Dapol Streamlined Railcar

[melmerby]

OK, I have now stripped out the driven bogie back down to component parts and scrubbed it all in white spirit with a tooth brush. I put a spot of light clock oil on the cogs and worm bearings only. YES IT DOES HAVE WHEEL BEARING PICKUPS, but the trailer is wiper on the wheel back. The bogie was put back and ran smoothly.

 

I've also pulled the motor apart, it's a 5 pole skew wound!

 

NOTHING, still exactly the same, hunting!

 

I did however remove my hard wired decoder so we are back on the Dapol PCB. I hope that doesn't prove to be a problem :-/ There is only so much I can take of cutting and re cutting tiny wires!

 

Still, on the plus side, this will be one model Dapol will never warranty for me, so that's a plus for them !!!!!!

 

1628 Mashima ordered !

Looking forward to seing your results as I really don't want to send mine back but equally It needs to run better.

 

Keith

[Prometheus]

I'm sorry to hear of the various travails mentioned above. With no intention of rubbing salt in any wounds, this one runs without any drama.

 

 

The valenced sides do make it tricky to rail however and a ramp is extremely useful for this.

 

Tony

[swiftbeam]

As long as you don’t mind losing the warrenty, keep hold of it for a bit. The motor is on its way, I’ll fit it as soon as it gets here. I’ll test at all speeds in DC and DCC and report back the same day.

If it turns out to be the motor and you guys need a hand to mount it, I have an option at my disposal that will easily help you out ;-)

I don’t think it’s the :-
PCB as I hard wired it without the board,
Powered bogie as I’ve stripped it and washed it out, runs smooth,
Pickups as I’ve cleaned them,
Drive shaft or UJ as they are free,

I really can’t see much left other than the motor or flywheel missmatch in some way????

Maybe it could run better in DCC if the CV’s were adjusted, but how do you explain why it hunts in DC??

I did think that maybe the wires are too small and not passing enough current? I’ll swap the wires today and run it on DC and report back.

I’m not giving up on the one I’m keeping until I’ve tried everything. If it comes to it l’ll Black Beetle’ it !!!!!!!!!!!!

Edited November 5, 2017 by swiftbeam

[swiftbeam]

I'm sorry to hear of the various travails mentioned above. With no intention of rubbing salt in any wounds, this one runs without any drama.

 

 

The valenced sides do make it tricky to rail however and a ramp is extremely useful for this.

 

Tony

Yes, she’s a beautiful looking model and one needs to stay on my railway :-)

[swiftbeam]

Prometheus, You say it runs "without any drama", and I'm sure she does :-)

 

Would you do me a small favour?

Run her at about 40% on DC, or speed step 50 on DCC.

 

If yours runs with no hunting at all, that rules out wires being to small and will save me the hassle of changing them :-)

 

Thanks.

[Prometheus]

Prometheus, You say it runs "without any drama", and I'm sure she does :-)

 

Would you do me a small favour?

Run her at about 40% on DC, or speed step 50 on DCC.

 

If yours runs with no hunting at all, that rules out wires being to small and will save me the hassle of changing them :-)

 

Thanks.

 

I will happily do this for you but I cannot until tomorrow night when I am at the club. It'll be the DC option as this one is not DCC fitted.

 

Tony

[Coach bogie]

As many others, mine runs fine on both my modern controller and equally as good on my veteran H&M controllers.

 

Seen here with my 25 year old MTK parcels car.

 

 

Mike Wiltshire

[bertiedog]

I have tried to induce the hunting but cannot get any on DC or a Lenz chip on DC or DCC. This is over the full range of speeds.,and with several quite different controllers.

 

It.seems very very odd that others get troubles with two or three examples, indicating the motor etc., must not suit the control system they have in use.

 

For it to be the same on DC and DCC is unfathomable, unless a mechanical problem.

 

The nature of the pickups should not make any difference, but with DCC the plug and suppressors might well be working to affect control. But it cannot affect DC unless a full feed back controller is in operation. Generally the frequency of the feedback is higher than DC. Also the clash in frequency will just cause noise, not hunting at the speeds involved.

 

A change of motor should not affect anything, the motor is standard in every way. It draws normal current at all speeds.

 

The conclusion is still a clash with suppression used, but how does this affect DC?

 

It is interesting the lights flash in time with the motor glitch, indicating an electrical issue, not mechanical problem, and with DCC it must be curable with the CV's, or shutting off feedback.

 

I have built and serviced locos since the 1960's and have never come across such a problem before. Plenty of mechanical issues like this, but not electrical.

 

If it was on my bench, then the first thing is to disconnect the motor, and attach flying leads to the motor and test on DC. This eliminates all mechanical problems.

 

Then try back on track with a jumper bypassing the suppressor and see what happens on DC, Then connect up as usual for DCC and see if it hunts.

 

At this point the tests have all returned the results and the DCC would bear the blame, (or not).
 

