minilathe speed reduction

[JasonBModerator @jasonb]

I do wonder how much of an increase in pully size you can fit without the belt rubbing on the plastic spacer, looks like it could be a bit tight to get a significant reduction in speed.

 

Edited By JasonB on 26/08/2018 20:13:38

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 26/08/2018 20:07:08:

I do wonder how much of an increase in pully size you can fit without the belt rubbing on the plastic space, looks like it could be a bit tight to get a significant reduction in speed.

.

That's why we need to reduce the size of the Motor pulley

… Which is, in turn, why we need Poly Vee.

MichaelG.

[JasonBModerator @jasonb]

Or you could just buy an aftermarket pulley pair and belt and instantly get a 40% speed reduction, several on the net such as this one or this one

Edited By JasonB on 26/08/2018 20:32:24

[blowlampParticipant @blowlamp]

If this is a brushless-motor equiped lathe, then I'd expect it to be set up to drive the headstock spindle directly without going through the more usual Hi/Low gears.

As shown here, picture from Arceurotrade Mini-Lathe stripdown:

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 26/08/2018 20:30:12:

Or you could just buy an aftermarket pulley pair and belt and instantly get a 40% speed reduction, several on the net such as this one or this one

.

Looks like 'case closed' [*]

Pity you didn't mention that before [when you were worrying about what might break, and the 'fact' that the size of the timing pulley on the motor couldn't be reduced much]

MichaelG.

.

[*] if an XL timing belt proves capable of transmitting the power !!

 

Edited By Michael Gilligan on 26/08/2018 20:47:08

[Michael James 5Participant @michaeljames5]

I d seen those Jason but never saw anything about 40% reduction.Unfortunately they have 15 mm bore mine are 10 and 8 – blanks are best I can do my own

[Michael James 5Participant @michaeljames5]

Please ignore that they are right!
Thank you everyone you havent left a stone unturned👍🍺

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 26/08/2018 20:42:08:

[*] if an XL timing belt proves capable of transmitting the power !!

.

A design calculation formula is available here: **LINK**

http://www.roymech.co.uk/Useful_Tables/Drive/Timing_belts.html

But I'm happy to go with my instinct, and would prefer to use Poly Vee

MichaelG.

[oldveloParticipant @oldvelo]

Hi

This one way to get more torque it is big bad and ugly. Functional not ornamental and works for me.

Spindle is on taper roller bearings

Eric

[Michael James 5Participant @michaeljames5]

If I find a v belt
I ll buy it!

[JasonBModerator @jasonb]

Michael G, My feelings are still the same about the off the shelf kit, there is more chance of the smaller pinion shredding the belt teeth, that combined with your comment on belt strength would mean that the belt becomes the weakest link in the chain. Not a bad thing as I would rather but a five quid belt than a new board if things went wrong.

Not knowing how capable the OP is the kit was suggested as a simple parts swap rather than having to make or modify multi vee pullies more then being the best drive solution.

Blowlamp. Depends what factory is making the "miniathe" For example Warco's super mini lathe has a brushless motor but still needs a high/low ratio to get the best out of the motor. Other suppliers have different boards and can access the chip on the board which is where the torque charicteristics of the motor can be adjusted to allow a single direct drive. I've had a few long chats with one of our suppliers about this last one being Friday.

[Michael James 5Participant @michaeljames5]

I think my capabilities probably dont stretch to making v belt pulleys.Thats a bit to exacting for the speeds involved.
Although I m quite impressed with the little Amadeal I m stilll rather relieved I have a little Flexispeed and an old Drummond to fall back on!Still dont trust all these millie amp things entirelt

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael James 5 on 27/08/2018 07:18:36:
I think my capabilities probably dont stretch to making v belt pulleys.Thats a bit to exacting for the speeds involved.

.

I think you would find it easier than you anticipate:

For convenient reference; here are the standard dimensions & tolerances of the grooves **LINK**

Poly-V Belt Pulleys

When I made mine from good [but unidentified] Aluminium alloy … I just ground a single point form-tool on the end of a parting blade and took plunge cuts. … Others [notably the late, great, John Stevenson] have used an 11tpi tap thread-chaser as a multi-point tool.

https://www.model-engineer.co.uk/forums/postings.asp?th=73720&p=2

MichaelG.

