34055 Fighter Pilot from an Airfix kit.

[Barclay]

I saw this running beautifully on the test track at Expo-EM yesterday.

[Wilton 34041]

Yes I watched it Saturday too. Interesting to actually see what I've been reading about and see it in action. Quite inspiring.

Regards Phil B.

[brightspark]

On Friday I had just enough time to put a bit of weight into the loco. I used the usual depleted uranium* tucked into and on top of the chassis as best I could to get the weight over the leading two driving axles. Then put some more weight into the body inside the firebox as close as possible to the rear driver.

Despite this rather large amount of weight, I should measure it, the loco was still prone to wheel spin even on my little test track. I then realised that the spring on the front bogie was too long. I replaced this with a shorter spring.

 

At the test track, I got out the loco with the idea that it would do some gentle running and proofing before we saw how much it could handle.

It set off with 6 Bachmann birdcages that it found quite easy.

Then Richard Stevenson said,

" that should be running with some Bulleid coaches."

Ahem...

How many are you putting on David?

 

Well it chugged around with 8 on and that is what Barclay and Wilton saw.

There was a bit of adjustment having to be made to the amount of drop on the front bogie. I had to loosen the retaining screw by 1.5mm as the trailing wheel was lifting off the rails on a couple of uneven bits.

 

We were concerned because the loco did not run very fast and the motor got quite hot. Although the train was heavy, the next loco that pulled it, my Hornby Merchant Navy, did not have the same problems.

 

That evening I took the body off and looked for anything that might cause drag. The only thing that I could see was a possible contact between the flywheel and one of the lead weights. I parred this back to give extra clearance and tried it the next day. 

The voltage drop was not as bad, but the motor still got hot and the speed still wasn't there. 

It also didn't like starting at a couple of places on the track. That could be dirt or more unevenness. I may consider adding some more pickups.

 

Mr Muz, came an had a look. We discussed the concern about the tender and after comparing notes we concluded that the tender is the correct length. The AG drawing does indeed have an error.

We also looked at the detail that I had added and was not sure that I had correct. Graham thinks that it looks right, but will have a look at the drawing and notes when he gets time.

 

So a successful day. 

 

 

 

* I am joking, I use lead, but don't tell anyone else.😄 

[JeffP]

Is the motor up to the job?

If not, that might make it run hot.

Or maybe the gears need to be better?

[brightspark]

A good question.

Mashima 14x26 on a 32:1 two stage gearbox.

 

I can't see any binding in the transmission and no fouling. The loco ran quite smoothly.

 

I wonder if I could help it with a heat sink or more ventilation into the bodywork?

 

Suggestions are most welcome.

 

[Barclay]

11 hours ago, brightspark said:

A good question.

Mashima 14x26 on a 32:1 two stage gearbox.

 

I can't see any binding in the transmission and no fouling. The loco ran quite smoothly.

 

I wonder if I could help it with a heat sink or more ventilation into the bodywork?

 

Suggestions are most welcome.

 

I would think the motor is up to the job - those 14/26 are quite powerful. Some motors do run a bit hot - is it too hot to touch, or just warm? Have you put a tiny speck of oil on each motor bearing? It might be educational to see what the current draw is, because as long as it's within the motor's normal parameters (though I don't know what they are!) it should be OK. Is there a slightly discernible end float, because I have known a Mashima to be a little tight. With care it can be taken apart and the bearing drifted fractionally further out.  Did you run it in on the bench before installing it, because this helps to bed in the brushes and bearings and will reduce current draw. Sorry to ramble, just some thoughts.

[1466]

The EM gauge Society's manual has a section on the performance and parameters of several electric motors.

[Barclay]

34 minutes ago, 1466 said:

The EM gauge Society's manual has a section on the performance and parameters of several electric motors.

Quite right !

 

I couldn't find it earlier but have now - recommended max current for a 14/26 is 400mA.

[brightspark]

11 hours ago, Barclay said:

I would think the motor is up to the job - those 14/26 are quite powerful. Some motors do run a bit hot - is it too hot to touch, or just warm? 

You could feel the heat through the body. It was getting very warm. 

