shooting fixture

[Selfbowman]

Wille I have about 20 sets of real clean drops from roughing out my long bows. So if you need to build some three piece take downs let me know. That’s my plan for them . Probably 26-29” long. Arvin

[willie]

Arvin

not sure what you are calling drops. Limbs without handles? limb length staves?

It was my plan at one time to build  risers for limbs that were pretested in the fixture. Of course, the handle needs not to be anything other than functional. and the mounting of the limbs could be permanent, semi-permanent or even be interchangeable if one desired.  A  good performing set of limbs might deserve a dedicated riser, and could be permanently glued and/or pegged and/or lashed. primitive qualification seems possible.......

I actually have no plans at present,  but please PM if you have ideas 

[Badger]

 Willie you can buy a mechanical release designed for the thumb which is a push instead of pull, a little easier to adapt to shooting machine

[willie]

I got an old trigger style one modded just like that, reversed the trigger. and just need to get away to the shop more often to work on this project. at the shop which is 70 miles from home, I can open the garage door and shoot 500 yards from inside the shop

[avcase]

Another option is to use a rotary latch. These are inexpensive, extremely durable, and usually very easy to adapt to be triggered by an adjustable finger.  I have used one for years on bows up to 300 pound draw weight.

Alan

[Badger]

Alan would it resemble a door latch on a truck?

[willie]

Another option is to use a rotary latch. These are inexpensive, extremely durable, and usually very easy to adapt to be triggered by an adjustable finger.  I have used one for years on bows up to 300 pound draw weight.

Alan

the rotary latch idea seems like something to look into if possible, was hoping alan might come back with some more details or a pic for badger......

[Badger]

  Allen works for Freightliner as an engineer, I used to be a freighrliner mechanic so I know the latches very well.

[avcase]

This shows they type of rotary latch I would use for a shooting machine. I mount it to a plate that slides on a piece of aluminum T-track. I hook the string on the little notch that I cut into the latch claw, and draw it back until the trigger lever contacts a finger on the shooting machine. I attach the trigger finger to the same piece of t-track so I can slide it to the desired draw length. As soon as the latch lever makes contact, it lets go. It is very repeatable and even a light duty latch like this will last for many thousands of shot cycles.

Alan

[willie]

thanks for the print, Alan

sliding in a track will work better than what I have going now

[avcase]

I think a couple more pictures would help. If you really want to get fancy, you can pick up a piece of “8020” T-track extrusion, and get one of the 8020 linear slide bearings to attach the rotary latch release to. 8020 is like the ultimate lego set for big kids. We use it all the tine at my work to quickly construct all kinds of test fixtures. I use it for the shooting fixture for my bows when I test arrow performance at the Alvord dry lake bed every summer.

You can probably come up with modifications to the latch to simulate a finger release also, if that is important.  I imagine you could fasten or weld a more blunt “hook” that would give more of a sideways deflection of the string upon release.

Alan

[willie]

alan.

like this  for the square 4 slot tube? 

Code: [Select]

https://www.amazon.com/80-20-Double-Flange-Bearing/dp/B006YVZ31K/ref=pd_day0_hl_328_2/147-7805217-4947045?_encoding=UTF8&pd_rd_i=B006YVZ31K&pd_rd_r=0bf6bbf4-2474-4e22-9a8d-a30431a83b24&pd_rd_w=gcVct&pd_rd_wg=YG7BQ&pf_rd_p=531c5da2-92c8-47a3-8df6-cb5fa8f00603&pf_rd_r=HZMHNHVX4YN0G0X1KV7G&psc=1&refRID=HZMHNHVX4YN0G0X1KV7G
that 80/20 kit looks like the way to go, but so far I have just been using scraps of plywood and unistrut, you got me thinking though. right now the snow is deeper than the arrows are long, so Its a good time to work out some designs on the sketch pad.

[avcase]

Those are not cheap, but they are sure nice and smooth and used for very precise and durable sliding fixtures. I made my own t-slot slide by milling out a piece of HDPE plastic using my table saw, and it works pretty well for my needs.  Will get a picture uploaded.

Alan

[Tuomo]

Thanks Alan for the information! Rotary clutch seems to be nice idea and especially the 8020-system. I think that I will make a new shooting fixture. It would be nice to see your shooting fixture, because I think  it is quite well design.

[avcase]

I love the 8020 system. I made my endless loop string jig, bow weighing fixture (for our flight shoot events, and many other things out of this. My regular shooting machine is all in pieces right now, but I will need to get it operational in the next couple of months in order to test some new Flight bow designs before I send them out to the archers who will be using them.  I rarely re-assemble the shooting machine the same way twice. I configure it on the fly depending on the types of bows I’m testing, and the types of tests I am performing.  For example, it will be configured a little different for test shots in the field where I am more co corned about measuring arrow performance, Vs. tests in the workshop where I am chronograph testing the bow.

Alan