Member postings for DiogenesII

I fitted a 3-phase motor/invertor to a small (1MT spindle capacity) milling head last year - I used a 0.37kw motor having a "56" frame size and a "B14" flange mount, the shaft is 14mm dia.

0.18kw-and up are available in this frame size. About £50 new - check the "min" operating frequency/torque values - cheaper motors suffer more in this area, more expensive ones are better spec'ed at the lower end.

The motor is c. 100mm in diameter, 180 long, and has a 60mm spigot with four 6mm bolts on a 75 (or is it 76) mm PCD - if this helps as a starting point for further research. Specs may differ by maker - check!

I used two step pulleys to get useable ranges from about 350-2500 rpm from a two-pole motor, might have got same speed & more torque from a (safely) over-driven 4-pole, maybe someone can comment?

About £56 new mid-range motor & £50 cheapy (but very well-featured, nonetheless) vfd..

Now I really MUST go to work...

D

Just got home to ask the same question as JB...?

Keith - commiserations! ..although from a slightly ghoulish perspective, very interesting and informative. I made an initial start on the same engine some weeks ago, and although not managing to progress quickly with it, it's enlightening to actually see physical evidence of the levels of stress that some parts are under. Best wishes for a successful conclusion..

If it helps to offset some of the pain of the extra troubles, I think your redesign was absolutely worth it - it looks very well indeed. The proportions and "black" look spot-on. Nice.

..that swarf will be a good source of phosphoros for the garden..

"Crystal" styrene would probably be the popular choice for an optically clear moulded product.. it's probably the only polymer that is clear enough / has the most convincing refractive properties to look like glass.. you'll be able to tell if you can burn a fragment of it - it's distinctively acrid..

..has this come about from your researches into the Grateful Dead, Neil? ..there's a certain relevance..

I've relatively recently discovered this;

Drawing Board App Features

..it's about £16 to buy the full package, but one can trial it for free.. ..I have no commercial interest in this product, I simply wanted a CAD package that can generate technical drawings in a way that I can get my head around in hours rather than days..

Don't be put off by the fact that it calls itself an "App" - I think they are somewhat underselling it.. Although it's not mentioned in "Features" linked to above, one can switch between absolute, relative, or polar coordinates in the same drawing, which I guess is what you will need for drawing your crossings out..

Agree with Paul, check the motor fan cover first. (Also, and profuse apologies if you know this, but the gears must be carefully selected before startng by turning the spindle back and forth as the engagement levers are operated until they are felt to go fully "home".. )

If you do need to check the action of the gear assembly, you need to remove the opposite cover - the one with the downfeed lever.. (Isolate the power - Remove the screw and washer, pull off the lever and dial, remove the (parallel/straight) pin and any washer or shim, then the cover screws - note that one may be shorter to avoid fouling the motor screw at the upper rear).

With the cover removed and rotating the spindle backwards & forwards by hand, switch each speed selector lever into it's high & low range - each lever acts to move a steel dog (keyed to it's respective shaft) into or out of mesh with one of a pair of (either phenolic, or ?acetal) gears which lie above and below it, and are free to rotate on the shaft.

The upper lever moves the dog between the pair on the output shaft to the spindle, the lower operates that between the pair on the countershaft which picks up the drive from the motor.

In each lever position, only one of the gears should be "connected" with the spindle via the dog - the "freewheeling" gear that is not engaged with the dog MUST still be CORRECTLY engaged with it's respective pinion on the other shaft - i.e., all four resin or plastic gears must sit squarely, evenly, and consistently, and be in constant mesh with their mating gear, irrespective of the position of the dog (- it is not unheard of for the (white) plastic gears to come loose from their internal bronze bushes, this case usually evidenced by wobbling or vertical misalignment that is obvious to the eye.

Which brings me back to the intruction regarding wiggling the spindle to ensure engagement of the dogs with the gears - the dog itself comprises only a simple tongue , and so the gears must be manually rotated to "pick up" the corresponding slots in the pinion to ensure correct drive before the motor is started.

