Telescopic Boom Designs

[SMP Design]

Hi All,

First post. I come across this site while doing some researching on telescopic boom designs. I'm a mechanical designer and I am currently designing a machine that has a 3 stage telescopic boom similar to a telehandler and also has an energy chain inside the boom sections to connect hydraulic hoses and low voltage wires to an attachment on the end.

I'm tyring to find information about the different types of boom drive systems. As far as I can tell there are three different types:

1. a single double acting cylinder with a rope and pulley system

2. a single double acting cylinder with a sprocket and chain system

3. 2 off double acting cylinders diametrically opposed to each other.

Basically I have ruled out option three because it takes up too much room inside the boom sections and doesn't allow enough room for the energy chain. I know that there is a school of thought from a maintenance perspective that the energy chains should be mounted externally for ease of access however the application is a very arduous environment and so much so that the energy chain is at high risk of impact damage.

For those interested the machine is a Liner Handler used to assist with the exchanging of worn liners inside a hard rock grinding mill.

Anyway my research has led me to believe that option 2 with the chain and pulley system is the preferred option of many manufacturers especially the telehandler machines. Having said that I am wondering where I could get my hands on some diagrams or manuals on how these systems are set-up. I've design numerous types of telescopic devices but never with a sprocket and chain drive system so any help, information or advice would gratefully be appreciated.

Cheers!
Anthony

 

[AndrewC]

JCB uses a fully hydraulic set up. I believe it is one cylinder (correct me if I'm wrong). 55ft reach. They claim they last longer pushing and they do seem to be better in an agricultural set up pushing in a silage pit.
JLG, carelift and genie all use the cylinder and a chain set up. They seem to work well in a material handling application but I have not heard or seen how they handle pushing ie. silage.

 

[SMP Design]

Hey guys another question. Does anybody know where design and engineering professionals involved in the design of construction equipment and cranes hang out on the internet. Are there like maybe some forums or something similar where you can hook up with designers, engineers or manufacturers of construction equipment and cranes?

 

[stondad]

G'day Mate,

Just noticed your thread and location.

Don't know if what I say will help or not but I'm a big believer in not re-inventing the wheel.
Aussie engineering is expected to be "cheap and cheerful".

Tele booms are very difficult and never perfect.
For a one or two off application, I suggest you look around existing machinery and just buy the boom as a spare part, or buy one second hand, thereby never having to go through the grief of discovering something that trashes your design, but someone else found out the hard way years ago.

Be careful of your load factor if you want to extend or retract near horizontal.
I saw a Manitou tear out the wear blocks when It was sucked in loaded @ the horizontal. It did it but the rest is obvious.

Years ago I won a job to supply a Nickel Ore sampler in Townsville.
The spec was very particular on how the sample was to be taken, size and shape of the "spoon" and the action as it took a bit out of a rail wagon.
I supplied a hydraulic power-pack, and an off-the-shelf mini-backhoe attachment for a Kubota or something and the spoon to spec.
The implement was mounted appropriately with the controls remote mounted.
Bingo! Instant ore sampler!

Your brief description of the job gives me goose bumps because I imagine you will be using hydraulic luffing with the boom near horizontal.
Very difficult to get smooth and accurate control out of counterbalance valves in that situation, but I can put you on to some very good people if you want to go that way.

Better to find a JLG or something that meets the specs and feels good, then mount it however you want.

Cheers. Maurie.

 

[norite]

What advantage would your machine have over a set of conveyor rollers, to slide the liners into the mill by hand. If you are thinking of a machine to place the liners in all positions without rolling the mill, look at the setup on tunnel boring machines, they place heavy precast concrete liners in all positions around the machine, similar to what you may be trying to do.

 

[SMP Design]

G'day Mate,

Just noticed your thread and location.

Don't know if what I say will help or not but I'm a big believer in not re-inventing the wheel.
Aussie engineering is expected to be "cheap and cheerful".

Tele booms are very difficult and never perfect.
For a one or two off application, I suggest you look around existing machinery and just buy the boom as a spare part, or buy one second hand, thereby never having to go through the grief of discovering something that trashes your design, but someone else found out the hard way years ago.

Be careful of your load factor if you want to extend or retract near horizontal.
I saw a Manitou tear out the wear blocks when It was sucked in loaded @ the horizontal. It did it but the rest is obvious.

Years ago I won a job to supply a Nickel Ore sampler in Townsville.
The spec was very particular on how the sample was to be taken, size and shape of the "spoon" and the action as it took a bit out of a rail wagon.
I supplied a hydraulic power-pack, and an off-the-shelf mini-backhoe attachment for a Kubota or something and the spoon to spec.
The implement was mounted appropriately with the controls remote mounted.
Bingo! Instant ore sampler!

Your brief description of the job gives me goose bumps because I imagine you will be using hydraulic luffing with the boom near horizontal.
Very difficult to get smooth and accurate control out of counterbalance valves in that situation, but I can put you on to some very good people if you want to go that way.

Better to find a JLG or something that meets the specs and feels good, then mount it however you want.

Cheers. Maurie.

Hi Maurie,

It sound's like you know a bit about the game. What's your business involved in. Are you a consultancy or do you have an engineeeing workshop. I've had a fair bit if experience with the design and construct of hydraulically contolled telescopic equipment although mostly where the boom is powered by cylinders. The machines I'm currently designing are for a global mining technology company and will be serially manufactured for a global market.

 

[JGS Parts]

We are currently in the mid process of putting together our first telescopic boom system for our new style loader. mate whats the reach you need on it? we are using a dual stage hydraulic ram as it has worked out easier for us this way. would be happy to talk to you more about it if i could help mate.

 

[icestationzebra]

As was said above, the design is not simple so if you can "steal" the boom from another machine you will be money ahead. You will have to put in a lot of development work. For example the load holding valves can not just be picked out of a catalog, we usually had to try a couple different ones to get one that didn't chatter or squeal. You will also have to make big assumptions on the friction levels, and if you are wrong you will have to resize everything.

And if you want a really impressive design, check out Lieberr's container handler that has a curved telescopic boom!

ISZ

 

[Dualie]

Personally i would just knock off a crane boom design of the size and capacity that you are looking for.

 

[SMP Design]

We are currently in the mid process of putting together our first telescopic boom system for our new style loader. mate whats the reach you need on it? we are using a dual stage hydraulic ram as it has worked out easier for us this way. would be happy to talk to you more about it if i could help mate.

Seeing as though you are from the Sunshine state I'd be more than happy to talk to you more about your experience. What would be the best way to contact you. I had a look at your website and it is very impressive.