Member postings for MW

Hi everyone, i'll try to address everyone.

Hi john, Yes i do have that article in the well thumbed issue somewhere, I'm sure alot of these designs require a proper PCB board, i dont have the time/equipment/knowledge to make one of these, so i'd either have to get someone else to make it or use breadboards/wires to link up all the components.

Thanks for the Reply mike, i think i'll try the 35mm spindle size then, as in my mind, for a task this small i dont have any concept of power or appropriate speeds so i just needed a starting point or rough guide. I keep looking at your website and i can really tell you have a background in electronics because of how well you've integrated the whole system. I will keep reading it for hints, thankyou.

Les, i was thinking along the route of using pulleys/timing belt with a tensioning idler spindle, a bit more common and easier than an encoder to do. I lost my spring balance a long time ago!

Thankyou,

Michael W

Hi,

I'm interested in making a DC motorized control for my lathe lead screw and i know there are lots of designs out there but i dont really know where to start with regards to where to buy a DC motor and what size/speed would be appropriate to drive a handle?

Michael W

"I put up with the curly swarf - Normally I use a pair of 10" surgeons forceps to pull it out of the way."

I love those forceps, i have an old set of sheffield ones inherited from my father, so handy.

To answer the question, technically it's both the tool and the lathe, because one would be lost without the other!

:P

Michael W

Wow, this sounds exciting i would love to see that up and running, completely unheard of these days. Dont let the past dissappear altogether!

Michael W

It's funny how when you've got a small machine you want a big one, then when you've got the big machine you want a small one.

Why not, the alternative might well be nothing otherwise, do it do it do it!

Michael W

Tbh, i would love to go and spend all my money at a premium tool dealer like Floyd automaton, Cutwel or even cromwell tooling, pratt bernard chucks, genuine jacobs drill chucks.

But then i woke up and realized this is the real world. I guess i'm just going to have to keep the chinese on their piece work for the sake of my indulgences.

The china-bashing thing has been done to death so i'm afraid i wont start that. A tool is only ever as good as the person wielding it, i've only got me, so i guess i'll have to do it regardless of what tolerances my cack hands may muster.

Long live China!

Michael W

"Of course you can control it.

It's called 'social skills' .............. A basic requirement nurtured from youth. Seems neglected by many these days though.

Nick"

So that you might bleat with the sheep and howl with the wolves?

Michael W

Ajohnw, i made the mistake of going into model engineering having learned on a colcester master, a completely different sort of animal for turning, but it was really old and kept putting a constant taper onto the work, i still enjoyed the huge range of gears and multiple feed screws it had to offer.

Then i saw the sherline, asked for it, decided they didnt want it and would let me have it. I wont make any bones about it, the DC motor is either a paperweight or a dust collector but not really worth being called a motor for anything other than lego. I have a strict aversion to variable speed DC motors for lathes because of it. However, that said, on soft metals it would produce a finish and tolerancing of a pro, the slides were tight and the movement was silky smooth, very well made, i just dont understand why they go to that trouble only to stick a lawn ornament of a motor on it.

I was sick of it at that point, so i saw the clarke, reckoned it would fit my remit so to speak and bought it. You're right though, its as reliable as a dog that constantly needs to go to the vet and like flogging a dead horse sometimes. I guess i'm just a cheap skate.

Oh well, back to making more saw dust.

Michael W

I guess this is advice you could give to anyone but do as you say, be yourself. The cultural fit is going to be the big determining factor and this isn't something you can really control, but alot people leave a job for a bad cultural fit. So good luck with that i guess.

Don't let the veterans frighten you off and don't worry about making mistakes, even they do and they didn't learn by being brilliant, so let their advice guide you i guess.

If you have the confidence, you can put forward some ideas on how to do a job, they might like that kinda enthoosiam.

Bring a pack of biscuits and share them round at tea break!

Michael W

Just an update,

I just entered the current, voltage and wattage (oddly stated as 0000.0kw?) as well as RPM of the motor into my inverter. Interpreted from the plate as the 230v delta configuration.

The settings were only a little off but it seems to run slightly smoother, doesnt whine as much as it used to on low frequencies.

