Design pyramid for marble track.

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fotoopa
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Design pyramid for marble track.

Beitrag von fotoopa » 24 Nov 2017, 18:59

I have been working for a year on a huge marble run. Many modules have already been completed. I use 4x Dynamic XL, 4X Creatieve box 1000, 4x Dynamic tunning set, powerset, XM motors etc. Most of the photos are on my Flickr:
http://www.flickr.com/photos/fotoopa_hs/
I just made a new module, a pyramid for the steel balls. Most modules will be ready within a few months. They are meant to work interactively for the grandchildren.

Some examples:
https://farm5.staticflickr.com/4577/379 ... 0cda_o.jpg
https://farm5.staticflickr.com/4569/385 ... 8274_o.jpg
https://farm5.staticflickr.com/4581/382 ... 4340_o.jpg
https://farm5.staticflickr.com/4527/266 ... 3d2d_o.jpg

I hope the links work, this is my first post. I use a self-assembly controller for the control ( 16 motors, 32 servo's, 128 color neoleds WS2812B, multiple in- and outputs, 4x20 char LCD display, rotary encoders, hall sensors, reflection sensors etc ).

Frans (fotoopa).

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PHabermehl
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Re: Design pyramid for marble track.

Beitrag von PHabermehl » 24 Nov 2017, 20:41

Hi Frans,
This is quite a lot of impressive stuff. I'm really curious to see the final marble monster...

But I don't understand the function of the pyramid yet - could you please explain a little more?

Thanks,
Peter
https://www.MINTronics.de -- der ftDuino & TX-Pi Shop!

viele Grüße
Peter

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geometer
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Re: Design pyramid for marble track.

Beitrag von geometer » 24 Nov 2017, 21:58

Hi.

the pyramid distributes the balls onto seven tracks. All axles are connected with gears. One of these axles is driven by a servo, so that children can interactively try to determine the path of the balls. The upper plate is tilted. The balls enter from the single gate at the top. One might call it a driven Galton board.

I quote the text that comes with the picture:

"Via de servo kan je het verloop van de kogelloop beinvloeden. Met heel veel tandwielen worden de assen verdraaid. De servo wordt met een knop bediend waar een Rotary encoder opstaat. De servo heeft 2 uiterste grenzen, eentje op 900 usec en eentje op 2100 usec. Als je deze grens bereikt hebt wordt de waarde niet meer gewijzigd tot je in de andere richting draait. Door de vele tandwielen is het moeilijk om de draairichting per asje bij te houden. Dit maakt het leuker want de kogel kan net de andere richting kiezen dan je dacht. Speciaal gemaakt voor de kleinkinderen die hiermee heel interactief kunnen spelen. Er komt nog kleurled aanduiding en een punten systeem als je een bepaalde uitgang bekomt."

Best,

Thomas

fotoopa
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Re: Design pyramid for marble track.

Beitrag von fotoopa » 25 Nov 2017, 10:09

Thanks Thomas for the translation. I did not know the name of "a driven Galton board". 60 years ago I saw such an board at the fun fair. I now wanted to recreate those with Fischertechnik parts but with the addition of an interactive element. The grandchildren are too young to build it (3 and 5 years) but they like to play with it.
Possibly I'm going to arrange the horizontal plane with a second servo. The horizontal plane has more influence on the trajectory of the balls. I first have to build all my basic modules before I connect the ball trajectories. That is why there is still a lot of work to be done.

My table surface is 1200x800mm.

Bild

In the background you can see here my Fischertechnik parts and another module under construction:

Bild

If there are more modules finished, I will show them here.

Frans.

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PHabermehl
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Re: Design pyramid for marble track.

Beitrag von PHabermehl » 25 Nov 2017, 14:15

Thanks for the explanation, guys.

Actually I know the Galton board, but I did not understand why the pins are geared together. I could imagine that a permanent rotation in one direction has a noticeable impact on the distribution, but can one really influence the distribution by the rather short moves of the servo? The pins don't have friction coating, do they? Maybe if you put pieces of silicon hose on them, the friction will increase, thus giving a stronger momentum to the balls.

Kind regards,
Peter
https://www.MINTronics.de -- der ftDuino & TX-Pi Shop!

viele Grüße
Peter

fotoopa
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Re: Design pyramid for marble track.

Beitrag von fotoopa » 25 Nov 2017, 14:56

Well, you still miss a small detail:

Bild

The clip 5, FT-37679 is mounted on the 4 mm shafts between the plexi plates. That clip is not completely round, there is a slit. During the assembly of all axes you can decide how this clip will be mounted. A slight random value is nice. Through this slot the steel ball can sometimes lie. A small movement of the servo can determine the direction. But it goes quickly and the rotation are difficult to predict by the successive gears. This now works excellent and is super fun for the children.
Because a servo can only turn a certain angle, you must first turn back to the other direction. Because of this you can not continuously keep a certain direction on the right or left.

Update:
Here a view of the last version:

Bild

Frans.

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PHabermehl
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Re: Design pyramid for marble track.

Beitrag von PHabermehl » 26 Nov 2017, 02:34

Okay, now it's clear. Hats off!

Kind regards,
Peter
https://www.MINTronics.de -- der ftDuino & TX-Pi Shop!

viele Grüße
Peter

fotoopa
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Re: Design pyramid for marble track.

Beitrag von fotoopa » 26 Nov 2017, 17:30

Thanks Peter!

Today I made a distribution module for the steel balls. This module determines how many steel balls must be forwarded to other modules. I have placed 6 neodymium magnets for position determination. At the top there must be a reflection detector to count the correct number of steel balls. Drive is with an XS engine.

Here the photos:

Bild
Bild

Here is a detail how I place a neodymium magnet in a Fischertechik block FT-38413:

Bild

I still have to build a few separate modules. Then I can interconnect the individual modules and make the pathways. Thereafter, may also be the signaling with neoleds. They are in a loop of 128 color leds.

Frans.

fotoopa
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Re: Design pyramid for marble track.

Beitrag von fotoopa » 05 Dez 2017, 14:18

Today I have adapted some FT 37468 blocks to fit a ball bearing D8xd4x3 mm. The steel shafts turn smoother with this bearing. I also mounted some neodymium magnets in the FT-37468 blocks. These are used as limit switches.

Bild

The blocks were first drilled out with D4.3 and then with a milling tool 8mm, 3.5mm deep to mount the ball bearings. The neodymium magnets are D3 x 3mm. The detector for this is the hall sensor AH3144EUA (Conrad : 1424999 ).

Update:

Check the polarity of the magnets for the hall detectors. Fischertechnik FT-119850 has not always the same polarity! The north pole (white line on the compass needle) must point towards the front of the magnet.

Bild
Bild

Frans.

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