|Richard S2||18/09/2019 22:18:34|
162 forum posts
Silver soldered the side plate parts and trial fitted the pump on my Wallis and Steevens Water Cart.
Used my recently obtained Vortex V3 blow torch and very pleased-
|Ian Johnson 1||18/09/2019 22:50:34|
|137 forum posts|
Is that a four inch ruler? First one I've seen! Nice work by the way.
|Jeff Dayman||19/09/2019 00:01:27|
|1621 forum posts|
Great work Richard! it's coming along.
|Nigel Graham 2||19/09/2019 00:03:21|
|386 forum posts|
Modified the steam-wagon's crankshaft slightly (it's a design as it goes project, having no drawings to speak of); and started to bore out the eccentrics. I'd made the sheaves and straps ages ago, but not the holes for the shaft as they were yet to be designed, after I could establish the valve travels.
Found the best way after a near-miss on the lathe that could have ruined the first, is to hold them gripped by the strap, with a slip of aluminium foil to turn slip to grip, flat on parallels on the milling-machine and use a drill, two successive end-mills then the boring head. Location control by two small angle-plates at right-angles to each other and to the table. I'd already made a simple, three-step plug-gauge to assess fit.
Also made two discreet centre-drill marks close to the edges of the sheaves, to allow aligning them by a square to drill the grub-screw holes.
The sheaves are cast-iron (from stock bar, not discreet castings), straps mild-steel. Rather than the difficulties of the Stuart-Turner and Maid of Kent designs I've used a guide, involving trying to turn an internal, flat-bottomed groove as the strap's bearing surface, I've opted for a circlip-like ring in narrow grooves in both strap and sheave.
Whilst setting up I discovered why I'd had so much grief trying to mill the crankshaft pin centring-blocks square despite clamping the bar material to one of those two small angle-plates. Running the dial gauge down the angle-plate face so as to miss the slots for setting it parallel to the machine, I found the angle-plate itself out of square by a good 0.002" over < 2"! For the present task that's not important, as it's simply a locating-plate for a flat on the work-piece.
|Mick B1||19/09/2019 09:41:12|
|1182 forum posts|
Finished off the sandpiper ornament I was making. It was cut on a scrollsaw from half-hard brass sandwiched between two bits of thin ply, 'feathered' with a bit of oak dowel in a bench drill chuck with a dab of slurry from the WD40/1500 grit wet&dry polishing and a smear of fine grinding paste. It looks a bit better in reality than in the photo.
It occurred to me that I should've represented the eye-bar that some sandpipers seem to show, but I'd already lacquered it before I thought of that.
The family like it, anyway...
|jimmy b||20/09/2019 19:19:54|
511 forum posts
Finally got around to buying a VFD set up for the Crusader!
Got home from work today and it had had been delivered! its now fitted, happy days!!
|Nigel Graham 2||20/09/2019 22:30:15|
|386 forum posts|
Finished machining the wagons' 4 eccentrics. Oh what a struggle!
Today's epic was cutting their keyways.
Lacking any form of slotting tool, I milled them with the eccentric flat on parallels, in the corner between two small angle-plates. I aligned the sheave, trapped in its strap by aluminium-foil packing, by tiny centre-drill spots I'd already made.
I considered using a vice, briefly, but my milling-vice has so much slop in it I don't trust it. However, this meant using clamps, and those commercial clamping-sets are so thick and clumsy they are frustratingly awkward to manipulate, and severely limit access for close-in work on small parts. So allowing spindle room meant barely-adequate clamping area on the disc, despite rather unorthodox clamp assembling.
Indeed a sudden, harsh vibration indicated the first eccentric was slipping round in its strap. Luckily this was on the first depth iteration of 0.05" so it has damaged only the entry edge of the keyway. Re-set it all, finished that and completed the other three without further ado. but taking only 0.03" deep cuts.
Yes I know the keyways are arched, but that does not matter as a grub-screw will lock onto the key.
Grub-screws.... Yesterday's epic. I realised if give the strap an oil-hole near the rod mounting, I could select their diameters to use them also for guiding the tapped hole in the sheave below. I marked the sheave and strap with tiny centre-drill dots for alignment, and set the assembly on one of the angle-plates, with an adjustable bevel to set the appropriate angle.
Drill clearance down to just below the circlip groove on the sheave's equator, taking care not to snatch the drill on the groove sides: gives tap guidance by what will be the oil-way.
Drill tapping-size down to the bore.
Enlarge the outer hole to 6mm, so giving adequate initial tapping depth below the floor of what will be the oiling-point.
Take drill-bit from chuck, lower the knee to comfortable working height for a short-++++ like me, tap the hole, M3.
Three eccentrics done, then ... Crack! "Bother" or similar, and despair. Dismantling showed the tap had broken in the circlip groove, with bits jammed irrecoverably in both components. I could reverse the sheave and drill its opposite shoulder, but I was faced with having to make a new sheave.
Luckily, I remembered what looked like a spare sheave, on the dining-room window-sill. Well, where else? (There is about as much engineering stuff indoors as in the workshop.) Phew! It was a spare sheave! And, the milling-machine's basic set-up for drilling and tapping was also that for boring the shaft hole, so still in place - though I took the precaution of verifying its co-ordinates..
