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CaptainSlug

Member Since 17 Feb 2006
Offline Last Active Jul 25 2019 12:48 PM

#359504 High Cap Magazine Collective Brain-Spew

Posted by CaptainSlug on 27 April 2017 - 11:42 AM

I have no idea. But I suspect 22 darts is likely to be the ceiling of being reasonable in terms of mag dimensions and spring load.
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#359483 Caliburn: Mag-fed Pump-action Springer

Posted by CaptainSlug on 26 April 2017 - 02:27 PM

Image dump. No big issues with assembly so far. A few spots that I had to file down will be modified in the STLs before I make them available. I'll do final assembly and test the catch tomorrow.
rs3_39.jpg
rs3_40.jpg
rs3_41.jpg
rs3_42.jpg
rs3_43.jpg
rs3_44.jpg
rs3_45.jpg
rs3_46.jpg


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#359341 What was the first known homemade?

Posted by CaptainSlug on 20 April 2017 - 12:02 PM

All the early homemade discussion was at NerfHQ, not here. So all of that information is largely lost.

 

Zero made some of the first war-usable homemades, but everything at that time was typically air-powered and it was pretty rare that their use was allowed. The SNAP series is pretty much the genesis of allowing homemades at Nerf Wars.


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#359260 THIS one simple design will have you in TEARS...

Posted by CaptainSlug on 15 April 2017 - 09:40 AM

I have one designed but will do the initial prototype through machining.

 

AND I'm going to break my usual habits a bit and make it entirely out of PVC. So screws will be used sparingly and some of the assemblies will just get glued together.


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#359231 THIS one simple design will have you in TEARS...

Posted by CaptainSlug on 14 April 2017 - 09:31 AM

Double-post of mechanical sexiness.

sp_09.jpg

The trigger and magazine release share the same spring, and the same pivot point.

sp_10.jpg

This means that the trigger guard itself is the magazine release. To drop the mag you just push your trigger finger forward inside the trigger well.

This is exceptionally novel and the only thing I can think of that's similar is the ring trigger on early revolvers that were used to index the cylinder.


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#359152 Caliburn: Mag-fed Pump-action Springer

Posted by CaptainSlug on 10 April 2017 - 07:05 PM

No progress today. Didn't have time or opportunity at work to use the oven, which shares an outlet with a chiller that is tied to a vacuum weld chamber.

 

Do you think you could put a k14 in this?

No. You would have to make almost all of the blaster pats out of much higher grade materials. I'm not interested in entertaining springs that nobody can actually prime. Especially when this blaster already hits 210 fps.

 

Although, on a related note I did just find a casting epoxy that's 90% of the strength of polycarbonate when cured.


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#359056 Replacing broken/ripped O-Rings

Posted by CaptainSlug on 06 April 2017 - 08:27 AM

I wrote this out to answer this question elsewhere and thought it might be good to store it here.

 

IF you break/rip/tear and O-Ring and you need to find a replacement for it, here's how you can do so.

 

1. Use a ruler to measure the length of the broken o-ring piece inside of the curve.

2. Use that length with this calculator set to "Given C"  http://www.calculato...lane/circle.php

3. Write that number down as you now have the actual ID of the O-Ring (or close to it).

4. Measure the thickness of the O-Ring as best you can. This number will be close to either a fractional size, or a millimeter size. It's best if you can use a caliper to get this number, but a ruler with both inches and millimeters will do. Always make sure to round DOWN to the nearest fraction or millimeter since o-rings are oversized. For example a "3/16" cord width O-Ring is going to have a NOMINAL width of .210".

5. Write that number down.

6. Take both numbers and poke through the McMaster catalog in the o-ring section. You can find the nearest ACTUAL SIZE for Inner Diameter from their list as well as the ACTUAL (or fractional) cord width.

https://www.mcmaster...-rings/=172uud9

 

Just pick BUNA-N as your material for now. The majority of the o-rings used for Nerf are that material.

 

dash.jpg

Now you have the DASH NUMBER of the o-ring you need. You can order the o-ring you need from McMaster, Amazon, Fastenal, or buy it from a hardware store. If you want to buy the o-ring from Home Depot you may need this chart to convert from DASH NUMBER sizes to the Danco brand o-ring part numbers.

http://captainslug.c..._reference.xlsx

 

Other brands may have different part numbers so check your nearest hardware store's online catalog before going to see what brand of o-rings they sell. If they don't list the products in DASH number sizes just e-mail the manufacturer and ask them for a similar conversion chart.


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#359017 Caliburn: Mag-fed Pump-action Springer

Posted by CaptainSlug on 04 April 2017 - 10:32 AM

rs3_29.jpg

rs3_30.jpg

 

Also, another video.

 


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#358767 THIS one simple design will have you in TEARS...