I hope that "your" noise is just a lack of proper engagement.. if the "grub screw" detents that you mention are located in the lever-bosses, they a standard fitment.

Oh, and do be mindful of aligning the selector lever forks with their slots in the dogs when you reassemble the left hand cover.. can't remember what the lever positions have to be in, without checking.. will be obvious, I'm sure..

Let us know how how things go..

Edited By DiogenesII on 26/06/2020 16:30:05

I have a Faithfull lever-action can - the brass end on the Flexi pipe is about 2.5mm at the tip, and so is small enough to push the ball down and seal against the edges of the hole on the 2.7mm-ish ball oilers on a Warco Major.. all the oil goes "in" and past the ball.. The part no. is FAIOC500;

Faithfull 500ml Lever Type Oilcan

Very pleased with it, like every lever oilcan I've owned, the pump rod (maybe?) draws a bit up so it's always a bit greasy on the outside, but never wet enough to leave a ring.. ..I'd buy another..

..well, if iti helps to provoke discussion, maybe they fitted plain slugs and secured them with a grubscrew, and then spotted the thread-centre through the leadscrew brackets after they were fitted-up, in order to ensure alignment.. ..wouldn't be odd for them to come out a bit off-centre..

If they are pressed in, they'd still have to be positively located by a screw/pin/collar to resist the thrust of the screw causing "creep"..

.

Apologies - I don't know what I was doing when talking about the depth of cut - it was well past my bedtime - somewhere from 0.08 to 0.15 mm reduces the strain on everything, maybe a bit less for finishing..

..light cuts for this gudgeon/piston pin, but the swarf came off deep blue and left a great finish..

..with that kind of gap you may be able to insert slips of shimstock either opposite to (or maybe better), 120 degrees either side of the screw?

..a bit expedient, I know..

There's a pretty good description of "how" here, about 13 mins in..

Youtube - ThatLazyMachinist

..he uses a similar mill and has some useful things to say..

Edited By DiogenesII on 22/06/2020 07:12:14

Following the more-or-less successful trial of the principal, I thought I'd try and find something to cut in a more "real-world" way.
I have some "as-cast", 56mm diameter iron collars in the scrap box, and thought that cleaning-up one of these might make a useful subject.

The tool was clamped on the topslide at 45 degrees to the lathe axis to enable facing and turning without having to disturb it - it is very compact, and gives good access to the work for measuring etc. At some point I'll replace the clamp stud with a shouldered one, and can then secure the drilled holder directly to the topslide with just a nut & washer.

The carbide rod was shortened and then ground off-hand with a Dremel "Tile Cutting" diamond wheel (SC545) run at slow speed with the toolbit fitted in the holder to provide a visual guide.

Cutting performance was good - both in quantity and quality. The tool would cut to radius depth, but felt happier at a bit less than this - perhaps .8mm - which I think is okay for a small lathe spinning CI at 250rpm. The inner "roughing" cut on the face was "pushed" a bit, but still looks crisp & consistent, and the chips from the "skinning" look good. The finishing is certainly acceptable to me in the "normal" working conditions in which it was done - I'm fairly confident that with more careful hand- or fine-feeding and everything snugged up, it would improve further.

The "Tivoly" brand bit remained in pristine condition at the completion of the job, and also retained it's setting without being pushed down in the holder, so the split clamp may stay just as it is for the present.

I'm happy with the results. I have a good tool that will reduce the need to change & set (my shamefully haphazard collection of brazed carbide & HSS) tools so often, that doesn't need shimming, and in which the hard toolbit is rigidly held just off the front corner of the soon-to-be-bare topslide.

..I have no doubt a little tweaking and refinement here & there will follow, and I'll try some tougher and some softer, material soon and see what it does with that.. more anon..

Thanks for all your help, Niels.

Thanks all for your comments -

Niels, that's a useful observation that I hadn't really considered - I guess I just drilled it halfway up the stock (and then reduced the height, anyway.. maybe I'll add that to the "to do" list.

