Member postings for Muzzer

Perhaps you could buy and dismantle one of those heavy duty "vaping" devices, install the functional parts in your engine and use nicotine-free fluid (which seems to be available). You'd need some form of air pump or compressed air tank obviously.

Most of the "smoke" generators actually vaporise propylene glycol, glycerine etc but these vaping things are a lot more compact than the devices you'd find in a disco / stage event and some appear to be capable of generating spectacular volumes of "smoke".

Murray

May I observe that an apostrophe looks remarkably like a pinhead....

18 TPI doesn't sound right.16 or 24 perhaps but surely not 18?

There's a list of "standard parts" at the end of the parts list for my Bantam (dated 1964) that lists all the fasteners. They are all either UNC or (a few) UNF.

Be aware that BSW has 55 degree thread angle, whereas UNC is 60 degrees. But the pitch is the same apart from the 1/2".

Murray

Everyone seems to be frantically agreeing that phase control / triac / thyristor soft start (they are all the same principle) is most appropriate and the ebay listings are probably the most cost effective way to implement them. A module from a hand power tool is obviously going to be more cost effective than an stand alone soft starter. And no need to make stuff if you can acquire it for peanuts.

The industrial soft starters are usually f expensive. Generally they use a phase controller to ramp in the voltage over a short period, so the suggestion of a dimmer type circuit isn't a million miles off. However, I doubt you'd want to be spinning knobs each time you start it up.

You can make up a sort of half way house / poor man's starter using a timer delay relay (perhaps 1/2 second or so) and a low-ish value resistor. I've got this arrangement on my giant TIG welder and it does the trick. The optimal value of resistor is a bit trial and error. Needs to be low enough to get things moving before you short out the resistor but high enough to limit the initial current surge below tripping level.

Murray

From time to time I used to get attacked by a badger on my bike on the way back from the local pub. Clearly it identified me as a rival that needed seeing to. It would rush out from the hedgerow but generally not make it too close. Hit it a glancing blow once but luckily neither party came to grief.

Murray

I haven't ever bought Korloy APKT H01 - only Mitsubishi from what I can see. However, looking at the Korloy milling insert catalogue (page 5), it seems the APKT comes in a whole range of weird and wonderful chipbreakers and materials. Yours is the "APKT MA" version, it seems. At least it seems to work well...

There's a whole world of inserts out there that leave most of us lost! We have only scratched the surface.

Murray

Nice, viscious-looking inserts, the uncoated ones. But they don't look as I'd expect from an ISO-compatible APKT insert - also interested to know where you got them. That geometry has the 90 degree corner and a "wiper" edge to give a flat (axial) surface when used to face off.

This is what Korloy APKT160404PDFR MA-H01 look like from Cutwel. The H-01 suffix denotes Korloy's non-ferrous grade. Cutwel sells them for £8.40 inc vat (each) and even with 30% off that is pretty expensive. As mentioned, I get mine from ebay, Aliexpress etc.

Incidentally, these inserts are capable of almost 16mm of axial DOC, so they can be used for roughing and finishing external vertical faces. Arguably, you are losing much of the insert's capability if you only make shallow facing passes with them. You can get smaller holders that take one or two of these inserts - down to under 10mm, if you use the smaller APKT11 insert. Then they become usable for slotting and pocketing. Same problem though - very intermittent, noisy cutting.

Murray

Here's a single insert, 16mm dia cutter doing its thing in loominum. It's actually a Mitsubishi BAP300-series holder but the insert is very similar to the APKT style. Because it has only one tooth, the feed rate and MRR is fairly low, despite running at 6000rpm. I've gone over to solid carbide cutters now, as you can shift a lot more swarf in the same time. Perhaps this kind of cutter is best for production volumes, where you actually wear out cutters over a relatively short period of time and the costs add up. Forgive the silly title but this was the first ever metal I cut on the CNC machine.

Edited By Muzzer on 09/05/2018 22:27:03

I got my genuine Korloy (Korean) 50mm face mill from a UK shop on ebay IIRC - unused but under half price. Then I got a couple of packs of APMT1604 coated (for steel) and APGT1604 (uncoated for loominum) inserts also from ebay. I went for Mitsubishi branded parts and as far as I can tell that's what they are.

