faw or rolling axle whipper

[woodchucker1]

Looking for thoughts/ideas for the axle setup. Would it be better with just 2 rollers or with a 4 roller carriage assembly?
Thanks for any replies!

[madmattd]

All of ours have always used 4 wheels (2/carriage) to ensure straight travel on the tracks. That said, I know JohnN has made at least one, and probably more, rolling axle machines using a single wheel on each end of the axle and has good success with it. This has the benefit of keeping the moving axle components far lighter, which leaves more counterweight energy around for the actual projectile. But if anything were to jam, I could see that ending poorly. So really, it depends on the machine size I guess. Smaller machines, I would say go for the single wheel solution. Large machines, where a misfire likely means massive destruction of the machine, I would err on the side of caution and put 2 wheels per side on.

My 2cents.

[woodchucker1]

Thanks for the reply Matt. I am building a small FAW based on JohnN's design. 5' track. 4" wheels 15" on center 12 spacing between the tracks. I have it set up now with just the 2 wheels, using a 5/8" axle and CW hanger attachment point {pivot}.
LA 32" SA 6.5". Build almost complete. Guess I'll just have to Test and Tweak when done. Your 2 cents worth much more. Thanks!

[TommyL]

I actually have War Twig (his 5' FAKA) in my back yard and it's the biggest one I have seen that still only uses one wheel per side.

I would say the dual wheels per side has more advantages that disadvantages.

With only one wheel per side, your wheel has to use the same axle size as the axle your TA hinges on unless you are up for some machining.
Since I want a beefy TA axle, you need to find the right wheels that use a large axle. With a carriage, you have a lot more options / combinations for wheel axles and TA axles.

That's just my 2 cents though,
Tommy

War Twig.jpg (202.15 KiB) Viewed 21043 times

smallcarriage.JPG (242.03 KiB) Viewed 21042 times

[woodchucker1]

Thanks for the the great info Tommy! The War Twig is a great Machine. Right now I went with the 2 wheel carriage. Was able to take a couple shots looked ok . Still need to iron out some issues before total completion. One being the best attachment for the trigger/arm holder line. Any info/ideas would be appreciated. I'll get a picture posted asap. Your expertise is worth more than 2 cents also!

[TommyL]

I'll be glad to help, I'm just not sure what you mean by the trigger / arm holder line.

[woodchucker1]

Hi Tommy Thanks. I mean the cocked position holding to release cable/line device? I know that this should be to the front of the base. Looking for ideas for the best way to set this up.

[TommyL]

I'm still a little unsure of what you mean. I have the primary trigger which I pull to start the CW falling forward. When the CW arm is about 90 degrees to the throwing arm, I have a secondary trigger which allows the throwing arm to be released and then it can spin around pulling the sling behind it. Another important feature is what I call the roll bar which keeps the whole mechanism from rolling forward before I pull the primary trigger. I'll be glad to help in any way, maybe a picture could clear things up?

[Thomas]

Woodchucker, are you using two triggers or a tipover system like Medieval Postal Service? The latter is pretty esoteric, mostly understood by Matt. There's lots of info on the two-trigger system. (Your explanation of what you mean is unclear to me, too.)

[woodchucker1]

This is the machine I have been working on.