[HELP] Lift Heavy Crane Boom

[Saberwing40k]

I'm building a very large mobile crane with a very heavy boom, and am in need of inspiration for how to lift it.

[Bzroom]

How does the real one lift it?

Probably a winch

[Bricktrain]

This is how I did mine, http://www.brickshelf.com/cgi-bin/gallery.cgi?i=3909612

hard to get the cylinder brackets cheaply now though, fortunately I have over 70 of them, though I could do with a few more

[Alasdair Ryan]

I would try to make a winch geared down along with some LA's.between the three of them you should be fine.

[Zerobricks]

You can use LA's or pneumatics. Pneumatics are more flexible and allow you to put at least 2 cylinders in serial and several in parallel position. If you are building a crawler crane, those usually mostly use winches.

[Bricktrain]

I guess you are talking a hydraulic boom rather than a lattice boom like the LG1550 at work, though the LG is also available with a hydraulic boom but still uses the luffing winch and derrick like the lattice boom.

[Tommy Styrvoky]

This may seem slightly off-topic but when my linear actuators are at their maximum extrnsion the rods on them are a bit wobbly.

[Milan]

If the boom is heavy, I would not suggest to use either pneumatics or LA. Build your own bricks-built linear actuator. They can take massive loads and looks realistic and cool.

[Saberwing40k]

If the boom is heavy, I would not suggest to use either pneumatics or LA. Build your own bricks-built linear actuator. They can take massive loads and looks realistic and cool.

I have already built large actuators,as described, and it is still not enough. Does anyone have good designs for massive actuators?

[Blakbird]

I have already built large actuators,as described, and it is still not enough. Does anyone have good designs for massive actuators?

You could use a Firgelli actuator like we did in the AC-50.

[Milan]

I have already built large actuators,as described, and it is still not enough. Does anyone have good designs for massive actuators?

I used this brick built actuators, with some friction, but practically indestructible, for massive excavator. They worked really good. Compact and slim. Dont have instructions though, but have some pictures on the brickshelf. They were used for the main boom of the excavator, also.

http://www.youtube.com/watch?v=kI-o7h7Uh9o

Edited May 20, 2014 by Milan

[Saberwing40k]

Yeah, I'm up against a boom that weighs 2.3 kg. How would I calculate mechanicl advantage, and power needed?

[Milan]

Can you post a picture of that actuator you built? Or the whole setup if you tried it?

[Bzroom]

How would I calculate mechanicl advantage, and power needed?

Class 3 lever

[Kumbbl]

I used this brick built actuators, with some friction, but practically indestructible, for massive excavator. They worked really good. Compact and slim. Dont have instructions though, but have some pictures on the brickshelf. They were used for the main boom of the excavator, also.

WOW!!! Great excavator boom section. Can't wait to see the whole machine...

[efferman]

i have a different solution which possble work

boom lift von efferman auf Flickr

the grey liftarm represents the boom actuator, the yellow liftarms the boom. the grey sled is connected with a rope to a winch. when the winch pulls the sled to the uppercarriage, the grey liftarm will push the boom upwards.

with a strong enough winch and rope there should be no limit on the size of the boom

Edited May 21, 2014 by efferman

[emilstorm]

boom lift von efferman auf Flickr

the grey liftarm represents the boom actuator, the yellow liftarms the boom. the grey sled is connected with a rope to a winch. when the winch pulls the sled to the uppercarriage, the grey liftarm will push the boom upwards.

with a strong enough winch and rope there should be no limit on the size of the boom

This one is quite brilliant! I had to read it and look at the picture a couple of times, I am dense, but that is a way of doing it i have never seen before.

[Jeroen Ottens]

Hi,

Here is a screenshot of my studyfile of the brick-build linear actuator for the Liebherr LTM11200 I built:

You can PM me if you want the LDD file.

Edited May 24, 2014 by Jeroen Ottens

[fasterthanlight]

I've used mouse trap springs before to create torque. It lessens the load of the actuators, but requires a very strong superstructure. If your boom weighs 2.3kg, you already have a very strong superstructure and frame.

[Saberwing40k]

What I'm wondering now is whether it is better with a brick built actuator to run the worm gear directly on the racks, or to run it through a geartrain first.

[anton1678]

A 6:1 gear ratio would probably work, it can pull large weights actually.

If it doesn't work, try a larger gear ratio, like 9:1

all you need is to position a motor at the base, then the gears, and then the boom.

Since that's not much support at the base, it could bend or slide off, make sure you connect it well.

It will move slowly, if it doesn't, it's the wrong gear ratio.

This is much simpler that an actuator, so i recommend using it if you don't have that many bricks, or don't have that much time.

Edited May 25, 2014 by anton1678