|Andrew Johnston||08/06/2020 22:04:15|
5635 forum posts
Today I've been doing the initial machining on one of my traction engine cylinder blocks. I have three sides, the top and the width of the flange done:
All machining has been done on the horizontal mill with an 80mm diameter insert cutter. Here's a typical set up:
The biggest cut was 2mm deep, full width, 420rpm and 420mm/min feed, not even a hint that the mill noticed it. I love it! And just to stir up the old versus new debate the horizontal mill cost me £175.
The iron casting machined beautifully, but was all over the place in terms of dimensions and squareness. At least I've ended up with all the sides and top square to each other and to dimension (in my CAD model) apart from the two faces parallel to the bores which are 15 thou under. The width of the parallel faces on the unmachined casting varied from 5 thou over nominal to 150 thou over, so somewhat on the skew. It's annoying to be a bit under, but it's not a problem in practice. Although I might tweak some of the port dimensions on the liners at a later stage.
The angle plates in the picture were indicated to be parallel to the Y-axis before using them. Just as well I checked, as setting them perpendicular to the front of the table with a set square meant they were many thou out. Since my horizontal mill is a universal (the table swivels for making helical cuts) I also indicated the table parallel to the column in X at the start.
Tomorrow I plan to fly the glider, before the bad weather sets in for the end of the week and the weekend.
|John Dean 2||09/06/2020 16:11:38|
|10 forum posts|
|Andrew Johnston||10/06/2020 21:40:51|
5635 forum posts
It was raining when I got up, equals double yippee. One, because the garden really, really needs it and two, because I can play in the workshop.
I decided to true up the second cylinder block. Having machined two surfaces square I started machining one of the faces perpendicular to the bores, with the casting slightly twisted to get the best alignment. I will true up the reference surface afterwards as there is still a lot of metal to remove from it. I was just starting the cuts with the second iteration of the twist when the power feed starting making intermittent noises. The immediate reaction was to ignore it. But if I do it'll only get worse, and there are no spares if something breaks. So I top up the gearbox from the motor to the feed gearbox - not much change. So next I fill up the feed gearbox, which due to poor design means I have to swivel the table (and lose my setup) to get to the filler. Do that and still not much change. The noise definitely sounds as if it is coming from the motor/gearbox. So take off the motor and gearbox combination:
A big gear on the feed gearbox input can just be seen to the left of the two levers that select the feedrate. It's a really messy job. Not only is the gearbox stripped, so was I as I don't want to get oil all over my decent shirt. On looking more closely I notice that the motor fan is loose as the bolt has unscrewed. The fan cover is removed and the fan is fixed. I ran the motor in this configuration and it "seemed" better. But annoyingly I damaged one of the rods holding the motor together. By the way the feed motor is 1hp.
The next tasks are to make a new rod, re-assemble the motor, refit the motor and gearbox and try it out. Then I might be able to get back to what I was doing.
At least the weather is going to be poor over the next few days. Which makes me glad I flew the big glider yesterday for a few hours of local soaring. It all went rather well given I haven't flown this glider for nine months. And I didn't make any boo-boos, which is a bonus.
|Martin King 2||10/06/2020 23:03:42|
|712 forum posts|
Completed the first of a few small flasks made from the top section on 30mm shell cases.
Good practice for my screw thread cutting, many thanks to Michael Gilligan for his help with that!
The interiors will be lined with a resin coating which has worked well on the shot "glasses" made from the bottom sections.
Quite a fun little job and good for ones confidence!
|Nigel Graham 2||10/06/2020 23:35:15|
|720 forum posts|
Broke the lathe...!
More specifically, the electric bits.
I'd had really got stuck in yesterday, and didn't finish in the workshop until midnight gone. I had turned and parted-off a large, phosphor-bronze bush to become the mounting-flange for the prominent globe-valve that the original builders thought appropriate for a steam-lorry's regulator.
However it needed a lot of careful trimming of the 3/4 X 26tpi thread's run-out to fit the bush actually in the boiler, plus the parted face trueing up. (No, I don't know why I had chosen brass threads several years ago. In hindsight, ME threads for up to 3/8 dia and BSP for above might have been better!)
Anyway that was today's first task, but half-way through there was a flash and loud 'POP!' noise, then silence from a stopped lathe and radio. The r.c.d. relay for the entire house had tripped, too, not that on the spur to the shed. The bronze swarf had been very long spirals, from a carbide insert, and though most were coming forwards, one had wormed its way round the corners and explored the lathe's motor.
