[MOC] Bucket Wheel

[doug72]

My attempt at making a bucket wheel.

Bucket Wheel is built using 8 pce. LEGO White Visor 2007 (57702)

Wheel rim is made from 16 pce. # 3 connectors.

Centre Hub: Efferman 8 hole dish, 5 stud diameter.

Spokes at an angle using 5L axles - to have radial spokes would require a 4.5L axle which not available.

At the moment intend use this either for a first attempt at a GBC or for a Bucket Wheel Trencher machine.

IMG_3508 by Doug Ridgway, on Flickr

IMG_3507 by Doug Ridgway, on Flickr

[Phantom59]

I was just wondering if you could have used "technic streeing link 6L http://www.peeron.com/inv/parts/2739a for the spokes

[doug72]

I was just wondering if you could have used "technic streeing link 6L http://www.peeron.com/inv/parts/2739a for the spokes

Thanks for the idea, just tried that and they are too short by 0.5L !!

Wheel is 16L diam. - Hub is 5L so for radial spokes they need to be 5.5L = axle 4.5L plus 2x #1 connectors.

Could cut 9L axles in 1/2 but don't like doing that.

Some old water wheels had spokes arranged like this.

Have tried other combinations of angled connectors but the the # 3 gives best result.

Edited April 21, 2016 by Doug72

[nerdsforprez]

I am sure there are many configurations. I used a similar configuration with the pulley wheels a while ago when I made an ultimate version of 42025

[doug72]

Plenty of options for 6 spokes but none I could come up with for 8 spokes using Lego part for the centre hub.

hence 3D printed disc by Efferman for me.

Edited April 22, 2016 by Doug72

[dr_spock]

I did a six spoke version for my Bucket Wheel Excavator GBC. I like the look of your 8 bucket wheel configuration. A bucket wheel trench digger GBC would be cool.

[doug72]

A bucket wheel trench digger GBC would be cool.

The wheel discharges onto the conveyor p/n 4597139 from the 4645 harbour set.

Wheel & conveyor have seperate motors.

Next challange is to figure out how the bucket picks up balls ( I'm using glass marbles for now to test it).

Return to collecting box will be via series of switch backs.

I'll post some images as the MOC progresses.

Edited April 22, 2016 by Doug72

[efferman]

How good the dimensions of the centerpiece fit?

[doug72]

How good the dimensions of the centerpiece fit?

Hi Efferman.

Brought two 8 hole dish, 5L diam. on extended delivery (cheaper postage) but arrived in just over a week.

Pin holes all OK.

Cross Hole: one appeared to be blocked but just loose dust from the flexible polishing.

One unit X hole a firm fit on axle the other slightly slack but OK if add 1L bush each side.

No problem with your design - just need shorter axle (4.5L) to have straight spokes but works OK with spokes angled as shown in images.

Also brought a set of train rollers and these are OK now with cross hole clear and not too tight a fit.

I use a Lego threaded axle to clean out the cross holes of any detritous from the 3D process.

[kolbjha]

I think your design is good as it is with 5L spokes with angle. If the spokes were totally radial, the hub would not transfer torque to the wheel very well.

[doug72]

For radial spokes to work they need to have a rigid connection at the hub end.

Did a test with an enlarged diamenter rim wheel with 8 hole dish using radial spokes but the dish tends to twist relative to the rim as it turns.

I,m satisfied with the wheel and hub with with angled spokes.

[doug72]

Built up bucket wheel using # 2 and #4 connectors with radial 4L spokes with 8 hole dish - 5L Diam.

The centre hub is stable. Only two buckets shown but would accomodate 8.

Each spoke has 1 x #1 connector and 1 x axle /bush connector.

IMG_3509 by Doug Ridgway, on Flickr

IMG_3510 by Doug Ridgway, on Flickr

Marble run machine (MOC) progress to date:-

Some images of the marble run machine I am attempting to build.

Bucket wheel driven by L motor with 72:1 reduction.

Conveyor is driven by M motor with 1:1 drive.

Next step is to find a satisfatory way to pick up marbles in the buckets. Its hand loaded at the moment.

