In the extreme Jintybash thread I referred to the chassis of Robert the Bruce making such a racket. This was traced to the claw/clutch arrangement between the motor and the worm shaft. To prevent further digression in the Jintybash tale, here is what I'm doing to silence the chassis.
First, a picture of the loco in its present state:
(https://forum.009society.com/proxy.php?request=http%3A%2F%2Fwww.009dutch.nl%2Farchive%2F2013%2Fgallery51%2Fimages%2FIMG_4722a.jpg&hash=d02aa61ab14345b1f97a8a8fe6bde38414ccc6a5)
The chassis is an old Arnold 2-6-4T probably made in the 1960s or early 1970s. It was bought as a good runner from the 009 Society sales many years ago, but soon afterwards the old motor packed up and I fitted a Mashima.
Here is a similar chassis with the original motor:
(https://forum.009society.com/proxy.php?request=http%3A%2F%2Fwww.009dutch.nl%2Farchive%2F2013%2Fgallery51%2Fimages%2FIMG_4741.jpg&hash=2f06633725aa71d8264886c938e4aa473b68d86f)
The motor is a loose fit in a cradle at the back of the chassis and is held in place by the zinc body shell. It can easily be flipped out:
(https://forum.009society.com/proxy.php?request=http%3A%2F%2Fwww.009dutch.nl%2Farchive%2F2013%2Fgallery51%2Fimages%2FIMG_4731.jpg&hash=0d2775e29081491656cbd06ad57eee62985b82fd)
What I did years ago is fit a brass shim floor in the cradle, and bed in a Mashima motor using silicone sealant. Obviously the clutch needs to be carefully aligned, but something went wrong and the chassis was noisy ever after. So after completing the L&MVR Kitson I put that on the Mail service and took the 'Bruce' off for overhaul. I removed the motor with some difficulty and replaced the thin cradle with a brass floor glued UNDER the cradle:
(https://forum.009society.com/proxy.php?request=http%3A%2F%2Fwww.009dutch.nl%2Farchive%2F2013%2Fgallery51%2Fimages%2FIMG_4726.jpg&hash=080681851c11ea6434e8617c3fc7d4c5d92f8476)
Note there is a brass strip glued on the floor to set the motor at the correct height. In addition there are plastic angle strips to either side which centralise the motor in the cradle.
Next, I glued the motor in using silicone sealant and checked carefully against further noise.
(https://forum.009society.com/proxy.php?request=http%3A%2F%2Fwww.009dutch.nl%2Farchive%2F2013%2Fgallery51%2Fimages%2FIMG_4727.jpg&hash=75d203fc055accd856fb3791acdbf8f35c14035a)
And presto! the noise seems to be at least halved. Not ideal, but a good result.
Despite the crude appearance and the fast gear ratio, the loco is a very smooth runner due to the excellent properties of the Mashima motor.
I now fitted the body on the chassis and it's far better than it ever used to be. The noise seems to have been produced by the rattling of the jaws of the clutch - the motor shaft was set slightly higher than the worm shaft and although it ran without binding, the notches on one half disengaged from the contact surface in the recesses of the other half with every revolution. Now they seem to run true.
Continuing improvements on the Arnold chassis, I found it was quiet in reverse and still a little noisy when going ahead. Investigating this at close quarters, the worm proved to have a little play. It moved forward when running forward, and back when reversing. In reverse, it pushed home the half of the clutch attached to the worm shaft. So it was seated better in reverse, cancelling out any vibration in the clutch. Adding a washer to the worm didn't help.
I had an idea and taped the two halves together with some very thin tape wound round the clutch. The noise was completely gone, and the motor ran smoothly. I expect locking the two together cancelled out the source of the noise.
(https://forum.009society.com/proxy.php?request=http%3A%2F%2Fwww.009dutch.nl%2Farchive%2F2013%2Fgallery51%2Fimages%2FIMG_4771.jpg&hash=3420d667dae9122da9cc8cf4647b0b31b10989d7)
I slept on it and this morning decided to put silicone sealant between the halves of the clutch to make a more permanent bond. I cleaned them using white spirit, then put a tiny amount of silicone into the gap. I pressed home the two halves, cleaned away the surplus and left the chassis till now. On trial running it proved to be completely silent and very smooth, running both ways. I hope this solved the problem!
(https://forum.009society.com/proxy.php?request=http%3A%2F%2Fwww.009dutch.nl%2Farchive%2F2013%2Fgallery51%2Fimages%2FIMG_4781.jpg&hash=d3e599d32ac3d36285b13f40473beaf2932a4579)
Ted, do you use the type of sealant that smells of vinegar? And if so, have you had any problems with corrosion from the acid released? {I have a suspicion this has been asked before.....}
(I know you can get sealants that do not produce acetic acid)
For what it is worth, I have used this type of sealant to secure at least two motors, and have had no problems to note.
Regards
Tim
I think the acetic acid question has been raised before, and as Tim says, I never experienced trouble.
I just uploaded a video of Robert the Bruce, before and after the upgrade. Just compare the difference.
http://www.youtube.com/watch?v=zQ2Yzk3QuwY (http://www.youtube.com/watch?v=zQ2Yzk3QuwY)
Ted
What a difference! Very good 10/10! Are you going to do the same with the turntable, says he with tongue firmly in cheek.
Roger
Yes the turntable is a noisy b****r, I'm afraid. I noticed the difference as well. The best that could be done is mount the gearbox and motor on a rubber pad, but it would be quite a job.
That is a really neat and innovative solution Ted.
I suspect you have achieved a silicone rubber buffer between the halves of the joint so there is no metal-to-metal contact now.
Great!
Frank
Thanks Frank. It must indeed be the silicone rubber buffer between the halves of the clutch. However it will work only if they have been lined up accurately, which I took care of first. Any mismatch and the silicone will cause binding on every revolution of the motor, as I found out some years ago when I tried it.
As ever Ted, an excellent piece of work! Well done! Nice to see engineering flourishing!
It's not a very good coupling. I assume the idea is to extend the motor shaft to the gear tower. The ball and socket joints NWSL sell would be a lot better.
But a good solution to a not-so-good set up.
Mal.
I agree a ball and socket set-up would be better. It is rather a primitive solution without self-centering properties - we are speaking about 50-year-old technology. As long as there is little wear in the clutch, and you have the original motor installed, it probably works all right, as the one in the other chassis I have is quite silent.