Hello and a part-built blowfly

[Lisa]

Feb 20, 2017 19:43:31 GMT GWR 101 said:

Lisa many thanks for that, most useful wish I had seen that some 40 plus years ago when I embarked on my build.

You're welcome.

Feb 20, 2017 19:43:31 GMT GWR 101 said:

Also following advice on here I reduced the bore of the axle pump slightly

I've reduced the axle pump bore on the Blowfly to 0... I didn't even put the 'pump stay' on the frames (though it is sitting in a drawer, should I ever feel like doing something silly).
While I may fit an axle pump to a small 3½" gauge loco, maybe, I'm not a fan of the things.

Meanwhile, it was quite lovely weather today, so I did a bit more.
The port face is now machined to length, next I'll get the two sides equal and machine out the mounting lugs which will get the port face to width. There's no dimension for the width of the mounting lugs, so I'm going to aim for about 7/16" as that suits the amount of material available.

[GWR 101]

Hi Lisa, yes one or two have suggested not fitting an axle pump. When I made mine I thought the pump stay on Juliet was a good strengthening part and as I had the casting I just machined it and fitted it, thinking it's easier to take it off than retro fit it,   but I do understand the other point of view.

I have also fitted an injector so hopefully I have all the bases covered, added to which once set up the axle pump means us older novices have one less thing to worry about and can just sit back and enjoy the ride.  Regards Paul

[suctionhose]

With smaller egines I find using a pump for the baseline water feed and the injector for demand fluctuations gives the driver more consistent steam pressure and the ability to control blowing off as you would wirh a larger boiler.

[Lisa]

Well my knee's back to about 90% of usual after a couple of days resting it, so I just a did bit more today.

One of the bolting faces/lugs milled out, so the port-face is half way to width now. This is used to bolt the cylinder to the frames, top and bottom, with M5 bolts; I might narrow them down a bit, we'll see.
Dad came down for a look too, which was nice; he ended up sitting out by the back door, watching the neighbour's ducks and asking me how it was going every now and then.

[Jim]

That's a nice job you're doing there Lisa, you and your dad should be very pleased with that. You've also answered the question I asked about you knee in my earlier post. Good to hear it's on the mend.

Jim

[Lisa]

Did a bit more today, one down, one to go.

I'll machine the other cylinder to the same state, and meanwhile I can experiment with possible boring setups in the lathe with the one that's done.

[Deleted]

looking very smart Lisa, very smart indeed...

Pete

[Roger]

That's a lovely job Lisa. I'm wondering why you aren't adding the fixing holes and ports while it's all set up true and you know where the centre is?

[Lisa]

Thanks Pete, and Roger.
The ports is a bit of habit and a bit of cautiousness; I'll do them after boring the cylinder. This way, should I discover a blow hole in the casting, I won't have wasted so much time on it before junking it. (edit: also means I don't have to worry about damaging the ports from doing something silly when clamping for boring).
The fixing holes though... I stood with my hand on the vice handle for about a minute arguing with myself about doing them now or when I do the ports, and eventually decided to do them with the ports. No real reason to that.

For boring, I'm leaning towards making a between-centres boring bar, and a mount for the cylinders on the cross slide, and doing it that way. I could do it in the chuck, but I would rather a larger chuck (can fit a 5" chuck to this lathe, but can't afford one) for holding them in that case. On the other hand, I could rough them with a boring head in the mill, then finish them with a between-centres boring bar in the lathe; which would at least mean I can use a larger boring bar without having to make two of them.

Vaguely related matter: I think I found Barry Potter, designer of Blowfly, on youtube: www.youtube.com/channel/UCIqvy3vzQdyuC-P3K1xO2gg

[Jim]

Hi Lisa,

That's Barry on the second of the double heading NSWGR D59 class locos hauling a pretty hefty load. I'm not sure where the track is but Barry always a very laid back driver, probably built both locomotives. At last count he'd built 55 or maybe more over the years for various customers.

Jim.

[dc309]

Hello Lisa,

Great work on your cylinder blocks. I shall be watching avidly as I'm getting to the stage of machining my cylinders very soon!

Regards,
Dan

[Lisa]

So in between milling the second cylinder block to the same state as the first, I'm experimenting with different set-ups in the lathe for boring the cylinders.
I tried a couple of different things, but between centres boring is the best option.

The bar between chucks is just there as a bit of a visual aid, obviously I need to make a proper boring bar for the job.
However the cylinder is packed to the correct height here, so I can see what needs doing to hold it in position; which will involve some drilling and tapping of the cross slide. I'm tempted to see if I can find a small T-slotted plate/table from somewhere that could be fitted, as it'd likely be more useful than just adding holes for the one task.
Another option could be a plate with a grid of tapped holes, rather than T-slots, which would be similarly useful.

