MItchell 45xx battery/radio control

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JackBlack
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Re: MItchell 45xx battery/radio control

Postby JackBlack » Tue Nov 12, 2019 8:40 pm

Thanks for the replies, I've actually not seen either of those boost boards, the smallest I could find are the ones I used. Do you get enough current though? The larger adjustable booster outputs 2A.

The 9V Pololu board looks ideal for an RX63 though so I'm going to order a couple to have a play around.

Having said all that, the desire to remove the need for a voltage booster has led me down the route of 4V motors and I'm getting good results with this latest one, the Mabuchi N30. So I'm going to see how it goes. Also for the price of a Mashima motor + Pololu 9v board I could buy 30 Mabuchi N30 motors!

The 45XX is very nearly finished so I'll post some more pics and videos later in the week.

Cheers, Nick

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JackBlack
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Re: MItchell 45xx battery/radio control

Postby JackBlack » Sun Nov 17, 2019 10:33 am

Back in Portugal, 4556 is basically finished. I now need to install the little connection board that allows the battery to be connected and the power to the RX/Motor that are in the chassis to be connected, and then locate the switch and charging socket in the cab. Some cab detailing still to be done. It currently weights 180gms, but it needs some more weight in the coal bunker as it's slightly front-heavy right now, and I think I can get some more weight in the tank sides once everything's put together.

IMG_20191116_212826386.jpg


IMG_20191116_213017990.jpg


More later. Cheers, Nick

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JackBlack
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Re: MItchell 45xx battery/radio control

Postby JackBlack » Fri Nov 22, 2019 5:12 pm

A bit of progress this week...

Chassis with the N30 motor and RX63...

01.jpg


These are the main parts, 14430 battery, switch, charging socket and my connector board.

02.jpg


The battery attaches to the connector board using two 12BA nuts. The same arrangement for the RX. I've ordered some 1.47mm pitch micro connectors for my next project so I can tidy this area up a bit.

03.jpg


The connector board is sandwiched between two pieces of plasticard and glued to a piece of lead which is for now blu-tacked to the underside of the firebox. Charging socket and switch are fed through to the cab.

04.jpg


Undercoated, but I forgot to attach the doors dammit...

05.jpg


Nearly there. Iron Mink 63229 watches with interest, gently reminding me that it's been waiting two years for buffers to be fitted...

06.jpg


07.jpg


All the parts ready for painting, doors attached!

08.jpg


Now to the painting...

Cheers, Nick

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Le Corbusier
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Re: MItchell 45xx battery/radio control

Postby Le Corbusier » Fri Nov 22, 2019 11:06 pm

I know this is meant to be about battery control .... but actually I am loving the loco build itself ;)
Tim Lee

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JackBlack
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Re: MItchell 45xx battery/radio control

Postby JackBlack » Sat Nov 23, 2019 10:29 am

Le Corbusier wrote:I know this is meant to be about battery control .... but actually I am loving the loco build itself ;)


Thanks! It's gone suspiciously smoothly so far, I'm still waiting for something to go wrong...

Last night and this morning basic colours have gone on. Undercoat is Halfords Grey Primer.

09.jpg


Humbrol matt black (which isn't matt)...

IMG_20191122_144935141.jpg


Precision GWR Loco Green and Buffer Beam Red and then Alclad II Copper Laquer for the chimney top.

IMG_20191123_101000634.jpg


IMG_20191123_101036014.jpg


I have a rather domestic weekend ahead of me, but hopefully this will be dry enough to put the decals on tomorrow evening and pick out the whistles and other details. After that weathering with oils on Monday, which takes a week to go off, and should be dry enough to bring back to London on the 1st....


Cheers, Nick

Alan Woodard
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Re: MItchell 45xx battery/radio control

Postby Alan Woodard » Sat Nov 23, 2019 12:42 pm

Enjoying the build also, and how the R/C goes together.

Regarding the Halfords primer paint. They do an Acid etch grey primer which is more expensive, but is better on Brass. It provides a stronger base for the top colour. Less chance of paint chipping off of cause.

Cheers.

Alan.

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JackBlack
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Re: MItchell 45xx battery/radio control

Postby JackBlack » Sun Nov 24, 2019 11:23 am

Thanks Alan. The next time I'm in Halfords I'll pick one up to try. I've had problems before with masking tape lifting off paint and primer back to the brass, which is really annoying! Maybe this will help. Cheers, Nick

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zebedeesknees
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Re: MItchell 45xx battery/radio control

Postby zebedeesknees » Mon Nov 25, 2019 4:26 pm

Dave Long wrote:-
I'd certainly look at the Pololu regulators, I've never seen the point in the adjustable versions or having a step down function, plus they are even smaller.


