My new project will involve a forestry machine used to collect fallen timber. I have a nice design for the drive and suspension but im having trouble making a good crane. Does any one have a good crane ideal like the one shown on the model? The link below is the model I plan to build.

You could look at the instructions for the 8049 "Tractor with Log Loader" set (which can be motorized), and get some good ideas. Replace the pneumatic elements with Linear Actuators and Power Functions Medium Motors. The "grabber" claw is already set up to handle "logs" of 2x2 Round Bricks, and if you add some 45590 "Technic, Axle Connector Double Flexible (Rubber)" as claw tips, it will really hold onto the logs well.

Is it really necessary to replace pneumatics with LAs? Motorized compressor can be used. I think that air pipes (or whatever are those parts called) look better than tones of gears needed to drive the actuators. But the idea of using 8049-like crane is good.

You could look at the instructions for the 8049 "Tractor with Log Loader" set (which can be motorized), and get some good ideas. Replace the pneumatic elements with Linear Actuators and Power Functions Medium Motors. The "grabber" claw is already set up to handle "logs" of 2x2 Round Bricks, and if you add some 45590 "Technic, Axle Connector Double Flexible (Rubber)" as claw tips, it will really hold onto the logs well.

Edited April 5, 201113 yr by peter_m

how big the vehicle will be?

This looks like a fun project!

What functions would you like your crane to have? Are you wanting to include a telescopic boom and rotating grapple? Those two items would the hardest to incorporate.

Will you be using pneumatics or LAs for your crane arm? Will you use any PF elements?

This looks like a fun project!

What functions would you like your crane to have? Are you wanting to include a telescopic boom and rotating grapple? Those two items would the hardest to incorporate.

Will you be using pneumatics or LAs for your crane arm? Will you use any PF elements?

I would like for the crane to have a telescopic boom and possibly a rotating grapple. I believe that the rotating grapple would be too hard to incorporate into the model also thgouh. It would look robust and add too much bulkness to the model. I would also use LA's for the crane arm and the model will be completely remote controlled with all elements including 8x8 drive possible with a fale six cylinder engine and I really look for the crane to set the model off with its functionality.

You could look at the instructions for the 8049 "Tractor with Log Loader" set (which can be motorized), and get some good ideas. Replace the pneumatic elements with Linear Actuators and Power Functions Medium Motors. The "grabber" claw is already set up to handle "logs" of 2x2 Round Bricks, and if you add some 45590 "Technic, Axle Connector Double Flexible (Rubber)" as claw tips, it will really hold onto the logs well.

Thats a great ideal for a nice base to the model and I will be using LA's for the model. I really like the grabbe claw but will still have to find a way to motorize the function since I want full control of all elements of the Cat Forwarder to be remote. Thank you very much for the idea and it will be a good model to start the crane system around. I usually dont ask for alot of help but I have never tried to build a fully functional crane like the one on this machine.

Because you are using an LA and motor for your grapple, I would suggest placing the motor at the backside of the telescopic portion of the boom. That way, the motor slides with the telescopic part of the boom. Connect your motor to the grapple via axles and a u-joint.

The only downside to the above idea is that it puts the weight of the motor in your boom. You may also be able to build the boom with the motor towards the base near the turntable (better for weight distribution), but this requires a complex drive system through the telescopic portion of the boom. This is the method I'm using on my current project, a JCB backhoe with telescopic stick. If you can give me a week or so, I can take some pictures of my solution, which I think may help in your situation. Not sure if you really want to go this route though (it's not really as necessary in your application).

Edited April 7, 201113 yr by dhc6twinotter

Because you are using an LA and motor for your grapple, I would suggest placing the motor at the backside of the telescopic portion of the boom. That way, the motor slides with the telescopic part of the boom. Connect your motor to the grapple via axles and a u-joint.

The only downside to the above idea is that it puts the weight of the motor in your boom. You may also be able to build the boom with the motor towards the base near the turntable (better for weight distribution), but this requires a complex drive system through the telescopic portion of the boom. This is the method I'm using on my current project, a JCB backhoe with telescopic stick. If you can give me a week or so, I can take some pictures of my solution, which I think may help in your situation. Not sure if you really want to go this route though (it's not really as necessary in your application).

Yeah, I can only build on the weekends when I go home from college. And i planned on trying to run a drive line with axles and u-joints to the grapple and possible the other LA. I know it will be a complex drive system but Im up for the challenge. If I must take out the telescopic portion to the build that would be one thing that I would be able to do with out. But I will try my best to incorperate it in the build. Thanks for all suggestions and possible improvements in helping design my first crane like system.

I once saw rotating, motorised grapple - it used the old 9V micro-motors... but I dont remember where... Perhaps one of Jennifer Clarks models?

Alanp has a good idea for a grab but it uses to micro motor's.

Edited May 16, 201311 yr by Alasdair Ryan

alanp has a good idea for a grap but it uses to micro moteres

If you could please post the ideal for the grapple and if i think that it will fit the scheme of my model I may buy a few micro motors.

If you could please post the ideal for the grapple and if i think that it will fit the scheme of my model I may buy a few micro motors.

I guess he means this one:

I haven't actually built it myself but if it's too slow you could replace the motor powering the opening/closing function with a PF M-motor.

Edited April 7, 201113 yr by allanp

You should also take a look at the 8049 b-model - it has a rotating pneumatic claw. You could replace the finger screw/gear with a micro motor to make it fully motorized. The desing seems to be somewhat similar to the one allanp posted, except the central micro motor is replaced with a pneumatic cylinder, taking advantage of the freely rotating rod of the pneumatic cylinder.

Allen this grapple ideal looks like it will work great with my design. Thank you very much for the images, I will be able to build the design from those.

Allen, I made some small modifications to the grapple but Im still going to use the micromotors. I just ordered 2 of them from bricklink and they should be here sometime in the next couple of weeks. Pictures coming this weekend of the progress

This is my pre-dark ages crane:

Allen, I made some small modifications to the grapple but Im still going to use the micromotors. I just ordered 2 of them from bricklink and they should be here sometime in the next couple of weeks. Pictures coming this weekend of the progress

That's cool. As I said before tho if the micro motor is too slow for the claw you may be better off using a PF M-motor. Happy building!