Member postings for ChrisH

My old Warco 'Economy' mill/drill has a single phase motor. It says it has a 750W motor, but the nameplate is also stamped 6.5 amps and a 90L - 4 frame, both of which suggest to me in my ignorance a 1.5kw motor. However, I don't have the original manual to check what it was sold as but have a Grizzly download manual of the same machine - all versions of the RF 25 I think - and that states a 1 HP motor, which is of course the real money equivalent of 750w. Confusing!

In the general scheme of things that would be a no worries situation if I didn't want to change things; however, I want to change to a 3 ph motor with a VFD inverter.

So what do I get? Looking at TEC motors, I could go for a 750w motor, a 1.1kw or a 1.5kw. The 750w is an 80 frame, the 1.1kw could be either a 80 or 90 frame and the 1.5kw is a 90 frame. Plus there is obviously a difference in cost for each power size. I forget what the advantages of a 3ph motor has over a 1ph motor has on power requirement, perhaps that can indicate a direction to go. An 80 frame would obviously have advantages in space requirements as well as cost over a 90, but a bigger power would perhaps have advantages in torque when running at low Hz (low rpm) settings from the VFD.

What do people think? Those who have done it, why did you go the way you went and did it work out well?

Chris

Clive - I did say it was tongue-in-cheek, it was playing with letters to achieve a comment. I am aware of the origin of EN numbers.

What would be good is some standardisation of what all suppliers call each product. Some will say EN1A, others will only answer to 230M70 for example, both are arguably the same product.

I also appreciate that odd hard bits can and do get found in all sorts of types of steel at random intervals and that the problem is a very old one. I can never legislate to avoid ever getting a bit of steel with a hard bit in it, but I can try and ascertain what other folks do to get round the problem and use that knowledge to help myself deal with the problem when I experience it, which is what this thread is all about.

Chris

In the merchant navy they years ago gave away the idea of a wood lined tube, lubricated by sea water, sealed by a packed gland to keep most of the sea outside the ship, to support the prop shaft as it exited the ship. They were replaced with (very well) sealed tubes containing a totally oil filled bearing under a considerable head of oil. Therefore absolutely no sea water through it at all. If sea water was leaking through that shaft bearing and seal you were definitely in the mire! Hope this is not the case here but suspect so.

Chris

Re Jason's comment "Better to remove the scale by pickling in acid" - what acid?

Would citric work or does it need something much stronger?

Chris

Clive, from what you write it's starting to get political ! Better off out the EU and away from EN steel and back to British Standard ( BS) specifications. All said a bit tongue-in-cheek really, with a bit of truth in it! Another plus for Brexit perhaps?

Chris

To answer Andrew, the provenance was the same as Jason's, was off a length of 40 x 50 mm I purchased from M-Machine Metals, as detailed in he invoice. Never had any worries with stuff from M-Machine Metals, always buy from them and have good results and service too, this is the only bit. I guess there might be something in it from somewhere, like SOD and others have suggested, I will give the stove heat treat method a go and if no good bin it and order some more, when I can get another shed day. Not a good time now in the run in to Christmas, SWMBO seems have have more priorities than I have time slots. Nothing new there then for most of us I guess. Be glad when it's over and can get back to normality!

Chris

I'll give EN3 a go first I think, Jason, see how it goes, EN8 will be worth remembering about but it's much more expensive. See they do Black in square too, cheaper still than EN32 and EN3, that may be another option still. Chris.

Strategy using the stove and grinding up a trashed cutter is a good one Jason, just have to hope that I can hand hold the cutter sufficiently well on the grinder as no tool cutter/jig made yet. Harold Hall's Tool Grinding Jig is on the to-do list, at times like this I wish I had got on with it before! Chris

Jason, so glad that I'm not the only one trashing cutters with this problem even though it was not good for you. Interesting you mention EN3 at 50mm sq. as I have just added that as a PS as an alternative. It would certainly be worth a go, no difference in price from m-Machine metals.

Chris

a PS to the OP. I do have a stove in my shed which heats the shed using one of the smokeless coal fuels. I could get that going red hot, chuck the steel on and then put more coal on top and leave it a good while.

Would this be any good to do?

Chris

Hi. I have not got much experience of machining EN32B steel. I am currently trying to machine a 75mm length of the stuff of what started out as 40 x 50 mm section to make a tool holder, so after cleaning up the sides to size and cutting out the slot for the tool am now machining a slot on the back, about 37mm wide initially, to make the dovetails to fit the QCTP.  However, I seem to have hit a largish hard spot which so far has trashed 3 HSS 12mm dia milling cutters in quick succession.

So, the question initially is: are hard sports common in EN32B or am I just unlucky, and how do you deal with them? I had thought of heating to red and cooling slowly but, I only have a propane torch for heating and wonder if I could get it hot enough but willing to give it a burst and see, but also if this would work anyway?

Am reluctant to machine further as I am running out of milling cutters! So the next question is how do I continue to machine, or rather, what do I do next? I don't have a shaper so that's out. I don't have a small enough flycutter but I do have an adjustable boring bar holder with carbide boring tools, but even if I cut the initial slot that way I am concerned that the dovetail milling cutter which is a HSS one will get trashed cutting the dovetails.

Or do I just bin this bit of material and get another bit and hope it's OK. I am actually making two tool holders, the other one cut from the same original length of steel has been OK so far, no worries.

