doug72

My through rotary dumper MOC does away with the need for an elevator !

In situations like this I normally use 3L axle with stop plus a half bush, that way you can pull the axle if when required.

@Courbet, thanks that would be great, I think many have been put off building the Rotary Dumper because it was unreliable. With four now built and proven, maybe more will be inspired to give it a try.

Your rendition of the Akiyuki system looks good, I couldn't replicate it as didn't have the parts to make the sharp radius curves. I like your MOD to make space for the motor PF cable to pass through, will convert all my train units next time I change the batteries. The elevator module seems to be the most problematic now - I have had all sorts of crashes !!! Re locating 1 x 2 bricks for ball container on train units. I too tried Blue Tac but even that failed after awhile so I will probably get my wrist slapped by the Lego Legal Police, but I have used a small amount of ABS solvent to fix them in place, later they can be parted again with a sharp blade. Agree the timing cam lock system was very un-relaible. My MOD cannot get out of sync. The through Dumper MOC also uses the same locked gearing train. Re trigger arm for dumper reverser, I found that sometimes the 15L trip beams on the train unit caught on the parts that hold the train down to engage the gears. I fitted shorter trip bars and now OK, they don't need to be 15L long 13L is OK. Re my Dumper MOD, can anyone make PDF instructions for this and add it to the GBC index along the @dunes LDD file ? PS I am still hunting for the many lost balls from the my testing sessions its amazing where they roll to !!

Doug’s Through Rotary Dumper Train System Conveyor Mk 2 This is longer than previous Mk 1 version with a chain length of 60 links giving an slope angle of approx 45º. Ball are lifted by 5L beams but some ball still fell l off backwards when conveyor in motion. Also rather large adding extra length to the whole module. Rejected & back to a previous idea I couldn’t get to work i.e. an enclosed vertical ball lift which also used 5L beams to lift the balls,. However it frequently jammed if too many balls tried to entered at the lower level due to tight clearances. Time to re-design it using studless technic instead of a mix of studded & studless parts. ====================================================================== Conveyor Mk 3 - Successful and working well, with a greatly reduced footprint. Conveyor chain is 36 links long and advances 24 links per trip cycle using a two lobe rotor in the train reverser. The train & hopper wagon make approx 3 trips per minute and can carry up to 30+ balls each time. This easily achieves the 1 ball per second criteria for GBC events. Trip time could be increased by adding extra plain 16L track beams. The amount of balls per cycle can be varied by reducing the number of lift pins.. Note there is a gap in the spacing of the lift pins every 12 links to prevent balls any balls discharging as train departs. This is because the conveyor only travels 2/3 rds. its length each loading cycle so each 12th link takes it turn to stop at the discharge point. Ball loading chute for testing purpose only would need to be re-built as per GBC rules for use at events. Conveyors. Mk 2 Left / Mk 3 right Overall view of module with vertical loading lift Mk 3 enclosed vertical ball conveyor. This has 36 links with blue 3L pins for carrying balls. Pins in pairs inserted every other link. The conveyor chain is kept taut by two small grey shock absorbers, seen at the top. This is essential for working of the vertical lift system. Next stage is the collection chute under the rotary dumper. I will probably build a smaller lift unit to lift balls onto a runway to allow them to roll by gravity back to the loading chute closing the loop to make a self contained system.

The UK lottery when you log onto your online account, uses a photo divided up into a 6 x 4 grid and you have click the squares containing parts of a car, road signs or other random image. Doug

Conveyor synchronisation: Different permutations. I have been working out the different combinations for the standard Akkiyuki reverser rotor and the number of conveyor links that are moved when using the large 10 notch sprocket wheels. The same result can be obtained using the small 6 notch sprocket wheel, if a 20:12 step up gears are used to drive the conveyor. Reverser: no. of rotor lobes. Number of chain links moved Degrees of rotor rotation 1 48 360 2 24 180 3 16 120 4 12 90 Multiples of these figures can be used for longer conveyors. i.e i have just built a 60 link conveyor which works OK with two lobe rotor. Expect you are wondering how to get 3 lobes on the reverser module. 2 pce. LEGO Half Beam with 3 Rotor Blades (44374)

Voting should be limited to Technic forum members only who have been active in the past six months before start date for contest. Plus a jury vote.

