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Ray's 4mm Workbench, Metalsmiths Turntable (end of P.13)


tender

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Tender,

 

Ymmv, but my turntable well warped over a few years. Perhaps worth planning to avoid that rather than fixing it after the event as I had to.

 

Herewith a link - it was 4 years back, you were there, I think! Thought I had some pix of the deck, on its frame, on the kitchen granite, whilst it all set, but can’t find them if so.

 

http://www.rmweb.co.uk/community/index.php?/topic/76732-stepper-motor-turntable-drive/?p=1227433

 

 

Best

Simon

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Tender,

 

Ymmv, but my turntable well warped over a few years. Perhaps worth planning to avoid that rather than fixing it after the event as I had to.

 

Herewith a link - it was 4 years back, you were there, I think! Thought I had some pix of the deck, on its frame, on the kitchen granite, whilst it all set, but can’t find them if so.

 

http://www.rmweb.co.uk/community/index.php?/topic/76732-stepper-motor-turntable-drive/?p=1227433

 

 

Best

Simon

And make sure if you don't fit it straight away store it 100% flat with something heavy on the top

 

Tony

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Tender,

 

Ymmv, but my turntable well warped over a few years. Perhaps worth planning to avoid that rather than fixing it after the event as I had to.

 

Herewith a link - it was 4 years back, you were there, I think! Thought I had some pix of the deck, on its frame, on the kitchen granite, whilst it all set, but can’t find them if so.

 

http://www.rmweb.co.uk/community/index.php?/topic/76732-stepper-motor-turntable-drive/?p=1227433

 

 

Best

Simon

 

Gosh, i'd forgotten that. Hopefully my 4mm scale turntable won't suffer so much with warping, but i'll keep a check on it all the same. Being a deeper well hopefully it will be a bit more stable once all glued up.

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I view of the above comments i departed from the instructions slightly, and instead of installing the deck rail next as per instructions I opted to glue in place the well side wall and top plate with 8mm spacers between it and the middle plate (hope i don't regret this). 

 

post-11105-0-25845400-1518254413_thumb.jpg

 

Now its had time to set overnight it's made a pretty ridged structure. Time will tell.

 

Edit: I might be tempted to glue a strip of ply or similar around the edges of the 3 boards 

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Next up was fitting the race rail. This was supplied in two semi circles and installed using the supplied gauge to drill a number of holes for vero pins to solder the rail to with plastic chairs to fill in the gaps. The two rails supply power to the turntable deck via the deck wheels. I opted to join the two rails electrically and supply just one deck rail, the other will be via the centre spindle giving me power on the deck all the time for sound locos.

 

post-11105-0-92896100-1518370909_thumb.jpg

 

A start was made on the bridge deck with some fold up etch stretchers bolted to Copper laminate sides with 12BA screws.

 

post-11105-0-46866000-1518371525_thumb.jpg

 

Followed by the wheel carriers.

 

post-11105-0-89942300-1518371639_thumb.jpg

 

Attaching the wheel bearings (complete with wheels) was fiddly as they just balance on a quarter moon shape at the end of the carrier. Inevitably one of the axels which come pre pressed into the wheels managed to solder its self to the bearing which slowed the process somewhat.

 

post-11105-0-21950400-1518372131_thumb.jpg

 

The deck itself was pretty straightforward, copper laminate topped with strip wood and chaired rails.

 

post-11105-0-17753100-1518372329_thumb.jpg

 

The gaps are for the fixing bolts to the under frame to be covered with chequer plate detail. 

 

 

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Today was mostly spent adding the girder detail to the Bridge.

 

post-11105-0-04045400-1518462081_thumb.jpg

 

Still a bit of cleaning up to do before it gets a coat of primer.

 

One thing i'm not keen on is the drive to the Bridge. This is by way fo a drive bar that the Bridge sits on over the centre spindle. The idea makes removing the Bridge Deck easy by just lifting off but the flimsy acrylic bar that is supposed to engage in two slots at the ends of the bridge by the wheels just bends down when replacing instead of engaging in the slots.

 

post-11105-0-70890900-1518462366_thumb.jpg

 

I'm looking at replacing the acrylic bar with something more ridged but still insulating as the wheel carriers with the slots in are 'live'.

 

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Handrails and locking levers added to the deck, plus the joining plates on the girder bridge that i forgot.

 

post-11105-0-17678500-1518610904_thumb.jpg

 

The girder bridge and deck now need painting before i can fix the deck to the top and add the chequer plating but the weathers to bad for spraying so i'll probably start work on motorising the deck.

 

 

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The Well installation kit comes with a mount for a DC motor and drive disc. I'm only using the Motor mount but modifying it for a stepper motor with toothed belt drive to the Bridge deck.

 

Four holes were drilled for the stepper and then 3 of them were elongated with a radius from the fixed hole to allow tensioning of the belt by rotating the motor around the fixed mounting hole and tightening the screws.

 

post-11105-0-00665900-1518642527_thumb.jpg

 

The four mounting pillars were shortened to allow just enough space for the drive pulleys.

 

post-11105-0-85885200-1518642540_thumb.jpg

 

The mounting board is quite springy so i'll be making some more pillars to support the centre.

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  • 2 weeks later...

The Arduino controller board has been added to the motor mount, just need to add a opto-sensor to detect a reflective strip on the toothed belt for a reference point.

 

post-11105-0-15100400-1519466175_thumb.jpg

 

The Manual control keypad and display also needs a proper vinyl overlay.

 

Going back to the acrylic drive bar, which drooped under its own weight and didn't engage in the slots of the deck properly. A 1/4"sq brass tube was slotted into the drive centre boss to give it some additional rigidity.

 

post-11105-0-83155800-1519466186_thumb.jpg

 

The deck now has a positive engagement with the acrylic drive bar when placed on top.

 

The deck is currently being painted and weathered.

 

 

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That's a fantastic looking turntable!

 

I am now following your thread with interest.

 

Thanks for your interest Jack.

The next job is to install the sensor to give a reference point for the deck and add a wiper pick-up on the centre shaft for one rail of the  track power, the other is via the race rail. Hope to get on with it today.

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Only managed to get the pick-ups for the centre spindle done today before the power went off.

 

post-11105-0-86218700-1519854636_thumb.jpg

 

Made from 4 strips of 0.5mm phosphor bronze wire soldered to a piece of PCB strip and glued in place on a wood block with the wires exerting a little pressure on the spindle to ensure good contacts.

 

Will try and mount the opto-sensor tomorrow.

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  • 2 weeks later...

Not much progress with the turntable apart from fitting the optical reference sensor. I thought i'd have to paint a stripe on the toothed belt but it picks up the edge of the manufacturers label nicely.

 

post-11105-0-29034700-1520552662_thumb.jpg

 

Spent some time programming the Arduino controller but its not been as straightforward as i'd hoped.

Working ok with the keypad/display or with DCC commands but getting the two to work together is proving a little tricky. At times like this i find a little break clears the mind so have made a start on some Cambrian LSWR 10 ton vans for the new layout.

 

post-11105-0-27329900-1520553790_thumb.jpg

 

The van behind is from a Finney 4mm etched brass kit i built a few years ago. Unfortunately unavailable since the range was sold to Brassmasters which is a shame as it makes up into a really nice model. But it does take an awful lot longer to put together.

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