Mesquite fork

John from Texas gave me this natural fork. It was very rustic, and obviously the grubs had been at it for some time. Seems like it was dead for at least a year, bone dry for sure.

First, I removed the bark. The grub canals came to dailight quickly.

I then decided upon the shape. I wanted to retain the forward canted angle of the fork, and at the same time I needed enough solid wood to make this a functional, strong slingshot. Took me while.

Then I cut the front and back. The typical hammer handle shape emerged for the first time. You can also see that the grub holes aren't that bad.

I closed the grub canals with a mix of the wood's own sawdust and tow component epoxy glue.

Then, I filed everything flush and started the sandpaper work. Here you can see it at the 80 grit stage.

This is the final slingshot, all polished and oiled (raw linseed oil)!

Some more pics of the beautiful frame:

One more caricature

Fellow forum member Raul from Brazil drew this for me...

Love it!

Be a TV star!

Next week Friday (June 7th), a German film team will visit me in my home at Burgkunstadt/Oberfranken.

They'd love to see and film some other slingshot fanatics, and therefore I cordially invite people to come over then. Filming will be in the afternoon, we'll do some slingshot shooting during and after that. BBQ in the evening!

Let me know if you want to join us.

jsprave@macrosystem.de

Lawrence Ross and Waterhead Show

I had a great (recorded) chat with the three guys from the LRWS. Enjoyed it a lot!

The podcast is here:

Find it on the LRWS homepage

Rubber science: Slingshot fridge

As shown earlier, rubber stores energy thermally. If you stretch a rubber band, it gets warm. If you relax it again, it gets cold.

This video uses a specifically designed contraption that uses this effect to cool a can of beer with nothing more than muscle power and rubber. In fact this may be the first rubber based artificial cooling device ever. Wikipedia is by now in need of an update!

The video clearly shows how an (empty) beer can is cooled down by 2 degrees centigrade in an instant. This is the proof of concept - the rest is design optimzation.

Of course the contraption doubles as a mini trebuchet - after all, this IS The Slingshot Channel :)

Greetings from sunny Gran Canaria!

No new video today, The Slingshot Channel is on vacation for  a week!

RUB-15: First "Upper Slingshot Receiver" finished

Even though I am not happy with the looks, the thing works too good to be thrown away... so I painted it black and attached a scope mount. I used a cheapo red dot.

I think I will make several other uppers, now that I know how this works.

Toilet brush machine gun: Getting closer

Worked some more on the weapon today. Added a nice front handle, Moorhammer style. Banded all four forks up.

I quickly encountered a huge problem: Return to senders and misfirings!

Those returners are dangerous. I mean seriously dangerous. One hit the door right next to my head... two inches to the right and I'd be in trouble now.

I don't really know what is going on - what I found out is that it works as long as you turn really slow. The fast spinning action of the battery drill is probably too much, destabilizes the "bolts" in flight.

I attached thin rubber bands to at least avoid the return to senders - this works fine. But there is still the issue of the tumbling bolts. About half of them do that. It must have something to do with the rotation - no problems at all if I turn by hand and push the bands up one at a time.

If all else fails, I will convert this baby to manual repeating action.

But it does look cool!

Toilet Brush Full Auto: First pics

I am working on the full auto version of the toilet brush shooter.

I want the same performance (excellent!), but I want four of these deadly cleaning items sent downrange in under one second.

This is basically a supersized version of my pistol dart shooter, just with only four rounds instead of eight (due to size restraints). I also had to employ a battery drill instead of a power screwdriver, the heavy parts need more momentum.

I first tried a more compact "fork wheel", but a misfiring occured and the toilet brush blew the 18mm plywood away. So I made a much larger wheel and had to adapt the frame accordingly.

I only attached one band set so far, more tests tomorrow. 

 

Google I/O showcase

Google will have their annual big event, called Google I/O, in a few days (15th to 17th of May), in San Francisco.

Read about it on wikipedia

YouTube will have a booth there and they want to play selected content from their partners.