Posted by CaptainSlug on 24 March 2017 - 04:05 PM

This is a pretty rough draft at the moment. I won't get any further on this for a while until I have time to try making a magazine. And given how many other things I SHOULD be working on, who knows when that will be.

I just wanted to see what the layout would have to be for a miniaturized mag-fed Piranha. And Chanclas was correct, it could totally work. There's just enough room to get 3-1/8 inch of plunger stroke out of a 1-1/4 SCH40 pipe.

sp_00.jpg

The cut in the front of the slide lets the cable feed through, but will pull on the eyelet of it to prime the plunger. I haven't decided on a return spring for the slide yet. One I have in mind might just barely fit over the barrel but may have to be stretched to get the right collapse length to extended length measurements. If I run out of room I'll probably just have to make the barrel a little bit further away from the plunger tube.

sp_01.jpg

sp_02.jpg

sp_03.jpg


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#358698 Caliburn: Mag-fed Pump-action Springer

Posted by CaptainSlug on 22 March 2017 - 03:10 PM

Raise your hand if you like RAILS.

rs3_22.jpg

Work apparently has some leftover Platinum molding silicone so I'm going to make a mold or two this week for some of the simpler parts I haven't had to revise.

 

I figured out how to make a 2-part mold for the mag well and that necessitated some changes that mushed up the styling so I had to reprofile it and the grip in a new pattern. So the lettering has been moved to the mag well.

 

The test print of the foregrip also lacked some vertical girth and was promoting weird hand-hold positions. So it gets a 5-point underside rail and a slight profile adjustment.

 

The grip has been split into 3-parts so that it will print much easier and subsequently be much MUCH easier to cast. The print orientation means that even a low infill percentage print of these parts should be more than strong enough.

rs3_23.jpg

 

It seems that the only part left to annoy me is the stock reducer. The cast part is going to have to be FAT if I want to make it from a one-sided mold and it really can't be avoided. So the printed version of that part will be slightly cooler looking as a result.

 

Time to order some supplies. Then I get to make 16 molds


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#358664 Caliburn: Mag-fed Pump-action Springer

Posted by CaptainSlug on 20 March 2017 - 07:02 PM

Use the STEP file until I can get the solidworks file set fixed.

 

002 and 003 made it safely to Singapore through an export agent.

 

Colorblind test prints check out.
rs3_19.jpg
rs3_20.jpg
"Charlotte" is a very homely yet sturdy thing

rs3_21.jpg


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#358328 1995 Crossbow CAD Files

Posted by CaptainSlug on 02 March 2017 - 11:23 AM

Full K26 version with stock extended by 1.500 inches. Also requires a separate nose piece to hold the end of the plunger tube which had to move 2.500 inches forward beyond the profile of the original shell.

c95_18.jpg

STEP 214: http://captainslug.c...Crossbow95b.zip(1.4mb)


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#358286 1995 Crossbow CAD Files

Posted by CaptainSlug on 28 February 2017 - 08:15 AM

Fusion360 and Sketchup can open/edit STEP or STL files. STEP is much preferred because it's a solid model format instead of a mesh format AND it supports exported assemblies. I can give you ONE STEP file that includes all of the parts in their correct assembled locations. STEP is also compatible with CAM software like MasterCAM. But most printers (and related software) take STL files exclusively.

 

The software I am using (Alibre Design 12) is quite old but functional and I really hate the new versions. 3D Systems bought them, changed their name, and turned the new versions into bloated garbage.

 

And it looks like I'm going with PurpleHeart since its natural oxidized color is perfect.


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#358278 Less-painful springs

Posted by CaptainSlug on 27 February 2017 - 10:15 PM

You can just use a much shorter barrel for indoor play. That way you still have the power needed to fire from a hopper, but the dart doesn't have enough time in the barrel it needs to reach a higher speed before leaving it.

 

Otherwise K25 springs are interchangeable with K26 springs and are rated 5ish pounds lower in total compression load.

 

The other option is to put multiple notches on the plunger rod so you can dial the priming stroke down a bit. I did that with the earliest revision of the plusbow when it was still based on the AR-15 buffer springs, which was even stiffer than a K26 and more difficult to prime quickly.

 

 

 

One option is to just use whatever spring you're currently using but reduce the length, which will make it less powerful if you compress it the same amount. You could also build your own air restrictor.

 

I don't recommend doing that because if the plunger tube is setup for a longer spring a much shorter one will rattle around in the dead space that results from cutting it short. If you don't file your cut ends down, the spring could put dents and gouges inside your plunger tube when it rattles around.


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#358222 1995 Crossbow CAD Files

Posted by CaptainSlug on 26 February 2017 - 09:29 AM

 

I could be wrong, but I believe the most common bed size is 200x200mm which is just under 8 inches squared.

c95_15.jpg

 

GRAH!


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