minilathe speed reduction

[Michael James 5Participant @michaeljames5]

I ll check when I get home tmrw ..

[Neil WyattModerator @neilwyatt]

Posted by blowlamp on 27/08/2018 21:15:41:

I don't think Warco states its Super Mini Lathe as having a brushless DC motor.

I'm pretty sure it is BLDC though. Brushless has become shorthand for BLDC.

Neil

[blowlampParticipant @blowlamp]

Posted by Neil Wyatt on 28/08/2018 11:40:18:

Posted by blowlamp on 27/08/2018 21:15:41:

I don't think Warco states its Super Mini Lathe as having a brushless DC motor.

I'm pretty sure it is BLDC though. Brushless has become shorthand for BLDC.

Neil

 

If so and it's got a backgear too, it should have loads of torque.

I'm just wondering what problem we're trying to cure.

 

 

Martin.

Edited By blowlamp on 28/08/2018 11:54:47

[Ketan SwaliParticipant @ketanswali79440]

Posted by blowlamp on 28/08/2018 11:53:45:

Posted by Neil Wyatt on 28/08/2018 11:40:18:

Posted by blowlamp on 27/08/2018 21:15:41:

I don't think Warco states its Super Mini Lathe as having a brushless DC motor.

I'm pretty sure it is BLDC though. Brushless has become shorthand for BLDC.

Neil

If so and it's got a backgear too, it should have loads of torque.

I'm just wondering what problem we're trying to cure.

Martin.

Edited By blowlamp on 28/08/2018 11:54:47

Hi Martin,

If it is a brushless motor version which Michael has, then perhaps there is a 'broad' direct/indirect relationship with this thread.

Ketan at ARC.

Edited By Ketan Swali on 28/08/2018 12:59:02

Edited By Ketan Swali on 28/08/2018 13:01:38

[Michael James 5Participant @michaeljames5]

Thanks Ketan

[Ketan SwaliParticipant @ketanswali79440]

Hi Michael J,

I think that Martin and the others are trying to help you.

During the past year, there have been plenty of offerings in the 'mini-lathe' category making various statements.

For example, the word 'Super' in the mini-lathe history was first used by SIEG. This word started to be used by various people – sellers and users, to describe their mini-lathes, forming various incorrect presumptions on motor type/power, belt/gear type of gears – metal/plastic etc..

We at ARC deal with at least five calls a week from customers wanting spares, thinking they have a particular SIEG brand machine, when they don't. Many times, this problem is amplified with electrical spares – namely motors and control boards.

To guide you clearly, it is therefore important to provide a definitive answer by the helpers asking you to present a picture of the motor and control board on your specific machine. Many well known sellers also state input power which is usually higher than output power. ARC and SIEG state Output power. To get a clearer idea of this it often also helps to provide the physical measurements of the motor you have, along with pictures of any labels on the motor.

If you try to do what you have in mind, the more information you provide, the more people can help. Pictures are ideal for this purpose.

Ketan at ARC.

[JasonBModerator @jasonb]

I thought those Adept boys were the first to used "Super" as a prefix to their machines

[Michael James 5Participant @michaeljames5]

Everyones been helpful and its been very interesting.Although if I d been sold a brushed motor instead it might be best if I dont find out now!!
Seriously though I ve ordered pulleys, if they dont fit they can go in the drawer marked ‘drawer for everythong that doesnt belong anywhere else.If theres space left .
Then probanly have a go at making v pulleys

[Michael James 5Participant @michaeljames5]

No thongs in it yet !

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Ketan Swali on 28/08/2018 21:10:58:

input power which is usually higher than output power.

Are you working on one where it isn't? If you succeed the world will beat a path to your door

Russell

[SillyOldDufferModerator @sillyoldduffer]

Posted by Michael James 5 on 29/08/2018 07:53:20:

… Although if I d been sold a brushed motor instead it might be best if I dont find out now!!
…

My old mini-lathe and brushed DC motor did a good job so I wouldn't worry about it too much. From worst to best:

• AC/DC Universal Motor. (Yuk!)
• Single Phase Motor. Vibrate, relatively poor torque, unreliable as their capacitor and/or centrifugal switches age. But note that they are widely used with great success on classic lathes like Myfords. No electronics to go wrong.
• Brushed DC Motor. Smooth, good torque, easy speed control, brushes wear out, vulnerable electronics
• Three Phase Motor. Smooth, good power, torque and efficiency, fixed speed, highly reliable. Requires 3-phase supply. No electronics.
• Three Phase Motor with VFD (more vulnerable electronics!). Advantages as 3-phase motor, plus speed control, improved efficiency and adaptive motor management. Practical at home because VFD can make 3-phase AC from a single phase domestic supply.
• Brushless DC Motor, a close relative of the 3-phase type rather than a brushed DC motor. Requires electronics to produce the timed DC pulses that turn the motor. Best all round performance, highly reliable apart from the electronics.

