DCC the Hornby R070 turntable?

[Bebbspoke]

Hi Peoples - please; - has anyone experience of running the Hornby R070 turntable via DCC?
I'm considering using the Digikeijs DR5052 via TrainController Gold...
Thanks in advance...
John

[Chrissaf]

There is a detailed 'How To' thread on this forum, detailing how to convert the Hornby R070 for use on a DCC layout. The conversion methodology has been put together as a consensus of several forum members and is an improved conversion method over the method documented by Hornby.

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You can read the 'How To' threads here:

http://www.hornby.com/uk-en/forum/r070-hornby-turn-table-to-dcc-including-images/?p=1

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R070 DCC Conversion – my version with a detailed drawing

https://www.hornby.com/uk-en/forum/post/view/topic_id/27722/?p=2

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I haven't done a full evaluation of the Digikeijs DR5052 Turntable DCC decoder, but my initial research assessment indicates that this decoder may not** be compatible with the Hornby R070, as the R070 does not have the 'bridge position sensors or stepper motor' technology that the DR5052 is designed to work with. The DCC conversion of the Hornby R070 uses a standard loco decoder which is more compatible with the motor technology used in the R070. The Hornby R070 uses a very mechanical bridge position indexing system based upon mechanical gears, and not the electronic position sensors used by the DR5052 decoder supported TT brand / models.

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The bulk of the 'How To' link above is devoted to the physical DCC modification of the Hornby R070 which is required to prevent 'short circuits' when used on a DCC layout. Out of the box, the R070 is designed for DC Analogue layouts and is not DCC friendly without being modified as documented.

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EDIT:

Note** After a bit more research, I am now of the strong opinion that the DR5052 decoder is not compatible at all with the way that the Hornby R070 operates. It is designed specifically for the following H0 scale turntables that have specific technical features that the DR5052 decoder is designed to work with:

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Link to DR5052 decoder online manual.

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TIP: As a newbie poster on the forum, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply to any of the posts, scroll down and write your reply in the reply text box at the bottom of the page and click the Green 'Reply' button.

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See also – further TIPs on how to get the best user experience from this forum.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

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[Bebbspoke]

Thank you Chrissaf for your reply - I may well look into the possibilities of a/ converting to use a stepper motor or b/ using opto or Hall effect switching - I've not (as yet) not had the questionable delights of perusing the Hornby "mechanical indexing"... but as it's been going a long time it must be fairly reliable... might be able to adapt such to sync with an opto or Hall... could be a fun(?) project to while awayb the boredom of lockdown... though stepper motor probably a safer bet as it will not be affected by any system processing delays... food for thought. Cheers.

[Bebbspoke]

Hmm... now one just needs to know which of the current "other manufacturer" TT's are stepper motor driven....?

[Ruffnut Thorston]

The Hornby turntable uses a 'Geneva Gear' system.

 

This is a large gear wheel with a raised bar which fits into channels under the rotating ring of the turntable.

 

The operation is therefore in 'steps', as the turntable is only moved as the raised bar is pulling it around.

 

The 'indexing' is purely the fact that there is a fixed pause while the turntable is aligned with an exit, while the gear is rotating with the bar clear of the rotating ring, giving the operator a chance to turn off the power supply to the turntable motor.

 

in fact, the pauses are at the same interval, so the turntable stops even if there are no exit tracks at that position, moving in a series of jerks.

 

in my opinion, there is no easy way to modify the Hornby turntable to use a stepper motor, or any other technology.

 

It would be easier to start with something else. 

[jane1707819582]

Hmm... now one just needs to know which of the current "other manufacturer" TT's are stepper motor driven....?

Adm turntables.

Metalsmith

The arduino system lends itself to this.

[96RAF]

Just Google Model Railway Stepper Motor Turntables. Lots of manufacturers and ideas out there.

[Chrissaf]

Before embarking on any expensive modifications or purchasing of turntables that are not in the decoder supported list. I would first of all FULLY RESEARCH the contents of the decoder manual to ascertain exactly what turntable technology it requires. My assessment was very brief and based upon just speed reading the introduction section. Therefore, do not take my 'it requires this XXX technology' comments as being gospel.

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Section 6 [starting page 36] of the manual clearly demonstrates the custom nature of the decoder product. I notice that the decoder retails at about £100 plus the supported turntables are unlikely to be cheap either. The risk of wasting your money is very high if you continue to go down the modify a non supported turntable path. Section 6 also shows that in some turntable configurations, additional decoder interface boards are required. The cost of those need to be factored in too. Section 6 seems to show that the DR5052 makes extensive use of 'Loconet' to provide 'feedback' to a Digikeijs DR5000 controller. This may not be compatible with your proposed 'controller'.

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My overriding inference that I got from looking at the decoder manual was that it was a very specific custom decoder specifically for the listed turntables, it talked about being compliant with those products communicating protocols. It may be that trying to replicate exactly how the supported turntables work is an impossible task. It may not be as simple as just using a turntable that deploys stepper motor technology [section 6.8 of the manual]. I totally agree with Sarah's comment.