5 inch 0-4-0 Shunter

Coming along nicely!

Good News/Bad News

The good news: The drive is all fitted and works very well. I was aiming for 632 rpm at the wheel for a top speed of 6 mph. On the bench the max rpm is 825 but unloaded of course so hopefully about right when loaded.

The bad news: Although the drive works well enough it is noisy and too noisy for my liking. I appreciate that I am standing directly over it and it is in the confines of a small workshop. Maybe loaded outside on a track it wouldnt be so bad or so noticeable. I am wondering if the motor mounting plate is too light, its currently 3mm steel . In hindsight (which is a wonderful thing) I am wondering if it would have been better in 6mm steel or 6mm alu. Plus the central axle bearing is an oilite, would that have been better as a ballrace.

I think I have 3 options: 1) live with it and see how it is on the track, though I am a bit reluctant to do that. 2) Un-press one of the wheels (each axle) and produce a heavier duty version of the motor plate, though this is only based on my assumption that a HD version would improve things. 3) Try and figure a way of adding something or a mod which would reduce the noise.

Will have to give it some thought, though I am pleased with the working of the drive.

Ron

You may be able to reduce the noise by adjusting the gear clearance.

Neil

Don't panic, I think your test is worst case. The motors are running flat out (unloaded) with nothing to contain the racket . Also your bench could be acting as a sounding board - try putting a bit of carpet underneath the chassis. In any case probably considerably quieter outdoors at service speeds with the motors shielded by bodywork.

Looks like the motor plate bears on the rods. If so may be worth putting some sort of cushion between the rods and motor plates to discourage sound conducting into the frame.

I like the design and build.

Dave

Hi Neil, I ran a folded piece of paper between the gears then slackened and re-tightened the fixing screws and it did help a bit, thanks for that.

Hi Dave, I sat the chassis on a sheet of polystyrene and it did take away some of the noise. There is a 0.5mm gap between the end of the motor plates and the tie bars but I think you are correct in the noise been generated by the motor plates. If I hold onto the plates whilst running the noise does reduce a bit plus the sound changes. Also I think the plates are as you suggest conducting the sound into the frame, if I press each axle box the sound reduces a bit.

Tomorrow I am going to run the drive for a couple of hours just to see if things bed in and if that makes any difference. I will run it outside on the garden table so I can see how it sounds outdoors without me standing over it.

Thanks guys

Ron

Hi Ron, You may find that ground level track may absorb quite a lot of noise into the rails, ties/sleepers, and the ballast. However, raised track may amplify noise, as will any hard tabletop. I'm not saying not to implement some of the noise reduction measures others have suggested, that is definitely advisable to do, I'm just suggesting the noise may not be as much of an issue when the engine is running on a track. As you said, the gears may get quieter as they "bed in" but be prepared to adjust the clearance again as the "bedding in" progresses - the gap will get slightly larger as the gears wear. I'd suggest using a few drops of oil on the gears during the "bedding in".

Just asking - are your gears and pinions from the same manufacturer, and are they the same module or DP (that is, are the teeth the same geometry, and intended to run together)? For ideal mesh, the gears and pinions should be same module or DP.

is the large gear metal or plastic? I think the commercial ones are usually plastic which will be a little quieter if that is the source of the noise. On the track there will be a lot of other noise from the carriage wheels.
BTW you should think of a way of shielding those big holes in the motor cases from all dirt - you will find there is a lot of rust dust and other crap around on a regular track.

Hi Jeff,

Thanks, yes the gears are from the same supplier Bearing Boys Ltd (excellent service). Both the pinion and the spur are MOD1 so the mesh should be good. The pinion is steel and the large spur is plastic and I have given them a light coat of lithium based grease. I dont know what the norm is for setting up gears but I used a thin piece of paper which measured 0.004" and placed that between the gears when securing the motor screws. I just wanted to make certain that I didnt have the gears too heavily meshed. The track I will be running on is a raised one so it will be interesting to find how it sounds.

Hi Bazyle,

The large gear is plastic and as I mentioned to Jeff I have lightly greased the gears with lithium grease but that sounds as if it is not a good idea if there is a lot of muck that could be picked up. The track I will be running on is raised, I,m guessing that it is probably a bit cleaner than ground level but I dont know. I can make a cover to shield the motors but allow a small gap to allow them some airflow.

