Building Don Young's Doncaster

[Deleted]

although the weather was against us and we all got wet, it did clear a little later long enough for a few pictures in natural daylight. Early morning and it looked pretty bleak as to how many may turn up and I wouldn't blame them but they are a hardy lot and we had a good number of engines running. Anyway, here's 3 of FS basking in the sun after her soaking despite the valiant efforts of all around to keep her dry. Thank you to all concerned...🙂







Pete

[Deleted]

One for the naysayers on working sanders..... apologies if the commentary is a little short. Kneeling down to film and then standing while talking was a little too much... To explain here, it had been pouring down earlier and during a short break in the weather, I thought it a good idea to test the gravity sanders. After all some (not many) had said they would clog too easily which is a fair comment as they do in full size. So after the rain, it seemed a good idea to test them out which I did a number of times during the day, this is a short video when I had help from Owen operating the lever while I filmed for which I'm most grateful.



Pete

[Deleted]

Evening all.. I've decided that my next task is to set the chassis up as well as I can at this stage in the build, there will be a fair bit more weight added but it shouldn't involve too much work in adjusting the springs to suit. Going by the current weighbridge results I have a fair amount of playing around to get the chassis balanced.
Why do this now I hear? simple, during transit on Saturday I broke a top leaf spring on the left-hand side trailing axle. All my own fault, I had tightened the spring hangers to the max to bring the weight down at the rear for when fitting the pistons/rods so that I could roll the chassis without needing to push down hard on the rear to get the chassis level, what I forgot to do was loosen the springs when the boiler was fitted and thus putting them under a lot of stress, with zero movement left in the spring during transit it was inevitable that hitting the first pothole would not end well. Some may recall that I have slowly been replacing steel for Tufnol on the rear Cartazzi springs as the weight increased and I had a better idea of how much springing I need. Going back even further into the build when the springs were first made, it took over 100lb to get the springs to sit at their ride height, clearly, the springs were far too strong but I left for the reason above.

So with all the weight greatly increased and suffering a broken spring ( only took an hour to make a new one and it could be fitted without removing anything else) it is time to get the chassis close to balanced and going by the results today, it has a long way to go.
This picture is weighbridge MK2, nothing wrong with the first except for me leaving it outside in the rain resulting in the screen no longer working, I could still see the weight via Bluetooth but wanted the screen to be working too. I have made better use of the original casing this time around but the basic design is the same as before.

I have made better rising plates which now have a machined recess so that they locate better on the weighing plate, as with before, with two plates fitted this weighs the axle, remove one plate to weigh the opposite wheel to it alone.



I have the prototype's axle weights from one of my reference books which I then scaled against the model's total weight against the known axle % rates

Prototype weights are engine 92 tons
Front bogie 17 ton
Leading driver 20 tons
main driver 20 tons
rear driver 20 tons
trailing axle 15 tons

percentage split, 18.5%, 21.7%, 21.7%, 21.7% and 16.3% respectively

using the above percentage splits and a little maths I can get a ballpark figure for the model

model weight (currently) is total of 231.4 lbs (more than I had thought, this makes the boiler alone over 90lbs empty, IIRC the volume is 9 Ltrs full, so nearly 20 lbs with perhaps 15-16 lbs running weight)
Front bogie leading-axle 33.8 lbs
Front bogie trailing axle 35.8 lbs
leading driver 20.8 lbs
main driver 27.8 lbs
rear driver 69.4 lbs
trailing axle 43.8 lbs


What I need to find with the current total weight approx is
front bogie (total weight) 42.8 lbs
leading driver 46.28 lbs
main driver 46.28 lbs
rear driver 46.28 lbs
Trailing axle 37.71 lbs

So I have a bit of work ahead of me in adjusting the spring rates to get them closer to those above.

