Mainline Manor chassis rebuild (zinc pest)

[97xx]

Thought I'd share this in case someone else is mad enough to want to undertake a fairly major repair to their diseased chassis.

 

have been going through my inventory of models, acquired initially when a lad, so mainly HD/Wrenn based. Towards the end of the 70s/early 80s when I was probably finding other distractions in life, I did acquire some 'modern' motive power - namely an Airfix 14xx, a Mainline 2251 Collet, and a Mainline Manor.

 

In its day it was revolutionary detail, albeit still suffering from the plastic 'signature' moulding flash atop the boiler/firebox. However, never a brilliant runner, which I probably put down to the missing half kilo of diecast vs. the HD/Wrenn!

 

However, cutting to now, tried to run the Manor and it would not. No continuity. Dismantled and found that aside needing a clean, the motor contacts to the casting were poor.

 

Cleaned up and continuity restored. Did notice one chassis half casting looked very 'coarse'.

 

Tried to run and barely would do so, and any more than 6 inches along it climbed off of the track.

 

Dismantled more fully to find quartering gone to pot on driven wheels - one wheel/stub axle had turned on the stupid plastic centre shaft. At this point I learned that all split chassis are shyte.

 

However, more obviously, the rear axle was not square to the chassis, nor was the front. It was plain that the chassis half which looked poorly had effectively 'expanded', so I had a permanent 2ft radius curve built in. Fine for a circular clockwise layout...

 

Further attempt to dissemble resulted in a piece of chassis literally falling off. Major cracks also visible when underframe removed.

 

You can see the damage, and also the sizeable difference in spacing of axle holes in the photo.

 

 

 

Edited May 7, 2020 by 97xx

[97xx]

So, at this point, it's a bin job. Or at least the 'awaiting scrap' lane of the MPD.

 

Luckily the 'good' half was stable, dimensionally OK and shows no signs of any distress. So, it's an acceptable pattern, although the halves are quite different on the inner faces. Luckily also, the 'good' half had the gear shafts.

 

Not to be outdone, and with a good deal more than usual time on my hands, decided to assess whether I could mill up a chassis half.

 

I chose aluminium as (a) didn't have an brass in stock big enough, and (b) steel would be a lot more work and care to machine when at this point I wasn't confident that I had a winning solution. Appreciate it's not 'hard wearing' but I suspect it will outlast me.

 

First step was to measure the one dimension that looked like it might be 'standard' - the wheelbase from the good half and luckily was spot on 28/31mm.

 

Drilled axle holes out to 4.9mm then reamed out to 5.0 for smoothness of bore (conscious that ali not that resilient, so smoother the better.)

 

Also drilled motor mounts as these are a vital reference.

 

Edited May 7, 2020 by 97xx

[97xx]

Then on to a monumental amount of milling work. Arduous as no drawings/dimensions other than those I could take off of various bits with vernier. So, some degree of inaccuracy/risk too.

 

Enormously fiddly, as I had to incorporate the various plastic spaces. Also, needed to be very thoughtful about order of work so as not to take away areas I would need for support/workholding in subsequent ones.

 

Particularly awkward was the tapering of the piece inside the boiler as it's a large-ish piece to mill when it becomes unsupported once one taper is done.

 

 

 

Edited May 7, 2020 by 97xx

[Les Bird]

You're a brave man. I look forward to the final result

[97xx]

Finally, quick spray of etch primer followed by weathered black.

 

And reassembled.

 

I did not like the huge amount of sideplay in the axles. Much no doubt to allow negotiating the tighter radii curves/points of the day BUT this is not necessary in all three axles.

 

My fears were confirmed on test running the chassis. Good news was that it ran smoothly mechanically, although I'd not call it 'refined'.

 

Trackwise it was sort of OK forwards, but in reverse the rear driven axle climbed just off of the rails if prompted by  a rail joint which wasn't 100% straight - like where the two lengths of flexible track were joined on my desk - being both curved slightly, the join had a slight angle in it.

 

The traction tyres also help it climb away.