I finished the task by using a mandrel handle, which kept loosening itself, just to add the aggravation.
I rang Newton-Tesla with the sad tale. It looks as I will have to send both the motor and controller back for repair, though they did make the hopeful comment was that the inverters are electrically very robust, depending to an extent on the nature of the short-circuit. They suggested first though, I dismantle the motor, clean it out, and if there is no obvious sign of harm, re-assemble it and test it.
I did, it still doesn't work.
Luckily I still have the previous, single-phase motor and its Kraus and Naimer reversing-switch, with the wiring instructions, to refit until the 3-ph system is repaired. I can also use the Harrison but that's a lot of lathe not really set up for the smaller parts.
Memo to self- make a better shield for the motor!
|Henry Brown||11/06/2020 19:21:07|
256 forum posts
I picked a spares or repair Verdict finger type DTI up on fleabay, it cane yesterday and after a quick look it was apparent that the little lever that changes rotation of the indicator was broken. This horrible little thing was made of plastic and had split under the pin. I contacted Verdict and had a prompt response, £11.25 plus £5.00 P&P plus VAT a total of £19.50. It was stressed that the replacement was made of spring steel as the plastic ones degrade over time!
I thought that this was a bit steep, especially the P&P, so I grabbed a bit of gash steel and made one, in fact I made two because I was given another version of the Verdict finger gauge and that part was missing...
Just as I was putting the pin in for the last time it shot out of the pliers and went behind the lathe which is backed up against the wall so a small brass pin was fitted. Result - two working DTI's for a few hours in the shop.
|Brian Oldford||11/06/2020 20:24:37|
684 forum posts
Whilst waiting for parts to arrive for my Clough42 ELS I made the housings and fitted lead-screw thrust bearings.
As the new arrangement is somewhat longer I've had to "steal" back some space by: -
Edited By Brian Oldford on 11/06/2020 20:26:47
|Robert B||11/06/2020 20:49:27|
|12 forum posts|
Not quite today, working out pictures and files. Swarf from parting 2" steel bar. OK for a 72 year old lathe and nearly as old operator. I managed to make 101 divisions on a new cross feed dial today.
|Andrew Johnston||11/06/2020 22:16:42|
5635 forum posts
This morning I did a grocery shop and delivery run for my mum.
This afternoon I made a new tie rod for the feed motor on the horizontal mill. Fortunately I had a 3/16" BSF die to hand. This evening I reassembled the motor and gearbox. Fixing the motor fan may have cured the problem, although the feed seems a bit noiser than I remember. We'll find out tomorrow when I recommence machining the cylinder. Out of interest here's a picture of the internals of the feed gearbox:
Seems logical; horizontal input shaft at the top and two sets of three gears to drive the lower shaft which then drives the vertical shaft via skew gears. That seems a bit odd as the drive must be transfered to the swivel point of the table to drive the leadscrew. It's many years since I've had the table off the mill so I can't remember the details.
|Nigel Graham 2||12/06/2020 15:44:38|
|720 forum posts|
Grrr! Don't talk to me about swarf!
I managed yesterday:
1) Put a bag of joules in the car's dying battery so I could drive to the nearest Post Office to...
2) post the Myford's motor and inverter back to Newton Tesla yesterday, for repairs after a long spiral of phosphor-bronze sneaked round the back of the lathe and into the motor. The short-circuit pulse tripped the circuit-breaker for the whole house. Then
3) Find the wiring-diagram and refit the original 1-phase motor and switch so that...
4) I could successfully make a special bulkhead fitting to take the blower-pipe into the steam-wagon's smoke-box; then
5) At nearly 1am today by now, close the workshop, make a hot drink and go to bed; thinking that:
Today I could:
1) Pop into town to pay a cheque into the bank, from selling a project I bought as unfinished and realised I'd never finish, with the proceeds less postage to buy sundries for the wagon. Those sundries including a package back in the Sorting Office because the post-man called when I was out or in the workshop. Only...
I thought wrong!
1) The car battery was so flat I had to put it on charge and take the bus to town to visit the bank (open) and Sorting Office,
2) but the Sorting Office was closed. 7am to 9am only, thanks to That Germ; and,
3) The parcels I was to post are still here. The Post Office that was only 50 yards away, was in one of the many branches of McColl's that closed down some months ago.
