doug72

See previous forum topic here:- http://www.eurobrick...pic=113124&st=0 Where lots of mods have already been posted for A & B models.

John, I have now made a test rig based on your design and enlarged it so that the main jiib is 45L long. Horse Head Level Luffing Test Rig: Set up in front of computer with the animation running on the screen to allow comparing with the test rig for max and min positions of the main jib. IMG_3023 by Doug Ridgway, on Flickr Diagram of linkage dimensions which best achieved level luffing. The white beams hanging off the horse head represent to hoist rope to determine the hook would stay level throughout. Achieved less than 1/4L deviation throughout full travel. Large linear actuator is used with full 5L travel LLC_links by Doug Ridgway, on Flickr Next crane project is go ! Doug

John, thanks for the comments. I have a book on the history of Stothert & Pitt which inspired me to build this MOC and also another MOC of an S & P Block Setting crane that used to be on the South Pier at the entrance of the Tyne near where I live. http://www.eurobricks.com/forum/index.php?showtopic=91929 Currently working out dimensions for a "horse head" type crane which will be to a similar scale to run on 15L gauge track. I used to love building cranes from Mecanno when I was a kid. Lego Technic gives the oppotunity to continue crane building.

Ludo, Thanks for your comments. It started out using standard parts but very difficult to squeeze in four built up worm gear boxes hence use of Efferman 3 x 3 x3 worm gearbox. Same with turntable where the topworks wobbled when rotating - new 3D parts eliminated that and made it very stable. Before it needed a heavy counterweight - now only battery box is sufficient. I enjoy build mechanisms to fit space availble. The jib took a while to figure out how to taper it in two directions towards the jib head. Used four LEGO Beam 4 with Ball Cup Socket (15459) to solve that. re Hieght variation: the real crane suffered the same problem at extreme positions. It was the best I could achieve using Lego hole spacings.

MOC completed. Click image to see the video. Top works completly re-built after installing the Efferman turntable support and wheel holders. It was quite a tsk to squeeze in four PF motors and their reduction gearboxes and to determine the correct loctaions for pulleys and jib pivot points. Slewing is fast with 96:1 reduction using a worm gearbox with an 8T gear meshing with the turntable 96T gear ring. Luffing a bit jerky due to the rope system friction. MVI_3020 by Doug Ridgway, on Flickr Next MOC will be level luffing crane using the "horse head' system possible using the new Lego rack system.

John, the link works but to show photos you need to "share them". At first I had some problem showing Flicka images but its quite easy. From Flicka Open the image you want to appear in your post - select the little right pointing arrow at bottom right of the Flicka page. (share photo) Then select BBCode - next select size of image and copy the URL code that is shown. Paste this code into your text for your posting. If posting muliple images I draft the text on my computer along with image codes then copy and paste onto the Forum entry. Hope that makes sense. Re My MOC Almost finished - the hardest part has been getting the level luffing to work smoothly & to find correct locations for the various pivots and pulleys. The hook is at same level at max / min postions of the jib but follows a slight hump in between. I'm sure the original crane did as well. The reason for this design was for very fast luffing of the jib with hook staying resonable level - this along with fast slewing gave quick unloading of cargos from a ship in the days when most loads were not very heavy. My MOC designed to show the mechanics of this type of crane as I always find it hard to do the asthetics to make it look nice ! I will be posting a video soon of it in action. My next crane will probaly be a level luffing crane of the type you describle.

Check out the link given in post # 1 for other colours available.

As requested: LEGO Rim Narrow Ø 18 x 7 M Cross (56903 Left, unpainted part left, Right after painting. Marker paint pen used. IMG_3013 by Doug Ridgway, on Flickr View of Efferman two 3 x 3 x 3 worm gearboxes installed in my R & R mobile crane. note; these were painted in situ. IMG_3014 by Doug Ridgway, on Flickr View of 3 x 3 x 3 worm gearbox installed in Dockside crane, Painted using a black marker pen prior to installing IMG_3016 by Doug Ridgway, on Flickr Ideally parts should be painted prior to installing and only on visible sections and not subject to wear. ie. Turntable support - don't paint running surface where wheel holder wheels ride or the tooth ring. Note marker pen used has 8mm tip, for finer detailing a 2.5mm tip would be better. The paint appears to adhere well to the slightly grainy surface of the 3D printed parts.