[Roger]

Mar 1, 2017 7:54:17 GMT Lisa said:

So in between milling the second cylinder block to the same state as the first, I'm experimenting with different set-ups in the lathe for boring the cylinders.
I tried a couple of different things, but between centres boring is the best option.

The bar between chucks is just there as a bit of a visual aid, obviously I need to make a proper boring bar for the job.
However the cylinder is packed to the correct height here, so I can see what needs doing to hold it in position; which will involve some drilling and tapping of the cross slide. I'm tempted to see if I can find a small T-slotted plate/table from somewhere that could be fitted, as it'd likely be more useful than just adding holes for the one task.
Another option could be a plate with a grid of tapped holes, rather than T-slots, which would be similarly useful.

That looks very promising Lisa, I presume you've checked to see that you've got enough travel for the tool to exit both ends?

I drilled an array of holes in the top slide of my old Southbend lathe which normally had blanking plugs in the holes when it was used. If you put them in accurately on a known grid, you can make whatever attachments you like to suit. I made a crude tilting angle plate for mine so I could mill a set of Dickson Toolpost tool holders. Those lugs are ideal for clamping down onto.

[itchyballs]

Feb 26, 2017 21:44:46 GMT Jim said:

Hi Lisa,

That's Barry on the second of the double heading NSWGR D59 class locos hauling a pretty hefty load. I'm not sure where the track is but Barry always a very laid back driver, probably built both locomotives. At last count he'd built 55 or maybe more over the years for various customers.

Jim.

that is a  private track at  on springwood road yarramundi near windsor/richmond area in nsw australia. again it is a private track. how private i do not know as it was featured  on tv about 20 years ago the builder

[Lisa]

Mar 1, 2017 8:26:36 GMT Roger said:

That looks very promising Lisa, I presume you've checked to see that you've got enough travel for the tool to exit both ends?

I drilled an array of holes in the top slide of my old Southbend lathe which normally had blanking plugs in the holes when it was used. If you put them in accurately on a known grid, you can make whatever attachments you like to suit. I made a crude tilting angle plate for mine so I could mill a set of Dickson Toolpost tool holders. Those lugs are ideal for clamping down onto.

Hi Roger,
Yes there's plenty of length there for the tool to exit both ends, don't judge by the rod in the picture, as there's easily another 6" or so of length available, it was just a handy offcut for sighting with.
I don't want to put too many holes in the cross slide, as it's not huge; about 10mm of depth above the V, and 65mm wide. However using a separate plate also has the advantage of being easier to clean, it can be drilled right through, so the holes won't fill with swarf. It would also cover the part of the compound slide that is captive on the cross slide, which again would keep swarf out of that (and make for a fully flat surface).
Fortunately I have a nice piece of 100x10mm steel that should do the job nicely (offcut from the loco frames), I just have to decide on a hole size and pitch. M10 would probably be most useful, as then it would match the clamp kit I have for the mill.

Here's the top of the cross slide with the cylinder moved out of the way:

[barlowworks]

Hi Lisa

If you go onto the Mrcrispin channel on Youtube there is a very good video on boring cylinders between centres and lots of other interesting stuff. If you haven't seen it already you might find it useful.

Mike

[Lisa]

Thanks Mike, I'm subscribed to Mr Crispin's channel, it's been interesting so far.

[RGR 60130]

Hi Lisa,

Perhaps one of the things you will want to mount on the cross-slide is a vertical slide. They still come in useful even when you have a milling machine. I always use one when machining cylinders. This is the set-up I've used a few times.
The great thing with this set up is that it allows you to remove one casting and replace it with another at each stage of the machining operation rather than doing one casting from start to finish before starting the next. It saves a whole lot of boring bar adjusting. I wouldn't chance swapping castings when down to the last thou but the repeatability of the set-up is very good.

Reg

[Lisa]

I have a vertical slide for the Taig lathe, which could be mounted on the Sieg lathe; or I could get a larger one (add it to the list of "things to get when slightly less broke"). A fairly universal bolting plate as planned should allow for many things to be bolted on to the cross slide, hopefully.

However, to make said bolting plate I need the mill (I could do it in the bench drill, but it'd be easier to get an accurate grid of holes on the mill), and at present it's in use milling the cylinder blocks, so:

There's been a couple of hard spots on this casting, that's meant lighter cuts, slower feeds, and just slower in general to get to this point. But now that I'm through the 'crust' of the casting the hard spots seem to have gone; so back to normal with machining from here on.

This afternoon though I just felt like using the lathe, so had a little play with one of the front cylinder covers:

This started out resembling a wobbly egg, but is now looking a bit more like a cylinder cover, still more to do on it, clearly, but it's getting there. Cast iron dust gets everywhere!

[Shawki Shlemon]

Lisa , have you seen the way I do it .

modeleng.proboards.com/thread/703/boring-cylinders-centres