 

11 hours ago, Barclay said:

Have you put a tiny speck of oil on each motor bearing? 

Yes

10 hours ago, Barclay said:

It might be educational to see what the current draw is, because as long as it's within the motor's normal parameters (though I don't know what they are!) it should be OK.

Some probes were put across the rails. On Saturday it was showing 10volt

On Sunday 11 volt.

Saturday we had it pulling 8  coaches on Sunday 6.

 

10 hours ago, Barclay said:

 Is there a slightly discernible end float, because I have known a Mashima to be a little tight. 

Yes there is end float. I have not measured it.

 

10 hours ago, Barclay said:

Did you run it in on the bench before installing it, because this helps to bed in the brushes and bearings and will reduce current draw. 

Good question. Yes, the motor and chassis had a run on the rollers for a good hour or so.

 

10 hours ago, Barclay said:

Sorry to ramble, just some thoughts.

Ramble away. All very good questions. 

This is not my area of expertise.

 

10 hours ago, 1466 said:

The EM gauge Society's manual has a section on the performance and parameters of several electric motors.

Why didn't think of that. And written by my good friend the late Douglas Smith.

 

9 hours ago, Barclay said:

Quite right !

 

I couldn't find it earlier but have now - recommended max current for a 14/26 is 400mA.

Found it sheet 5.1.1.(9) sheet 18 &19.

I have just read the the introduction on sheet 5.1.1.(0) . On sheet 4 below Fig 7  Doug warns of heating and more pertinently on sheet 6 second paragraph were he advises against putting in too much ballast and suggests that the model should be able slip when pushing against a buffer. 

Hmm I didn't do that.

But I have now and it seems ok.

I have tried running it up and down my short test track and looking at the stall voltage. Hmm varies between 4 to 6 volts. At 6.9 volts it starts and with a jump. Could be a pick up problem there though.

But the motor does get hot quite quickly.

 

I wonder if it was just struggling with a heavy train.

Time to carry on with the build. The run on Swaynton is quite short with lots of cooling time between runs. Plus the trains are not so heavy. 

Hopefully next years visit to the test track will yield better results.

Thanks for the input. If there is anything else I can try, please let me know.

[Barclay]

10 hours ago, brightspark said:

You could feel the heat through the body. It was getting very warm. 

 

Yes

Some probes were put across the rails. On Saturday it was showing 10volt

On Sunday 11 volt.

Saturday we had it pulling 8  coaches on Sunday 6.

 

Yes there is end float. I have not measured it.

 

Good question. Yes, the motor and chassis had a run on the rollers for a good hour or so.

 

Ramble away. All very good questions. 

This is not my area of expertise.

 

Why didn't think of that. And written by my good friend the late Douglas Smith.

 

Found it sheet 5.1.1.(9) sheet 18 &19.

I have just read the the introduction on sheet 5.1.1.(0) . On sheet 4 below Fig 7  Doug warns of heating and more pertinently on sheet 6 second paragraph were he advises against putting in too much ballast and suggests that the model should be able slip when pushing against a buffer. 

Hmm I didn't do that.

But I have now and it seems ok.

I have tried running it up and down my short test track and looking at the stall voltage. Hmm varies between 4 to 6 volts. At 6.9 volts it starts and with a jump. Could be a pick up problem there though.

But the motor does get hot quite quickly.

 

I wonder if it was just struggling with a heavy train.

Time to carry on with the build. The run on Swaynton is quite short with lots of cooling time between runs. Plus the trains are not so heavy. 

Hopefully next years visit to the test track will yield better results.

Thanks for the input. If there is anything else I can try, please let me know.

Hi - assuming the system doesn't deliver more than 12 volts then it's a high current draw that could kill it. Held back and with the wheels slipping it shouldn't be drawing more than 400mA according to the data sheet. If it is then there is a risk of meltdown. For measuring current of course the meter should be 'in-line' on one of the power feed wires rather than across the rails as we measure current in series and voltage in parallel, with apologies if I'm trying to teach my grandmother !

[JeffP]

It's not voltages you need to measure, it's current.

Current draw when pulling a load and stall current.

Ammeters are placed in series with the motor*

Not across the tracks.