 

So to resolve...

 

 

[97xx]

As an aside, you may wonder why I didn't produce both sides anew. Basically as I do not have a CNC mill, this would be hard work - the two sides are different where it matters (internal faces) and also the fact that they're 'mirrored' doesn't lend itself to any great economy of machining. I do however, have the other half in the raw if we ever suffer another of China's 'presents' in the future...

 

To the desperately bad running:

 

What it needed was something to reduce sideplay in the driven axle - this would (a) not interfere with the ability to corner, and (b) would encourage closer alignment of gears, and (c) put less stress on more complex rod pins on centre axle (where you could see the maximum opposite sideplay was really angling the joins).

 

Evidently sideplay reduction could be a bit experimental, but there was no way I was going to pull apart, repeatedly, the now loctited driven axle and wheels.

 

I reckoned about 0.6 - 0.7mm of reduced play might work - enough to centralise but not bind. 

 

The answer came in nylon M5 washers. These tend to be 1mm thick. Stuck to a piece of wood with DS tape, they could be sanded  down against a flat plate.

 

Then simply make one radial cut in the washer - then it can be fitted over the axle, when lifted out of the frame, by simply twisting it.

 

One each side - seen here hopefully.

 

Edited May 7, 2020 by 97xx

[97xx]

After all this work, the Manor is back together.

 

It runs, and well enough to be presentable.

 

I can't seem to add a movie file sadly, as it probably takes some believing...!

 

However, here is a link to a QT video in Box. Let me know if you can't access it.

 

Hopefully if I can run it in a bit, it may improve. But I'm happy enough with that after nearly 40 years.

 

The rail joint you can see is the one where it previously derailed the rear drivers in reverse 100% of the time.

 

https://app.box.com/s/4ib3fwdiz7hb9zcrbxyfbokfdc0l1m13

Edited May 7, 2020 by 97xx

[hayfield]

Hats off for doing this, I would have bought a Comet chassis

[97xx]

9 minutes ago, hayfield said:

Hats off for doing this, I would have bought a Comet chassis

 

You're not the first person to suggest that, but I just don't think the body is good enough to merit it as I imagine I'd be looking at £40 chassis, £30 wheels, plus £30 motor & gearbox and so on.

 

Aside time, this cost me two nylon washers...

 

I'd rather just go make/build a really good one - body and chassis.

 

What I will probably do now is weather it which will probably reach a happy end state of effort vs. outcome.

Edited May 7, 2020 by 97xx

[hayfield]

Look at your numbers again

 

Chassis  £35.50

Wheels  £50 for Romfords Loco only

Gearbox £10 to £18

Motor a decent one £30

 

I snapped up a partially made body and chassis kit, I doubt if I paid much more that the cost of a new chassis, is destined to go under a K's 63xx (which is probably worse than the Mainline one) but to EM standards. I have just picked up a Branchlines chassis and completion kit for a GWR City loco with a spare set of Romfords for a 0-6-0 tender loco (and a couple of Airfix Loco kits) for £60, it does not have to be expensive to rebuild locos if you just look out for parts.

 

I prefer kit built locos, they may have less detail but the weight of them relays something the cheaper RTR does not do , plus if something goes wrong us mere mortals can repair them

 

I have a Bemo loco absolutely a stunning piece of engineering, but if it ever went wrong I would not have a clue where to start

 

Back to your loco, if you put as much effort into the body as you have with the chassis I expect it would be a show stopper, I wish I had your engineering skills and machines    

[97xx]

1 hour ago, hayfield said:

I prefer kit built locos, they may have less detail but the weight of them relays something the cheaper RTR does not do , plus if something goes wrong us mere mortals can repair them

 

 

 

Agree!

 

I think you've seen my 97xx thread (which is what started all this off!) but for the benefit of others who haven't, it's a 1960s K's 97xx 'Bodyline' kit (sprayed matt black with the HD chassis protruding the bufferbeam!) completely dismantled, stripped, rebuilt, repainted etc...

 

There weren't any issues getting THAT chassis to run true!