The next step would be to hard wire without the suppressor

 

I still fail to see how it can be on three units without being a control issue, and curable.

 

Stephen

Edited November 5, 2017 by bertiedog

[bertiedog]

Maybe it could run better in DCC if the CV’s were adjusted, but how do you explain why it hunts in DC

 

Easy if the DC is feedback type......

[longchap]

I was pleased to hear Hattons had received these lovely models and ordered the twin cities crested No 8, without the bogie valances. On reading the latest on this thread, I was saddened to see several versions from more than one member are suffering similar running abnormalities.

 

The following is offered and hopefully may help confirm or eradicate some factors: test run today on DC in both directions, from crawl, slow and moderate speeds up to around 60% of full power. This was on the circle of track from the Bachmann GWR 57xx freight 'train set' with its standard modern DC controller and it runs impressively smoothly and quietly with no hunting or lighting flicker.

 

The lights are a great unexpected bonus and can be more selectively configured with DCC, in due course. I'll be using a Lenz Silver decoder with the NCE 3 Amp controller.

 

Best possible good fortune to all concerned and I'll be rooting for a satisfactory solution for all affected DCC users.

 

I particularly wish swiftbeam a happy conclusion, as no one deserves that amount of disappointment and these are exceedingly beautiful models which add elegance and grace to the layout.

 

Best,

 

Bill

 

 

 

[swiftbeam]

Hi,

 

I have the Gaugemaster D for DC,

Sin-natrak for DCC.

Both controllers work perfectly with every loco and decoder I own, so find it hard to think they are the problem.

 

I have now disconnected to motor and bogies totally from the original wires and connected the trailer directly to the motor with much bigger wires (no suppressors). I have tested this setup on two different decoders, TCS, Zimo MX600 and DC, I can confirm the hunting still persists. It is most noticeable at 30% on DC, speed step 40 on DCC.

 

Therefore the problem must be, motor, flywheel, drivetrain related on my model. I'm now running the basic hard wired system on full power. It will have about 3 hours in both directions, I think that should free up the drivetrain if that is the problem, and take it form there.

 

I doubt it's a drivetrain issue as the problem would smooth its self out at higher speeds. The fact it finds a 'sweet spot' and hunts the most in that spot says to me it's an oscillation/frequency issue, a slight mismatch somewhere. That would explain why some have problems and some do not. 

 

It maybe a case of everything has a 'working tolerance' and if there are enough parts fitted together with the tolerances at either end of the working spectrum, stuff happens.

 

This is a great model and Dapol have done it nicely, many others have good working loco's so I don't think Dapol have got it wrong, I will persist to fix

mine.

 

P.S.

 

Thank you Longchap, it's good to hear your model runs well, it gives me hope :-)

Edited November 5, 2017 by swiftbeam

[Miss Prism]

What is the relationship of the spigot orientation on each end of the UJ?

[swiftbeam]

90 degrees,

 

If that is no good, I can cut it in half, turn up a close fitting brass tube and set it back up parallel.

Edited November 5, 2017 by swiftbeam

[bertiedog]

Never set universals at any but 90 to each other, it produces the Hooks effect, where it will cause exactly the effects you have, but it is difficult in this design to get it wrong. U/J's are not constant velocity joints but at 90 degree each cancels the others oscillation out.

You could check if the assembly is able to be assembled wrong, I can't on mine as away for a couple of days.

This is the only area it can be if it is a mechanical problem.
The shaft must float freely, nothing tight when the bogie is running on straight track. The motor must be mounted tight, any play might make it worse.

At worst it needs a new U/J, but it is more likely it is miss assembled, and needs re-assembly correctly.

 

Stephen

[Miss Prism]

90 degrees,

 

Good. (Just checking!)

[swiftbeam]

I've just checked the drive shaft at 1/8th intervals, all nice a free, no tight spots. 

The bogie has undergone 3/4 of an hour at 80% speed in each direction.

The bogie is built (rebuilt in my case) correctly and everything is as it should be and very lightly oiled (original heavy grease washed out).

Still hunts.

[woodenhead]

Finally put power to my No.11 and to my horror nothing,nada, nilch.

 

A few moments pushing it back and forth trying to coax it to life, thought I might even have to blow on it then I saw I had set my points to isolate the fiddle.

 

Phew, it runs lovely, couldn't see any hunting.

[bertiedog]

It is coming down to one factor, the fore and aft play between the worm and the housing. At light loading the thrust of the worm keeps the worn in contact with the one end of the housing, but as speed and load varies, it begins to hunt in relation to the load.

To cure it may need a very thin washer to take up the play and thick grease on the gears.

 

If the play is there but small, then the bearing might need machining to get a bigger gap to fit a thicker washer.

 

Equally the bearing could be moved if it is not part of the moulding. I have not looked inside the gear box

 

Stephen

Edited November 5, 2017 by bertiedog

[swiftbeam]

Good point !!!