    *You'd need to detach the track or rolling road feed, place ammeter +ve to the original feed wire and ammeter -ve to track or rolling road feed.

Make sure ammeter is set to mA.

Edited May 18, 2023 by JeffP

[brightspark]

Thanks all.

So I have in my hand my multimeter that I connected to the track to measure the voltage.

Borrowed from the test lab, a Fluke, as it has a better scale for amps that makes sense to me(miliamps, the Amp scale goes down to 3 decimal places.) and a tachometer so I can measure rpm.

I have done some testing this evening and will present some numbers tomorrow evening.

 

Hopefully I have identified the culprit(s)

 

 

[brightspark]

OK, so I have spent a few happy hours testing.

What have I learnt?

1. make sure that you have the multi-meter set correctly ( V- not V~)

2. running the model on rollers suggests faults that are not there when it runs on the track.

3. The Fluke has a nice display that is easier to read.

 

Now to the model.

 

I first tested the controller output volts (see note 1) and then set up the test bed and compared results to check for any irregularity.

The test bed is a short length of track onto which I can place a set of rollers.

A multi-meter set to volts was clipped to the rails and a second multi-meter, the Fluke) was wired in line with the feed.

So I could see what the voltage and amperage was.

I also had a tachometer so that I could measure motor speed. 

A reflective strip is placed onto the fly wheel and the hand held device will measure the number of times this passes, so giving RPM.

 

ready for testing. on lower left you can see the power leads clamped to the track and the multi-meter probes that will record voltage.

 

It seemed a good idea to test each part of the transmission in turn.

So I began by removing the body and disconnecting the motor from the gear box by removing the worm gear.

Doug noted that motors will require more voltage to get the initial movement and suggested that 1volt is normal on the motors we use.

I found that the motor started at around 0.8volts pulling 45ma (0.045amp) and 2051rpm.

Doug's test involved running the motor at 12v and applying load using a home made dynameter. See MRC May 1980.

So this made testing using a normal transformer difficult.

The only way that I could test the output was to run the motor at a measured 12volt and check amperage and compare to rpm.

I ran the motor at 12v and with no load it hit 18000rpm. 

Projecting the hatched line on the table, this looks about right.

At this point I took time to make sure that the motor mount was not affecting performance. 

The motor casing is quite thin and if squeezed it would affect the speed of the motor.

34055's motor sits on a metal bracket and is fixed with a metal strap. This is not pinching the motor body so no problem here.

Seeing nothing amiss I connected the gearbox but undid the grub-screw connecting the axle.

The motor started at the around the same point requiring an extra 0.1volt and pulling 53ma (+10) and the motor spinning at 1117rpm.

I slowly increased the voltage to see what was happening and at around mid range decided to stop the test and check the gear box as it was making a bit of a racket. I couldn't see anything really wrong so gave a good dose of oil, gave it a spin and wiped off the excess. The oil was quite dark, suggesting load (this is an area that I am familiar with) but no metal flakes. This may need regular oiling until it is bedded in.

A retest, and things had quietened down a bit. 

I had stopped the test at 8volts with the amps at 77ma and 11163rpm. After lubrication at 8 volts it was pulling 63ma and 12465rpm.

At a measured 12volts it was pulling 72ma and 18712rpm.

So no drag in the gearbox, so long as it is well lubricated.

 

Next was to connect to the wheels and coupling rods.

This was done on the rollers.

Starting voltage was 2.97 and pulling between 107 and 113ma. rpm was 69.

At 12v we had 108ma  to 119 ma 13000rpm. This is the same as the chart.

The variation between the milliamp readings is tight spots on the chassis.

 

The body was put on in two stages as I got some poor results.

The first was to rest the body onto the chassis. At 12v it was pulling 117 to 121ma. 

 

The next stage was to screw down the body and here I got some quite high resistance with the 12volt reading giving 134 to 175 ma. 

The higher reading was due the clamping down onto the slidebar assembly causing a change in the angle of the piston stroke and higher resistance.

I am going to have to look at this.

 

However, as said in note 2, the rollers seemed to highlight features not noticed when running on the rails.

