Dapol J94 motor - suggestions for quietening?!

[SteveyDee68]

Dear fellow RMWebbers

 

Having recently acquired a Dapol J94 from you-know-who-Bay, I have had it on my rolling road and played tested it over some temporarily set up track, and despite using a very dated H&M Clipper controller, have achieved some really slow running with the loco, with no stalling on insulfrog points.  So far, so good.

 

However, the motor makes a noise "like stirring a bucket of gravel" (borrowed from another posting, but such a good description). Any hints or tips on how to stop it sounding like a diesel?!

 

I would be very grateful if you speak to me like a complete imbecile - I may have recently repaired the valve gear on a Hornby 4-6-2 for a pupil, but when it comes to matters of electrical engineering I am completely lost!

 

I have a tube of lubricating oil with a needle tip on it, as I know that is something I should have.  What I should oil, how often, how much etc I am completely in the dark.

 

Not expecting an answer until after the festivities are over, so in the meantime to anyone reading this ...

 

Merry Christmas!

 

Regards

 

Steve S

[peterfgf]

Dear fellow RMWebbers

 

Having recently acquired a Dapol J94 from you-know-who-Bay, I have had it on my rolling road and played tested it over some temporarily set up track, and despite using a very dated H&M Clipper controller, have achieved some really slow running with the loco, with no stalling on insulfrog points.  So far, so good.

 

However, the motor makes a noise "like stirring a bucket of gravel" (borrowed from another posting, but such a good description). Any hints or tips on how to stop it sounding like a diesel?!

 

I would be very grateful if you speak to me like a complete imbecile - I may have recently repaired the valve gear on a Hornby 4-6-2 for a pupil, but when it comes to matters of electrical engineering I am completely lost!

 

I have a tube of lubricating oil with a needle tip on it, as I know that is something I should have.  What I should oil, how often, how much etc I am completely in the dark.

 

Not expecting an answer until after the festivities are over, so in the meantime to anyone reading this ...

 

Merry Christmas!

 

Regards

 

Steve S

There's some relevant information here:http://www.rmweb.co.uk/community/index.php?/topic/83043-oo-gauge-j94-austerity-tank-locomotive/page-1

Some thoughts:

1. With checking in too great detail, I think the motor is coreless which may not have the high inertia of older motors and thus it is susceptible to supply voltage fluctuations (i.e. it will vibrate at any high frequencies present in the supply).

2. Not all DC controllers are alike and, depending on the circuitry, some supply only a rough approximation of a steady DC voltage (hence people's preference for one or another type).  Maybe try a battery supply as a first check. There is information elsewhere on RMWeb and elsewhere on the Internet (search for model railway controllers).

3.  The model has an unnecessarily complicated drive train with gear drive to all wheels which duplicates the action of the connecting rods.  These are commercial quality gears and may be the source of the noise: a judicious choice of lubricating oil may help (high viscosity will reduce the noise but increase the power loss).

Sorry that I've not been more specific.

Peterfgf

[Izzy]

There's some relevant information here:http://www.rmweb.co.uk/community/index.php?/topic/83043-oo-gauge-j94-austerity-tank-locomotive/page-1

Some thoughts:

1. With checking in too great detail, I think the motor is coreless which may not have the high inertia of older motors and thus it is susceptible to supply voltage fluctuations (i.e. it will vibrate at any high frequencies present in the supply).

2. Not all DC controllers are alike and, depending on the circuitry, some supply only a rough approximation of a steady DC voltage (hence people's preference for one or another type).  Maybe try a battery supply as a first check. There is information elsewhere on RMWeb and elsewhere on the Internet (search for model railway controllers).

3.  The model has an unnecessarily complicated drive train with gear drive to all wheels which duplicates the action of the connecting rods.  These are commercial quality gears and may be the source of the noise: a judicious choice of lubricating oil may help (high viscosity will reduce the noise but increase the power loss).

Sorry that I've not been more specific.

Peterfgf

I think you are confusing the Dapol J94 with the newer offering from DJ Models. It is the latter which has the features you refer to. The Dapol then Hornby J94 has the small motor used in a lot of the smaller current Hornby locos and details of how to take it apart for oiling etc can be found on the DCC fitting guides section - under Hornby J94 conversion ( as it’s basically the same model). I believe it’s on page three.

 

Hope this helps,

 

Izzy

[peterfgf]

I think you are confusing the Dapol J94 with the newer offering from DJ Models. It is the latter which has the features you refer to. The Dapol then Hornby J94 has the small motor used in a lot of the smaller current Hornby locos and details of how to take it apart for oiling etc can be found on the DCC fitting guides section - under Hornby J94 conversion ( as it’s basically the same model). I believe it’s on page three.

 

Hope this helps,

 

Izzy

Izzy and Steve S,

Apologies, I was indeed confusing the two. Slap on hand to make sure I read posts more carefully in future.

Peterfgf

[SteveyDee68]

Thank you for the replies at this busy time of year - wasn't expecting that! No excuse for me not to have a little "project" over Christmas now! Will report back on results in due course. Merry Xmas!

[Gordon A]

Try putting a drop of oil on the motor bearings and gears.

Another option is to remove the motor from the loco and test run.

If that is OK refit the motor then drop the wheels out and test run the motor and gears.

 

It is a case of isolating and testing various components the re linking them back together stage by stage.

 

Patience is the order of the day.

 

Gordon A

[34theletterbetweenB&D]

Have you had the motor out of the loco for a test run, independent of the rest of the mechanism?

 

If the motor is noisy on its own, then the best course is to simply replace it (Peter's Spares). It is a very low cost motor, and some are apt to be noisy.

 

That the mechanism runs smoothly down to low speed is a sign of not much wrong there. If the motor is quiet when off the mechanism. one possibility is that the worm isn't meshing well with the pinion. The construction simply clamps the motor in place in plastic mouldings, and is not very precise in locating the motor relative to the gears. A little filing and fiddling to get the worm engagement running sweetly fixes this. There should be a 'fagpaper' gap between the worm and the pinion teeth. (In the old days Rizla roll up papers were used as simple gauges for this task.)

 

It is worth persisting with this item whether of the earlier Dapol manufacture, or by Hornby after they purchased the tools. Even real 'coffee grinders' can be got to run sweetly and quietly with some adjustment, and/or a new motor if it is an irreducibly noisy specimen.

Edited December 24, 2018 by 34theletterbetweenB&D

[MarkK]

I have the Hornby ex Dapol J94.  Ir runs quietly on DCC. As peterfgf suggested, try it from a pure DC supply to rule out the controller before taking the loco apart.

 

 

Mark

[D9020 Nimbus]

These locos have reduction gearing— about 50:1 I think, so some oiling might be necessary there.

[SteveyDee68]

Thank you for all of the advice/suggestions. Once the overindulgence in various alcohols has worked its way out of my system (so my eyesight is no longer blurred and I drop things randomly!) I shall sit down and try all of them. I am encouraged by the comment that it is possible to get these models running sweetly with some work - just don't want to muck up its slow running qualities in the process of my own ham fisted fettling!

 

Will report back in due course (hopefully positively)

 

Regards to all

Steve