So that's the sale proceeds quite possibly wiped out by a filament of phosphor-bronze and a car battery; the latter seeming to be as dead now as the sparrow I found in the rain in my yard, on my return home.
Ah well, Rest In Peace, poor little bird.
|Michael Gilligan||12/06/2020 16:17:58|
16202 forum posts
Just treat it as a ‘safety measure’ Robert
When you think you’ve finished the work ... there’s just a tiny bit more to go.
|Andrew Johnston||12/06/2020 17:22:36|
5635 forum posts
After the interregnum caused by the horizontal mill feed gearbox 'noise' both cylinders now have four faces machined square and to consistent dimensions, plus the sides of the flange have been cleaned up:
It's now over to the vertical mill (and DRO) to machine one more reference surface and then start machining cutouts, bores and tapped holes for studs.
It turned out that the loose motor cooling fan was the cause of the gearbox 'noise'. That's a relief in one sense, as it was an easy no cost fix. But if I'd known that from the start I wouldn't have needed to dismantle everything. I could have got to the fan simply by removing the sheet metal cover round the motor.
Not sure when I'll get back to the cylinders as it looks like the weekend is going to disappear with glider surveys and airworthiness reviews.
|Nigel Graham 2||13/06/2020 00:29:41|
|720 forum posts|
101 divisions? Working to tenths of thous then! Or the basis of a Vernier dial?
I thought it was only me who'd do a thing like that! Mind you, when I was working I frequently came across something similar, and from Gates Towers no less.
I had to plot polar graphs, using Microsoft 'Excel' - MS calls them 'radar charts' - usually at 5 or even 3 degree intervals. For some unfathomable reason, no-one had told the programmers that the 0º and 360º angles are equivalent on a circle, so the graphs were always 0 - 360 then a little bit extra.
Bit further forwards.
The parts I ordered from EKP Supplies arrived this afternoon, so thank-you to them!
I'm building in the option of a non-prototypical super-heater on the steam-wagon, and the unusual design means needing to hide long, external flow and return pipes in the cladding, and discreetly through the wide ring that supports the tube-plate in the smoke-box. This afternoon I fitted their apertures with two blanking-plugs that can therefore be converted to pipe-connectors - their through-holes are already pilot-drilled, but tapped for M5 sealing screws. The blower supply is arranged similarly but of course will be "live" from the start.
Had another go with the sheet-metal jenny. I found it had come with instructions (I had thought it didn't - I had forgotten where I had put them), so cut up a couple of empty, clean food tins to provide practice pieces. More practice needed!
|Michael Gilligan||13/06/2020 08:12:47|
16202 forum posts
Nothing quite so devious I’m afraid, Nigel
I just meant that by taking each division as one hundredth of a turn, one would be left with a tiny contingency allowance for the final finishing cut & polish.
Regarding Excel: I fondly [?] remember when they introduced the ability to represent the value in a cell graphically, as a proportion of a target value. ... I suffered enormous frustration with this, on one important presentation, until I finally realised that it is only very rough.
|Neil Wyatt||13/06/2020 09:31:01|
18139 forum posts
Like the confusion with DRO systems that plot circles on a PCD.
Excel is a constant source of joy...
It calculates the number of 'poles' from the number of data points You need to present your data as 0 to 359 or 1-360, as 0-260 is 361 steps.
They would argue you should have combined your 0 and 360 data!
|Andrew Johnston||13/06/2020 09:45:49|
5635 forum posts
That takes me back to the great zero-one controversy. Many years ago when I was designing active noise control systems I labelled microphone inputs and speaker outputs from 1 to N whereas the softies labelled them 0 to N-1. For the first system I designed N was 64. That's a lot of hardware when the boards were wirewrapped or point to point wired using the expensive Verospeed system.
|Nigel Graham 2||13/06/2020 13:02:58|
|720 forum posts|
I think I could do with a 101 - division dial on my ML7!
I suppose it's a combination of worn machine, measuring-tools out of calibration and not least, a machinist worn and out-of-calibration, but if the measuring says cut 0.002 " deep, and I turn the dial 2 divisions... it cuts 0.003 or so deep!
1 to N seems perfectly logical for electrical sockets and connections, given that they are physical things with other physical things connected to them! 0 perhaps for the minimum on a volume control scale up to 10 if it genuinely mutes the signal - which re minds me of an old paen to heavy-rock ( I forget by whom) whose title and chorus couplet are Real Men Play On Ten / Never gonna turn it down again!