Ron

I set the chassis up on the garden table and ran it for a couple of hours this afternoon to bed things in. It certainly didnt seem as noisy outside of the shed out in the open. I also thought it a bit quieter after the couple of hours running but that could have been wishful thinking on my part...lol.

I am going to carry on with it as is and see how it turns out when loaded and running on a track. When I say its noisy, its not horrendous, its just a bit more "clunky sounding" than I expected yet the drive train run smoothly enough.

Ron

Well, not that far from having a working rolling chassis, the chassis and parts have been primed and painted and re-assembled. I mentioned previously that the drive assembly was noisy so I carried out a couple of mods. The motor plates run on the axles and they were mounted via a 16mm long oilite bearing, I have doubled the length of the bearing to 30mm to offer more support. I have also added a nylon guide roller at each end of the motor plate to prevent any metal to metal contact when the plate moves vertically with the axle suspension.

The mods have certainly reduced the noise and it certainly sounds better than it did. I also noticed that when the drive is running a little finger pressure at each end of the motor plate improves it further. I am thinking of adding an extension spring at each end of the motor plate connected between the top of the plate and the underside of the chassis top plate. I,m hoping this will load the plate and have the same result as some finger pressure does but we will see..?

As you can tell a lot of this is trial and error and working it out as I go but one thing is for certain, it is FUN.

Pictures below:

A picture of the nylon guide roller.

Coming along nicely Ron!

Thanks Neil

I must admit I am enjoying it.

Ron

Chassis top plate (3mm steel) added as well as the front and rear plates again in 3mm steel. Need to turn up some buffers and add a front and rear clevis type coupling as well as a bit of detail for the plates and chassis side frames.

It will then be the body to build, I,ve decided on 6mm MDF for the main body parts and yes it will be sealed, primed and painted so quite weather proof. The beauty of MDF is the sheets are generally very flat and the surface finish is very good so its not too difficult to produce a good finish.

I have decided to go with a class 08 shunter type body though as I mentioned before this is obviously not a scale loco but a look alike. Our two great grand daughters for whom I am building the loco keep mentioning a Thomas the Tank face on the front and one of them even suggested the loco should be pink...

Regards

Ron

Yeah! Go with PINK. If Force India can do it for their F1 car why not for a nice little shunter. Just add some suitable "go faster" decals

John

Welcome to the cruel world of Model Engineering Ron! We spend several hundred hours producing a superb engineering triumph, only to have faults pointed out, the colour rejected, and Thomas the Tank Engine features requested.

Bad news: the customer is always right.

I think to really appreciate Model Engineering, it's essential to have made something yourself. That's why I admire your achievements, well-done!

Dave

Thanks guys,

I was going with British Rail Green with more black and yellow chevrons on the front and at the rear of the cab.

Pink...? I just cant get my head around that at the moment, I,m hoping it will be forgotten and go away but knowing the great grand daughters it probably wont.

Ron

You can't beat wasp stripes!

Neil

Hi Ron, the locomotive is looking great. For dealing with the pink idea, how about making two body shells, one green one pink/Thomas face? The green one could be metal or a mix of wood and metal with some detailing. The pink /Thomas face one could be simpler wood construction of course, or even a vacuum formed PC or PETG plastic shell to fit over the green body. Some RC car models use vacformed shells for their painted bodywork.

By doing quick release fastenings at say 4 points, like spring latches or thumb screws, the locomotive could "change identity" as needed for your great granddaughters. Just food for thought.

Hi Jeff,

Why didnt I think of that..? Thats a great idea, a body for the girls and one for me when I want to be a bit more serious about it.

Thanks Jeff

Ron

You're welcome Ron. Good luck with the loco bodies.

Re your bandsaw tire thread - I've used 1/8" thick neoprene rubber strips for bandsaw tires in the past with success, fastened with contact cement, and with scarfed ends. (angled cuts both pieces). I recommended this method a while ago to Mike Cox on the forum, who had similar tire trouble. He also reported success with the method. Neoprene sheet or strip is commonly available from seal and gasket dealers at reasonable cost.