Believe it or not, they want to play one of my videos too!

I am much honored and gave them full permission, of course.

Weaponizing toilet brushes

My wife gave me this as a surpise:

Funny! I really have to admit I spend too much time on the John, usually reading in the undisturbed solitude a man can often only enjoy while sitting on the bowl.

The gift made me thinking. Can I turn a toilet brush into a deadly projectile?

Well... yes, I can.

Video:

Ram-bone from Texas persimmon natural

Seems that whenever I come up with a new design, I always have to make a natural before my mind can refocus. The Ram-bone is at a stage where a natural was inevitable. 

I still had one fork left from the four Texas parsimmon shipment John sent me a few months ago. It was cracked and also one of the branches was dead, rotten dark. So I was a bit afraid if it was possible to salvage it.

I had to carefully choose the cuts in order to not run into the deep crack that ran all the way through the dead branch and trunk.

I wanted to integrate a part of the dead wood simply because of the color. This forced me to make the handle a little fatter, but less deep. You have to do that when working on naturals - making the best out of the shape nature provided.

It came out real nice!

New design for a plastic mould

A friend of mine wants to start selling slingshots and asked me if I could provide a design. Sure!

This one is a mix between the Moorhammer (handle) and the Hand Mortar (for Cold Steel), The fork is wider than the Hand Mortar's, and also the fork arms a thicker. The handle is pure Moorhammer, but sports a lanyard hole. The idea is that the user can saw the hole part off if desired. Also the slot for the looped bands should not be sawed through as it is a bit of a problem for flat bands - you have to attach those fairly low so they don't slip into the slot.

This is a great slingshot! The fork is 15mm higher than the Moorhammer's, more safe for beginners but still fairly low, The handle is very very comfortable.

RUB-15 - first shooting setup

Have been working on it some more. Made an encapsulated front part, for silencing and rubber protection purposes.

I still have to attach brushes to the front and back holes, but it already is very quiet. I also might include a band heating system.

Equipped with 3,1cm x 3,1cm bands (four strips per side), it shoots the 40 gramm aluminum arrow with mighty force. The field tips penetrate about 3cm into massive oak panels. The field tip is pushed down the shaft in the process.

As happy as I am with the functionality, as unhappy am I about the looks. Boxy, clumsy, foolish. Back to the drawig board.

Zombie Go Boom Cooperation

I have been a follower of the Zombie Go Boom guys for a long time. Gotta love Zombie destruction tests!

Their heads have been getting better and better - the current iteration is really getting there.

Gorgeous, won't rot, simulate flesh, skin, blood, and bone - just amazing!

They sent me two of these and I tested the first one. Commercial slingshot didn't do much damage (if any). Homemade one, lots better.

RUB15 homemade crossbow upper receiver for M16 / AR-15

Here are the first pictures of the build...

Will do a pure arrow shooter first, just to learn what works and what doesn't.

Removed the upper receiver and also the trigger/hammer assembly. Then I made a base plate from 18mm multiplex. Added a trigger and my usual lock, used a nail that I can bend into shape.

The lock works like a charm!

I will use two 16mm steel tubes as "barrel" and "rail" parts. The draw is 100% inline with the rails. I plan to make a cocking slide for fast action. This crossbow will be quick.

No changes to the original M16A1.

Upcoming coverage on German TV

The German TV network "MDR" will cover me in their format "Außenseiter Spitzenreiter", on May 1st (9:15 PM GMT+1).

See the details on the MDR homepage

The episode will be available online for a while, will post the link as soon as it becomes available. German language of course. 

Popular Mechanics Article

Read the article at the popular mechanics website

Back to the roots

Mini Magazine Shooter

The spring has come. Once again we can spend some time outdoors!

Of course one must ALWAYS have a slingshot around. But on a Sunday morning walk with the family, a bulky Moorhammer isn't appropriate. So I always carry a mini slingshot.

Ammo is another concern. I actually loved LW's magazine idea

See his original model

so much that I decided to make another mini, with that mag design included.

