PSA: This is not an anvil

[Jason Fry]

I'm not a rookie, but I made a rookie mistake I'll share with you folks as a public service announcement.  I responded to an ad on FB marketplace for an anvil.  Pics were clear-ish, but dimensions were not.  Seller made no claims of weight.  I made a deal to meet the guy halfway, 80 miles from my house.  Ended up he was running so late that I went all the way to his place.  Instead of meeting at 8 pm as agreed, I ended up at his house by 10:30 and back home by midnight.  We loaded it in the dark.  All along I'm thinking some kind of sawyer's anvil.  He had repeatedly not provided dimensions, and I knew it was smaller than I'd hoped, but still a useful size.  I looked it over with my phone light and paid the man. 

So what I ended up with was this:  A cool looking cast iron 75 lb. tractor weight.  It has about 40% rebound, and I'll use it, but it sure as heck ISNT an anvil. I'll keep it around and maybe take it to demos or something, or use it as a cutting plate, or IDK yet. 

[Latticino]

Well, I guess we can all get burned.  I certainly have in the past, just not on anvils yet...

Looks like it could be a nice anvil stand if it was the right height for you.

[Jason Fry]

It's only about 12 by 12 by 4.  Not going to be useful for much, although I'm going to keep it around.  Didn't overpay for an anvil, but did overpay for an ASO, so no real chance to pass it on and recover my investment.

[ThomasPowers]

Use it as one of the counterweights for your trebuchet!

[Jason Fry]

Heck yeah

[ThomasPowers]

If life gives you lemons---commit mayhem with them!

[Jason Fry]

Dang it, Thomas, now I have another rabbit trail I didn't need.  Saw a guy who rigged a trebuchet with the pivot only about 1 meter high to throw a tennis ball at 100 mph with only 15 kg of weight.  Now I'm thinking about how much velocity you could get out of a 75 lb weight throwing concrete dixie cups

[ThomasPowers]

Concrete Dixie Cups == Hard Liquor????

[Frosty]

Just remember the weight CAN only fall so fast so a heavier counter weight doesn't make a faster throw. Provided the trebouchet isn't near it's max throw weight of course. 

I always thought I'd try altering the counter to fling arm ratio while adding weight.  Instead of 1:3, 1:4 with an undiminished fall time should provide 33% more velocity. Of course that's just my thinking, not calculated or based on knowledge.

Frosty The Lucky.

[Jason Fry]

Excellent resource and time waster

http://www.virtualtrebuchet.com/

[ThomasPowers]

You can add a spring to add a bit more umph at the start---like some of the tilt hammers did with a flexible board pushing down on the helve as it reached max height.  As far as smithing goes the "trigger" mechanism is probably the most notable part and may require a lot of tweaking to get it just right to hold under a lot of force but give way under a reasonable amount.  Sir Ralph  Payne-Gallwey; once curator of ancient weapons in the British Museum once built a catapult and information on it is found as an appendix to his work on the Crossbow.

[Jason Fry]

Spring loaded blacksmithy trebuchet.  Now we're getting somewhere.

[JHCC]

Using springs as the motive force for a trebuchet is simply a modern update of the original traction trebuchet. I believe there's an entire division of the Pumpkin Chunkin competition devoted to such machines.

[ThomasPowers]

Are you familiar with stone bows?  A type of crossbow designed to fling rocks; once used for hunting birds...  Also crossbows could get quite large when mounted on castle walls, the Metropolitan Museum of Art in NYC has one with a 1100 pound draw weight.  Using the cranequin to span it only takes 15# however but a LOT of turns cranking it.   (Steel bow and steel, blacksmith made gears in the cranequin.)

John; not as the only motive force; but  as a booster to get it from full stop to moving allowing the gravity weights to not waste time/energy going from static friction to rolling friction.

As for springalds, onagers, mangonels, ballistas they all have pluses and minuses; some being more easily used from atop a castle wall than others.  But the Trebuchet was generally the easiest and safest to build, gravity being a fairly easy force to deal with rather than various types of spring tension.

[JHCC]

1 hour ago, ThomasPowers said:

not as the only motive force

Here are a couple that are springs-only:

(Photos from this site.)