And so i didnt intend to, but i've learned my lesson today.

It's like trying to read aramaic in my manual. It isn't sign posted very well.

Ajohn, I took a look at the peatol machine and laughed when i saw it, reminds me of the sherline lathe i have (but dont use) and that couldnt take a cut out of anything remotely hard . Its a clarke cl430; brute of a thing. If what you say is true then mines a wimp.

Michael W

Edited By Michael Walters on 07/03/2016 15:26:15

Maybe i've been a bit daft or something because i dont remember needing to enter current rating into my inverter, it only stipulates the frequency. I'm using an IMO idrive2 so maybe i've gotta flick back through that cryptic manual and see if i missed a setup step quite important and just willfully overlooked. perhaps i'm not getting what i should out of it because of my operational error.

Michael W

I think it's interesting, because i've run a 750 watt motor on a 750watt inverter on a lathe into a long piece of 1" square mild steel on a 1mm cut, on the leadscrew auto feed gear train and a tailstock centre and through coolant running, got about half way through it and the overload warning comes on. I've done the same thing with a 1.5kw inverter, motor no different and it doesnt complain. So duty cycle can be important.

Obviously i'm not the judge of what other people need to do, but i needed this to do that, so all i can say is buyer beware. I should add that i think my named counterpart has some good points, its true that it doesnt start under load and this new inverter was fan cooled rather than totally enclosed, so i could be wrong but it worked anyway.

Michael W

Edited By Michael Walters on 07/03/2016 12:40:22

Im actually slightly envious of that lathe, welcome to MEW forums.

Michael W

If hes changed the rated output from what you believed the original product should normally produce, then its miss-selling you, I'd get your money back and stay clear. Its not right for the customer, thanks for the heads up though.

Ps. This is a big no-no because when you buy a motor for use with an inverter, it's best to get an inverter that can handle 25%-50% more than your motors rated output so that it will operate well under sustained duty cycles. It will just keep overheating after more than maybe 30-40minutes usage. 

Michael W

Edited By Michael Walters on 07/03/2016 10:09:26

Are you taking the mick? :P

It's a shame you can't get the rubber vee belting that has a woven intermesh throughout, they last for years. But i dont know who'd sell it.

I'd strongly recommend having a way to bolt this motor to its set tension, belting relies on consistent tension in order to drive properly, the cutting forces could force the spindle to slow down because the belt will ride up. 

Michael W

Edited By Michael Walters on 07/03/2016 08:59:37

Edited By Michael Walters on 07/03/2016 09:03:23

Edited By Michael Walters on 07/03/2016 09:04:49

I would've said check your D.I.Y shop for perspex people use it for greenhouses.

But given how thick it is, i doubt they'd sell it so, i do know an engineering plastics firm called Anglia Plastics, they will sell to small users and i once bought a 2" square block of clear acrylic from them for a jig. The website appears to be down but you can find their phone no online.

Rgds,

Michael W

I don't blame the inspector myself, mainly because i've been in their shoes and it isn't worth letting things go if you're unsure of the job in question. I mean, i cant relate to this specific case but i did learn from my experience of "telltale" signs of what you'd call "general" tolerancing and "tightly held" tolerances, especially if they were not specifically referred to. But at the end of the day, you just don't know because you didn't work on the design of it, it's not worth your job to let it go when, as author correctly pointed out, it's much nicer to resolve a problem in house, even if you have spent a bit longer sorting it, than to let it go out, boomerangs back in and not only call into doubt the image of your product, but spend yet even longer still on it.

Michael W

Thats quite an interesting tale you've got there, Nigel, i only wish i could've been in your shoes to see it. Since i dont have that much experience in industry, and never seen or really understood vertical boring machines. I know that my clarke isn't completely solid but it's atleast a good few inches deep even if the base is hollow. I didnt have much time to look at it as my main concern was hoofin' the damn thing into place.

I have to say it's an unfortunate habit of mine to ask and pontificate a little bit more than what i consider the average joe would. Context seems important but also tends to wander.

I'll have to take that as a compliment, Michael G, and at the risk of taking this conversation even further from the authors intention, i'll leave it at that.

Michael W