Accucraft C19, C16 and C21

A

adverse camber

Registered
2 Dec 2009
187
73
East Anglia
Anyone have any experience or knowledge of these electric locos running on DCC. Are they easy to convert from DC? Are they reliable or do they have vices?
Any feedback would be appreciated
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
2,212
587
San Diego
www.elmassian.com
Accucraft typically used Pittman gearhead servo motors, they cannot take prolonged high loads and normally these locos were freewheeling, so it often played havoc with BEMF on many decoders.

I'd recommend Zimo, that has been the most successful over here. I have several Accucraft / AML locos with these motors.

Greg
 
A

adverse camber

Registered
2 Dec 2009
187
73
East Anglia
thanks Greg that is very helpful. If anyone lese has any experience of chipping these or other Accucraft locos I would be grateful to hear if they have had the same problems. Nothing worse than splashing out on an expensive loco only to find chipping it up turns into an even more expensive nightmare
 
Rhinochugger

Rhinochugger

Retired Oik
27 Oct 2009
23,475
3,286
North West Norfolk
I think Maxi-model did one recently :think::think:
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
2,212
587
San Diego
www.elmassian.com
Often these locos come with a wiring diagram. My K4 pacific did, but the diagram was inaccurate...

Also, there was a 6v regulator tucked in a very sneaky place in the loco, so I basically discovered and documented all the wiring. I also rewired the plug between the loco and tender to take advantage of more control, many of the positions in the connector were unused.

Reading what I did and how I went about it might help:
K4 QSI rewire & install

Greg
 
maxi-model

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
4,303
500
Bucks/Oxon/Northants area
I think Maxi-model did one recently :think::think:
Nah. It was a battery/RC conversion on an Accucraft K-27 with a Sierra sound card. No DCC involved. Got all the bits together but still got to summon up the courage to dove in and do it. Some very helpful, knowledgeable and generous folk here :inlove:. There was a lot of mucking about ensuring the Sierra didn't get fed any PWM.......I think. Bridge rectifiers, oh my head !

I was advised that the wiring on these locos could vary from batch to batch and the factory in China would not issue specific wiring schematics to Accucraft US. Yes, they do have 6v voltage regulators for the lights - check in the smoke box and tender. In Greg we trust :). Max
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
2,212
587
San Diego
www.elmassian.com
My 6v regulator was found underneath part of the casting that supported the drive... turns out that it was a 3 terminal regulator, and you could not see it from above. a wire went from the head of the loco, through this structure and back out. what made me nuts was how it got converted to 6v... thought it was just a wire going through, but turns out the regulator was grounded to the metal, so while it looked as a single wire going through it was one in, connected to the regulator, then the one out was on the regulator output. Elsewhere the ground to the chassis was found, that supplied the 3rd connection to the regulator... very tricky!

I actually found it by feel, following the wire with my finger, and finding a lump!

Trust no one ha ha!

Seriously, do it bit by bit, all the while checking that the wires you are using are truly isolated from others, I start with the motor, then speaker, then headlight, etc. one by one.

Greg
 
Rhinochugger

Rhinochugger

Retired Oik
27 Oct 2009
23,475
3,286
North West Norfolk
Nah. It was a battery/RC conversion on an Accucraft K-27 with a Sierra sound card. No DCC involved. Got all the bits together but still got to summon up the courage to dove in and do it. Some very helpful, knowledgeable and generous folk here :inlove:. There was a lot of mucking about ensuring the Sierra didn't get fed any PWM.......I think. Bridge rectifiers, oh my head !

I was advised that the wiring on these locos could vary from batch to batch and the factory in China would not issue specific wiring schematics to Accucraft US. Yes, they do have 6v voltage regulators for the lights - check in the smoke box and tender. In Greg we trust :). Max
You can actually buy a bridge rectifier as a single electronic component now. The first time I came across the concept, when the rectifier failed on my 150cc Honda motorbike, a friend made me a wheatstone bridge out of four miniature valve diodes o_Oo_O
 
