doug72

I have made test rig of my idea and works but with a slight jolt as wheel starts to rotate again. Here is a video which demonstrates how it works. Needs a lot of refining to improve it and made more compact. Also find a way to lessen the jolt. The blocking arm is normally down and stops rotation until the trip lever drum / lever mechanism raises it and frees the wheel. The rotating arm uses the small turntable as I have plenty of them.

Intersted in building this GBC and have been trying to come up with a simple retarding mechanism. On my Ferris Wheel GBC if the arms jam then the white clutch gear slips and arms stop - once jam is fixed rotation continues without any jerks. I have come up with a possible solution that might work, using a worm drive to the white clucth gear with a normal 24T gear engaged with the clutch gear. Red axle = input from drive motor. Yellow axle = drive for lift rotation. The 24T gear on the grey axle has a disc which 4 holes around its circumference - two holes have axle /ball pins which would engage with a trip mechanism to block rotation at 180 deg intervals. With white 24 T gear slipping the 24T gear still rotates activating the trip system, once trip de-activated and releases the lift, white gear drives the yellow axle again for another 180 deg. rotation. Re Geneva Gear: I have been hunting on line for a two arm version without luck but came a cross a 3 arm version - still hunting ! Another possibility is a Scotch Yoke / Crank device with built in dwell.

Thanks for the info and download link. Will be installing it soon.

Great GBC - well done. I have long wanted to build a Falkirk Wheel but never got around to it ! Unfortunately can't open the zip file on Mac OS.

Thanks for the comments. As a retired ships engineer I like the technical challenges of building Lego Technic and GBC modules. Re another chain side by side - lack of chain links prevent this and I want to use what links I have for a early land dredger / excavator. Hence re-build & testing with large track links. The test rig using large track links looks promising and up to notch 5 using the 8879 PF controller with M motor drive with 3:1 reduction and using the lage sproket wheels. Just need to improve the loading hopper and devise a 1 ball at a time mechanism. Should be able to use at least 4 scoops. When its working OK I will post a video. I too have to have periodic clear outs to sort parts back into correct storage boxes !!

The evidence is all over my hobby room - still hunting for lost balls !! I am a relative novice at building GBC. My attempts are more SBC (Small Ball Contraptions) Currently working on a two scoop test rig module using the large track links. Moderate success so far but one scoop works fine the other fails intermittently, even though they are both aligned correctly at loading point - still trouble shooting the reason why. Had thoughts on increasing output by using larger scoops (p/n 15361 or 20430) if can devise a way to attach them to a chain. OR Use the p/n 15361 half cylinder with a double lever / chain system to load balls - raise it to discharge point and tip the cylinder to eject the balls. http://www.brickowl.com/catalog/lego-cylinder-half-3-x-8-x-5-with-3-holes-15361 http://www.brickowl.com/catalog/lego-cylinder-2-x-4-x-4-6218-6259-20430

For inspiration and ideas the new series of Robot Wars starts on BBC 2 - Sunday March 5th at 19:00 hrs.

Tried that by changing the 20T/12T step up gears to 24T/8T step up gears. Result - ball chaos as buckets would not deploy quick enough to load ball & when unloading balls skipped off the ball chute ! As it is very doubtfull I could participate in a GBC convention - it suits my requrements for larger GBC loop I am putting togerther. Maybe others can develop my idea to achieve 1BPS rate ? I intend to build a new version using the large track links with double buckets (as above) to see how this would perform.

At present its 1 ball every 4 seconds. Eight buckets would halve this but due to the closed loop ball run they tend to arrive too early at loading point and jam the next bucket. Will try with an L motor with the 20/12 step up gears replaced by 24/8 step to see what timing it achieves. Meanwhile I have devised ways of mounting the visors onto readilly available caterpiller tracks - see images. The bucket visor are still able to tilt as the chain rotates. Single & double bucket versions shown. Parts use should be obvious from the photos. The single bucket will allow a vertical lift whereas the double bucket only about 60 degs otherwise balls will fall out. A double bucket should easilly achieve the required 1 BPS rule. I will build this and then use the large lego chain links for another project I have in mind.

Possibly, an early rail mounted excavator for digging canals or a modern wheeled trencher !! Canal-digger2 by Doug Ridgway, on Flickr 800wheeledtrencher by Doug Ridgway, on Flickr 800WheeledBWT by Doug Ridgway, on Flickr

White Visor http://www.brickowl.com/catalog/lego-visor-2007-57702 Large lego chain link http://www.brickowl.com/catalog/lego-large-chain-link

Thanks. At present the ball carriers deform and put a small kink in the chain. Going to try a fix by using a 2 x 1 plate on the chain studs then mount the Technic Cross Block/Fork 2X2 & ball the carrier on that, but will need clearances adjusting slightly.

