[GBC] Akiyuki Train System: Type 2 mods and improvements

[doug72]

19 hours ago, dunes said:

had a successful evening/night. but came across an issue. U used the Type 2 turntable for your z56 timing gear. which I dont have. tried with Type 3 but the small 8T gear wont fit. If I change the the gears the timing wont match.

Do U have any tips on fixing this problem without buying Type 2 turntable? I have a bunch of Type 3 here.

 

Good progress.

A Z56 turntable must be used in order to get a 7:1 reduction to get the timing correct. i.e. 56 / 8 = 7 plus the 3:1 stage gives 21:1 reduction for correct timing

This cannot be achieved using a Z60 turntable as only the 12T gear will mesh and only gives a 5:1 reduction.

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Found another annoying issue which I have yet to solve, the dreaded 1/2 L problem !

Although the train unit enters the dumper, rotates and exists OK there is an issue in that the track within the dumper is not level & horizontal.
The track at the static ring end is lower by 1/2 L when track at the exit lines up with the output track to the elevator.

This can cause the 8T gear on the train axle ends to not engage with the 4L gear rack segements as train exits the dumper due to the slight hump - hence the section of 4L gear racks over lapping the rotating gear rings.

This 1/2 L discrepancy is caused by the gearing arrangement in the rotation frame connecting to the trip section 

The distance between the black 20T gear axle and the pins joining the gear ring quadrants is 4.5L 
Tried rotating it 180 degs but this makes the distance 5.5L

Somehow need to find if possible to get it correct at 5L

A 12T double bevel gear with 18mm wedge guide wheels will work without fouling the gear ring and will be able to get the correct overall 21:1 reduction

Still investigating if this can be solved with a redesign of the rotating frame but may have to put up with it.

Doug

Edited July 18, 2018 by Doug72

[doug72]

It is possible to use a Z28 turntable instead of the Z56 turntable by changing the two 16T gears (1:1) to  24T /8T gears. (3:1)

This will give the required reduction. i.e. 3 x 3 x 28 / 12 = 21:1

The 12TDBG would have to be at a right angle to the turntable 28T gear so another right angle drive would be required.

Use the 24T gear to get the timing right to release the train as the track lines up.

Heres a mock up of possible gear layout. Its a tight squeeze to fit in place.

 

 

Edited July 18, 2018 by Doug72

[doug72]

Rotary Dumper  Dougs MOD Mk 3

After a lot of head scratching, trial & error and a number of false starts,  I have finally eliminated the 1/2 L problem and kept the timing gears the same.

First attempt I raised the mounting points for the static gear rings by 1/2 L but was not successful.

A new rotating frame had to be developed that incorporated a 0.5 thin 5L beam between the two 5 x 7 frames, to ensure all eight 20T gears ran on the curved racks smoothly..
This allowed the attachment points for the drive unit to remain the same.

First test was not successful as the unit rotated the wrong way !!

The black 20T gear no longer requires a 16T idler gear, instead it meshes directly with the tan 20T gears that engage with the gear rings.

Simple fix - reposition the tan 12T gear to the other side of the right angle gear frame - see photo.

Trip timing had to be reset correctly again.

All yellow gear quadrant gears are now on the same plane and track beams now all level throughout.
Rotation is also smoother.

End view

Side view

Location where 12T bevel gear had to be repositioned to get correct rotation.

 

Edited July 19, 2018 by Doug72

[dunes]

thanks Doug. Mod applied.

next is to add your Z28 turntable mod.

[doug72]

12 minutes ago, dunes said:

thanks Doug. Mod applied.

next is to add your Z28 turntable mod.

That was quick  !

Fitting the Z28 MOD will be a tight fit, I,ve not actually done it and keeped the Z56 version.

Look forward to see your solution and how it performs.

The top connection between ball discharge chute and the gear ring at the entry from the elevator is a bit flimsy & relies on a single axle causing the ring to flex as the unit rotates, think I have found a way to improve it

Will try it tomorrow & post the Mod.

