled, would it self delaminate and pop off? These questions can't be answered likely now but food for

>experimentation perhaps.

Bonding, rivets or hardware is the only practical way to attach them. It would be very tricky, for a number of reasons, to print onto them.

>Would the printer make a precise enough scale to not have to sand/work it to fit the metal or G10 core?

I think I could make one precise enough!

What would be the advantage to 3D printing scales when band sawing them would be much faster? So is this idea of mine about making scales on a printer, a moot point?

A laser cutter and CNC tools might be a better approach for this, just like a small hobby mill that fits on one's kitchen table works better than a 3D printer for making AR15 lowers and many other gun parts!


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## calinb

Thanks, Bill!

Yes--please let me know what you think we might be able to do together and you can always PM me for my phone number too. I'm printing a Boy Scout with stiffeners printed into it now. I'll send a couple of them to you to check out, once I'm happy with my latest improvements.

I want to try printing them in my newfangled high-strength PolyMax PLA and polycarbonate eventually too. These "boutique" 3D printing materials are less flexible than nylon but similar in strength (or significantly stronger in the case of polycarbonate's impact strength). I need to upgrade my 3D printer to handle about 300 C nozzle temps for the polycarbonate. 275C is about the limit for my current setup. However, the PolyMax reportedly prints easily at typical 3D printer-supported temps and, like regular PLA, should not have the weaker "grain" direction (z-layers) of some 3D printing materials.



Bill Hays said:


> Okay... that's pretty close to the coolest thing ever...
> 
> We'll definitely get something going.
> 
> For a long time I've been trying to do my small part to get and keep true artisans and real shooters interested and involved in slingshots... it's quite obvious we have another one in our midst!


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## Tremoside

calinb said:


> The problem with my Boy Scout slingshot project is it actually takes longer to make the CAD model than to simply make one slingshot by hand from wood or PET, HDPE, G10, or whatever. But that's just for ONE! The benefit of 3D printing and CAD is, once you have a good design and model, you can make subsequent copies quickly, easily and economically.


Hi Calinb,

Excuse me for editing your post, one particular thing made my attention so just wanted to keep a focus on that.

Congratulations on your effort. You're really into this! Cool.

What you just said is totally true. My average build time for a natural (a detailed carving) is about 25-35 hrs. For a bit detailed CAD build it rises around 50 hrs. When it's actually a designed frame and have to make multiple prints and modifications with a great complexity it rises up to months of work. That's usually 5-10 iterations.

Love nylon as a printing material. I'm using SLS, so no crosshatch fill for me. Using internal ribs instead and usually making interior tunnels to remove supportive material particles.

Ease of replication is really depending on the complexity of the design. Like resolution in printing and standing orientation for avoiding stepping made by low res printers. This ussually makes a lot of headache for me.

http://slingshotforum.com/topic/39628-vesa-for-leon/#entry487646

http://slingshotforum.com/topic/32952-the-wrench/#entry437276

Thank you very much for the detailed descriptions and your knowledge sharing attitude!

Have a nice day,

Mark


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## calinb

Tremoside said:


> Thank you very much for the detailed descriptions and your knowledge sharing attitude!
> 
> Have a nice day,
> 
> Mark


Thanks for sharing links to your 3D printing projects here, Mark. Wow--I can identify a lot of labor in your labors of love. Your detailed design work and talent are amazing!

I may end up placing tunnels into my printed slingshots too. It's just so easy and inexpensive to press-in metal stiffeners after they are printed. I want to see what I can do with just the printed internal structures first though.

You have a nice day too, and thanks again for sharing and posting.

-Cal


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## Tag

Love the color


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