wonky running.

This loco has been well run in and still has a tight spot/hesitation at a certain point in the wheel rotation. Today I stripped it down to the chassis. I couldn't get the reduction gears out, the pins are too tight a fit. I found congealed grease and dirt in there. I think I've either got a model that's been on the shelf a long time, or more likely, a return.

Anyway I thoroughly cleaned the gears and lubricated them with teflon grease and reassembled it, making sure the wheels were clean and bearings clean and oiled. Rods aren't catching, slide bars and piston rods all move nicely.

On to the track and …. exactly the same.  :thud

I'll take it apart again when I feel as though it won't go flying. The last ditch thing I can think of is quartering, so I'll have to bite the bullet and try to check.

 

[user=1120]peterm[/user] wrote:

This loco has been well run in and still has a tight spot/hesitation at a certain point in the wheel rotation. Today I stripped it down to the chassis. I couldn't get the reduction gears out, the pins are too tight a fit. I found congealed grease and dirt in there. I think I've either got a model that's been on the shelf a long time, or more likely, a return.

Anyway I thoroughly cleaned the gears and lubricated them with teflon grease and reassembled it, making sure the wheels were clean and bearings clean and oiled. Rods aren't catching, slide bars and piston rods all move nicely.

On to the track and …. exactly the same.  :thud

I'll take it apart again when I feel as though it won't go flying. The last ditch thing I can think of is quartering, so I'll have to bite the bullet and try to check.

  My quartering is done by eye. I've made 2 levers with pins that engage the spokes to hold / move the wheels.

Hi Pete,

Were both wheels geared? Before you dive in and quarter without a jig, try running without the rods. Why?….


You mentioned the idler gear pins were tight (they should drift out using a metal rod and hammer). Did you check to see how much the holes through the gears were worn? If they are worn and enlarged it is possible for one to skip a tooth as it wobbles, or for the gear to catch on the sides. If it still runs badly without the rods it's not the quartering that's the issue.


Dirty and congealed grease is an excellent indicator of age/ill-use. Was it sold as a new model or NOS? The latest version is set up for a 21 pin decoder and speaker in the tender.


Nigel

Clive,

I've only had success with quartering by eye once. I'm really dubious about trying it again.

Nigel,

I don't know when this loco was first released, but it did have the 21 pin socket. It was sold as new by RoS, but it's hard to reconcile the amount of stuff inside it with a new loco.

Age must be catching up with me because I hadn't thought of running this without the rods. I'll try it today.

Forgot to say Nigel: no, only one gear. So far it's H1 three Peter nil. I did try it without the rods, and also with the motor disengaged. There was the problem or so I thought. The rods were tightening up around the 3 to 9 O'clock position. I fettled the rods, filing the holes horizontally and then with the rods back on I turned the driven wheel with very light finger pressure: all OK so far. Checked without the body on and it seemed to be all right. Reattached the cylinders/slide bars etc and still OK. Body on and there's the problem again!

There's nothing on the body that's touching anything. It's not a tight fit.
For today I'm stumped. Back into it tomorrow.

 I used to be able to strip down and rebuild engines, diesel or petrol, gearboxes, manual or auto. I can't even get a model loco to run properly now!

[user=1120]peterm[/user] wrote:

I don't know when this loco was first released, but it did have the 21 pin socket. It was sold as new by RoS, but it's hard to reconcile the amount of stuff inside it with a new loco.

The Railway Model Database only shows one Bachmann release #31-910 - in 2018. That's usually a reliable source. It has a 21 pin socket.

My home made quartering levers.
By placing a crank in line with a connecting rod, and then looking at the opposite wheel and moving to 90deg - and trying and adjusting…

I have aligned a good few of my locos.
I start with the axle with the drive gear.

As for the body fitting bringing back the problem - I have no idea.
Good luck.

Hi Pete,

RoS - 'nuff said.