IMG_3511 by Doug Ridgway, on Flickr

IMG_3512 by Doug Ridgway, on Flickr

IMG_3513 by Doug Ridgway, on Flickr

IMG_3514 by Doug Ridgway, on Flickr

IMG_3515 by Doug Ridgway, on Flickr

Edited April 23, 2016 by Doug72

[DrJB]

Very nice. I bought 60+ of those buckets and wanted to do a GBC with them. Project still sitting on back burner though. Depending on which connectors you use, you can do either 8 or 16 buckets.

Edited April 23, 2016 by DrJB

[dr_spock]

Very nice. I bought 60+ of those buckets and wanted to do a GBC with them. Project still sitting on back burner though. Depending on which connectors you use, you can do either 8 or 16 buckets.

Wtih 60+ buckets, we hope to see a chain bucket excavator GBC from you.

[DrJB]

With 60+ buckets, we hope to see a chain bucket excavator GBC from you.

Hehe ... Yup, when the time comes of course :)

Now, I was able to fit an 'exact' octagon around 2× large gears (z40) and 4× 5L liftarms. I was also able to do a 16-bucket wheel in LDD, but can't find the file now. Note: If it works in LDD, it means the parts are not stressed in real-life. What I learned is that those large circles are easy to build with the connectors, however, often the 'challenge' is to find a hub that fits 'perfectly'. In fact, there is no special pythgoras version that works here. If you remove just one spoke, the construction is not stable and the gears can rotate relative to the outer rim (I'm talking here about the 16-bucket version. For the smaller one below, the 5L liftarm is held by 2× 3L blue pins, and as such it is already fixed). With three spokes, the contraption is a 'mechanism' i.e., parts can move relative to one another. The fourth spoke eliminates the extra/remaining degree-of-freedom, and voila! The only catch with such design/attachment approach is that you can't do more than 4 spokes (there are no lego technic parts with 8 equally spaced pin holes around the circumference. One possibly could extend to 6 spokes, but in such case, the connectors making the outer rim need to have 150 or 165 degrees.

In the above picture, the buckets are not available in LDD, so I made up my own 'contraption. Those buckets came in only one set (in white): The Mars Mission Crystal Reaper. They did come also in various bionicle sets but in Trans-Blue.

Edited April 24, 2016 by DrJB

[DrJB]

Since we're at it, I was able to re-create the 16-bucket version. With only 4 spokes, it's a bit flimsier than its smaller sibling, and that is why I added thin 5L liftarms to prevent the connectors from coming apart, around the circumference. The wheel is a bit offset, but one can make the spokes/rim similar to the 8-bucket version. And, yes, it's perfectly feasible without stressing any of the parts.

Edited April 24, 2016 by DrJB

[doug72]

What I learned is that those large circles are easy to build with the connectors, however, often the 'challenge' is to find a hub that fits 'perfectly'.

Which is why I asked Efferman to design an 8 hole hub, now available at Shapeways:-

https://www.shapeway...d&utm_content=2

Have designed a ball release mechanism to release one ball at a time into a bucket - just need to figure out how to syncronise the ball dropping as each bucket passes.

Edited April 24, 2016 by Doug72

[DrJB]

Any update on the ball release mechanism?

[doug72]

Any update on the ball release mechanism?

Progress is slow !

The actual ball release is simple - just a pair of 3L x 3L thin lift arms placed between the guides the balls roll along.

As this rotates 90 degrees it allows one ball at a time to pass but stops any balls behind it moving until the next cycle.

Had hoped to link this movement by a gearing arrangement linked to the bucket wheel rotation.

For one revolution of the bucket wheel the ball release has to operate 8 times meaning an 8:1 step up gear box linked to a crank arms that rotate the lift arms.

Only way to get 8:1 step up was to use three stage 2:1 step up gears ( 2 x 2 x 2 = 8 ) but didn’t work when connected to crank arm due to too much friction.

Finally gave up on that and went for a trip lever system.

Bucket wheel re-designed using 8 each # 2 & 4 connectors making an octagonal bucket wheel

The 8 spokes connect to the 8 hole hub with # 1 connectors and with # 6 connectors at the rim.

Spoke are 8L and arranged at an angle, and has no tendency to twist.

The # 6 connector at the rim allows a fixing point for the trip rollers which as they pass move an arm linked to the ball release via two 3L crank arms, a push rod and a 3:1 step gears up to rotate the ball lift arms the required 90 degrees.