Conveyor synchronisation: Had my calculator out and found I can lengthened the conveyor belt to 60 links and by using the large sprocket wheels with 10 notches, have managed to get it in sync with the train reverser. Each time the train enters the loading station it moves the conveyor belt 24 links before reverser trips the train to exit for another trip cycle. The reverser still uses the 2 lobe rotor. As conveyor belt is 5 x 12 links = 60 it will always stay in sync. The longer length allows for a shallower gradient to reach the discharge into the hopper wagon. The conveyor angle is now approx. 45º. Rebuilding conveyor with improved ball carrying and entry ball box.

Doug’s Through Rotary Dumper system. Conveyor Mk 1 built and uses Lego track links and 5L beams to carry the GBC balls.. Three balls do not always sit on the beam side by side and sometimes the centre ball falls back down again. At present there are 7 beams spaced 4L apart, this to be reduced to 3L apart to carry more balls per loading cycle. Solution:- Rebuild & widen conveyor structure to give 6L between the sides, ball should then sit OK and transport without jamming or falling back down. Only way to reduce the slope angle is either to raise the entry box or install a longer conveyor belt, with problems synchronising again with the train reverser. Next length that will synchronise is 72 links, which is approx 39L between sprocket centers which is too long. Its amazing how balls find places to escape. Also need to devise a better ball entry box for the conveyor, as balls tend to jam if there too are many in the box. Does anyone one have a better design for an entry box which has a stirring arm to agitate the balls ? VIDEO:- It took 10 attempts to get a half decent video, with balls ending up all over my hobby room !!! Its a bit shaky just like me but then I am not Cecil BeMille. Sorting out some odd quirks, mainly with loading the hopper wagon, that cropped up when shooting the video but its getting more reliable. All part of the fun building GBC modules.

Loader conveyor module finally built after several frustrating failed attempts to get it to synchronise with the train reverser at the loading end. The conveyor uses the the small sprocket 6 teeth wheels & with a 20:16 gear step up gearing runs at the same speed as Akiyuki version. Top of the hopper wagon had to be modified slightly to allow the 5L ball carrying beams clearance. The conveyor belt is tensioned using two small grey shock absorbers to prevent the chain hanging loose on the return run. Conveyor belt has 48 links, (as per Akiyuki version) & moves 24 links per loading cycle. Balls per trip cycle = 18 but could be increased to 21 or more if 5L beams placed closer together. Conveyor module plugs into the loading end reverser module ( 4 x Red 3L pins with bush ). A bit more tidying up and bracing to do. The angle of conveyor is a bit steep at 60º but balls travel OK. May be able to reduce this once I build the ball input box. Had a few escaped balls, tested OK and now all balls drop into the hopper. Loading conveyor module: Overall view of transfer system: Next: Ball collecting chute & discharge conveyor.

6: 10 10: 6 12: 4 5: 3 8: 2 1: 1

Once you get to build it, pay close attention to the step on page 3 of 15 to get the racks correctly positioned. I got It wrong to begin with until Jonas pointed out the error, see an earlier post about this.

A pint being one that springs to mind & hand !

Thanks for the info. Will you have a minifig standing by to umplug charging cable & change the point switch ? My hopper waggon can easily carry 60+ balls so should be able to cope with a rush of balls. Going to adapt one of my loaders to suit the new Through Rotary Dumper. I will try to use the standard GBC boxes from parts I have - fairly limited number of parts, probably be multi coloured. I notice some GBC entry boxes have a rotating part to stir up the balls so they don't jam. May have to raide my grandson's collection of Lego now that he has moved onto other interests !!

