American 7260 crawler crane

[kerst]

Originally Posted by 9W Monighan

That formula is interesting. 15 to the third power, can you explain?

Weight is related to volume.
Dimensions are in a certain scale, then areas are in this scale to the 2nd power and volume to the 3rd power.
Does this make sense?

Kerst

[9W Monighan]

Originally Posted by kerst

Weight is related to volume.
Dimensions are in a certain scale, then areas are in this scale to the 2nd power and volume to the 3rd power.
Does this make sense?

Kerst

Now I see. I never could visualize it that way. I did that formula with my machine and given the approximate weight it come close to the 1:1 machine.

Model: / 1:1 Machine:
aprox wt 250# 1,030,000#
bucket full 12# max load = 50,500#

[eef7260]

Thanks for explaining that one for me Kerst.
I was already thinking how am gone do that with my basic school English.

[eef7260]

Hello everybody

W900snowman : Why did i used steel for the boom ?
It's cheap and was available at my workshop also it was as close to reality as possible.
Also it can be copper welded and silver soldered and that is stronggggg.
OK it might be over-constructed looking at it afterwards but i am happy with it.
But using brass and using soft solder might be a good choice.
( i used brass with my jib because those sizes where easily available in brass , but i used silver solder )
There is is one major problem with copper welding or silver solder and that is the temperature.
This generates so much tension in the boom , but it can be done.
You have to give it a try and learn by trial and error.

Here are the pic's that Steve asked for these are the best i have got.
The pictures are from an P&H 5300 from a friend of mine Cees.
He also made an American 5299 both in 1:16 scale.
We spent a lot time together on shows.
Most amazing about these models is that are controlled by one single motor.
Everything is controlled with small levers on the crane and works with with clutches and brakes.
He build these models long time ago and these models where my inspiration to build my model.
After all those years he is done with hobby and moved on to other things in life so he selling them.
Don't now if it's allowed in this section ( if not moderator please remove the link )
but here is a link to his selling page with some more pic's.
http://members.home.nl/cjrotering/

Another good friend of mine is building a 5299 American in 1:10 scale can post some pics of that as well ??

next post : about the tracks.

Eef