Author Topic: 31/2" Tich  (Read 6019 times)

Offline samc88

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Re: 31/2" Tich
« Reply #45 on: March 06, 2021, 09:59:02 PM »
Back in business, I've recently moved house so obviously all work on this came to a halt, upon further looking into the drawings I decided that it would be easier to drill the holes for the brake shaft bearing with the frames apart so they were stripped down again and tidied up and the hole drilled. I've recently acquired a Warco WM12 milling machine is so much better than the vertical slide, more travel for one thing and it saves the hassle of stripping the machine down every time. The first picture is the workshop, yes my washing machine and dryer also lives in there

Since I had a miller I took the opportunity to redo the buffer beams and tidy up things I wasn't really happy with, these are meant to be 3/4 angle but I used 20mm and forgot about the extra mm so they didn't sit right on the frames. Whilst doing this I decided I'd prefer the rivet heads to be visible on the outside which I prefer. I also tidied up the horn guides as these were slightly undersize and I wasn't happy with the finish and the uneven heights whihh was a legacy of struggling with the vertical slide when the lathe still had ball bearings rather than taper ones

As it stands the frames are now properly bolted together and ready for the frame stretcher to go in, I've diverted slightly from LBSC and fitted lock nuts to the bolts rather than solely relying on the 7BA tapped holes in the buffer angles (can see them coming loose with vibration possibly). Long way round to where I am, learning to deal with smaller machines than the large ones in work and the challenges that come with them has been quite enjoyable however

 







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« Last Edit: August 07, 2021, 12:05:56 PM by samc88 »

Offline samc88

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Re: 31/2" Tich
« Reply #46 on: March 08, 2021, 09:05:16 PM »
Pump stay milled to width this evening, haven't got any pics of the actual machining unfortunately. Quite happy with how it's turning out, pleased to see the casting details are still fairly even after machining. Tomorrow I'll look at sorting the height and drilling and tapping the mounting holes for the chassis and also the water pump as it turns out I have the right taps for that. I think I'll also take the casting number off it



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« Last Edit: August 07, 2021, 12:06:22 PM by samc88 »

Offline samc88

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Re: 31/2" Tich
« Reply #47 on: March 11, 2021, 09:37:01 PM »
Been a productive evening, the frame stretcher was finished and fitted and then I made up the reverse shaft bushes from bronze and fitted them, had a piece of 1/4" silver steel lying around so used that to check alignment and it spins over nicely.
As the bronze is still in the lathe I'll make the brake shaft bearings tomorrow.
 





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« Last Edit: August 07, 2021, 12:06:46 PM by samc88 »

Offline samc88

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Re: 31/2" Tich
« Reply #48 on: March 14, 2021, 12:29:26 AM »
Got the brake shaft bearings made up today, turned the 8mm section down from 5/8" bronze bar and then filed to size. Just need to get a drill to tap 9ba and these can be fitted. Quite a fun little part to make







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« Last Edit: August 07, 2021, 12:07:23 PM by samc88 »

Offline samc88

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Re: 31/2" Tich
« Reply #49 on: August 19, 2021, 11:27:49 AM »
Been doing some bits and pieces on this and hoping to get going again on it now the house is pretty much sorted.
It's a proper rolling chassis now with springs and things and hornstays made up.

I also knocked up a couple of mock conrods with some spare material I had to check the quartering and all looks good!


I've ordered some material for the coupling rods but in the meantime I thought I'd start on the water pump and it's fittings, the picture is of the three castings post fettling with a file, Ill look at making a start on them later on,
Cheers,
Sam

Offline samc88

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Re: 31/2" Tich
« Reply #50 on: September 25, 2021, 10:36:28 PM »
More progress, I just keep forgetting to update the thread. Pump is finished and is working well, only thing I haven't done yet is the drive rod which i think is my next thing to do. I did modify the pump ram to take a small o-ring which works really well, plenty of suction in the pump

I also made the coupling rods, bushes and crank pin washers and everything turns over nicely. I'll get a video this week on YouTube.