Looks really good, is the track switch opertated by the reverser or is the the green train just sitting on the siding getting charged. Assume the orange train being fed by the conveyor and GBC ball input box. Re My Train system. Will probably be a stand alone system but will see if can adapt to GBC requirements. What are the standars for input /output boxes etc. Now working out the throughput required on the conveyor, so far it would running at 15 balls per trip cycle but easy to increase by adding closer spaced lift beams and changing the drive gear ratio. Each trip cycle takes about 17 secs. so x 15 = 52 balls per min so by adding more beams should get 21 balls per trip = 74 balls per minute. Inconnecting track can be as long as required using standard Lego track with adaptors to connect to the 16L track beams without any gaps.

Your ride looks good. This would be a stronger chain using the old Lego gears cogs & studded chain links which come in several colours & sizes. and replicate the chain drives used on many old fairground rides. The chain links are 2L wide.

Don't look at it

Doug’s GBC Train system: A module in two halves:- Now completed and tested OK with some minor issues sorted. The two modules plug together and easier for storage / transport. Both removed from baseplates and now supported on a higher support framing. Transfer from baseplates not straight forward due the 1/2 L offset problem, but now resolved. + = Hopper wagon wheels:- Update Under carriage now re-designed to be able to use train wheels on 6L axles, rides along guide beams OK and much smoother without any bumps. Next stage is to build a module to load the hopper wagon and then the discharge conveyor module, both to be driven by the train unit. Video coming soon.

Loading end reverser installed and testing commenced with GBC balls. Two issues found:- 1/. Reverser trigger snaged on the sides of the hopper wagon due to the side ribs on the 8 x 8 Lego panels.These shifted over 1 stud and the exposed studs were covered use tiles, the 3 x 3 swing lever on trigger arm now runs along these OK. 2/. Some balls escaped as dumper rotated, shifting Lego panels prevented some balls hanging up on the lip caused by the locking beam. Others escaped at the ends of the hopper. Two LEGO Lattice for Frame 4 x 6 (92589 added to the rotating dumper prevent this. Re-tested and all balls now fall into the container below. The four 2 x 4 angle beams had to be reversed to order fit the lattice frames. Collection chute still to build. Hopper wagon can carry and dump up my entire stock of 72 balls. More than enough to meet GBC ball rates. ————————————————————————————————- The drive from the the reverser to rotate the dumper has to run through two 90º turns Also due to use of studded & studless technic beams there was a slight alignment problem. Now re-building rotary dumper on a frame instead of studded baseplates. Original version - complicated and unable to accommodate alignment issue Improved version which use the LEGO Minfigure Neck Bracket (42446) to correct the alignment problem.

Might see if it would work with the unloader module, which has very tight clearance to grip the sides of ball hopper & raise it to dump balls. Often the hopper fails to enter the lifting arms.

Thanks, downloaded the link and saved to my PC si I can study more fully how it works. How on earth did somebody design that & get it working. I wish you success in replicating the mechanism. Maybe an idea for a GBC grab ?

Yep that’s what I got I searched the US patent number !

WOW that’s quick, LDD looks great. As Train & Hopper reverse out of the dumper the restraining beams swing back down again due frictionless pins. Almost finished the bespoke reverser for the loading end & made a small mod to the rubber band trigger arm. The cross block 90º 1 x 2 gives added support for ther trigger arm.

Doug’e Rotary Through Dumper Module. Hopper wagon, improvements Have discarded the original hopper retaining system of 4 rollers high above the hopper wagon. It was hard to get the position of the retaining beams correct to hold the hopper in place, being either too tight or too loose. Improved system built which has two beams that can swing slightly. As the hopper wagon enters the dumper is raises the beams slightly to allow hopper to enter, these then lock in place and prevent the hopper moving as dumper rotates and dump the balls. Restraining beams in lowered position. Restraining beams locked. Short video of improved hopper wagon dumping balls. Best viewed at half speed. Hand operated for testing purposes.