So the final test were done on the short length of rail.

 

First pulling away. This I recorded at 1.8 volts which I think is respectable, but can be improved upon with some fettling.

The top end figure is spinning at 12volts it is pulling 300ma.

I also tried to see what happens when it has a heavy load.

I put increasing weight on the tender until I got to around 800grams.  At 12v it will go up to 325ma before slipping. Just before it slip there is a spike of 415ma  before slipping at 300ma and eventually dropping to 275ma.

 

It wouldn't quite take a kilo but this 800grams with about 100 grams of lead inside the tender.

 

So I conclude that the motor is not overloading, but it does get warm quite quickly as it get towards the 12volt tests even without a load on. The readings that I took and compared to Doug Smiths data suggests that it is within limits.

 

I can only conclude that the slow speed was due the train being heavy and the Hornby MN is a slightly newer design of motor in a different design of chassis.

 

Perhaps it just needs more running in and should not have been put on such a heavy train so early?

 

 

 

Edited July 19, 2023 by brightspark
edit for typo

[Pebbles]

With the motor speeds quoted, I can't help but feel that you need gearing of at least 40:1. 

[JeffP]

I agree.

Do helical gearboxes exist in OO?

[Adam]

1 hour ago, JeffP said:

I agree.

Do helical gearboxes exist in OO?

 

There's the Portescaps, of course (second hand), this from Wizard Models: https://www.wizardmodels.ltd/shop/locomotive/mgb1/ and I think Slater's do something broadly similar: https://slatersplastikard.com/linePage.php?suffix=JPG&code=SG4C.

 

Adam

[brightspark]

5 hours ago, Pebbles said:

With the motor speeds quoted, I can't help but feel that you need gearing of at least 40:1. 

30:1 is the recommended gearbox. 

40:1 would make it run slower.

Brian of Branchlines advises that this is a big motor and bigger motors have more grunt but less speed at the top end.

Is this what we are seeing?

 

3 hours ago, JeffP said:

I agree.

Do helical gearboxes exist in OO?

I assume that you are referring to what is available in the senior scale. Big motors and bags of room. (although there is a lot of room inside the body of this one)

 

2 hours ago, Adam said:

 

There's the Portescaps, of course (second hand), this from Wizard Models: https://www.wizardmodels.ltd/shop/locomotive/mgb1/ and I think Slater's do something broadly similar: https://slatersplastikard.com/linePage.php?suffix=JPG&code=SG4C.

 

Adam

Gosh the Slaters box looks nice. But I see the note about a quick blow fuse needs to be fitted. What is that about!

 

Thanks for the input guys.

I think for the moment, that there is not much that I can or want do with this except more miles on it and a look to remove the tight spots. 

[Pebbles]

Confusing power with toque. A  bigger motor maybe slower - this is not always the case, but dependent on the windings - it will however most likely have less of a drop in rpm between free running and load.  I should add that in my book the 14x26 is not large, but medium large. 

[brightspark]

 

After a couple of weeks and few happy hours trying to understand how to measure motor performance and puzzling over some of the more confusing aspects of this, it is time to move back onto the construction of the model.

But before we leave the motor problem alone, it was suggested to me by a member of SLAG that a google search was made on the motor. He seem to recall that they had read that these can run hot.

Sure enough on this very forum we have this with the same symptom. Apparently there is something in Scalefour portal that says the same, but I couldn't find it. 

Anyway fit, form and function, the motor fitted will do vey well as the trains that it will haul are short and the distance that it hauls them is short and it will have plenty of rest between each duty.

Once again thanks for the input. The coreless options do look good, but I will resist for the moment.

 

So on with the build. 

The tender seemed a good place to continue. If you recall back in early May I had started on this using the Airfix sides and the rear of the tender being a casting from RT models.

 

Following the instructions from AG the sides were extended at the bottom by  0.040" while the top was thinned to give a better edge. There is also a little re-profiling to be done. This is just some gentle bending of the plastic side to get it to match the back.

The top of the tender box is the Airfix moulding. But this was also modified. First to go was the water filler cap and then the bunker sides. The bunker is slightly too narrow so the fix is to cut down the top level with the moulded coal and add new sides. The toolbox's at the front are another casting.