5 rounds of 8mm steel! Held in place by a 3mm neodyme. Orange Osage on 9mm multiplex, finished in Linseed.

I put on very short bands, just 10cm active length. Kept the bands a bit wider so the 8mm still have decent power.

Bar Fight Dominator - The Video

The Bar Fight Dominator

Had two days off, made the ashtray shooter.

It is chambered for the 75x30mm Ashtrays. Those weigh 245 gramms (0.56 lb) each. The weapon holds four of them in the clip, 1 more in the chamber.

A pump action shooter that you put against your chest and the draw back with both arms. Thanks to the specifically designed mechanism that isn't very hard.

The ashtrays land with a mighty force! Video coming up Sunday.


Enlarge this image Click to see fullsize


The thing also has a mounting for broken off beer bottles, as bayonets.


Enlarge this image Click to see fullsize


The magazine is gravity fed. This weapon is surprisingly accurate!


Enlarge this image Click to see fullsize

Word from the Gates Foundation

I had messaged the Bill Gates foundation and told them that my "condom gun" isn't a serious competitor, just a piece of comedy, and they got back to me today.


Here is an excerpt from their mail:

....We wanted to let you know that your video has drawn the 2nd most amount of traffic to our site since March 22, second only to the Gates Foundation website.... By creating a fun video, you were able to draw so many viewers to this topic, and we hope that one of these applicants could have a solution that could really help save lives. Thank you for sharing this opportunity with the world and for bringing people’s attention to this important topic.

If you wouldn’t mind sending us your mailing address, our team would like to send something as a token of our appreciation.

Wow! I feel like a hero now.

Reddit IAMA on the 10th

Reddit is a huge bulletin board style website, immensely popular. It is also called the "frontpage of the internet".

The members create posts about interesting things they find on the web, and other members can up- and downvote the post. If a post makes the front page, it is very popular - and will be even more popular soon, thanks to the participating members.

Some of my videos have been featured on reddit, and the last one (condom gun) even made the top of the front page. Yay!

Reddit also has a way to interview people online. They call it "IAMA". One of their users posted a request for me to be interviewed:

See the request over at Reddit

Of course I will gladly be available for questions.

So on Wednesday, April 10th, I will be answering questions live from 8 PM GMT+1 (EST+6). So that would be 2 PM NYC time.

Looking forward to that!

UPDATE: The AMA is over, it was lots of fun. I typed three hours non stop. We even made the reddit front page!

Here is the entire discussion:

See the Jörg Sprave AMA on reddit

Bill Gates Calls, I shall answer!

The Bill and Melinda Gates Foundation offers 100,000 USD for projects that improve things around condoms.

Read about it on the Foundation Website

"Application of knowledge from other fields" is explicitly called for. Bill looks for "attributes that increase ease-of-use" and designs that make it "easier to properly apply" a preservative.

Of course I HAD to come forth and help the visionary billionaire on his lofty quest. Therefore, this video brings to you the world's first condom applicator slingshot gun!

See for yourself.

Please keep in mind this is comedy and NOT a serious project. :)

Ammo for the next project.

:)

At last. A pump gun slingshot tutorial.

So many people wanted blueprints and tuts for my pump actions.

But of course the Oreo one is useless, and the cardboard one is flimsy and weak.

So I decided to make a really nice one that shoots M10 hexnuts. Those are very cheap (I buy 100 pcs for five Euros), last forever, and have the right weight. About 10 gramms is ideal for a pump gun, as draw length and weight is limited if you want to be able to fire quickly. I made one a long time ago for 20mm steel balls, but those are too heavy, three time as much as the M10 hexnuts.

Also the weapon is pretty thin, just under 30 mm wide and 80 cm long.

The magazine fits 40 rounds!

The mechanism is really the same as for the Oreo shooter - but I put in a rare earth magnet to hold the "active" nut in place. Nice, you hear a clicking noise when you repeat, and then you know everything's fine.

I have a set of blueprints and also a private how to video online:
See the related post on my forum