Grasping at straws time. When you say it runs OK without the body on, is that with power? Is the body too low? Or skewed? Sound like you may have a rod hitting a low spot on the running plate/inside wheel arch. Best checked with a 10x loup.


Are all the screws holding the rods in square? Are the wheels square to the axles? (Any wobble?). Have you checked for any wear on the outside rim or boss indicating the wheels are rubbing? 


If you remove the motor and run it body on by hand with lateral pressure left and right does it bind?


What gauge did Bachmann set it at? Should be ~14.5mm from previous Bachmann models I have had. 


How springy are the pickups? are they the same on both sides? If they are unequal then torque will push them more to one side. 


Does it bind in both forward and reverse? On both inside and outside curves?


Is the keeper plate on square?


If you've opened up the rod holes and they are still loose at the binding spot I doubt it's the quartering. Because of the green plastic it's often difficult to see rubbing spots, especially the inside of the wheel arches. Paint them white or yellow with acrylic. It's one of the compromises OO manufactures have to make, wheel arches, foot plates and pistons have to be moved in. I had the same problem when I regauged a Bachmann pannier to EM gauge. Binding, which was due to 2 wheels fouling the inside of the wheel arches, which of course were only meant for OO gauged wheels. If this is NOS from 2018 Bachmann may have quietly changed the tooling. The only revision I could find was a 2020 one dealing with Zimo decoders.


Nigel

[user=2170]Colin W[/user] wrote:

[user=1120]peterm[/user] wrote:

I don't know when this loco was first released, but it did have the 21 pin socket. It was sold as new by RoS, but it's hard to reconcile the amount of stuff inside it with a new loco.

The Railway Model Database only shows one Bachmann release #31-910 - in 2018. That's usually a reliable source. It has a 21 pin socket.

 

Thanks Colin,

It's too late now for returning it as I've modified it to take an MX 645 and larger speaker, But I'm now convinced I've got a 'returned faulty' model.

[user=2262]CliveFa[/user] wrote:

Thanks Clive,

I'll get round to making myself a pair of those.

[user=1632]BCDR[/user] wrote:

Hi Pete,

RoS - 'nuff said.
I'm thinking the same.

Grasping at straws time. When you say it runs OK without the body on, is that with power? Is the body too low? Or skewed? Sound like you may have a rod hitting a low spot on the running plate/inside wheel arch. Best checked with a 10x loup.
Yep, glasses on and one of those magnifying visors and can't see any binding.

Are all the screws holding the rods in square? Are the wheels square to the axles? (Any wobble?). Have you checked for any wear on the outside rim or boss indicating the wheels are rubbing? 
All screws square, no binding of rods. Body on and upside down in a cradle, it runs perfectly.

If you remove the motor and run it body on by hand with lateral pressure left and right does it bind?
No, no binding there either.

What gauge did Bachmann set it at? Should be ~14.5mm from previous Bachmann models I have had. 
Yes, 14.5mm.

How springy are the pickups? are they the same on both sides? If they are unequal then torque will push them more to one side. 
Pickups seem OK but I'll have another check.

Does it bind in both forward and reverse? On both inside and outside curves?
Worse in reverse.

Is the keeper plate on square?
Yes, it has csk screws which line it up.

If you've opened up the rod holes and they are still loose at the binding spot I doubt it's the quartering. Because of the green plastic it's often difficult to see rubbing spots, especially the inside of the wheel arches. Paint them white or yellow with acrylic. It's one of the compromises OO manufactures have to make, wheel arches, foot plates and pistons have to be moved in. I had the same problem when I regauged a Bachmann pannier to EM gauge. Binding, which was due to 2 wheels fouling the inside of the wheel arches, which of course were only meant for OO gauged wheels. If this is NOS from 2018 Bachmann may have quietly changed the tooling. The only revision I could find was a 2020 one dealing with Zimo decoders.
I'll revisit that with some paint. It's worth a try. I'll be leaving it for today, I'm not the best. The joys of getting old.
Ps: What's NOS?
Nigel

[user=1120]peterm[/user] wrote:

Thanks Colin,

It's too late now for returning it as I've modified it to take an MX 645 and larger speaker, But I'm now convinced I've got a 'returned faulty' model.