Many thanks for this info Dave, I/we hadn't discovered those. the RobotShop was out of stock of the 12 volt ones, but I found a source in Germany and they arrived last week. 'Even smaller' is an understatement! They are tiny, I can lay two to just cover one thumbnail.. Which bothered me a little, as looking at the graph of the output, the volts start to drop as the current exceeds 300mA.

On testing one today with a relatively high current old ModelTorque motor, I found that after about ten seconds under full power and maximum load with the clutches stopped, at 380mA the volts dropped, then pulsed, then the output folded back to zero. Power off, then on again, it came up to the original 12.12 volts. So I did it again, and after the output ceased, I touched the chip and burned my pinkie!

I deduce that it was a thermal shutdown, protecting the Pololu, -and the motor if it is stalled and drawing over-current. Thoroughly recommended, with the reservation that it should not be mounted too close to anything that might be damaged or melted by temperature in excess of 60°C.

Ted.

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JackBlack
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Re: MItchell 45xx battery/radio control

Postby JackBlack » Thu Nov 28, 2019 11:36 am

4556 is basically finished now, with a bit of light weathering using oils and powders. I just need to fit the buffers, coupling hooks and add some coal which I'll do over the next couple of days.

It runs nicely, and I was going to make a video to demonstrate, however it seems to have lost a crankpin nut on one of the front wheels. So I'm going to have to wait until I get back to London on Sunday to replace it and figure out why it came off...

IMG_20191127_184356_721.jpg


Cheers, Nick

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JackBlack
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Re: MItchell 45xx battery/radio control

Postby JackBlack » Sun Dec 01, 2019 10:42 pm

4556 with it crankpin nut fixed, buffers, coupling hooks and coal. I've somehow managed to get the weight up to 232gm. It runs nicely on my tiny test track, but on Saturday we'll hopefully see what it'll pull using Ted's traction testing thingy.

I've also figured out that the videos look better if you turn your phone sideways...



Cheers, Nick

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Le Corbusier
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Re: MItchell 45xx battery/radio control

Postby Le Corbusier » Sun Dec 01, 2019 10:49 pm

JackBlack wrote:4556 with it crankpin nut fixed, buffers, coupling hooks and coal. I've somehow managed to get the weight up to 232gm. It runs nicely on my tiny test track, but on Saturday we'll hopefully see what it'll pull using Ted's traction testing thingy.

I've also figured out that the videos look better if you turn your phone sideways...



Cheers, Nick


Well impressed ..... and that's just the music :thumb
Tim Lee

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Mike Garwood
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Re: MItchell 45xx battery/radio control

Postby Mike Garwood » Mon Dec 02, 2019 4:40 pm

Nice loco and excellent choice of music!

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JackBlack
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Re: MItchell 45xx battery/radio control

Postby JackBlack » Tue Dec 03, 2019 6:47 pm

Can't beat a bit of Floyd on a Sunday evening...

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JackBlack
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Re: MItchell 45xx battery/radio control

Postby JackBlack » Sun Dec 08, 2019 4:47 pm

So I just wanted to close this thread out before I do a post about my next project.

I took 4556 to Mr Scannell's house yesterday so we could measure the traction pull on his test track. If any of you have seen this you'll know how it works, but basically it has a little pulley and a weight and some scales to test how much weight the loco can pull before it spins the wheels. What you don't want to see is the motor stall.

So with a weight of 232g the 45xx could pull 60g until the wheels spun. The motor didn't stall. This compares with Ted's Bachmann Cl.20, re-wheeled with track pick-up, weighing 400g could pull 80g. The theory is that a loco should pull 2g per axle, so for the 45xx - 15 wagons or 7 maybe 8 coaches. We didn't test that. Would be interesting to compare this with the same kit built with conventional pick-up and a 12v motor.

As for battery life, the 45xx, fitted with the 14430 750mAh lipo battery, when fully charged will run for just under 5 hours, measured upside down in my loco cradle at full speed. Under load we don't know how much that would reduced by, would be interesting to see, but for that we need a roundy-roundy...

It's very nice to see the interest that I've had in this build, and I find that it motivates me to continue and ultimately finish the project (unusual for me I'm afraid...). So thank you all for that.

Cheers, Nick

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zebedeesknees
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Re: MItchell 45xx battery/radio control

Postby zebedeesknees » Sun Dec 08, 2019 7:12 pm

Mea culpa! I know I shouldn't rely on my memory, but sometimes I forget...
The drawbar pull theory was that it takes about 2g per carriage to keep it rolling, and a little more, perhaps 2.5g, to lift one from rest.
So JackBlack's 45xx should be good to lift 20 carriages or more on the straight and level.
We would love a chance to test that!