At least when looking at the current axle weights and noting how tail heavy the loco currently is I can understand why the trailing axle spring failed when it had been left badly adjusted at full deflection, it's not surprising that the top leaf snapped on one side. I should also add that my son's van is lowered with large alloy wheels and the side nearest the loco's broken spring has its own suspension issues with a damaged spring resulting in it sitting lower that side. Something that I wasn't aware of at the time of loading and had secured the loco down on that side as it was the opposite side to the driver and thus trying to equal the weight and also following good practice and not sit with a heavy weight behind me.

This info isn't on the blog, two reasons, one where the server is located is having some maintenance by Virgin and thus it's down and two I have been asked to do an article covering the weighbridge for the mag which will be in much more detail and will hopefully include the final measurements and pictures of the weighbridge construction.

Hope this is of interest, it's very much early days and the final figures will change. The current weight shows that the model is certainly going to weigh a fair bit more than Don's design, at 231 lb now ( design weight with tender is listed at 230lb), and with still a lot more parts to be added she's not going to be light. All those extra details and the modified boiler will see to this for sure..

Pete

[steamer5]

Hi Pete,
Can I suggest that in the future when transporting your wonderful loco from home to were ever & back, no matter how short the trip, that you install blocks under the loco frame & have threaded rod, bolts or purpose made metal hold downs ( sorry ratchet straps don’t cut it for doing this) to pull the loco down onto the blocks.
My dad & I have done many hundreds of kilometres with our locos held down like this, the only time we had an issue was taking them down to the local track when we didn’t block them, the track is less than 5 km away! As to how well this works, some years ago dad had the wheel break away from his trailer with 2 locos on it, the impact of the trailer axel on the road bent it, no damage what so ever to the locos.

Cheers Kerrin

[Deleted]

Thanks Kerrin

You"ve not the first to show me where I'm going wrong, had the same suggestion made to me at the club today...
Hopefully, before I next need to transport the model I will have sorted a proper carrying cradel for it.

Kind regards

Pete

[Deleted]

On returning from our short trip North there were 3 parcels awaiting my return, all 4472 related of course.
The first two are new books, well new to me, LNER by Peter Huges and the Yeadon's volume on numbered tenders, both should make some good bedtime reading.



The 3rd parcel is again something that I hadn't seen before, this time a model, a very small model of 4472 including two Gresley Teak coaches and a small length of display track. All in 'Z' gauge (1/220 scale) from Atlas, putting aside the incorrect motion the die-cast models are very good with plenty of detail.





The trip was fun except for our return, we all took covid home tests and my daughter and son have tested positive, my daughter is double jabbed, my son hasn't had any. I hope he's going to be ok...my wife and I along with our kid's partners have all tested negative so far, we'll probably do another test each tomorrow.
It just goes to show that the risks of going back to normality too soon are very risky, the holiday resort took zero precautions, we wore masks for shopping but not for the entertainment, I guess that we should have done so.

Fingers crossed they will both be ok, take care out there folk.

Pete

[simplyloco]

'Locomotive Tender Numbering'. Not my idea of bedtime reading I'm afraid, even at my age!

[Deleted]

Aug 20, 2021 15:46:55 GMT simplyloco said:

'Locomotive Tender Numbering'. Not my idea of bedtime reading I'm afraid, even at my age!

Bedtime reading for me John as it's reference material which may be helpful to my build. Having a quick browse there are some great pictures which I've seen before but not in this high a resolution. The written content is going to take some time to digest, it's not easily laid out if looking for one tender/loco although FS does seem to pop up in various chapters.

Pete

[Midland]

Hi Pete
I can understand your devotion to the good old FS and your desire to collect all the reference books you can. I hope you have exhausted the search engine at York. I still remember being up with her all night in Fort Wayne Indiana clearing all the muck out of her fire grate ready for the next days run to Chicago. Got the fire built up to 170 lbs before the firman took over. Ernie Kirk was his name, peculiar bloke!
Cheers David

[Deleted]

Hi David

Thank you for sharing your experiences with FS, I'm not jealous.....honest....🤣🤣

Pete

[Deleted]

good day all, last time I posted I said that I was going to spend some time weighing the axles to get the model close to the prototype percentage-wise as a baseline. I haven't finished yet but am getting close with mainly the rear and main driving axles needing attention. Once those are closer I'll then measure each wheel independently to get the axles balanced on each side. I have filmed another video showing the weighbridge in action, if you compare the last readings with the targets given in my last post, I hope you can see that I'm going in the right direction.



