Which material for main frames?

I am embarking on the construction of a 3,1/2" Evening Star locomotive which will be my first locomotive build.

My question is what material is best for the main frames? I'm struggling to find 1/8" bright mild bar wide enough (3.3/4". I have ground down several grades of 1/4" steel I had lying around, (bright, black, sheared plate and even the middle section of an old RSJ) but all had to be abandoned due to distortion.

my options as i see it are:

1. Locate 1/8" bar in bright or black steel. (any recommendations of suppliers welcome)

2. Purchase gauge plate (any recommendations of suppliers welcome)

3. Flatten out 1/8" sheared plate (again any recommendations welcome)

4. Use 1/4" material and compensate for this on the drawings

I'm open to any other ideas and to see what other people use. Also if anybody has parts for this loco lying under a workbench that they would be interested in selling, please let me know.

Regards

Dom

Option 5 use readily available 3mm sheet* or 3mm Black flat stock and adjust the stretches etc to suit the change in length.

You will have to do this with all plate on the older designs as sheet material is now sold in metric thicknesses.

Frames are not a good thing to make from Bright steel as it will tend to move when you cut out teh axle boxes

* Reeves sell sheared plate in suitable sizes for many loco frames or your local lazer or water jet cutter can provid ea couple of strips if you don't want them fully lazer cut. M-Machine do 3x100 Black flat

J

Edited By JasonB on 29/01/2014 20:13:49

Jason

4000 Posts - Congratulations!!

We've seen your models too but what do you do in your spare time?

Regards

Norman

Hi Dominic

Jason is 100% right, use black 3mm plate. Bright or cold rolled steel has a nasty habit of trying to imitate a banana. I am not saying that black or hot rolled steel will not, but it is less prone to it. I once tried to stress relieve some 1/8" x 3" BMS, it had more umps and ollers than the rocky road to Dublin when it came out of the oven (not domestic) . It went straight in the scrap bin.

I go out to work for a rest

Hi Dominic

Go to www.modelengineerslaser.co.uk they will cost about £60 all cut out and holes spotted

Regards

Stan

I agree with Stan, having put alot of the above mentioned material in the scrapper for one reason or another. I bit the bullet and went down the 'someone else can do it road'

Have not regretted it. all axleboxes cut to perfection, and if you want it, he will also spot all the drill holes for you. That way when you drill both frames should/will be indentical and will certainly assist you in gettig them and the frame stretchers all 100% square

hi dominic,

ive made all my loco frames out of steel plate. these days instead of 1/8" it will be 3mm as commented on above. personally ive never had a problem with 3mm steel strip, though scale on surface so not quite BMS. be careful if you go down the laser cut route as the edges etc become quite hardened. personally i think there is an awful lot of satisfaction to be gained from making the frames yourself from 3mm strip rather than laser cut. an 18 per inch tooth hacksaw blade makes very quick work of same, and the 9F frames arent complicated. just be careful when you get to the throatplate on the boiler - the original design is a bit 'iffy' and has caused quite a few problems. a proper double flanged throatplate would be far better IMHO

cheers,

julian

Thanks for all the advice.

I really would like to make the frames myself and so have sheared off some more 1/8" plate which has come out flatter than previous attempts. Some manual handling should see these perfectly flat.

Thank you for the advice on the boiler, I am going to take the drawings to the next ME meeting and get the boiler tester's advice before any copper is cut.

Any more potential sticking points are most welcome, its far easier to solve them at this stage before anything is cut.

Regards Dom

I once tried to make frames from BMS. What a disaster!!!! I braced it, heat/stress relieved it and it still came out like a banana!

Yes, I did the same - cooked them in a bonfire and left them overnight in the ashes to cool slowly. They still bent when I cut out the axle box holes

Russell.

The last loco I built I used BMS for the frames, never again! Gauge plate is expensive but it arrives flat and stays flat, and straight. Compared to cost of castings and copper for boiler, and the end value of the project I think it is worth every penny

Thank you all for the advice. I have now cut the main frames and am pleased to say they have come out flat. I used 1/8" mild steel plate and sheared the "blanks" leaving a good 2" all round. When the frames came off the mill the excess material was like a banana but thankfully the frames were perfectly flat. Whilst I had the "soft bed" bolted to the mill I also cut the Tender frames. next job will be the horn blocks.

Hi Dominic,

Obviously a bit late, but...

Most of us mortals don't have the capacity to shear our own plate, especially of that size. Several of the trade suppliers will shear plate for you and their machines leave it pretty much flat.

The ultimate solution is laser cut frames, which don't have the distorted edge of sheared plate.

Neil

Wot, no guillotine? Mind you I've only got room for a baby guillotine, capacity 1/8" by 4 feet, for mild steel. I normally cut to size on my guillotine, but if I was really concerned about the sheared edges I'd leave 1/8" to 1/4" per edge for clean up.

Regards,

Andrew

Andrew

You must be the man who has everything - several lathes, two gliders etc etc. and now, you tell us, a guillotine ! ! ! As one who used to have a glider, still has one lathe and found access to a (pneumatic) guillotine at work very handy pretty much every day - I'm envious.

( However our kitchen is MUCH tidier than yours !)

N

Evening all,

No doubt some of the steel plate supplied today as frame material will distort as the stresses are relived and probably the same will happen with water jet cutting should the material retain stresses from its rolling. Years ago old man Kennion at one time supplied what he called "normalised" steel plate for frames and excellent material it was. Cutting it out was a pleasure, a drop of cutting oil on the blade and it would sail through the plate like a knife through butter. I must be reasonably lucky for all the frames I've cut out over the years I cannot recall ever having a problem with distortion. I must be one of the last model engineers not to use water jet / laser cut frames and components, marking out and cutting frames is one of the simpler operations when building a locomotive.

Regards,

Bob

hi bob,

you + me makes two! couldnt agree with you more!

cheers,

julian

Norman,

Actually three gliders! Although that will soon be two, as it looks like the syndicate has finally sold the Janus, payment this week if we're lucky. A shame in its way, but I haven't flown it for some years, two of the syndicate members have died, and some of the remainder were not paying their annual dues. I'm happy that I've had a lot of fun, and a few wobblies, in it over the years. A highlight was a diamond height in it while doing a site check at Aboyne. On the downside breaking cloud over Aboyne at 1200 feet was a bit hairy.

My guillotine is an Edwards 'Truecut', bought secondhand on Ebay.

One can never have enough toys, although I'm running out of space. I see that one of the dealers has a full size Burrell SCC for sale. But sadly out of my price range. On the flying side a P51D would be nice, but would require a serious lottery win.

Regards,

Andrew

Andrew, try this,Ian S C