Finally came indoors at about 11pm, knackered but now with four eccentrics all back up to the same stage.
While at it, today I enlarged the grub-screw holes to M4. Still to make the circlips fit properly, or make new ones. Or buy! I have discovered you can buy similar, and quite cheaply, for such applications. They resemble piston-rings but of opposite proportions, and without the usual circlip lugs. The existing, mild-steel and parted from bar stock, are slightly too thick.
|Nigel Graham 2||21/09/2019 23:06:11|
|386 forum posts|
Had a rest from making swarf.
Lovely sunny day though a bit of a bite to the breeze now and then, but spent the day at the club.
A couple of members were running their garden-scale locos on the raised track; another was using a battery-electric loco to tow his a newly-built long-wheelbase 4-wheel chassis round the 7.25"g track to see if it would manage the tightest curve. It does!
Witnessed two boiler steam-tests (why does the system and its forms have to be so bloomin' confusing?); and sat in the sun watching the owners of those and 2 other traction-engines from 3 to 4" scale have a steam-up. Only four but still a good line up in the sunshine for photos!
Then a couple of hours this evening translating 'Maid of Kent' motion parts into steam-wagon ditto - not an exact match as though I am using the basic geometry, I am widening the eccentrics and expansion-links for larger bearing surfaces. This in TurboCAD, which allows direct 2D workshop drawings, rather than this picture-then-orthographic rigmarole - anyway I'm not clever enough for 3D CAD!
Those published drawings leave things to be desired. The expansion-link and eccentric rod are a riot of thirty-tooths and haphazard data faces; and so poorly dimensioned you almost need to redraw the whole assembly to work out the unstated references and sizes. I am working in decimals, as my machine-tools use "thous", from as few data faces as possible; and I do not need to equate strict binary fractions of inches for this project. (For instance, the crank-pins are a nice round 0.600" diameter... +/- a thou or so and at least I hope nice and round.)
|Andrew Johnston||21/09/2019 23:41:54|
4851 forum posts
FInally finished the oilers for my traction engine slidebars:
Both the slidebars, machined from gauge plate, and the oilers have been redesigned to accord with pictures of a fullsize engine. The oilers are intended to be proper wick feed; time will tell if they work.
All external threads (32tpi and 40tpi ME) were screwcut; internal threads used taps. One would have thought that these were all simple parts - don't you believe it! I bought a set of 7/16" x 32 taps for an internal thread. I'm pretty sure the taps are screwcut carbon steel. The bottom tap takes out a few thou more compared to the taper tap. There is a model engineering saw that says this, although I've never seen it stated in the literature. Also never seen it with ground HSS taps. The thread size was off too. For the mating external thread, starting at nominal diameter, the internal thread was a rattling good fit nearly 5 thou before the theoretical thread depth of 20 thou was reached. Never seen that before either, normally have to go full thread depth plus a couple of thou to get a nice fit.
Given how simple it should be I had a lot of trouble with the elliptical base. Easy enough to draw in 3D CAD. But for some reason on import into my CAM program it fudged the model making it difficult to select features and causing my CAM program to fall over ever time I tried to generate a toolpath. I also discovered that the hole pocketing routine in my CAM program doesn't work. It claimed to generate a helical ramp down and then a clean up. But backplotting the G-code just gave a straight plunge, and PathPilot barfed at the code with all sorts of circular plane errors. Once I got working G-code it only took 50 seconds to pocket the central hole and profile the outside.
All I can say is I hope future parts go rather better, or I'm going to working on the engines for a loooooong time.
Edited By Andrew Johnston on 21/09/2019 23:43:18
|405 forum posts|
I pulled a carpet size piece of "wet and dry " type abrasive 100 grit out of a skip ! Barely used too. 15 ft x 4 ft I guess its for one of those door sanders , where the whole door goes through under the sanding belt... It had a small nick in it ,so i suppose it wouldn't be any good to use .. What to do with it ? Flatting cylinder heads ? Good score though eh ? I did ask before i took it
|Mark Rand||22/09/2019 01:05:48|
|756 forum posts|
Spent a couple more hours stripping ex-server hard disk drives into their component parts. Quite a lot of it goes to the tip as ferrous metals, recyclable electronics and landfill. The remainder is getting kept as potential aluminium stock. There are three tote bins full now and the collection of disks will mostly fill one more. Then I can get the furnace going and turn them into ingots for future use. Got a couple of bin bags of swarf and some castings that can have the same treatment. I'm telling SWMBO that it's all part of tidying the shed up.
16240 forum posts
Andrew, your elipse problem may be down to Alibre, following the recent major update there were issues exporting elipses, I got a temorary fix from Jeff via support though the very latest smaller update may have fixed it now.
I've also had/got some sloppy ME taps and dies, I see you.
|Andrew Johnston||22/09/2019 11:35:12|
4851 forum posts
More down to Geomagic. On my old computer I'm still using a 2014 version of Geomagic. In desperation I created a new part on my new computer which which runs Alibre 2019, and imported that into the CAM program. It still had the strange artifacts on the model, but circles and edges could be selected, unlike before.