[hayfield]

A superb job on the body, a set of Mainly Trains coupling rods will partially desguise the HD chassis

[97xx]

Still a scrappy runner by comparison to a 40-year old HD 0-6-0- shunter I've just overhauled which is a silent powerful and smooth runner.

 

Two issues apparent:

1. A degree of inaccuracy in (old part of) chassis, so some fettling to axle slots with a fine rat tail file - then checking the 'twist' by using three 5mm steel rods and fettling until aligned. Quite an improvement - now fairly smooth when running.

2 But clearly poor pickup and continuity through the hopeless split axles and rubbish split chassis design - notable by too much shunt between loco and tender, and occasional 'Hand of God' required. Unacceptable.

 

There's a paradox in that the small spring used to load the bogie causes the nearest drivers to be slightly lifted naturally and load shifted to the (traction-tyred) rears. Positive to load the tyred drivers yes, but negative to lift the conducting front drivers - which are of course half the picking up ones given rears with tyres do little.

 

So, tender pickups added to outer 4 wheels, and a very substantial improvement immediately. 

 

An absolute step change in slow running once the high starting 'friction' of the rather shabby three-pole pancake motor is overcome. Again, impressive how the big old 3-pole HD Ringfield just glides away from a standstill!

 

Now the pickups are proven, will add a plug/socket to the tender-loco wires as tethered will annoy me.

 

I may now have a model that runs well enough to do some detailing/weathering. Had a go at the cab with a fine sable brush...  ...just about passable.

Edited May 10, 2020 by 97xx

[97xx]

Overall, it's an interesting lesson in how NOT to design a model locomotive:

• Plastic body so little mass - unavoidable in RTR I accept
• Pancake motor - can only fit in firebox area. Little mass as the motor is plastic bodied. Flawed design/tech.
• So has to drive rear axle, and traction tyres fitted. No longer preferred.
• Front and middle axles are thus main pick up wheels, but middle are 'sprung' (tiny coil springs in frames over axle) - presumably to keep them on rails due to large sideplay to allow negotiating sharper curves
• Additional ballast is fitted, but in front of boiler area - where it is least needed and in fact counterweights chassis AWAY from tyred wheels
• Excess sideplay in REAR driven axles for no obvious reason.
• Consequence: driven wheels ride off of track in reverse. Flawed design, corrected with nylon washers as posted before.
• A bogie spring is fitted to bogie to try to shift weight back onto drivers
• Which has consequence of LIFTING front drivers, reducing continuity
• Springs on middle drivers also work against keeping front drivers on rails, exacerbating above

I'm sure you all know this, but has been a voyage of discovery for me after so long away from the hobby.

 

All I know is when I re-chassis my old Q1:

1. I won't be buying anything Chinese
2. I'll be using 1/8" steel axles
3. Ditto a Mashima motor
4. Worm drive
5. I won't be using split frames
6. Or traction tyres
7. Or pancake motors
8. Or plastic gears
9. It will get tender pickups

[hayfield]

97xx

 

As far as gears are concerned, pay a little more for a gearbox rather than a motor mount. High Level are the market leaders, both Branchlines and Comet Coaches both also sell good units.

 

I think as far as Chinese is concerned they do sell good motors as well as bad ones, Mashima motors are not made any more, those that are still available are fetching high premiums. I have actually seen them at a higher cost than High Level's coreless motors which are far superior. Gearboxes seem not to mix both metal and plastic gears, its more about quality of the components, I have some older metal gears that fail to mesh, others very noisey !!! 

 

Sorry for seemingly contradicting you, as I do actually agree with your message. Poorly designed and made products should be avoided at all times, spend a bit more for quality

[hayfield]

97xx

 

Many would steer well clear of N C Keyser products, they would echo your sentiments on substandard products. You have shown that with a little care an average model can be lifted to another level, using a strong RTR chassis in one way helps a lot.