Most 3D printed parts are white with coloured alternatives costing more. As an experiment I sourced a grey paint marker pen on line. Arrived today and tested on white lego parts and on white 3D printed parts. The marker pen works well, is resonably quick drying with a matt finish. Pen used :- Posca grey 8mm Bold Marker Pen, i.d. 148924000 £3.99 each with free postage. Obtained from: easichalk.com Colour is a very close match to Lego Light Grey. Pen I brought has a 8mm chisel point which OK for large surface areas but a smaller 2mm pen would be better for finer details, recesses etc.

My post: http://www.eurobricks.com/forum/index.php?showtopic=117595entry2437779 This shows how the new Efferman 13L turntable support is mounted on a crane base and wheel holders are installed on my dockside crane MOC. The rotation is very stable and smooth.

Correction - it is possible to mount four wheel holders around the turntable support using four Cross Block Beam Bent 90 Degrees with 4 Pins (55615) see photo - note the four red 7L beams show where the wheelholders would be located - mine are now built into my WIP- MOC. My crane MOC uses only two wheelholders but is very stable when rotating without any wobble. IMG_3012 by Doug Ridgway, on Flickr

Technic Pin with Friction with Click Rotation Pin (47455) Is there a part that connects to this ? Found it:- Technic Pin with Friction with Click Rotation Ring (41680)

Thats 5 x 3 but something similar with 4 x 4 with 3 horizontal pin holes on each side with a vertical pin hole in the corner.

New turntable parts received and prior to using them on my crane build I tried the suggestion that 4 wheel holders could be used and connected by Lego 90 deg connectors. It doesn't work - a 4L x 4L- 90 deg connector would be required to get aligment correct.

New Efferman turntable support ring and wheel holders received today. Prior to receiving the new parts I modified the travelling under carriage to provide the locations for the eight 3/4 pins needed to locate the 13L turntable support ring. Pins installed for turntable support ring IMG_3005 by Doug Ridgway, on Flickr With the previous arrangement the transmission to the track wheels would have fouled the underside of the new turntable support ring and thus had to be lowered by 2L and re-routed. This had the added bonus of eliminating the two universal couplings with the drive now direct down the legs to the track wheels. Underside of traveling carriage. IMG_3006 by Doug Ridgway, on Flickr Side view of track drive. IMG_3007 by Doug Ridgway, on Flickr Slewing ring installed. IMG_3008 by Doug Ridgway, on Flickr Wheel holders installed IMG_3009 by Doug Ridgway, on Flickr The slewing ring and wheel holders will be coloured later using a grey permanent marker pen. Rotating crane house, motors and gear drives has now to be rebuilt. At the moment undecided to continue this MOC as a level luffing crane or to build a more conventional dockside crane.

Friction

Check out the new Efferman 3D printed turntable support and wheel holder for turntable here. Turntable is 13L diameter. If 4 wheel holders used then has 12 wheels to support the load. I am awaiting arrival of these parts today so I can proceed with my Dockside Crane MOC

Good test video. If you fit a rear skid unit as on the Renault FT-17 tank from WW1 allowing it to cross trenches without toppling backwards it will climb even higher obstacles.