Ted.

David Catton
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Re: MItchell 45xx battery/radio control

Postby David Catton » Sun Dec 08, 2019 9:23 pm

I'm gradually building up my stock of RC bits and pieces so I can join in the fun. I'd been sceptical about all this RC stuff until I read about Nick's 45XX and his exploits with Ted Scannell at Scaleforum. I confess that buying from China is a revelation - so many useful items at prices that make it easy to buy in bulk. Our postie has given me a talking-to because the Post Office receives no payment for delivering little jiffy bags from China (post-free!) but that seems to be where most of the items we need are made - and available at very reasonable prices. Honourable mention should go to UK suppliers <https://www.componentshop.co.uk/>, <http://www.hobbytronics.co.uk/index.php?route=common/home> and <http://www.micronradiocontrol.co.uk/rc_model_rail.html> from whom I have bought as well as those well to the east of the UK, e.g. Alibaba and Banggood.

So what have I bought so far?

Far more motors than I will probably ever use as the locos I have so far are all equipped with 12V motors and run well enough so I will probably resort to voltage boosters to allow me to keep them as close as possible to as-built. Today I ordered some MT3608 DC-DC Step Up Power Module Booster Power Module MAX Output 2A from <https://www.ebay.co.uk/usr/ai_smart?ul_noapp=true> for 33p each!

I've also ordered various connectors and switches but the recommended transmitter and receivers are OOS at present but should be in stock again by the end of the week when I will place my order.

One little snag is batteries with protection circuits so I'm hoping posting this message might lead to revelations about what are the best products to buy. I'm tempted to think that flat batteries (similar to those in mobile phones) might be best for installation in the tenders of tender locos and perhaps also in diesel locos. If the size is right they might be OK in the tanks of larger tank locos but Nick's use of a cylindrical battery in his 45XX suggests that that shape might be preferable.

All in all, I have to say I'm excited by the possibilities of RC and hope that those experimenting contribute to this thread so we can all benefit from the results.

Cheers,

David C

PS Should we change the title of this thread to make it more general?

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grovenor-2685
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Re: MItchell 45xx battery/radio control

Postby grovenor-2685 » Sun Dec 08, 2019 10:20 pm

PS Should we change the title of this thread to make it more general?

No, start a new thread (topic).
Regards
Keith
Grovenor Sidings

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JackBlack
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Re: MItchell 45xx battery/radio control

Postby JackBlack » Sun Dec 08, 2019 11:39 pm

I agree with Keith, lets start a new thread. There's already one for motors, maybe start one for batteries?

David Catton wrote:One little snag is batteries with protection circuits so I'm hoping posting this message might lead to revelations about what are the best products to buy. I'm tempted to think that flat batteries (similar to those in mobile phones) might be best for installation in the tenders of tender locos and perhaps also in diesel locos. If the size is right they might be OK in the tanks of larger tank locos but Nick's use of a cylindrical battery in his 45XX suggests that that shape might be preferable.


All the little flat batteries that you see on eBay for drones, eg this kind of thing:

https://www.ebay.co.uk/itm/240-1000mAh-3-7v-20c-Lipo-Battery-with-PCB-for-RC-h37-Quadcopter-Drone-U45-763E/123231648240

These are all good and you can get them up to 1000mAh easily enough and they have the protection circuit and will charge fine.

You can go beyond this, which will be the subject of my next project, where I'm using one of Ted's 18650 batteries that's been fitted with the strip-style protection circuit (this: HERE), and packs a mighty 3800mAh, and fits nicely in a GWR 4000 gallon tender.

So we have lots of options, it just depends on the shape/space you're trying to fit the battery into. I failed miserably to get square battery into the side of a tank loco, they are bigger and fatter than you expect, but the cylindrical 14430's and 14500's fit perfectly in the boiler/smokebox (and the name refers to the size - 14430 - 14mm by 43mm, 14500 - 14mm x 50mm (AA size), 18650 - 18mm x 65mm - these are vape batteries).

But lets discuss this further on another thread!

Cheers, Nick

Lindsay G
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Re: MItchell 45xx battery/radio control

Postby Lindsay G » Mon Dec 09, 2019 12:18 am

All we need is someone to initiate that thread - I'd be interested but with zero knowledge have nothing to contribute. Jack, over to you?

Lindsay

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grovenor-2685
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Re: MItchell 45xx battery/radio control

Postby grovenor-2685 » Mon Dec 09, 2019 3:06 pm

Everybody can initiate threads (topics) just back off into 'radio control' and start new topic.
I will be able to move appropriate posts from here when there is a new topic.
Rgds
Regards
Keith
Grovenor Sidings


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