Proper inserts must be used by the billion out there, given the range and volume of stuff they churn out. so it's hardly surprising that some make their way onto the market. I stick with Korloy, Mitsubishi, Taegutec etc and if you shop around they cost around £2 per insert inc P&P. Aliexpress is also a good source for inserts, both turning and milling. Good prices and generally pukka parts.

Murray

That's what you'd hope to see. If the "back" of the cutter didn't make any kind of contact, it would suggest your head isn't trammed correctly and you will end up with a slightly concave surface.

It's not possible to conclude anything solid from the comments and video. Opinions perhaps but you'd need to do some more objective / methodical tests to narrow down what's happening. So for instance, to see if all the inserts are cutting, you'd need to examine them and possibly mark them to see if there is any contact. And measure the runout, particularly the axial runout etc with a decent indicator. I think that's one thing John Doubleboost missed out on.

The speeds and feeds are important for these indexable tools. It's not clear if there were any calculations done or if the handles were just being turned. Even without CNC, it's got to be a good idea to set your power feed to the right speed range recommended by the insert manufacturers.

Murray

For reference, for mild steel I would be using 1000rpm and 0.1mm / tooth ie about 500mm / min for a 5 insert cutter. Good idea to use coolant or WD40 even.

Edited By Muzzer on 06/05/2018 20:32:38

Stewart - slap it on and be done with it. I doubt you'd have any problem and it's not going to be massively over powered whatever happens.

Murray

That was last year. Since then I've been using manually applied compressed air to clear the swarf and haven't had a repeat of the experience. The longer term fix is a full enclosure so that I can use high pressure coolant to do the job without swarf and coolant spraying everywhere. It's almost complete but I got distracted changing the CNC controller.

Murray

Clearing the chips is critical, even with lots of coolant or lube to reduce the likelihood of welding. If the chips are able to hang about in the cutting zone, they are liable to "recut" ie get dragged back into the cutter where they get squashed against the tool. Once they start to get dragged round with the tool, you get the heat buildup and welding that results in the problem under discussion. The tool doesn't stand a chance of working with a large lump of metal where the cuttinge edge should be. At this point you are lucky to have the challenge of removing welded metal, as the tool was likely at the verge of snapping off.

Here's an example of it happening in real time. I merrily watched the swarf erupting out of the hole I was making, giving no thought to how the cutter would be coping with it. Finally, a second or so before the end, you can hear the cutter trying to stir weld its way through the material with little success. The broken end of the cutter looked like the one at the beginning of this post.

I am much more careful now about ensuring the swarf is cleared - the best way is to drill through first, to allow gravity to assist. I also use polished, uncoated cutters for loominum, as they are less prone to the problem.

Edited By Muzzer on 04/05/2018 10:05:13

That's a neat solution, avoiding all that ballache with the dividing plates, gear trains etc. Functional and effective.

Looks as if you have the weight supported by the spindle (no problem), with the white bracket keeping the table base from rotating. And 3 spacers tying the large pulley to the slotted table. Presumably some form of drawbar / expanding mandrel inside the spindle?

Murray

Dear god, yes. This surely takes the tightly contested angels / pinhead award for the week. Incredible. Just incredible.

Could you simply use plumber's flux? That's pretty active and easily available. Warm it up and it becomes quite mobile.

So you don't stink. Bit like having a shower every day. Or is that a weekly event too?

Dunno about them but I've been using Giffgaff for about 3 years and they seem to be unbeatable for cost and service. They are actually O2 as well. I use unlimited data, calls and text (£20/ mo) but they also do low usage plans from £5. You can change your plan each month and there's no contract.

Murray

How small is your family? Can you do all your washing in one load of a 5kg machine per week? I assume you actually wear fresh clothes each day?

Can your machine do a 20C or 40C wash? That requires a lot less energy to heat the water.

Murray

Edited By Muzzer on 30/04/2018 19:23:24