Video of my MOC in action, excuse the poor driving its quite hard getting use to steering it as for each 180 deg. rotation of the steering unit the drive goes the other way. If not try this:

(MOC) Worlds first mobile crane was built by Ransome & Rapier - Ipswich, England kevin-real by Doug Ridgway, on Flickr My MOC IMG_2996 by Doug Ridgway, on Flickr My representation of an early mobile crane, designed and built by Ransomes & Rapier - Ipswich England. These versatile mobile petrol-electric cranes first made their debut in England 1923. This crane also features as Kevin in the Thomas the Tank Engine books and films. For more information and a video of a restored crane in action see:- http://www.pegnsean....eries/kevin.htm I have replicated all the crane functions with the structure as close as possible using Lego Technic and power functions. IMG_2996 by Doug Ridgway, on Flickr IMG_3002 by Doug Ridgway, on Flickr The model has four functions:- 1/ Drive - M motor 2/. Steering - M motor 3/. Hoisting - L motor 4/. Jib up/down - M motor The two PF Receivers are located where the petrol engine drove the dynamo for the four electric motors Steering and drive are contained on the rear pair of wheels and uses castor steering using a turntable driven by a worm gear. First build used a Z56 turntable but later decided to make the drivers steering wheel rotate at the same time, which meant a rebuild using the Z60 turntable so that a 12T double bevel gear could be used to achieve this. The actual crane had no power steering - so it took a lot of effort to manually steer. The drive is passed down through the turntable to a differential to drive both wheels. The model uses three Efferman 3 x 3 x 3 worm gear box units which allow for a more compact build. Hoisting and jib up/down is via two rope drums. IMG_2997 by Doug Ridgway, on Flickr Underside IMG_3000 by Doug Ridgway, on Flickr Motor compartment Lower left M motor - steering, via 288:1 reduction Lower right M motor - drive to the rear wheels via 11.2:1 reduction. Upper right M motor Jib rope drum via 8;1 reduction and 4 fold rope purchase. Hoist L motor can just be seen in upper left of photo 8:1 reduction. IMG_3001 by Doug Ridgway, on Flickr Rear view of steering / drive unit which can rotate through 360 degs. in either direction. IMG_2998 by Doug Ridgway, on Flickr With wheels turned IMG_2999 by Doug Ridgway, on Flickr A video showing this model in action will be posted later.

Progress report:- Hoist motor and gearbox installed . Jib now all one colour and tapers in both planes towards the jib head OK. Geometry for level luffing rope system almost figured out - the hook stays at same height when jib is at max. & min. positions. In between the hook rises in a very shallow hump. Progress on hold at present awaiting the Efferman turntable system as weight of the jib tips the whole rotating cabin forward despite counter balancing with two steel blocks at the rear. The Efferman 3 x 3 x 3 wormgear boxes would have allowed for an easier build of all four motor / drives. Currently building a MOC, using these gearbox units, of the worlds first true mobile crane built in the late 1920,s by Ransome & Rapier, which used a petro/electric system with castor steering and drive.

This "fix" was mentioned in a previous thread about batteries not connecting. Screw a piece of tin foil into a small ball and insert between +ve terminal of the lego battery box and the +ve of the battery. And Try an alternative battery to Duracell.

Re Worm Gear case 3 x 3 x 3 complete gearbox for 8 and 24Z gears Version 2 just received - cross holes a bit tight at first but by using a cross axle pin connector gently in and out to ease them the fit is OK. Pin / plain axle holes required a little bit of cleaning. Worm gear box can be mounted directly onto the face of M & L motors OK when a 24T gear used. 24T gear teeth catch XL motor casing if directly mounted - so a 1L spacer would be required. OK when an 8T gear is used. Just seen your post about the new turntatble - looks great with an easy connection to the centering turntable.

Re Double Flange wheels for cranes. Have come up with a solution that uses standard 16T gear on same axle as wheel. A 20T double bevel gear meshes with both 16T gears on wheel axles - offset by 1L higher, 12T thin bevel provided the drive to the bogie. This prevents the 20T DB gear from fouling the track. So only require track wheels with cross hole as per drawing without attached 16t gear. Groove profile to suit Lego Straight track 3288. Thanks for your patience. Doug

Efferman: Too thick - Its was to get the alignment between bevel gears correct. Do you have a 16T double bevel gear design as that would solve it I think. i.e. Double flange bogie wheel with 16T double bevel gear on same axle which would mesh with an idler 16T double bevel gear to drive the other bogie wheel. That would prevent gears catching the track and allow vertical drive to connect on any axle. Thanks for all the design work you do - you have really good ideas and solutions. Doug