 

The worm does have shims as standard by Dapol, but as you say, may need more. I'll check now, report back :-)

 

P.S,

 

There is a black removable 0.010" shim and a white shim that is trapped by the worm and drive cup on the opposite end.

 

I was able to fit in two extra shims that total 0.007", so I have a total of 0.017".

 

The worm is free to rotate and is not tight at all, but has no 'end float' at all.

 

Still hunts at 30% DC and 50% DCC :-(

 

I still think it maybe the motor, but the worm end float was a GOOD call, thank you for that suggestion :-)

 

P.P.S

 

I'VE JUST PUT A PP3 BATTERY ONTO MY RAILS, IT STILL HUNTS POWERED BY A BATTERY !!! :-0

Edited November 5, 2017 by swiftbeam

[swiftbeam]

Yay, I just won a new GWR Hornby Railcar as a stablemate to my Dapol. 

I bet it will be a simple case of plug in the decoder and off we go!

[bertiedog]

Then if not the float, then eccentric gears or wheels or both, every thing else has been eliminated.

The only part you could change is the U/J to a CV joint with silicon sleeving tube, but........

 

Other than that I would eliminate the motor, there is no earthly reason it should hunt........apart from the brushes being too stiff in the slides or the springs too weak.

 

Also it could be an oily commutator, with a coating of carbon black and oil.

 

Modern motors are rarely opened up but in this case it should be, as it is the last possible cause.

 

The most unbelievable case is one pole is not wired in properly causing unbalance to the rotation. Fit a new motor, almost any small motor will fit, £5 upwards on Ebay, double ended type with same shaft size.

 

Stephen

[swiftbeam]

The motor was opened up as I said in an earlier post, that's how I know it's a 5 pole skew wound :-)

Nothing to see there. I raced RC cars for years and years when we had brushed motors (remember those days x racers!!) So I know what looks wrong inside a motor, it 'looked' all good, new infact!

 

As I say, I have a Mashima 1628 on it's way. I'll make a new flywheel on my lathe and mill so I don't have to wreck the Dapol unit. The Dapol flywheel is locked on some how, bonded or press fit, but it doesn't want to come off. Also if I make a flywheel, it will be a different size and weight, so maybe a roll of the dice and it will give a different outcome?

 

As you say, if not the motor it must be bad gearing, there is literally nothing else left!

It can't be the wheels as the body is super still when running.

 

I'm now hovering over the Black Beetle and Tenshodo spud power bogies. The size I'd need is 28mm centres with 11.6mm wheel (12mm will do I'm sure)

So if anybody thought £125 was expensive, I'm in for a £30 motor and then a £50 Spud!

 

It will run, I promise you!!!

 

Poor DCC Supplies, they are going to have fun with this one !

 

At least when the new motor or Spud goes in, I can remodel the seats, so every cloud has a silver lining and she'll look beautiful in all her Banana'ness :-)

Edited November 5, 2017 by swiftbeam

[cctransuk]

The motor was opened up as I said in an earlier post, that's how I know it's a 5 pole skew wound :-)

Nothing to see there. I raced RC cars for years and years when we had brushed motors (remember those days x racers!!) So I know what looks wrong inside a motor, it 'looked' all good, new infact!

 

As I say, I have a Mashima 1628 on it's way. I'll make a new flywheel on my lathe and mill so I don't have to wreck the Dapol unit. The Dapol flywheel is locked on some how, bonded or press fit, but it doesn't want to come off. Also if I make a flywheel, it will be a different size and weight, so maybe a roll of the dice and it will give a different outcome?

 

As you say, if not the motor it must be bad gearing, there is literally nothing else left!

It can't be the wheels as the body is super still when running.

 

I'm now hovering over the Black Beetle and Tenshodo spud power bogies. The size I'd need is 28mm centres with 11.6mm wheel (12mm will do I'm sure)

So if anybody thought £125 was expensive, I'm in for a £30 motor and then a £50 Spud!

 

It will run, I promise you!!!

 

Poor DCC Supplies, they are going to have fun with this one !

 

At least when the new motor or Spud goes in, I can remodel the seats, so every cloud has a silver lining and she'll look beautiful in all her Banana'ness :-)

 

If you have to - get a Black Beetle, not a Tenshedo Spud.

 

Regards,

John Isherwood.

[swiftbeam]

Thank you, I asked the question in another post and BB came back as the winner in about 1 minute :-)

 

Black Beetle now ordered as a standby!!

 

Thanks.

Edited November 5, 2017 by swiftbeam

[melmerby]

Thank you, I asked the question in another post and BB came back as the winner in about 1 minute :-)

 

Black Beetle now ordered as a standby!!

 

Thanks.

I've a BB in my Lima railcar.

Just the job and it contains a Mashima motor to boot!

 

Is the Dapol wheel 11.6mm? If so it's a tad undersize. The real diameter is 3' 1" which works out at 12.33mm. The later angular cars are 3' 2"

The Lima cars were also undersize.

 

Keith

Edited November 5, 2017 by melmerby