AS fas as 'Excel' goes MS really had no excuse because if others could write polar-graph routines that make 0 = 360º then so could they. However, I don't think the company really appreciated what people use graphs for, because although you could edit their Cartesian line, bar and column graphs very well, it was extremely difficult and clumsy to make a fine-increment "radar chart" [sic] look half-decent. I did find work-rounds, such as omitting the last data-pair, and manually deleting sets of values from the table's angle-column, but such should not be necessary.
One thing I never understood was why MS went through an arty-f*rty phase with oddities called Bubble Charts and Cone Charts. (I wonder if their use of chart instead of graph was a copyright or patent device?) These two were pretty-picture plots of little or no serious value, but probably appealed to the 'Power-Point' jockeys with pretentious titles like "Chief Marketing Officer".
I did find their column graphs rather good for representing data-sets relating both maxima and minima as a series of floating columns. I found the trick was to overlay the coloured Y=0 to Max graph column with a white Y = 0 to Min column. It took me a while to twig this, as trying to plot simply Y = min to max gave full-height columns. You do need specify a white infill.
I found an equivalent in TurboCAD when creating a 3D geological diagram in black-and-white only gave a very odd-looking result, until I realised I needed to fill the appropriate generating polyline white before extruding it.
I used this overlay method to illustrate the relative depths and altitudes of the swallet-caves up on the Mendip Hills, that feed the river emerging from Gough's Cave, in Cheddar Gorge. I made Y=0 the Ordnance Survey sea-level datum, and Ymax and Ymin the respective altitudes of the entrances and lowest surveyed points of each cave to each other and to the rising. (I forget the actual height but the Gough's Cave rising is not far above present sea-level - not the show-cave entrance but a short way down-hill, where the stream, not seen in the tourist section of the cave, resurges into the daylight.)
|Nick Clarke 3||13/06/2020 13:11:57|
855 forum posts
As 101 is a prime number I presume you have put larger indexes every - er - um -er ?
|Nicholas Farr||14/06/2020 00:13:50|
2406 forum posts
Hi, it was last week I decided that there was too much wasted space around my Major milling machine, so I set about making a special trolley that could be bolted together, to lift the mill with its stand and move it to a suitable new space. I used as much old bits and pieces of steel as I could find, as I didn't want to used new stuff that would only probably be used once, On Thursday last, my trolley was ready and was set up around and under the stand so it could be lifted to put the castors on, wooden bearers were put under the stand and trolley as a safety precaution while bolting on the castors.
It was then moved by a bit of manoeuvring forwards and backward using two swivelling castors at the front. Today my trolley was reconfigured without the castors or the side tie bars, so that the weight could be just taken off the feet, to allow a bit of sliding movement to get it into a position where I could get maximum X travel without the handles hitting adjacent walls while the table was at the closest position to the column.
Next job was to lift out my Boxford onto a different trolley and move it into the same room as the mill and my Warco lathe, which needed a bit of joggling and lifting just off the trolley, to enable the trolley to be realigned to the doorway and both the other two machines.
The Boxford is now ready to be put into its final position on Monday. In hindsight though, I should have mitred the front two corners of the tray under the milling machine, which would give me about 40/50mm more clearance between that and the Boxford when it's in position, but I may still do that or even both corners by hacksawing them off and bolting and sealing a bridge piece on.
|Nigel Graham 2||14/06/2020 01:40:51|
|720 forum posts|
Nicely done, Nicholas.
Milling-machines are remarkably greedy for space!
Is the idea to leave the milling-machine on that trolley, so you can tuck it away more tightly when necessary? (I think you'd need put levelling / stabilising feet on the frame so it's standing directly and fully on the floor when in use.)
That is something that's occurred to me with some of my kit, including a small Denbigh horizontal mill patiently awaiting putting back into service. The Myford mill is too big and heavy for that.
I have mounted the horizontal band-saw (another space-hungry beast) on castors, as its original two wheels and crude handle were just too crude, and worn out; and the effort has paid off. Another possibility is a double-decked trolley for my two welding sets.
I am building, in stages, an overhead travelling crane for my workshop. but limited headroom and fairly light construction mean it won't lift a complete, large machine-tool, but I did not intend that. It's primarily for work on large models, and handling heavy machine-tool accessories. However, with due thought about storage it might well help smaller machines such as tool-grinders being stored away and brought out as needed.
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