A

adverse camber

Registered
2 Dec 2009
187
73
East Anglia
It does not sound as if this is for the amateur like me. I do vaguely recall bridge rectifiers from school physics but not had many know encounters with them since. Happy enough to take the feed from the track and motor and plug into a chip but this sound a lot more complex. Very useful to know since if I do buy one of these locos I think I will need to budget for having it professionally chiped
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
21,797
2,673
Tamworth, Staffs.
You can actually buy a bridge rectifier as a single electronic component now. The first time I came across the concept, when the rectifier failed on my 150cc Honda motorbike, a friend made me a wheatstone bridge out of four miniature valve diodes o_Oo_O
I'll let you off.. (others may not)! :giggle::giggle:

But a Wheatstone Bridge, and a Bridge Rectifier, are two totally different animals:

wheatstone bridge


A Wheatstone bridge is an electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component. The primary benefit of the circuit is its ability to provide extremely accurate measurements.Wikiped

bridge rectifier


Bridge rectifier..
 
Reactions: Rhinochugger
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
21,797
2,673
Tamworth, Staffs.
I wonder if you had to wait for the heaters, before you could start the the engine?
 
P

Paradise

Registered
28 Jan 2010
462
201
One thing that needs to be considered is that some of Accucraft's locomotives pick up one polarity from the tender rather than opposite locomotive wheels. The draw-bar becomes electrical continuity.
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
21,797
2,673
Tamworth, Staffs.
One thing that needs to be considered is that some of Accucraft's locomotives pick up one polarity from the tender rather than opposite locomotive wheels. The draw-bar becomes electrical continuity.
Does this mean the whole chassis becomes same polarity as one rail, or is the drawbar isolated within the loco?
 
maxi-model

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
4,303
500
Bucks/Oxon/Northants area
Does this mean the whole chassis becomes same polarity as one rail, or is the drawbar isolated within the loco?
On my early model K-27 the pick ups on one rail are on the drivers only and on the other side on the tender. The loco's chassis my be used as the ground in this instance. On later models all wheels picked up. The give away should be if there are copper "wipers" on both sides of the tender bogies or just one. The drawbar is isolated on mine. Check the loco's manual if you have one. This could be the same with the C16/19/21's. Max
 
P

Paradise

Registered
28 Jan 2010
462
201
My early Accucraft C-16 and C-19 both have only one side of the tender wheels insulated at the axle which makes the tender body one polarity.
My Accucraft C&S B4C 2-8-0 has graphite wipers on all tender wheels.
 
beavercreek

beavercreek

Travel, Art, Theatre, Music, Photography, Trains
24 Oct 2009
17,224
702
East Anglia
www.facebook.com
It depends on the model of the C16 and C19.
The early issue were the same as the K27..right side loco drivers, left side tender wheels (or the other way around).
But the later issue had 'normal' pickups and all of the wiring in the tender ready for sound and DCC.
I have an RC Accucraft C16 using this as it was the later issue (you can tell by the multi-pin connector from loco to tender).
 
P

Paradise

Registered
28 Jan 2010
462
201
I think the issue irises on metal bodied, rail powered locomotives that have metal rods attached to the wheels. It's a matter of where and how to insulate the two sides.
There were also different gear ratios over the years on models C-16 and C-19. First was similar to other manufacturers but too fast for prototype. Second was nice and slow but motor/gear speed noisy and third was somewhere in the middle.
 
Last edited:
maxi-model

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
4,303
500
Bucks/Oxon/Northants area
So, Adverse Camber, it sounds like you do not yet own one of the models you are seeking information on. It seems to start with you need to avoid earlier production models which do not have pick-ups on all wheels and somewhat varying wiring.

At this point we then go into the realms of what these products are like generally. I have Accucraft 1:20.3 locos (C-19, K-27, K-28, Shay, Climax and Porter) both track powered and live steam. Each model type, whether electric or steam powered, share the same basic structures and motions. They are generally well built and reliable products. And visually pleasing and accurate models to boot. To my mind though they suffer from very poor documentation and schematics information, unlike Bachmann's similarly scaled products that you may or may not be familiar with. As mentioned before, it depends on when they were produced as to how they are wired up and what prime mover is installed. And Accucraft, as I found out, in all probability won't be able to help you either with advise on that.

So yes, its a PITA if you are going to do any serious work to repurpose their stock electrickery. But fear not, help is at hand here - I would not have countenanced trying to delve into my own K-27 without the not inconsiderable advise and generosity of others here - particularly Greg and PhilP. Max