[dunes]

42 minutes ago, Doug72 said:

Fitting the Z28 MOD will be a tight fit, I,ve not actually done it and keeped the Z56 version.

Look forward to see your solution and how it performs.

My 1st attempt. Timing is not set correct atm but the manual drive is fine

[doug72]

20 minutes ago, dunes said:

My 1st attempt. Timing is not set correct atm but the manual drive is fine

Looks good and there is good clearance of the Z28 t/t from the yellow gear rings.

Can you post a pic of the 24T / 8T reduction gear side.

Edited July 19, 2018 by Doug72

[dunes]

[doug72]

Thanks for the photo, 

The Z28 mod fits in very well. Hope the timing works OK.

Now modified the connection between the ball discharge chute and yellow gear rings. Now a much more rigid connection & no flexing. Tested and OK.

Parts required:-
2 x blue axle pin connectors .
2 x 4L thin beam with axle holes each end (Red)
2 x 3L axle

Edited July 20, 2018 by Doug72

[dunes]

Looks good. will add it later to my model.

Rotating is quite accurate but the force to move the spring backwards is to high. sometimes its stop close before release. and its not a battery problem. Used the old train control to provide the power.

On a bigger wheel the force is higher on the output. so will need to get  the Z56 T/T.

[doug72]

21 minutes ago, dunes said:

Looks good. will add it later to my model.

Rotating is quite accurate but the force to move the spring backwards is to high. sometimes its stop close before release. and its not a battery problem. Used the old train control to provide the power.

On a bigger wheel the force is higher on the output. so will need to get  the Z56 T/T.

Worth a try, the larger 56t gear driven by the 8T gear has more turning force.

At least you have proved the timing works OK and track lines up.

Even on mine using the 56T turntable the rotation slows down a bit as the spring compresses.

The last mod has got the distance between fixed and rotating gear rings constant all round.

[doug72]

Rotary Dumper - reversing unit using rubber bands & Z56 Turntable gear.

I have now developed a reverser unit using Lego red silicon bands. Trip arm travel is 2L.
More compact and the overhang is reduced by 2L to give more clearance for ball chutes.

The two  LEGO Minfigure Neck Brackets (42446) are no longer required.

See photos, video tomorrow once camera battery recharged.

Edited July 24, 2018 by Doug72
correct image added

[doug72]

Camera battery recharged:-

Video of rubber band reverser unit for the Rotary Dumper.
 Temporary track set up to demonstrate.

Reverser at other end has 4 lobes hence the quick reversing.

Now will rebuild using a Z28 turntable to see if will function OK.

Now tested with Z28 T/T & it does not work.
Managed to eliminate the extra right angle drive but the 16T idler gear keeps skipping as too much torque required to rotate the Z28 gear when the red arm starts to push the trip system against the force of the rubber bands.

So a Z56 turntable is only option for the Dumper mod.

See next post

Edited July 25, 2018 by Doug72

[doug72]

Rotary Dumper Reversing unit:-
Finally got a Z28 turntable to work using rubber bands.

The problem with skipping gears has been overcome as shown in the photo.

Two 12T double bevel gears in series mesh with the Z28 gear ring by using thin 3L beams with axle holes (green) as spacers to get the two 12T bevel gears to mesh together.

Tested using two rubber bands and train reverses OK.
Also tested using a single rubber band and enough power to hit trip bar and still reverse the train OK.

I found the solution in Machines & Mechanisms Book by Isogawa

 

Edited July 25, 2018 by Doug72

[Berthil]

Just wanted to say I'm following your work with great interest and hope all problems are solved resulting in a digital file from dunes so I can replicate before it is October as I intend to show this at Lego World in Utrecht the whole week (so has to be reliable). With almost 100.000 visitors in one week it is the biggest LEGO event in the world. Really appreciate it. I will try to fit it in the setup I have with combined lift and rotator.

Edited July 25, 2018 by Berthil

[doug72]

On 7/25/2018 at 6:03 PM, Berthil said:

Just wanted to say I'm following your work with great interest and hope all problems are solved resulting in a digital file from dunes so I can replicate before it is October as I intend to show this at Lego World in Utrecht the whole week (so has to be reliable). With almost 100.000 visitors in one week it is the biggest LEGO event in the world.