Once I get the pump drive sorted I'll make a start on the cylinders and actual steam enginey bits
Cheers,
Sam









Offline Trevorc

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Re: 31/2" Tich
« Reply #51 on: September 26, 2021, 10:38:00 AM »
Hello samc
Looks like you are making good steady progress. Looking at your postings is a memory trip for myself having built a 7 1/4 inch gauge version. During that build I discovered there were some errors in dimensions of valve gear items( too long ago to remember) so beware.
I used the LBSC book and doubled most of dimensions.
Best wishes
Trevorc

Offline samc88

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Re: 31/2" Tich
« Reply #52 on: September 26, 2021, 11:37:56 AM »
Thank you Trevor, I've gained my enthusiasm back now I've got the rods done. I have heard to be wary of the valve dimensions but I've noticed the dimensions on the drawings I have are slightly different to the ones in the book so maybe they've been updated at some point?

Offline samc88

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Re: 31/2" Tich
« Reply #53 on: September 27, 2021, 09:49:02 PM »
Drive rod for the water pump finished. Rather than mill a slot in the eccentric to take the rod like the drawing, I simply milled a 3mm step into it to take the rod which i think will be stronger as there's not much meat in the eccentric. I riveted them together but thought I'd have a go silver soldering as I've not done it before and it's an ideal practice piece, after all it's riveted anyway so have nothing to lose. It came out okay, hopefully I'll improve with practice.

With that done I've made a start on the castings for the cylinders. With my ebay casting set was a complete cylinder kit, as Im unsure of their provenance I thought I'd start on the easiest bit and mill the valve chest covers to get a feel for the material. My fly cutter did a lovely job on them. First I held the chucking piece in the vice to fly cut the top flat, then I faced two sides and marked the dimensions out. The DTIs are used to dial in the final cuts, my lathe is imperial and the mill metric, using the dti just saves confusion until I can get a DRO. Very happy with how these came out, all dimensions within a thou, I know these don't have to be too accurate but it's good practice.

With those done I then set off on a bigger casting which is the valve chest. Cleaned up the casting with files and stuck it in a three jaw chuck getting it to run relatively true by eye. First job is to turn the cast on boss to 5/8" diameter. Hopefully do a bit more on this tomorrow. All in all quite pleased with progress lately













« Last Edit: September 27, 2021, 10:00:06 PM by samc88 »

Offline Admiral_dk

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Re: 31/2" Tich
« Reply #54 on: September 27, 2021, 10:22:23 PM »
It's always nice when things go your way, without any nasty surprises - especially on such complex project as a lokomotive  :cheers:

Offline Kim

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Re: 31/2" Tich
« Reply #55 on: September 27, 2021, 10:40:12 PM »
Nice looking water pump, Samc!  And great start on the steam chest.   Enjoying following your build!
Kim

Offline samc88

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Re: 31/2" Tich
« Reply #56 on: September 29, 2021, 08:55:04 PM »
Thank you both, got some more progress done on the chests tonight. The end I turned with the 3 jaw was then put in my collet chuck which allowed me to turn the other side. As this side is going to be drilled for the valve rod I put a centre in to give me more support when facing the chest. I couldn't resist trying out the valve chest cover on the valve chest, hopefully get the other faces machined up tomorrow and then order the drills and taps I need to finish them on Friday as it's payday









Offline Kim

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Re: 31/2" Tich
« Reply #57 on: September 29, 2021, 11:34:51 PM »
Very pretty steam chest & cover!

So, in that first picture, are you using a dead center between your part and the live center? Does that give you much support?  An interesting setup.

Kim


Offline samc88

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Re: 31/2" Tich
« Reply #58 on: September 29, 2021, 11:41:46 PM »
Very pretty steam chest & cover!

So, in that first picture, are you using a dead center between your part and the live center? Does that give you much support?  An interesting setup.

Kim

Yes it is, I use it a fair amount for this sort of work where the live center or the tailstock gets in the way of the tool post, Works pretty well, especially for the small cuts taken with the mini lathe. I wasn't too sure how my collet chuck would react to the off centre interrupted cut so at least this helps keep it more secure. It's also a handy way of centering odd shapes with a 4 jaw chuck when you've got a centre punch mark to put it against.

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Offline samc88

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Re: 31/2" Tich
« Reply #59 on: October 03, 2021, 04:00:20 PM »
Productive morning today and finished off the machining of the steam chests. Next operation is drilling the mounting holes and also drilling and tapping for the gland (guess what drills I don't have?), so it's stop on these until they turn up in the post. In the meantime I might have a look at the cylinder castings.

I've got some material coming too so I can hopefully make a start on the valves and pistons too so the actual steam side of things can get done and tested before working on the valve gear itself