.

Final thought : You may get away with grooving only the motor pulley [making the large pulley just a flat blank] … it really depends on the amount of wrap on the large pulley … Washing Machine manufacturers seem to have adopted this as standard practice.

Edited By Michael Gilligan on 27/08/2018 08:21:30

[Russell EberhardtParticipant @russelleberhardt48058]

I don't have a mini lathe but I have an old Burgess bandsaw on which is timing belt driven. I replaced the motor pulley with a ten tooth one to reduce the speed to enable me to cut steel with it many years ago and not had any problems.

Russell

[Michael James 5Participant @michaeljames5]

I never expected this much help and information!
I ve been a beginner for 30 years !but th8ngs are goi g to change as I give up full time work at Christmas.
I ve ordered Jasons timing belt kit see how it gets on and as soon as time permits I ll try to machine a v pulley.Thank you .

[Brian GParticipant @briang]

This may seem like a silly question but does your lathe have a backgear? The photo Blowlamp posted was a Sieg with brushless motor, but I thought Amadeal sold Real Bull lathes. Warco's specification for the mini lathe with brushless motor includes steel gears fitted to headstock and if yours is the same there will be no room for a larger pulley.

Brian

[JasonBModerator @jasonb]

Michael J is there any chance you could post a photo of the lathe with cover removed so we can see the motor and if it drives the countershaft or direct to the spindle. It seems strange that you say you have a brushless one yet there is no mention of this selling point on Amadeal's site. It may affect the diameters of the motor spindle as I believe the ones in most of the tune up sets are meant for brushed motors.

 

J

 

Edited By JasonB on 27/08/2018 17:18:13

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 27/08/2018 16:12:30:

Michael G is there any chance you could post a photo of the lathe with cover removed so we can see the motor and if it drives the countershaft or direct to the spindle. It seems strange that you say you have a brushless one …

.

Jason,

May I suggest that you re-direct that question to Michael James 5

I assume [since Michael made no objection, and the tooth counts on the timing-pulleys match] that the drive is as illustrated in the extract that I posted, from the manual … but I may be wrong.

MichaelG.

.

The gear clusters are marked 14 and 24

Edited By Michael Gilligan on 27/08/2018 17:10:55

[JasonBModerator @jasonb]

Sorry Mr G, I'll edit my post.

Yes it does sound like it has the layshaft but odd that Amadeal don't mention it is brushless which would be a big selling point.

[Michael GilliganParticipant @michaelgilligan61133]

… and maybe even odder that they list motor brushes as spares for it

[but that may just be a 'catching-up' job for the web-page]

MichaelG.

.

https://www.amadeal.co.uk/acatalog/CJ18A_Motor.html

Edited By Michael Gilligan on 27/08/2018 17:23:18

[Michael James 5Participant @michaeljames5]

I think they sell both but mine is definitely brushless

[JasonBModerator @jasonb]

Thats odd as Hugh says on his e-bay adverts that there is a review of the Mini-lathe on the web and that says it is a 550W BRUSHED motor

Does it look like this?

Edited By JasonB on 27/08/2018 20:19:20

[Neil WyattModerator @neilwyatt]

Posted by JasonB on 27/08/2018 20:07:15:

Thats odd as Hugh says on his e-bay adverts that there is a review of the Mini-lathe on the web and that says it is a 550W BRUSHED motor

Does it look like this?

Edited By JasonB on 27/08/2018 20:19:20

And if it does, adjust the motor back straight and the belt will last longer

[Brian GParticipant @briang]

Real Bull do now make a brushless mini lathe as Warco offer it (and claim a 50 rpm minimum speed). Perhaps Amadeal do as well but the site isn't yet updated.

Brian

[blowlampParticipant @blowlamp]

Posted by Brian G on 27/08/2018 21:04:30:

Real Bull do now make a brushless mini lathe as Warco offer it (and claim a 50 rpm minimum speed). Perhaps Amadeal do as well but the site isn't yet updated.

Brian

 

 

So if the OP's lathe has a brushless DC motor and a backgear, I wonder 'why does it need more torque?'

 

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

 

 

Edited By blowlamp on 27/08/2018 21:23:09

Edited By blowlamp on 27/08/2018 21:25:53

Edited By blowlamp on 27/08/2018 21:29:59

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