# Modifying my starship



## ARB (Dec 31, 2009)

After watching one of Joerg's videos on making a steel slingshot without welding equipment, I expanded on his idea to make a wrist braced starship with a 2 foot fork extension







It uses eye bolts for the forks and the "Chinese" attachment method. The rubber is currently doubled blue Thera tubing. See attached pic of the forks. However the performance is not very good, it is not much more powerful and and obviously more awkward than my commercial slingshots fitted with silver and black Thera tubing

It is very easy to unbolt the eye bolts and replace them with some other sort of bolt, see the 2nd attached pic. I could slip tubes onto these, the attachment method would then be the same as that used by many commercial slingshots.

What I would really like to do is use the "Clamp on" method for flatbands and tubes by bolting some L shaped pieces of flat steel to the existing fork base.

Has anybody got any comments or otehr ideas? Perhaps this gives people ideas for their own custom slingshots


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## JoergS (Dec 17, 2009)

I recommend using different rubber, thin flatband (Thera Band black or blue). A forward extension with tubes would only show effects if you use really heavy bullets, as the tubes are slow and hit their max speed very early (about 60 m/s, 196 fps).

Also keep in mind that forward extended forks need longer rubber bands. In order to get more power, you should still draw out to the same anchor point as always. That simply requires longer bands.

Regards

Jörg


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## ARB (Dec 31, 2009)

OK, i have modified it to use a clamp on attachment method. Instead of a baseplate + eye bolts for the forks, it now has a U shaped piece of plate steel, the rubber is clamped onto it using two short pieces of plate steel + 4 bolts. The fork is a bit wider than it was before. I think the 2 foot fork extension was a bit much, have swapped the extension bar for a 13 inch version that I made at the same time . The only flat rubber I have at the moment is Gold Theraband. Seems to shoot well and accurately. I think the clamp on method may be an excellent one. It could also be used for tubes.

No pics as my camera battery died. The forks are like cruder and heavier versions of the forks on Jack Koehler's Sling Cat.

Sling Cat pic
http://www.melchiorm...jackkoehler.jpg


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## NightKnight (Dec 16, 2009)

Sounds cool! I cannot wait to see pics!


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## ARB (Dec 31, 2009)

Took some pics with my mobile phone. pics are not good quality and the slingshot is not finished yet but the main structure is clear to see. The forks may be a little too high but I can rectify that by mounting them under the extension bar rather than on top of it.

The other work that needs to be done
-I set the bands too short and tied them at the pouch using zip ties which is not a satisfactory pouch attachment method for flatbands. 
-The grip needs Fimo or Epoxy putty to make it ergonomic.
-Unused parts of bolts need to be cut off
-Rough and sharp edges need to be filed down
-It could do with some padding in the wrist brace


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## NightKnight (Dec 16, 2009)

Nice job man!


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## fish (Dec 24, 2009)

how much does it weigh?


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## ARB (Dec 31, 2009)

fish said:


> how much does it weigh?


Not sure, but it is pretty heavy. The heaviest part of it is the steel (6 mm plate) for the wrist brace. It would probably be tiring to hold for hundreds of shots but the weight also makes it feel stable.


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## ARB (Dec 31, 2009)

Tried the slingshot with silver Thera tubing, it is very nice to shoot. I love the clamp on method and the wide fork - even if the fork width reduces power somewhat. No chrony tests yet.


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