There is also a little bit of widening required on this as the tender is a little narrow here.

 

I was puzzled by the two mouldings on the top of tender either side of the bunker.

Graham Muz was also puzzled by these and put it down to Airfix/Rosebud getting it wrong.

 

 

But I realised that these are the front fillers mentioned in the MN book by Derry. The idea was that the fireman could fill the tender from teh cab. These were quickly plated over when it was found that under braking that the water in the tender would surge forward break open the cap and flood the footplate.

A few strokes of the file and they were dealt with.

 

The tender top should curve away to the sides. AG's instructions say bend the top moulding, but I could see how you could do this. So I glued a former onto the top of the flat part and onto this attached styrene sheet that matches the profile of the tender back.

 

Onto this I fixed the replacement filler cap, the four tanks, the TIA dosser box, and lifting eyes. 

Hopefully I have them in the correct place.

 

Attached to the rear are the two ladders. Foot steps on the sides and thin Plastikard for the small roof.

 

Unless I missed anything, I think that the tender is ready for paint. 

(Buffers, coupling hook and brake standard to be added after paint. Oh and the the windows)

 

One more thing, that heavy lump of white metal on the rear makes the tender very tail heavy, so much so that it would sit up resting on the rear buffer beam. Adding some lead to the front end counteracts this but makes the tender quite heavy.

 

Andy

[Richard_A]

I love projects like this, shame I don't have the time, parts or skills to do one. 🤪

[brightspark]

Hello dear reader,

It is time that I did another update.

 

Before I continue, I would like to offer RKA some encouragement.

Time is what you can snatch, it's not a race, you don't have a time limit or a clock to watch.

Parts can be purchased, I try to give reference to where I source things from.

Skills, well they have to be learnt. There is no quick way to do this apart from try, try, and try again. I look back at some of my early stuff and it really is not up to the standard that I hope to achieve today. But they are all part of the learning curve. More importantly it is something that I have made. That is reward in itself.

Go on have a go. Try something simple to start off with and try to progress from there.

I suggest a model aeroplane kit. Say an Airfix Spitfire. Make it up as per instructions, then think about how you could have done it better, then make another Airfix Spitfire but improve it. for instance, add more detail, change the squadron, it doesn't matter if you mess it up as you are learning.

 

So back to the progress.

This has been slow due to the hot weather and life getting in the way. See Mr RKA, no rush, no race. I let the modelling mojo take a back seat and I recharge my batteries on something else.  

 

I left the last report with the tender progressed as much as possible pre-paint.

Since then the loco body was also progressed up to paint.

 

In the above photo you can that areas were being filled. Most obviously around the cab and the rear of the tender side.

The cab also now has the etched windows from RT.

I addition I have added the drain cocks. These are from the chassis kit and have a nice representation of the lever mechanism. I have not seen this modelled before.

The gap above the cylinders was filled as this should be flush.

I took too much off the front fairings as I misunderstood the instructions from AG. They are a little hard to read.

RKA, it doesn't matter if mistakes are made, they can be corrected.

 

The smoke deflectors are from RT. The shape is a little awkward as it has some tight bends in it.

There is a lovely bit of origami that folds up and form the lamps that solder to the inside of the deflectors.

Its a pleasing detail.

 

 

I have also considered the cab and made up a styrene floor with representation of the seats for the driver and fireman. This will compliment the boiler backhead, again from RT.

 

So onto paint.

Due to the heat I had to pick the right conditions so that slowed things down a bit. 

This had the advantage of forcing me to take my time and properly prepare each coat.

I also had in mind that this the first loco (that I have done for some time) that is not plain black.

 

I started off by degreasing the assembly  and parts. This is done with washing up liquid and /or a bathroom cleaner for removing limescale.

Uneven gaps, voids and errors were corrected with filler, I used fine Milliput, and this was then sanded back before Halfords grey primer was applied. When dry a check was made on the bodywork to correct any rough areas. 

So fill, rub back and re-prime, then check again.

 A long process.

When I was happy with the preparation, Halfords Gloss black was applied.

