dscott
Elder Statesman
Posts: 2,438
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Post by dscott on Oct 20, 2014 9:40:52 GMT
My dear wife has just recognized the frames well they are still in the kitchen, and we now have a Rob Roy sat in the sitting room with Katie's toys so she is very understanding.
Yes the health and safety and not taking any more interest in Students past a robotic yes here it is these days otherwise your jobs on the line. My ex boss tried to get me on a Blonde student that we got upgraded by taking an interest from a fail to a 2-1. This was serious until he met my wife...Chinese!!! Then he dug up everything he could...so that's why I am in Reading! There is a HUGE problem in education today and I think that the whole system needs looking at seriously!!!
And everybody on here who met us over the weekend either at Didcot or the Model Engineer Show on Sunday knows that Lily is very not Blonde. Speedie's are black as well!
Well done Mr Morgan. Probably the last of the best before pay checks, ticking STATS boxes and League tables sponsored by the local estate agents came into force.
David.
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Post by Rob on Oct 20, 2014 9:44:03 GMT
I don't think there's any way you can deduce what will work better, all we have is the combined experience of other modellers to go on. The attraction for me in doing it this way is the ease of manufacture, particularly when it comes to opening out the exhaust passages from two holes. Whatever you choose to do, it's going to work anyway so we're probably splitting hairs. What's the worst that can happen? The only down side I can see is that there's steam in contact with the frame, but I might cover everything except the hole with the thin gasket material I bought for the purpose. Agreed - I don't intend to enter IMLEC! The only concern I have is that I'd like it to be be a workhorse, just pulling myself around doesn't appeal so I'd it like to make enough power (and steam!) to 'earn' it's living. I was originally intending to sandwich an O ring between the cylinder and the flange of the blast pipe, that sits in the hole in the frame, but with this casting that won't be possible, so a full gasket seems like the only solution.
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Post by Roger on Oct 20, 2014 9:51:54 GMT
I think you'll find that any SPEEDY reasonably built will have tons of pulling power. That's one reason why I opted for steel tyres in a bit to get that power onto the rails
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Post by Rob on Oct 20, 2014 23:26:09 GMT
I think you'll find that any SPEEDY reasonably built will have tons of pulling power. That's one reason why I opted for steel tyres in a bit to get that power onto the rails I like the idea of tyres, but I'm not sure if I have the ability to trepan with my ML7. I struggle enough with parting, and I imagine the trepanning stresses to be that much greater due to the large radius. I did look for some large diameter thick walled 'tube', but nothing I could find comes close to the sizes necessary. Anyway! I feel like I've made reasonable progress today, had the day off work so spent half of it in the garage setting up for opening up the hornblock jaws to size. Apologies for the rather dull and uninteresting updates with little eye candy, I realise that you've all seen and done this before, but it's new and interesting to me . This is how my set up ended up: I realised too late that the slot size in my angle plate is 10 mm, whereas my T-nut studs are 12. By that time, I'd already spent some time setting this up so I couldn't be arsed to dismantle it all again to mill out the slots, hence the slightly unusual set up with the clamps. The vertical slide is also suited to an ML7 with it's tiny T-nut size, so again I had to be a little creative. The whole set up and clocking took me about 6 hours! But, it's now within about half a thou end to end horizontally and vertically. The vertically clamped parallel that seemingly does nothing is my datum point. My original datum mark is between the vice jaws, so I extended it out 3" and clamped the parallel to it, and using this and the DRO I programmed in the centres of each pair of hornblocks. From that, I then calculated how much I'd need to traverse in each direction to achieve the correct size with my 5/8" end mill. I checked three times before switching off tonight that it saved my points in memory! I was two thirds of the way through machining the middle hornblocks before I called it a night this evening. I'm hoping that my vertical slide and angle plate stay put when I get to either end, I'll just have to keep the cuts really light to err on the side of caution as I'm a little limited for space for extra clamping. Cheers, Rob
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Post by Roger on Oct 21, 2014 6:46:00 GMT
I don't think anyone tires of seeing a job done well, and that's a first class setup. Thorwing every piece of hardware at a job like that is the right approach, it doesn't need to be pretty. I'm sure you're finding that it's paying dividends.
Don't forget to add the holes for the keeps, it's easy to add them at this stage.
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Post by fostergp6nhp on Oct 21, 2014 6:57:54 GMT
In the absence of thick wall tube how about plasma cutting the middle out of slices of bar stock?
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Post by Roger on Oct 21, 2014 7:55:30 GMT
I wouldn't trepan the middle out of bar, it's easier to remove the whole of the middle. It takes time on a smaller lathe but it's still possible. It's probably better to find someone with a larger machine. It didn't take long at all on the Warco.