Pete,

A few lessons for all of us in this sad tale. I think we're between a rock and a hard place over here as returns have become more problematic (time and costs) while problems have become more common over time in my experience. Worth developing a plan of action regarding acceptability testing of new incoming purchases.

Regarding the retailer, based on my various favourable experiences with them I'd be more suspicious of just a simple manufacturing "lemon" or a customer "pulling a swiftie" on them somehow by getting a return accepted. I see that the product is still a current stock item. Can't see any reason at all why they would willingly foist a product with a known problem onto a second customer - asking for trouble. Especially when that product is from a key supplier with whom they have a strong relationship (almost 700 products listed on their site as of now).

Yes, a good counter argument. A customer pulling a swifty is a possible of course.

Bottom line is though, that it's up to me to sort it out.

Hi Pete,

NOS - New Old Stock. Usually sat on a shelf for several years. Warrants a hefty discount.


Sound like you may have exhausted the likely and unlikely. Interesting that it runs worse backwards. That is usually symptomatic of a gearing issue. So if you run it without the rods on (and where quartering is not an issue) how does it perform? If it still runs like a goat it's not the quartering. 


Colin has a good point about developing a check list.  Number one on mine is run it on DC. If it runs badly on DC it will do the same on DCC. 


I face the same issue that you and many face - how to deal with returns of items from the UK. I stopped dealing with RoS because of this when I bought what was clearly a citron.


Nigel

"Body on and upside down in a cradle - runs perfectly" I'd have thought gives a clue ………………..

If it runs fine upside down, it's something to do with sitting it upright ………. :hmm

I'd be inclined to give Nigel's "modeller's blue" a go - paint some white acrylic around where the wheels "might" catch and see if any rubs off…………………. :roll:

Just to complicate matters more… I lied. It's the same with the body off. I did end up going back to it yesterday and eased the rods a touch more: no change. I've checked the rods for straightness and also the piston rods/main rods

I can see that nothing is catching the chassis, so I'll have to try again to get those reduction gears out. Not looking forward to that with the shafts being so tight.

Well here we are nearly eight hours later and it's running nearly right. It wasn't long after this mornings post that I went back to the garage to do battle .

I stripped it down and this time I'd made up me mind, Those gears were coming out! I decided to sacrifice a 1.5mm drill bit and used it as a drift. I might even have not damaged said bit. Anyway, I was surprised to find swarf mixed up in grease. I think this one must have missed out on cleaning between the machine shop and the assembly room. It all got a good wash out. No burrs or rough spots for gears to catch on. No damage to the gears so they went back in after a lube.

It went on the track with no rods, all good. With rods, still good. Cylinders on and connected, back to hairy goat mode.
I couldn't find anything wrong with the cylinders or piston rods etc, so the wheels came off again and everything was OK. Believe it or not I hadn't sworn yet, but it was getting close.

Ages later I had a brainwave. I loosened the keeper plate screws and it ran like a dream. I really can't see why this made a difference because the axles are in brass or phosphor bronze bearings and it's the bearings that are held by the plate. It still has a slight catch in reverse… sometimes, so I'll leave it alone for now.

I do hope you all enjoyed this saga which proves that you should try the easy things first, except in my case there was still all that muck in the gearbox. I suppose Chinese factories have Friday afternoons and Monday mornings just like us.

BTW, this is an expurgated version.  

Hi Pete,

Definitely a "Would you #@%&$ believe it?!" moment or three. Plus lots of horlicks and sugar.


Nigel

Yep, there was a fair bit of grumbling going on, but I didn't want to subject my wife to what I was thinking.

I have to say a thank you to all involved.