Halfords don't seem to have a suitable green for this loco so I used Railmatch BR Loco Green 2300.

This is a departure from my usual method of using rattle cans. The loco had to be masked and my new airbrush was broken out.

Again I made an error in misreading Gods instructions and forgot to add the 2" black line along the bottom of the bodywork on the loco side.

Soon remedied with more careful masking and over painting.

I note that the Hornby model does not have this 2" line. (So 1 up for me)

I applied several thin coats of the green as small imperfections that were found after each coat was dressed out and re-sprayed.

As I said a slow process.

Although the Railmatch paint is the correct colour and has a lovely semi gloss sheen, I would really prefer a high gloss finish. This so that the transfers take better and you don't get silvering.

I was going to apply a coat of Halfords clear varnish, but read Stu Davies article in the EMGS Newsletter 237 about modellers who Johnson Klear. Having a bottle of this (now called Pledge Multi-surface wax. Stu also suggests Quickshine Floor Finish from Lakeland) I thought that I would give it a go.

 

My first attempt was too thick. But I quickly learnt that you can brush on several thin (very thin) layers and build up a good smooth and very glossy finish.

When hardened I could apply the transfers.

The cabside numbers are ModelMaster. I am not too happy with the results as the carrier film is a bit too visible for my eyes. This is supposed to be able to be removed after 24 hours leaving the printed letters on the model. But I find that the transfer is not 100% successful. I will probably go over the area with more Klear.

The other transfers are by Fox. The long lines are tricky to get into a straight line. Too much adjustment and either the glue goes off or the transfer breaks up. So you have to be quick and accuarate. 

The number and nameplates go on later.

The cab has a white roof and the top half is painted in cream (Lining cream).

The photo of 34084 at Hither Green in Derry was helpful in determining what was painted in what colour.

 

The next task is start adding on the rest of the detail.

 

 

I have lost count as to how long I have spent on this now. Possibly, on and off, 30+ hours just on the paint. So around 150 hours in total so far.

I think that it has paid off as the paint is immaculate. Shame that it will have to be weathered.

 

Cheers

 

Andy

 

[sagaguy]

Fox lining is best cut into shorter lengths and line up using a small brush and water.One the hardest and time consuming was this tender for my Dulo conversion to Sir William Stanier Ivatt duchess.The red lining had to be fitted first and when dry,the cream lining hed to applied inside the red.

 

Just a warning,don`t use washing up liquid to clean your models prior to painting.It contains lanolin which stops the paint from adhering to the body properly.

 

 

                       Ray.

Edited July 19, 2023 by sagaguy

[brightspark]

19 hours ago, sagaguy said:

Just a warning,don`t use washing up liquid to clean your models prior to painting.It contains lanolin which stops the paint from adhering to the body properly.

 

 

                       Ray.

Hi Ray,

It depends on which brand. Fairy definitely does, other brands less so.

I have only had problems with Fairy.

I use detergent on plastics to remove the release agent that had been applied to the mould and of course any finger marks.

If anyone is still worried use the sink cleaner...but test on a scrap bit of material before use just in case it affects it.

What do you use?

 

Thanks for the tip on small sections of lining. Now he tells us 😄. I effectively ended up doing that on one section. 

 

The finish on your Duchess is superb. I hope that I can match that. (apart from the different colour, loco type and track standards. 🙂)

 

 

[sagaguy]

I use Cif or similar on cast metal bodies and plastic but the citric acid in that reactes with solder so i degrease with a non bio washing powder and a toothbrush.

 

The finish on that loco was Halfords satin  black,Fox transfers finished with Railmatch gloss enamel varnish.

 

                         Ray

Edited July 21, 2023 by sagaguy

[brightspark]

5 hours ago, sagaguy said:

I use Cif or similar on cast metal bodies and plastic but the citric acid in that reactes with solder so i degrease with a non bio washing powder and a toothbrush.

 

The finish on that loco was Halfords satin gloss black,Fox transfers finished with Railmatch gloss enamel varnish.

 

                         Ray

Cif - That is interesting. I hadn't considered that.

 

Ah and the trusty toothbrush.

I strongly suspect that this bit of kit is the real hero of the story.