[97xx]

1 hour ago, hayfield said:

97xx

 

Many would steer well clear of N C Keyser products, they would echo your sentiments on substandard products. You have shown that with a little care an average model can be lifted to another level, using a strong RTR chassis in one way helps a lot.

 

Agree - they are pretty dreadful, but I've enjoyed the challenge of making them presentable. The Q1 will be getting a custom chassis, I have a MAshima for it, and indeed a very good gearbox will be happening, so we'll see how my chassis-building gets on. Although the Manor is I suppose 50% custom chassis now...!

 

 

[hayfield]

The Southeastern Finecast Chassis is ideal, whilst this is one of the more detailed chassis they are very well designed and quite easy to build

[97xx]

4 hours ago, hayfield said:

The Southeastern Finecast Chassis is ideal, whilst this is one of the more detailed chassis they are very well designed and quite easy to build

 

Thanks I have dropped them a note enquiring.

[hayfield]

97xx

 

Website  http://www.sefinecast.co.uk/Prices.htm

 

Complete kit

F173 SR Q1 £ 93.95_____

 

Chassis

FC173 SR Q1 £35.95

 

I would also (if you have not done so already) send a self addressed stamped large letter and ask for a spares price list for the loco, but the chassis kit is I believe for the loco and tender and may also include cast parts for the chassis. Photo below is what is included in the LNER K3 chassis plus instructions

As you can see is a bag of castings, some of which are to convert the Wills body to accept the new etched chassis rather than the RTR chassis

[97xx]

For those with the fortitude to carry on reading, I have now made the pickup connections presentable.

 

Firstly, small sockets (the kind used for smallest LiPo RC batteries minus the plastic covers) fitted to base of tender, and given a tiny wrap of heat shrink.

 

Secondly, wires from loco given wrap of 36SWG to make them look like 'hoses'.

 

Third, small plugs (ditto) added with tiny bit of heatshrink at ends.

 

Connected and all works. Admittedly hanging a little low...  ...but no big deal to adjust.

 

Once all is fully proven, will paint them black to make look like water hoses.

 

 

Edited May 11, 2020 by 97xx

[97xx]

42 minutes ago, hayfield said:

97xx

 

Website  http://www.sefinecast.co.uk/Prices.htm

 

Complete kit

F173 SR Q1 £ 93.95_____

 

Chassis

FC173 SR Q1 £35.95

 

Very helpful, thank you. I did in my email ask if they could send me the instructions so I could judge how well it might go into the K's loco and tender.

 

reading your reply suggests SAE better?

[The Johnster]

20 hours ago, 97xx said:

 

There's a paradox in that the small spring used to load the bogie causes the nearest drivers to be slightly lifted naturally and load shifted to the (traction-tyred) rears. Positive to load the tyred drivers yes, but negative to lift the conducting front drivers - which are of course half the picking up ones given rears with tyres do little.

 

One can alter the pressure of this spring, which is clearly too powerful if it can lift the front drivers, which will both upset pickup performance and increase the likelihood of derailment on anything but absolutely 100% perfectly laid track (which does not exist in this universe, though we try our best).  To increase the pressure, stretch the spring, but you don't want to do that so reduce it by trimming the end.  Finish off carefully with emery to make a nice domed end so it won't trip itself up on anything when the bogie moves about in curves, and take off a little at a time as it is a one chance only trial and error job to get the pressure right.  Bit of lube on the end and away you go (and the loco will run better as well...).

 

 

8 hours ago, 97xx said:

Overall, it's an interesting lesson in how NOT to design a model locomotive:

 

Preaching to the choir.  All of my Mainline chassis and mechs let me down eventually.  But it was a brave attempt.  You may view it less unsympathetically in the light of the thinking behind the split chassis experiment.  At the time Mainline arrived on the scene, there had been much complaint for many years in the modelling press about the standard of RTR.  Triang Hornby were the only game in town for a long while and had not advanced beyond plastic skirts beneath boilers to hide mechs, smaller centre drivers, and no attempt at detail below the running plates.