I am not sure EN32B is the right steel to use but it was the only material in the size I wanted.

Chris

PS  Not quite true that EN32B was the only steel available, I could have got some EN3 square but there would have been a bit more waste and I was not sure if EN3 would be robust enough.

Edited By ChrisH on 17/12/2017 11:44:26

Edited By ChrisH on 17/12/2017 11:57:36

"At long last maybe some thing useful that might keep SWMBO quiet for a couple of hours !" If that works tell the rest of us, PLEASE! A quiet SWMBO - how do they work? Never seen one!

Looks a very interesting build, and lovely machining so far. Keep on with the updates please - I will enjoy following this one!

Chris

Not had any experience of these two lathes but looking on the internet they should do very nicely, if it's as good as it looks you should be well pleased!

Chris

Bill, you say it's an oiled compressor, by which I take it you mean it's not an oil-free compressor but has oil in the crankcase. Therefore some oil will always get by the piston rings and into the compressed air stream; whether that coats the inside of the air bottle nicely is another issue! If you want to paint spray you will need a filter/dryer in the line anyway, get one that catches oil!

You could use an auto-drain trap tee'd off the drain line, Spirex-Sarco used to sell them I think, they have a little disc inside that the water (condensate) builds up behind and it auto lifts every now and then if you really wanted it. The simplest is to just open the drain valve at close of play each day and leave it open until you switch on again.

Chris

+1 on "don't be discouraged" Alan, once you experience the variable speed control a vfd gives you'll wonder why they aren't fitted as standard and how you ever lived without it.

One word of warning - hope it's not teaching granny to suck eggs - but watch the motor temp on low frequencies, if the motor goes too slowly it doesn't get enough cooling air, the motor fan is going too slowly to shift the air, and the motor can overheat. If you find that happening rig up a stand-alone fan to blow air over the motor, an old computer fan seems to work well (and could well be free!), but I don't go that slow for that long a time for it to have ever been a problem for me, so don't have a fan, but I do check the motor when I do.  That's usually only when screw cutting do I go that slow because I'm a bit of a scaredy cat not wanting to louse things up. But the beauty of the vfd is that I can go that slow, say 35 rpm, when I need to!

I also fixed up a rpm indicator using a package of led display, preassembled circuit board, proximity sensor and magnet got off E-Bay for about £6.50 inc delivery from Hong Kong to the UK - how did they do that for the money AND make a profit I asked myself - put the display and pcb in a little plastic box, made up a mount for the proximity sensor and magnet on the end of the head shaft and gave it a 12v dc supply and that's well worth it too - with a vfd and a variator on the lathe belt drive I didn't have a clue what revs I'd dialled in for the lathe before! See other threads on here for that - they feature the package and how to wire it up.

Chris

Edited By ChrisH on 07/12/2017 11:27:10

Neil - thinking about it a bit more, there was a perfectly logically reason why the Renault 4 had a dash mounted 'umbrella' gear change lever - I suspect the Citroen 2CV had the same reason but not sure. The Reno 4 was front wheel drive but the engine and gearbox were not mounted transversely as is the norm these days but longitudinally, with the gearbox in front of the engine. The gear change shaft stood up vertically from the gearbox and so the route from the gear change shaft to umbrella handle was a straight line across from the dash over the top of the engine to the gearbox - simples. All the best ideas are that - simples! Chris

Taking of torque, I had a P4 Rover 90 - otherwise known as an Auntie Car - which had a very long cranked gear lever with a ball pivot at the crank. It gave plenty of leg room but it had a design fault being so long and whippy. It snapped. Twice. No worries - to get a replacement each time I drove about 10 miles each way to the Rover dealer the other side of the nearest town in 4th; she pulled away from traffic lights and other stoppages no worries with not much more clutch than normal. And had a useful bench seat - useful if you were courting that is - and quiet well appointed solid feel to the whole car. Plus it would cruise all day at 85 down the motorway without batting an eyelid although the fuel gauge did go down somewhat. Oh happy days!

Chris

"Better than a friends ghastly French car in the early 80s which had an umbrella handle sticking out the dash" I disagree Neil.

I had a Reno 4 in the 1970's, with the 845cc engine and the gear lever - umbrella handle sticking out the dash - was spring loaded to the middle vertical of an elongated 'H' - (elongated meaning it had 3 verticals in the 'H', R-1 up/down on the left, 2-3 up/down in the middle and 4 up on the right!) which gave the 2nd and 3rd gears. The system worked so well, going up and down 1-2-3-4-3-2-3-4-etc the box was so logical and easy, made driving a pleasure. You just push/pulled as required and gave a little turn to the right for 4 and left for 1 or R and it was as quick to change as I can write it!

Mind you, the car did need half an hours notice of trying to overtake anything but it was a very fun car to run and drive.

Chris

Edited By ChrisH on 28/11/2017 14:08:29

Many thanks for that info BobH - all is clear now. Very good idea, I will keep it in mind for my lawn tractor, it usually gets used as a tractor unit to tow a trailer of logs or hedge cuttings around when it's not being used to trail a load of gravel up, obtained for free, from down the road. That's when it's not cutting grass that is (I hesitate to upgrade it to saying lawns, our French 'lawn' and grass field can't be called a lawn!)

Chris