Many thanks, I think all the problems have now been resolved.
I run it every day and it has proven to be very reliable, with consistent discharging of the empty train unit.
This is the version using Z56 turntable and a shock absorber.

The trip unit with Z28 turntable version using rubber bands also is reliable and I intend to install it in the dumper to test its reliability.

Both T/Ts give the rquired 21:1 gear ratio to rotate dumper and syncronise the train trip unit.
Only thing that needs changing is the position of one 12T single bevel gear to get correct rotation of the trip rotor arm and the gear train that drives the Z28 T / T.
Discharge chutes as required to suit your needs for GBC connection.

Only train module that occasionly gives bother is the elevator dropping before the latch holds the lift platform, working on improving that.

I hope you can build this in time and look forward to seeing a video of it in action at Utrecht.

 

 

Edited July 28, 2018 by Doug72

[dunes]

Great to see U got it working with the Z28 T/T. I built it my self and its working like in your video.

and done the LXF for that too. Available at my bricksafe.

Did some optimization on the base during building process. And there is room for more. Will do it later when we figured out what Ive forgot or done wrong in digital building process xD

[doug72]

8 hours ago, dunes said:

Great to see U got it working with the Z28 T/T. I built it my self and its working like in your video.

and done the LXF for that too. Available at my bricksafe.

Thanks for your excellent work.

Can you also do the other variations i.e Z56 with shock absorber and Z56 with rubber bands.

I will be away from my main computer and Lego work station all next week (dog sitting !) but will have access to an iPad so I can review the LXF files when they are ready.

[doug72]

Checked the LXF file and all OK except the trip arm where I made a small change as the 3L thin beam could sometimes catch as arm fully retracted.

2L thin beams (blue) used instead, with 3L axle kept - which helps guide the arm as it fully retracts.  Photos show this

Edited July 26, 2018 by Doug72

[dunes]

3 hours ago, Doug72 said:

Checked the LXF file and all OK except the trip arm where I made a small change as the 3L thin beam could sometimes catch as arm fully retracted.

2L thin beams (blue) used instead, with 3L axle kept - which helps guide the arm as it fully retracts. 

I‘ll update the LXF with 2L thin beams in the evening and also do one with the Z56 T/T.

[doug72]

One final fix, the vee reverser using rubber bands has enough force to knock the front wheels of the train off the track as it exits.

Easy fix, 15L side beam added to prevent this.

All problems now resolved.

Edited July 26, 2018 by Doug72

[dunes]

Reverser Unit Z56 T/T with rubber bands,

Reverser Unit Z28 T/T with rubber bands

- used Technic Bush instead of 2L Thin Beam

Reverser Unit with rubber bands

- added 13L beam

[dunes]

Intergrated the Z28 T/T in the Rotary Dumper.

Timing is correct. Manuel drive is fine. I might have a problem with my train unit. sometimes the motor just stop with no reason. Switch is changed. same issue. 

Tomorrow Im going to build a 2nd one and test again.

 

LXF in the works

Edited July 26, 2018 by dunes
render added

[doug72]

16 hours ago, dunes said:

Intergrated the Z28 T/T in the Rotary Dumper.

Timing is correct. Manuel drive is fine. I might have a problem with my train unit. sometimes the motor just stop with no reason. Switch is changed. same issue. 

Tomorrow Im going to build a 2nd one and test again.

LXF in the works

 

Does Train un it work when you manually push the trip bars ?

If so there might be not enough force from the rubber bands to rmove them fully.

Try increasing the rubber band tension.

Also check PF cables are not impeding thie trip bar travel.

Check the PF connectors for poor contacts.

LXF looks good.

Doug

Edited July 27, 2018 by Doug72

[doug72]

Lego 25mm rubber bands, Red v Blue.

Do they have the same tension force ?

It seems there are two sizes of blue bands, 25mm & 26mm.

So a 26mm will have less tension then a 25mm Red band.

Edited July 28, 2018 by Doug72