After he contacted me, I was going to make this as a gift for Pete, but it looks like he has his own similar, but very exciting plans so I'll move onto new projects. As a parting comment on this idea, having spoken to danny on this, I have come to the conclusion that it would probably be quite dangerous
as drawn if cast in thin aluminium. The 'open ears' design in Chinese slingshots depends on a thick section of laser cut stainless steel. This design is much weaker for these reasons:
- Aluminum is more likely to flex and fatigue than stainless
- Castings are weaker than cut billet
- The Milbro is thinner than Chinese ball-in-tube slingshots
- The ears as drawn show weaker a form than the Chinese design
- Any casting flaws or inconsistent finishing could be catastrophic. Pete has a high standard of work, but the potential is there
The main danger is the 'ears' opening up and releasing the tube end to slap the user in the eyes. A secondary danger is the arms may fail at the stress riser below the 'ears' flinging the tube, ball and ear back at the shooter.
If a similar design is implemented, then it should use 'closed ears' rather than 'open ears' which have a slot for more mechanical strength. The 'ears' should be more built up, possibly utilising a flange and the arms should be engineered to bend rather than fail at one point. The whole design must be extensively tested before marketing.
If you're having trouble with terminology of Chinese tubes with terms like 'ears', please refer to danny's thread on Mel's forum (Link
Great idea ZDP, I like your renderings.
You can do them on a milbro just like on a natural, only you need slightly thicker tubes than what I have, or slightly smaller holes or they tend to slip and need to be adjusted often,
Thanks. That looks like a good idea and closer to the original design. Another idea would be to simply engineer a hole suitable for a single Chinese Tube in a 'closed ears' configuiration, but both ideas still need testing before being promoted commercially.