In practice, on a hobby lathe, only Universal Motors are to be avoided. But it's worth knowing what your lathe is fitted with in case something goes wrong. For example the weak point of a brushed DC motor is the brushes. Brushes wear out and sometimes break prematurely. First port of call on a wonky brushed motor is to check the brushes. They are easily replaced. The round black screw cover bottom left corner of Jason's photo covers a brush, and there's a second on the other side of the motor.

Dave

Edited By SillyOldDuffer on 29/08/2018 09:39:17

[Ron LadenParticipant @ronladen17547]

Hi Michael,

I havnt followed all of this thread but if your minilathe is a CJ18a from Amadeal then it is a brushed dc motor.

I have a CJ18 and I was just speaking to Amadeal about something else and I asked them about brushless minilathes. They have a brushless version which is about to be announced but they wont have stock for another month. So all their minilathes to date have been brushed motors.

Can I just ask why you feel it necessary to go to the trouble of modifying your lathe, your choice of course but my CJ18 I think is fine speed wise. Low gear: 39 – 1080 High gear: 97 – 2504 and I dont think it is short of torque it seems to have plenty of power.

Ron

[Ketan SwaliParticipant @ketanswali79440]

Posted by Russell Eberhardt on 29/08/2018 08:54:24:

Posted by Ketan Swali on 28/08/2018 21:10:58:

input power which is usually higher than output power.

Are you working on one where it isn't? If you succeed the world will beat a path to your door

Russell

Apologies Russell, I should have clarified. Many of our competitors in the mini-lathe product field state 'POWER = xxxW'… for marketing purpose. They fail to state or use the word 'INPUT' in front of the word POWER in their marketing. So, for example, when a new person is making comparisons they read POWER: 600w in the specifications of a competitor, and think that it is better than 500w Output POWER which is stated on SIEG specifications, because their eyes only focus on the word POWER.

There are many such examples, but potential buyers only find out if they ask us, or if and when they need replacement parts.

Ketan at ARC.

[Russell EberhardtParticipant @russelleberhardt48058]

Apologies not needed Ketan. Such misleading marketing must be annoying for you. Still, it's not as bad as the quoted power ratings of much audio equipment.

Russell

[Neil WyattModerator @neilwyatt]

Posted by SillyOldDuffer on 29/08/2018 09:38:43:

Excuse me for not quoting the long post, but it might give some the impression that all electronics are unreliable

Experience seems to be showing that 3-phase inverters and brushless DC motor controllers are more reliable than brushed motor controllers. We seem to be getting few if any reports of the latter failing compared to a regular trickle of failed brushed motor controller boards.

I suspect this is due to the lack of potential hazards like arcing and build up of carbon causing shorts (I must strip my mll's motor and clean it out/fit new brushes as a precaution!) which don't affect the other motor types. Also the more sophisticated motors often have SOAR protection (safe operating area) and guess when things may be goiing wrong and decrease output (or just stop!)

Neil

[John RuddParticipant @johnrudd16576]

Posted by Neil Wyatt on 29/08/2018 16:41:52:

Posted by SillyOldDuffer on 29/08/2018 09:38:43:

Excuse me for not quoting the long post, but it might give some the impression that all electronics are unreliable

Also the more sophisticated motors often have SOAR protection (safe operating area) and guess when things may be goiing wrong and decrease output (or just stop!)

Neil

Never heard of SOAR being applied to an electromech device such as a motor that has 'intelligence' to know when things are going wrong….Please elaborate…

I have a brushless SC2 mill and SC3 lathe, if they are overdriven they stop and the fault light comes on.

[Tim StevensParticipant @timstevens64731]

There is a view that all 'marketing' is intended to be misleading.

Tim

[Ketan SwaliParticipant @ketanswali79440]

Posted by John Rudd on 29/08/2018 16:53:31:

I have a brushless SX2 mill and SC3 lathe, if they are overdriven they stop and the fault light comes on.