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Post by ejparrott on Oct 21, 2014 8:11:39 GMT
I regularly trepan middles out, far quicker than boring. Let me know what sort of size rings you want and I'll get you a material price if you want.
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bhk
Part of the e-furniture
Posts: 458
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Post by bhk on Oct 21, 2014 8:51:18 GMT
Just get some rings laser cut from plate
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Post by Roger on Oct 21, 2014 9:03:56 GMT
I regularly trepan middles out, far quicker than boring. Let me know what sort of size rings you want and I'll get you a material price if you want. I'm not sure you'd manage that on an ML7. I bored the whole bar in one go and then parted off the tyres, it didn't take long at all.
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Post by ejparrott on Oct 21, 2014 9:41:50 GMT
Have done in the past, try to avoid those horrible Mygaud things now though...
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Post by GWR 101 on Oct 21, 2014 16:04:12 GMT
Not sure which Newport you are located in but have you tried Le Bas Tube, they stock "Carbon hollow bar" which is aimed at the follow on machining market. No direct connection but used to supply them with large seamless tubes when I worked in the steel industry and remembered the name, believe they have a distribution network. Hope this helps regards Paul.
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Post by Deleted on Oct 21, 2014 18:00:03 GMT
An option for the Tyre material is available from Steel Express here:- www.steelexpress.co.uk/structuralsteel/seamless-tubes.htmlI've just had some "Slices" of HFS Seamless Tube for my Castles Driving, Bogie and Tender wheels :- Not the cheapest option but probably the easiest, given that they are to be machined on my Super 7. ------------------------------------------- and 8 more for a certain Bear tender wheels as well..........Nick, please PM me with the price for the BOGIE tyres as these are the same for me also---------Will get back to you regarding the radial truck wheel size later------- Alan R
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jma1009
Elder Statesman
Posts: 5,901
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Post by jma1009 on Oct 21, 2014 18:08:02 GMT
hi rob, although ive one loco with steel wheels, steel tyres are quite rare in 3.5"g and 5"g and not the norm, so unless you want to follow roger's excellent standards it's not something you need worry about at all. excellent progress by the way on the horns and frames! one of my locos has been running since 1994 with cast iron wheels/tyres and seen a hell of a lot of use and no wear apparent on the treads - though they were quite hard castings. however when i turned Stepney's wheel castings from Blackgates 3 years ago i thought the cast iron rather soft. so suggest you turn your wheel castings first to see how good the cast iron is. cheers, julian
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Post by ejparrott on Oct 21, 2014 21:28:24 GMT
I can confirm Hub Le Bas stock vast ranges of tube, they supply us now and again
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Post by Rob on Oct 21, 2014 21:40:20 GMT
Thanks everyone, that certainly adds a few extra options! I came across Steelexpress when I was searching before, but for whatever reason I completely missed the HFS section and wrote them off as the walls were all too thin. I'm in the South Wales Newport! I regularly trepan middles out, far quicker than boring. Let me know what sort of size rings you want and I'll get you a material price if you want. That's very generous, I'd say about 5.125" OD, but as for ID i'm not sure what would be scale in 5"! hi rob, although ive one loco with steel wheels, steel tyres are quite rare in 3.5"g and 5"g and not the norm, so unless you want to follow roger's excellent standards it's not something you need worry about at all. excellent progress by the way on the horns and frames! one of my locos has been running since 1994 with cast iron wheels/tyres and seen a hell of a lot of use and no wear apparent on the treads - though they were quite hard castings. however when i turned Stepney's wheel castings from Blackgates 3 years ago i thought the cast iron rather soft. so suggest you turn your wheel castings first to see how good the cast iron is. cheers, julian Thanks Julian, I'm getting there slowly! I've just finished up one set this evening. I've machined them with a thou clearance on either side and my gauge block just nicely starts in them. It'll need some relieving further down the slot though I think. I think it's seeing Roger's finished wheels that's sent me down this path, as I hadn't originally considered doing it at all. It may be a solution if I make a mistake in turning the castings. As you say, perhaps I should see how the wheels I have turn up and make a decision then!
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Post by Roger on Oct 21, 2014 21:50:57 GMT
Let me know if you want the drawings, I've got it all 3D modelled.
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Post by Deleted on Oct 21, 2014 22:19:18 GMT
Apart from being the "Correct" practice a-la- full size, it also allows you to re-life any tired or worn cast-iron treads...
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Post by Rob on Oct 21, 2014 22:31:51 GMT
Cheers Roger, that'll certainly be a help!
Yes, that is other great benefit! Though I suppose you could always add tyres after your cast-iron treads have worn if you turn the lot between centres.
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Post by ejparrott on Oct 22, 2014 8:49:02 GMT
What thickness?
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