Howard, I understand your motivation completely - I must admit that I have held on to some bits & pieces for years because I have had a destiny (loosely) planned for them, and it's the most satisfying thing to have exercised brain as well as arm in making something worthwhile. It'll be good to see it..

Paul, thanks for that - you've thought it through better than I did - I kind of pushed the idea to the back of my mind on the basis that I didn't want to abrade the top "reference" surface, and didn't think much further, but your idea makes sense and is feasible.

I'd bought a couple of Dremel diamond cut-off wheels which arrived today and which I used at slow speed to cut the rod into more convenient lengths; using the side also put a perfect flat top onto the bit, so I will see how that goes.

I had great success turning and facing without having to adjust the tool position (which was one of the things I was after) this afternoon, on an iron casting..

I'll post a description and some pics tomorrow..

Ah! - I really couldn't figure out what you were making, it would have made a great "what is it?"

..that will be a very satisfying one to bring to completion - at risk of being nosey, are you building in order to fulfil a particular need, or is this a project purely for personal interest?

Following a week (and more) out of the workshop, I've finished a second toolholder.

Having digested the information provided in Niels' links and following a little correspondence, comment (thank you) and thought, the new version features a small but worthwhile adjustment to the tool angle, improved side clearance, and stronger tool-bit clamping.
I also bought a couple of 2mm round "Tivoly" carbide toolbits.

One of the first revisions was to amend the angle of the toolbit - in the original, I'd been fairly cavalier in the set-up and ended up with an angle of slightly less than the 12 degrees I'd shot for, so with this holder I was careful to err on the generous side to gain myself a little more side clearance.

The upper surface of the tool is machined to centre-height - this makes setting tool height easy, as the holder only needs to be inverted on a flat surface and the tool tip set to touch, whilst the clamp is tightened.
Currently, the tool is ground at the same angle to that in which it is inclined, to give a neutral rake that sits flat on the plate whilst setting - this means that the correct orientation of the tool can be both seen and felt during setting.

The nose of the new holder has an included angle of 80 degrees - reduced from the 85 used on the first tool, it makes acquiring the clearances for facing/turning less critical, and reduces the need to create extra easement by additional hand-filing of the nose.

The "flanks" of the nose were machined with the holder clamped horizontally - on my prototype, I machined them in the same "inclined-at-12-degrees" set-up as drilling for the toolbit, which looked neat & purposeful, but resulted in rather thin jaws, and I think the extra metal in the later version is a positive improvement - It also simplifies the making, as it requires only a simple (rather than a compound) angle to be made. I used a home-made 40 degree angle gauge cut from a piece of 6mm flat bar to align the holder on it's side in the mill vise.

The clamp screw size was upped to M4, the cap head being modified to provide clearance along the flank of the holder.

The tool cuts as one would wish a neutral-rake carbide tool to cut - the photo's below show a tough cap-head screw of unknown (but tough) grade, and a m/c wheel spindle. The results were from the very first off-hand grinding and are certainly acceptable - the spindle had a huge overhang in spite of being shoved up the 'ole as far as I could get it (and was unsupported at the free end because of the shortcomings of the Hobbymat tailstock).

I might make a simple jig to hold the tool for flatting with a lap, just because it's small and slips in the fingers.

I still have a couple of ideas to try regarding the the fixing of the toolbit - although the clamp isn't that onerous to make, it still requires a number of set-ups and operations that it would be nice to reduce, and requires compromises to be made the balance of which are difficult to resolve without making and testing.. a number of options are possible, some tried by others, and some perhaps not..

I'll update once I get a chance to do more with it..

..also belated thanks to John Haine for his link, and Howard, what was that thread project, and was it successful?

..what degree of tool height repeatability is available with R8?

..I don't want to cause alarm 'cos the guy might be perfectly innocent, but I have heard similar tales before - I'd be very mindful in securing the vehicle for a while.. Maybe it's bad to be so alarmist.. second opinions, anyone?