True, and this idea of stopping under overdriven event, initially took a while for SIEG to sort out, when programing the chip on its control board for the brushless motor.

Reading the other thread, where Keith Moat has a brushless motor version, with gears, he seems to be having issues with 'the motor seems to want to take teeth off the drive belt rather than stall as I found out when the tool dug in once'…. so it is difficult to say in his case how and/or at what point is the 'overdriven' issue addressed, in such a combination of brushless motor with metal gears drive.

I would only slightly correct Neil. The control boards for SIEG's brushless motor offering are more reliable, but there are still a few failing due to various reasons – mainly loose wire connection (due to transit) – user related – or dirty power supply related. Very few are direct component related.

Ketan at ARC.

Edited By Ketan Swali on 29/08/2018 17:42:03

[Neil WyattModerator @neilwyatt]

Posted by John Rudd on 29/08/2018 16:53:31:

Posted by Neil Wyatt on 29/08/2018 16:41:52:

Posted by SillyOldDuffer on 29/08/2018 09:38:43:

Excuse me for not quoting the long post, but it might give some the impression that all electronics are unreliable

Also the more sophisticated motors often have SOAR protection (safe operating area) and guess when things may be goiing wrong and decrease output (or just stop!)

Neil

Never heard of SOAR being applied to an electromech device such as a motor that has 'intelligence' to know when things are going wrong….Please elaborate…

I have a brushless SC2 mill and SC3 lathe, if they are overdriven they stop and the fault light comes on.

For example, my VFD models the temperature profile of a typical motor and calculates its temperature given the use it's given. It derates the motor if it calculates that it is likely to overheat. The modelling can be made more accurate by by adding motor-specific data.

I'm not saying all controllers are this sophisticated (although some are cleverer!) but even the stop if overloaded (in software rather than through a cutout) is something i would count as an example of this.

Neil

[John RuddParticipant @johnrudd16576]

"Also the more sophisticated motors often have SOAR protection (safe operating area) and guess when things may be goiing wrong and decrease output (or just stop!)"

Sorry Neil, but your post came across as tho' the 'intelligence' resided with the motor….not the controller you eluded to in your response to my question..

Edited By John Rudd on 29/08/2018 19:38:33

[SillyOldDufferModerator @sillyoldduffer]

Are electronics reliable? When I were a lad transistors were '3 legged fuses'. Capacitors went bang, resistors open circuit, joints dried, selenium stank, and colour TVs caught fire. As the whole world has gone to hell since a 12 year old girl from Human Resources made me retire, the same must be true of electronics. In my opinion mini-lathes are worse than mobile phones – I never use one without wearing an aluminium foil hat and a lead apron.

Meanwhile, back in the real world, Nurse tells me electronics are less likely to fail than the mechanicals. Certainly true of all the cars I've scrapped!

Dave

PS very happy with all the electronic controllers in my workshop.

Edited By SillyOldDuffer on 29/08/2018 20:01:33

[Neil WyattModerator @neilwyatt]

Posted by John Rudd on 29/08/2018 19:34:59:

"Also the more sophisticated motors often have SOAR protection (safe operating area) and guess when things may be goiing wrong and decrease output (or just stop!)"

Sorry Neil, but your post came across as tho' the 'intelligence' resided with the motor….not the controller you eluded to in your response to my question..

Edited By John Rudd on 29/08/2018 19:38:33

Ah we've crossed wires – a hazardous situation for any motor!

Neil

[Anonymous]

Posted by SillyOldDuffer on 29/08/2018 20:01:00:

Are electronics reliable?

I wouldn't trust it meself – but what do I know.

What the regular postings on motor drive board issues confirm is that any idiot can design a circuit that will drive a motor. But skill and experience is needed to select components, and add components if required, to allow the drive to ride through motor faults and external problems such as under and over-voltage and transients without failing.

It's one reason why industrial electronics is more expensive than that found on hobby grade machines.

Andrew

[Michael James 5Participant @michaeljames5]

Thank you.
I m not going any further into this other than to say I have been looking unsuccesfully for my email where I asked for a brushless motor.All I can do now is reccommend another firm if to anyone looking for a minilathe

[Ketan SwaliParticipant @ketanswali79440]

Don’t worry about it Michael J. This is a hobby, relax, use your lathe and make some swarf.

Ketan at ARC

[Author]

Posts