Semi auto rubber band gun

No, I will have a look when I get a few minutes. Thanks!

well I made a working prototype.

I did a few modifications here and there over 2 iterations to improve overall tolerances, also converted it to metric dowel sizes. It now slides very smoothly and doesnā€™t lock up. This is important bc on the last rubberband the pulling force of that last one must be greater than the friction resistance, which - for me - was an issue with the original files.

Looks like it works pretty good already. I have some finetuning ideas but I suspect the next version will be perfect.

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iā€™ll do that when Iā€™m 100% happy.

I may try to lasercut one instead of milling.

Iā€™m going to test the new iteration tomorrow, and if successful Iā€™ll post the svg.
but hereā€™s a quickie:

  • converted to 6.2mm holes to fit 6mm dowels. This fit is pretty snug, and yet doesnā€™t need to be hammered in.
  • the ā€˜slideā€™ holes are 6.5mm in height for maximum slideability, and minimum resistance or play.
  • I moved the holes on the trigger/slider assembly for improved leverage, but this is probably overkill. But I like the look better than the 2 holes on top of each other.
  • I trimmed the bottom of the trigger by a mm or so
  • I got rid of the hard edges on the middle piece
  • deepened the backside grooves a tad on the slider pieces
  • and i always sand the trigger surface a little bit, so thereā€™s no friction inside.

think thatā€™s about it

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Did one modification today.

The bottom rubberband kept popping up before its turn. This is also seen in my video. After the first shot the 5th and 6th rubberband are in the same slot for the rest of the sequence.

So I reworked the grooves on the back of the slide. Thereā€™s about a 6.5Ā° angle between the top and bottom rubberband, so i adjusted the angle of those grooves accordingly. This should do it.

Iā€™m also interested to see whether I can cut the shapes on my laser cutterā€¦ Maybe tomorrow

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OK, the last version turned out being perfect in every way.

Hereā€™s my svg for anyone that is interested. To be milled with a 1/8" or 3mm bit.
http://manmademayhem.com/6mm%20flat%20parts.svg
A video is on the way laying out the whole process.

I use 6mm dowels, so US people will have to change the hole sizes to match their dowel diameter. For 6mm dowels, the tolerances are press-fit, but a bit of glue is never a bad thing.
Note that I 3D-carve the grips, but the outlines are included in the svg.

Be sure to cut along grain, for less friction on the slide. Also shave off a hair of he triggerā€™s total thickness.

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When I open up your SVG the dowel holes are 4.96mm - I had to resize the whole drawing by 25% to get 6.2mm. This brings the main body of the gun to about 240 x 138. Is that right?

strange, When I open it (in illustrator), it is correctā€¦

Your dimensions are correct, 240,23mm by 138,13mm

should come out perfectly.

just make friends with someone here that owns guns and visitsā€¦dont need anything special to go to the shooting rangeā€¦except in the state of illinois. they suck

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Thatā€™d be quite the drive

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I thought I was being clever with a project I was working on. This is a model from rbguns modified for easel with some extra pieces added that can have details carved in.

Edit : this is a work in progress might need some fine tuning before you carve.

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Iā€™d love to make the trip one day to shoot some guns

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Iā€™d like to join that party! but the 9 hour, one way would kinda suck!

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when you cut this is it set to on path, outside or inside

The svg for the main body is one peice dowel holes and outline are one so if you set the body to outline the dowel holes go to outline as well.I just wasnā€™t sure if he had it set up for everything being correct when it is set to on path. I can use exploder or take it to another prog and modify it. I was just wondering if he has it setup to go.

not sure I understand the question.

But as Phil says, profiles are set to outside. Just select everything and choose a profile on the outside. A nested shape (ie dowel holes) will in most CAM packages be recognized and be automatically cut on the inside. A bit counterintuitive, but extremely helpful.

and to be cut with a 1/8 or smaller obviously

my version made from quarter saw oak pallet board and white oakthanks for posting this Iā€™ll be making a few more for Christmas time .

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I used the svg from @anon68752607 I didnā€™t even change the hole size from metric I just sanded the 1/4" rod to a super tight fit I did have to file I guess what you would call the feed ramps to get it to feed correctly

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Can you tell me where you got the model? I would love to build these