For some time now I have been trying to find a successful use for the Large Lego Chain & White Visors I had. The curved chain lift I built using BWE Quadrants was not a success ! Next attempt to build a chain lift would not discharge balls above a 45 deg. angle as the ball carrier design was not good as it was too rigid. Being off-centred over the chain it fouled parts of the structure as the chain rotated. Balls ended up all over the place !! Next attempt is successful and now the chain is at an 80 deg. angle which gives a good height for ball discharge. The chain tensioned by two grey shock absorbers at the top chain wheel. The chain lift is driven by an M motor with a reduction gearbox giving 14.4 ratio. Took awhile to devise a reliable ball pick up hopper and also the discharge at the top. Zig Zag ball run added to return balls to the start again. The ball carriers are made using the white visors but this time they are centred and also pivot as they pass over the top chain wheel. Originally used 8 ball carriers but they overloaded the loading hopper so reduced to 4 carriers and now works fine. During testing used a PF train controller to vary the speed. Now runs OK at full speed. As the chain rotates the ball carriers as they pass under the lower chain wheel assume the correct position to scoop up a ball. At the top the ball falls out and at same time the ball carrier flips forward to tuck under to just clear the discharge ball run as it passes before descending. Parts used for the two types of ball carriers: On the the left of-centred / on right centred type. Both attach to the chain studs. Video:

Not tested the dual arm GBC for continuous running yet as need to set up a return ball run. It took a lot of trial & error to get the levers & cranks working smoothly. Some of my other GBC modules have been run for a long time and functioning OK still. I don't anticipate going to an event and not sure is any are held in the UK. Intention is to link them all up on a 6 ft x 3 ft board. Thanks for advising I had duplicated the image - now corrected in original post above. At the moment trying to get a GBC bucket chain lift working which uses a Large Lego chain and the white visors as the ball holder. First attempt failed but 2nd one looking better. Will post once working OK.

After completing my Bucket Wheel GBC Lift I had 10 pcd White Visors spare waiting for a new use ! Finally used two visors for a module based on the Nxtstep101 module Dual arm lift GBC. Adapted to use parts I had available. The loading gates are my own standard design operated by trips actuated by the bucket. Driven by M motor at 24:1 reduction with arms 180 deg apart. PS think I have been bitten by the GBC bug !

The Yellow axle is connected to the centre 8T gear. The Red axle is connected to the two wedge pulleys which have the two 8T gears on them which contact the internal 24T gear in centre of the turntable, and the 8T gear on the yellow axle.

Aminnich: heres the extra images you requested. Note options 3 & 4 are not realy viable as you need to lock the two halves of the turntable together - to do this the yellow 3L beam (gray in previous image) then obstructs the turntable external gearing. If you only want a 1:4 reduction then my build will work if turntable is fixed into the structure. Please note my adaption is based on the planetry gear show in Sariel's guide book minus the L motor and with the turntable locked.

Here's one I built earlier to figure out how it works. There are four possible outputs:- 1/. With turntable stationary 1 revolution of Red crank = 4 revolutions at Yellow crank in same direction. 2/. With turntable stationary 4 revolution of Yellow crank = 1 revolution at red crank in same direction. 3/. With Red crank stationary, 4 revs. at Yellow crank = 1 rev. of turntable in reverse direction. 4/. With Yellow crank stationary, 1 rev, of Red crank = 4 revs of the turntable in same direction.

You need to use the 56Z turntable and if it is held stationary then depending on which axle is the input & which is the output you can get either 1:4 step up ot 4:1 step down. All is explained in Sariel's "Unofficial Lego Technic Builders Guide" Second edition in Chapter 21 - pages 349 - 353 with details on how to build them.

To prevent sag add a King post or Queen posts above the horizontal beam. See: https://en.wikipedia.org/wiki/King_post

Further modifications made. Gearing: Now uses only 12T double bevel gears. Ball loading: Uses the same arrangement as I developed for my Bucket Wheel GBC lift and is operated by trip levers. Unloading balls: As the original design of this GBC module discharges balls at a low level it was not possible to connect up to a return runway or to another GBC module. Therefore have made the last ball transfer arm longer and it is now able to lift balls up to the return runway at 11L height ( possible longer arms would also work). M motor drives the last arm then the other 3 short arms via the eight 12T double bevel gears. I had trouble with some balls getting stuck in the transfer arms so changed the pin/ball pins to blue pin/axle and now works well. IMG_4369 by Doug Ridgway, on Flickr IMG_4372 by Doug Ridgway, on Flickr Video:

Now built the Nxtstep101 GBC Mechanical Chain module using the original design for ball transfer arms driven by 10 x 16T gears. Found that excessive gear backlash caused problems with the timing and settings for the ball arms and can only run OK with M motor running in one direction. With motor reversed balls failed to transfer properly. Original drive system:- IMG_4357 by Doug Ridgway, on Flickr Set out to improve the drive system and eliminate the 16T gears, modified drive system uses 12T bevel gears. Result runs much smoother with no gearing backlash. M motor with 8:1 reduction for slighly faster running than original design with 9:1 reduction and more compact. The image shows how. IMG_4359 by Doug Ridgway, on Flickr Next step is to build the ball loading and unloading mechanisms.

Now built the ball transfer section and it doesn't like any sort of incline, highest it worked at was a slope of 1:32. Any higher balls don't transfer and jam. There is alot of backlash in the gears. Have had to set it up so the M motor runs in one direction only. Took awhile to figure out the ball holders as I had used the wrong part causing balls to stick in the holders. hard to see from the video as most ball holder parts are black. Used a cross block 90 deg - 1 x 2 axle / pin instead of a 1 x 2 axle / pin or 2 x 0.5 with axle holes.

For a slope of 1 in 16 you need to support the balls by their sides (i.e. at 5 & 7 o'clock) so that the hole in the ball does not run on a surface. I use 16L straight Lego rail track to achieve this, studded beams with smooth plates over the studs or studded beams turned upside down. Lego roofing bricks also make good ball runs.

Have studied the video many times, sorted out parts required & now building this to suit my requirements. Once built will test to see the maximum angle it will function at.