Finishing off a 5" Gauge Simplex Loco

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sbwhart:
Cheers Nick it was good chating engineering with you my Boss just looks at me blank :D

Corrected the horn blocks today

As the frame was bolted it stripped down easily if it had been welded I'd have been stuffed.

First job from the drawing identify the datum hole and line the two sides up by putting a tight fitting number drill through the datum hole check all the other holes line up and bolt the frames together with some M4 screws.

Then from the datum hole find the correct position for the centre on the midle horn block and mark it with a centre pop, from this centre pop mark the 7 1/8 position to the other two horn block and mark these.

The frame is to big to machine all three horn blocks in one setting and the job realy needs two vices or to angle plates i've got one of each :scratch:

So put the vice in the midle of the table and grip the frame with one horn either side of the vice, and starting with the centre horn suport the other side of it with the angle plate when machined index to the other horn and move the angle plate over to support it whilst its machined

To locate the centre of the midle horn use a pointer on the centre pop and zero the DRO

I used a long long series milling cutter, its a regrind that I picked up at a show for no other reson that I may need it some time, nows its time.

Index over with an alowance for the cutter diameter and taking 1mm deep cut nible away the horn, index over the same amount to the other side and mill that side out.

A quik check with slip gauges shows it to be 1.247" that will do me.

Index over 7 1/8" to other horn swap the supporting angle plate over and mill that out the same

To do the remaining horn you have to take the fram out of the vice to reposition it, first clock the cut centre horn verticaly to check its in the vice square.

Then find the edge of this horn.

Index to its centre and zero the DRO then index over 7 1/8" to the remaining horn, machine this the same as the oother two.

this is an overall shot of the complete set up.

A check with slips and a vernier showed that width of each horn to be 1.247" 1.247" and 1.245" and the centre distance to be 7.127"and 7.124"

That will do.

:D

Stew

saw:
This is so intressting to follow, you have an wonder full tecnic and I am learning a lott. :smart:
Thank you. :headbang:

NickG:
Great stuff Stew, absolutely spot on! :thumbup:

I guess that is the same setup if you are doing it from scratch? Leave the final bit of cutting until you've got the frames clamped together to ensure they are all in line?

Cheers,

Nick

sbwhart:
Thanks for your support and interest Nick and Saw

Whilst i'd got the frames stripped thought I'd take the oportunity to tidy up a bit of butchery inflicted on them to line up the boiler blow down valve.

They key hole shape just didn't look like, so cleaned up the hole that was far from round.

Anbd turned up a top hat shaped plug the was a tight fit in the hole, when firmly fixed in placed filed the remaining hole to match, it looks a lot neater now.

I painted the frame parts first with a primer coat then a Hammerite Smooth came out a bit patchy but not too bad as most of the frame will be hidden behind things.

Had one bugger of a job to square up the frames I could get the driving and leading axles horns square but no way would the driving and trailing axles horns square up I tried all sorts of combinations of assembly bending and general jiggery pockery to try and get them square, in the end put it to one side whilst I did something else and godgitated on the problem, this morning I had a brain wave, check out the squareness of the streachers, sure enough the face of the streacher between the driving and trailing axles is out of square by quite some margine, so that needs making new.

Also found out that Loctite thread loc is a great paintstripper :Doh:

These are the axles I pulled the wheels off, you can see the fit was bodged by centre punching around it to make the tight fit on the wheel, this and the fact they were under size on the bearings propted me to make new.

So took delivery of some 3/4 mild steel bar,

First operation with a true running collet, centre drill each end and stick a oiling hole down the midle of each end.

Then cross drill 1.5mm into the oil hole this will make oiling the bearings easy.

Then between centres carfully turn down for a nice push tight fit in the wheels, you don't want this fit to tight or you'll split the casting but you don't want it too slack. The advantages of working between centres is that the two wheels will be running true and you can remove it to try the fit and put it back and it will still be true in the lathe.

I was planning to use some cast iron that I had in my stash box for the bearing blocks but when I came to cut it to size the first bit cut great but the second bit was glass hard I cocked up two slitting saws tring to cut it, it must have been chilled when cast it needs anealing, so gave that up as a bad job and order some material from Blackgates.

Just spent the last two days flycutting them to size.

More maching still needed to fit them into the horn blocks and drill to fit the axles, but thats a job for next week.

Stew

Stilldrillin:
I love a good, creative bodge, to put right some butchery. :thumbup:

But....... I'd rather not have the butchery in the first place! :loco: :doh:

I hope that's the end of all the nasties now Stew........ Onwards an upwards! :)

David D

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