A counterweight arm resets the ball release after trip lever disengages from each trip roller allowing next ball to enter the trip arm.

Trying to synchronise this is the headache - to get balls to roll down the track and into a bucket. Nearly there just a bit more tweaking required.

Had hoped to load balls at a low level but balls tend to catch on the lip of the bucket so have had to raise the loading point for drop balls in without bouncing out again.

As I don’t have any Lego balls have substituted glass marbles !

Images hopefully will make this clearer.

IMG_3517 by Doug Ridgway, on Flickr

IMG_3516 by Doug Ridgway, on Flickr

The two rollers in this image should have rubber tires like the others - none left in my parts box.

Edited April 28, 2016 by Doug72

[DrJB]

Nice, thank you for sharing. Makes me wanna pull my buckets and restart this fun project.

Have you seen Akiyuki's latest 'Planets' GBC? He has an ingenious rotating/unloading mechanism and I wonder if it can be adapted here.

Edited April 28, 2016 by DrJB

[doug72]

Finally devised a reliable marble ball transfer system for loading balls into each bucket as the wheel rotates.

Bucket wheel operates a trip lever and cranks to release one ball at a time - while holding the next ball until next bucket arrives.

Marbles drop from the conveyor onto guides which returns the balls back to the start.

Lego roofing bricks make good ball guides.

General View of Bucket Wheel ball lift.

IMG_3529 by Doug Ridgway, on Flickr

Close up of ball transfer station with ball ready to be launched into the next bucket.

IMG_3525 by Doug Ridgway, on Flickr

Close up showing how the quadrant stops the ball behind from moving unitl the next bucket come along.

IMG_3526 by Doug Ridgway, on Flickr

Video of Bucket Wheel Lift in motion.

MVI_3533 by Doug Ridgway, on Flickr

Edited May 2, 2016 by Doug72

[DrJB]

Sounds very interesting. I've struggled for a long time for a release mechanism for the ball, without having to rely on gravity.

Could you kindly post a video of how it works?

[doug72]

Sounds very interesting. I've struggled for a long time for a release mechanism for the ball, without having to rely on gravity.

Could you kindly post a video of how it works?

Took a lot of experimenting to get it to work correctly every time to drop a ball into a bucket.

Projections on the wheel rim hit a trip lever which operates the ball release - a counterweight returns the ball release to allow next ball to roll onto the "L" lever ready for the trip arm to release it. As the "L" arm rotates 90 degrees the 1/4 quadrant stops any more balls from moving.

3:1 step up gears are used to get desired operating speed.

Once ball releases it rolls down a short ramp to drop into the bucket.

The ball release mechanism can be seen operating in the video in my previous post.

I will make a larger close up video later plus parts required to make it.

First attempt saw ball transfering OK into the bucket but as the counterweight returned the "L" shape 3 x 3 thin arms to pick up the next ball it tended to flick it back up the entry slope. The ball then didn't enter the release mechanism until next cycle and only if it had to have other balls behind it to push it in.

Edited May 4, 2016 by Doug72

[doug72]

Could you kindly post a video of how it works?

As requested :-

Video close up showing ball release operating sequence:

You Tube Video:

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The Ball release lever & quadrant which rotate through 90 degrees.

Trip lever turns this to transfer the ball which rolls down into the bucket.

Quadrant prevents next ball from moving until counterweight returns the ball release to the ball loading position which limited by a stop.

IMG_3534 by Doug Ridgway, on Flickr

Ball ready to be released by operation of trip lever.

IMG_3535 by Doug Ridgway, on Flickr

Quadrant holds back next ball.

IMG_3536 by Doug Ridgway, on Flickr

Side view showing trip lever and push rod / cranks.

IMG_3537 by Doug Ridgway, on Flickr

Camera holder:

IMG_3539 by Doug Ridgway, on Flickr

Edited May 5, 2016 by Doug72

[doug72]

For DrJb

As per private message - images attached.

Ball about to drop from bucket into conveyor hopper:

The side ribs on the axle/bush connector (32039) help retain the ball until the drop zone:

IMG_3548 by Doug Ridgway, on Flickr

Conveyor: ball anti bounce lever.

IMG_3547 by Doug Ridgway, on Flickr