One of these days I'll move all the Burrell stuff over to the new computer.
Edit: after I'd created the new part Alibre offered me an update. Big mistake, after a hiccup in the process it "helpfully" wiped Alibre from my computer. With some help from the UK agent I eventually got it all back again, including my custom text file that lets me explicitiy use English threads, such as BSF, BSP, BSW and BA in models.
Edited By Andrew Johnston on 22/09/2019 11:39:24
|601 forum posts|
Well, As usual prepped the Loco for its regular Sunday afternoon club run out. Trouble is the weather looks to be letting us down at the moment, just waiting for the go ahead.
We haven't missed many days this year, and its always a shame when the kids ( and parents) don't get their weekly rides.
Still, it might clear up
Edited By FMES on 22/09/2019 11:53:41
4719 forum posts
Went up to the track (35minutes) in time to help clear up and empty the fire buckets (30 minutes) and returned home (35 minutes). Tipped down during the return journey so probably just as well it was abandoned. If only we met on Saturdays as yesterday was such a contrast.
Can spend the afternoon preparing for the club 2 day exhibition nest weekend.
|Neil Wyatt||22/09/2019 18:49:30|
16559 forum posts
Wow you are a busy lot, and some really nice work here too!
|Swarf, Mostly!||22/09/2019 19:12:30|
|497 forum posts|
I don't remember who asked "Who else but the English would write 'FIRE' on a bucket and then fill it with water?!?! ".
Do yours have the hemispherical bottoms?
|Ian Johnson 1||24/09/2019 21:56:25|
|137 forum posts|
Finally got round to making a base for my Moore & Wright upside down micrometer head, which I've had in the drawer for about thirty years, so it deserved a day out! Now I've got a 1 inch depth micrometer!
The base is a piece of key steel which was tough stuff for my little machines. There is a small built in deliberate error, the height is a couple of thou small, but the little brass screw allows the head to be self calibrated easily enough, it then holds things nice and tight. Although thinking about it I might just try rotating the sleeve to take up the error doh! I checked for perpendicularity by rotating the head 90 / 120 degrees and was about 0.0002" out, which isn't too bad.
The main reason I made it was because of restricted height on my small mills, I've been using a 6 inch digital caliper which is not ideal.
4719 forum posts
mmmm hadn't realised why fire buckets have round bottoms until I googled it. Ours are red and plastic and the flat bottom makes it easier to run them round to station on the passenger trolley. That is from the station to their station which of course is not a station but is their station. Do other languages have different words for these two positions?
|Nigel Graham 2||24/09/2019 23:24:40|
|386 forum posts|
First off- buy a length of 40mm dia steel bar for my connecting-rods. £20 for a metre... not bad. It was a piece a fairly-local fabricator had on his racks.
Set up to carve the wagon's compound-engine's valve-chests from rectangular blocks of cast-iron stock, whilst simultaneously starting to make their mild-steel covers.
Simultaneously? Multi-tasking? How?
I had already drilled all the holes round the chests-to-be, according to a sketch of each, giving the co-ordinates.
Take a piece of 6mm plate comfortably longer than the chests, X enough for both blocks to sit on it side-by side with ample cutting-off and trimming allowances.
Drill 6 10mm holes so it can be screwed directly to the milling-machine table without faffing with bloomin' great bar-clamps. Those get in the way then throw their step-blocks on the floor when you release them. There is of course a thick plywood spacer below the plate: any slight height variations across it won't be significant.
Lay the first chest on the plate, sight the (0,0) corner against a small centre-drill; remove the chest and move the table to the first co-ordinate (0.22, 0.22)".
Go round, spotting the holes, 14 for each block, in the plate. Round again, drilling through... BUT....
... Be careful! Drill clearance in all except 4 at tapping-size!
And tap those 4.
Lay embryo chest 2 on the plate, with some jiggling because someone put the machine's column in the way; but I found a suitable compromise point. Repeat as above.
The plate screwed to the table is now the jig on which to screw the blocks to machine their cavities.
THEN: turn that valve-chest machining-jig into the ready-drilled valve-chest covers!
Open the tapped holes to clearance, skim the mating areas; then, turn it over and put a shallow rebate of (probably) more aesthetic than structural value, in what will be the outer faces.
Finally, separate them from the stock plate and trim to size!
Treating the Myford VMC mill to a Machine-DRO set was helped by a retirement collection. It was extremely awkward to fit, with lots of tricky compound bracket-making, and I have not completed the vertical axis; but it's proven a real blessing in the last few days. No "spotting-through" and consequent parts-matching: have the confidence in setting to within thous!
The shopping-list now includes 3/8"BSW set-screws of various short lengths, to fit the T-nuts for future similar set-ups. (Sets-up?)
BSW, or UNC?
Same 16tpi, albeit 55º v. 60º. I've not managed to determine that thread-type satisfactorily. These are on the usual type of clamp sets our traders sell. Does anyone know, please, which they are? In practice it may not matter very much: the commercial threads are not too close-fitting; but UNC is now the easier to find.
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