 

Within a very short time of each other, 3 companies broke into the UK RTR market; Lima, Airfix, and Mainline.  Lima disposed of the plastic skirts and showed daylight beneath boilers in the appropriate places, and the other two went a step further and provided good levels of detail below the running plates; we had made the first step towards current RTR.  In the decade or so prior to this Chris Petherton had perfected the art of scratchbuilding spilt chassis, which in conjunction with compensation, Portescap motors, and the excellent RG4 gearbox, ran very nearly perfectly and eliminated problems with pickups.  This was the production design road Mainline chose.

 

They made RTR that was stunning for the time, but the Petherton type chassis was a mistake for volume production.  The Portescap/RG4 mech was too costly, and to enable  clear daylight viewing when the loco was viewed side on a conventional mech was out as well, so they used pancake motors which were not powerful enough unless they ran at very high revs and were reduced through spur gears, and even then traction tyres had to be used to get the locos to pull reasonable loads controllably, which impaired pick up.  These spur gears were plastic, cheap, and nasty, and induced friction into what should have been a frictionless chassis.  Another weak point was the interface between the plastic stub axles necessary for split chassis pickup and the '½ axles', really 'one third axles' that held the wheels.  And, after all this, the spur gears were still visible!  To sum up they were poorly designed, poorly built, and used poor quality materials.  And then, too make things even worse, the bulky pancake motor housed in the firebox of the Manor and 43xx meant that the firebox on these models is too wide; imagine the outcry if anyone tried that nowadays, after all the kerfuffle over the Ox DG...

 

The competition, Airfix (and Hornby whey they began to get their act together and re-tooled for the new world) were by no means perfect; awful tender drives or tank engines with motors filling the cabs were the order of the day.  Airfix experimented with sprung plunger pickups on their (in)famous 14xx, which again sounded like a good idea but dirt got in the plungers and seized them.  This model had a very good flexible drive shaft but would have been better with the (conventional open frame) motor mounted further forward to allow cab detail.  Their large prairie drove the front axle and still fouled the cab with motor.

 

To be fair to Mainline, they never resorted to tender drives (I hate tender drives) which the others did, with the spur gears of the diesel power bogie derived mechanisms visible on one side of the tender.  I also hate traction tyres, and will immediately remove them from any loco I have that carries them and cut them so that nobody is tempted to refit them.  Slow running and pickup improves immediately, the track is cleaner, and haulage is not a problem on my small BLT.

 

My advice is to trim the bogie spring and replace the traction tyred wheels on your Manor.  If I'd been milling a new chassis I'd have looked at replacing the mech with a can motor and metal worm/cog drive as well.

[hayfield]

2 hours ago, 97xx said:

Very helpful, thank you. I did in my email ask if they could send me the instructions so I could judge how well it might go into the K's loco and tender.

 

reading your reply suggests SAE better?

 

I would like to remind all modellers that the traders who supply our needs are not big multi nationals but usually small cottage industries just ticking over. Dave at SEF is so helpful and I guess has a thriving parts business, he is happy to supply a parts list for a kit providing you give him a large self addressed envelope with a stamp. If I want a set of instructions from him I both ask to buy it and order it when I give him an order for other things. Some traders especially those switched on with modern communication are happy to email a file. Others unless you buy something from them refuse any assistance. 

 

Just make an offer to pay, whilst its our hobby its their livelihood.

[97xx]

3 minutes ago, hayfield said:

 

I would like to remind all modellers that the traders who supply our needs are not big multi nationals but usually small cottage industries just ticking over. Dave at SEF is so helpful and I guess has a thriving parts business, he is happy to supply a parts list for a kit providing you give him a large self addressed envelope with a stamp. If I want a set of instructions from him I both ask to buy it and order it when I give him an order for other things. Some traders especially those switched on with modern communication are happy to email a file. Others unless you buy something from them refuse any assistance. 

 

Just make an offer to pay, whilst its our hobby its their livelihood.

 

yes sounds fine to me - I can see for sure how the landscape has changed since I last modelled, so I'm very cognisant of your point about a dwindling source base that needs nurturing and encouraging.