Pete

[theflyingscotsman]

i like the blue tooth idea, as you say its loggable and an easy way to see whats going on

[Deleted]

Aug 23, 2021 22:45:24 GMT theflyingscotsman said:

i like the blue tooth idea, as you say its loggable and an easy way to see whats going on

Anything for an easy life..🤣

[theflyingscotsman]

😁 nowt wrong with that, just because model engineering is sometimes challenging it doesn't need to be hard work

[Deleted]

Today I have played around with balancing the chassis and have to say that I am very happy with how this has worked out. The model is now getting pretty close to the correct scaled percentage weights for each axle. I could take it further, perhaps even getting it spot on but see no need as the weight will continue to change and grow by a fair amount before the model is complete. I'll do the final tweaks when finished, the important thing is that the weighbridge and adjustments to the springs have proved themselves very able to hit the required targets when that time comes. I have given full details in the blog, hope it's of interest...



4472flyingscotsman.co.uk/locomotive-weighbridge/

Pete

[steamer5]

Hi Pete,
Great explanation in the blog!
One thought, do you think that sticky leaf springs would have a greater or little effect on the weighing, ie dry as apposed to oil/lubricated with something slippery?
Then if the model follows full size & has no adjustment any bright ideas?

Cheers Kerrin

[Deleted]

Hi Kerrin

I guess resistance between the leafs must have some effect which is why I assembled mine before painting to remove the possibility of paint adding to this. Perhaps if they are too sticky you could spray them with a lubricant to help? I've not had this issue so haven't needed to experiment but I can see the logic.
If running out of adjustment just add a few washers between shock absorber and bottom nut, or remove the spring hangers and add a little more thread to them, both methods will allow more adjustment. I have added a few washers to mine, it makes it quicker to setup if the nuts need doing up a lot, ie less threato turn.

Kind regards

Pete

[steamer5]

Hi Pete,
Thanks for the reply & the thoughts. My thoughts were also along what happens down the track, ie once you paint the springs may undo some or more of your good work, also because they aren’t far above the ground what ends up working it’s way in! Guess you will find out before us!

On K1’s springs….there is no adjustment….well an easy one anyway, short of changing plates or making new spring links!

Cheers Kerrin

[Deleted]

Hi Kerrin, my springs are already painted, following advice this was done after assembly, they work great. As for what happens on the track, well the full-size guys have the same issue, it takes approx 2 hours to set the springs up where they should be, I'm told that once the loco moves a hundred yards down the track this has all changed again. It's just how things are, I suspect our models will stay in trim for longer than our full-size brothers...

Pete.

[Deleted]

Hi guys

I received a question on Facebook about reading individual wheels, I guess that I hadn't explained myself very well and to be fair I should have included this in the write-up.
Anyway, this morning I removed one of the lifting plates and measured one wheel on the trailing axle, weight recorded was 21.4 lbs which is uncannily close to half the axle of 42.4, just a lucky hit I guess..

Picture to show one wheel being weighed...the question asked was mainly about would the weight only on one side of the weighing plate cause the silicone to fail? I think the picture speaks for itself, I will quantify though that I did use a pretty strong silicone although suspect that most will be up to the job at hand...



In other news, I received today the new wider splasher brass trim pieces from Ed at MEL, looks like I got the extra width right.. Sorry about the photo quality and no, I still haven't adjusted the nameplate to be level...



This lovely card also appeared in the post over the weekend, such a lovely gesture from a fellow NLSME member. This was from Ron, a very well respected and superbly talented model engineer, I very much enjoy my chats with him and sharing info on each other's models. I count myself blessed to know such people and we have a few at our club.



Pete