Major? Spindle play

Interesting that it claims to be direct drive "no belt" with motor on spindle and shows a graphic of a outrunner type brushless DC motor. I guess it is geared. Not what I'd call direct drive.
I can't find a manual online.
Looks like your consumer rights are similar to UK/EU. I'd ask for my money back...

Robert.

Edited By Robert Atkinson 2 on 02/05/2023 12:33:58

Direct Drive Motor: The mini metal lathe machine adopts a direct drive motor, no belt drive, and no need to replace the belt. 800W brushless motor that provides more power and avoids the need for brush replacements, saving time and effort.

The EU Vevor site has a link to "manual" for this machine which has a cursory wiring diagram that shows only 2 wires to the motor. No parts list in the manual. Photos of the leadscrew gearing end of the headtstock show no belt or other mechanical input shaft., but there isn't a whole lot of room in a mini lathe headstock (particularly with a large bore spinlde that this machine appears to have) to build in a motor of any kind. The lowest speed of 150 rpm is less than the old geared head DC motor machines & I wonder how much power it has at this speed.

I would agree with the "send it back" route as being best option. Doesn't look like this is a straightforward headstock to start diving into. This must be a very recent development - not seen anyone else offering this configuraton yet. This arrangement would be a lot more difficult to rig up an alternative drive to when the built-in motor or drive fails, so if suitable spares are not available from the supplier (and Vevor are just "box shifters" ) then the machine is potentially totally dead.

Interesting that this has appeared just a few days after such spinlde drives were mooted on another thread !

Nigel B.

ps. That gib strip looks a bit grim.

I regard all the product descriptions given on Banggood, Aliexpress, Vevor and Amazon as purely a 'guide' rather than an exact and true definition of what is being sold. Amazon seem to get away largely by just showing as little as possible rather than a full description.

The Australian Vevor lathe linked to by the OP has a 'Main material' of HT200 Cast iron with a lifespan of 3 years! what on Earth is that meant to mean?

Regarding the drive/motor arrangement. They do stress the 'no belt' drive and I find it unlikely they would use a geared drive, it would be nice to think that the direct drive motor has a large hollow spindle but its probably my wishful thinking.

If it is a direct drive motor then one would hope that the spindle design and the bearings its mounted on are in keeping with it being a lathe headstock rather than just a general purpose brushless motor.

Ian P

I see a friend Mr Ali who sends things express delivery does a "Built-in 1.1kw Motor Headstock" which would seem to look like a motor wrapped around a spindle with suitable chuck mounting flange so quite possible what is inside this lathe

Edited By JasonB on 02/05/2023 13:56:42

The customs & trading standards people have destroyed / blocked quite a few Vevor items:

Office for Product Safety and Standards

(No, I didn't know we had one, either.)

Ah that is why I could not see any lathes on their site.

There is a video of the one on Ali running.

IS the play in the Spindle bearings, (Check with a Morse taper abor direct in the spindle ) or just when the chuck is fitted?

It might be that the chuck is not seated properly, there may be excess clearance between flange and chuck register of the chuck may be faulty.

Rewmove, clean and check, refit chuck and recheck run out / play

If the chuck registetration is slack either the spindle flange is undersize or the chuck register is oversize.

Either way, the faulty item should be rejected and returned for replacement or refund.

Either way, not a boster for confidence in the supplkier, or the products that they sell.

Would a refund and change of supplier be the way to go?

Howard

Edited By Howard Lewis on 02/05/2023 14:29:33

Claims a 1.26" hole through the spindle so must have gears.

Don't let your dog chew parts of your lathe anymore it invalidates your warranty.

No must about it, hollow shaft motors are available.

Ian P

No sign of gears on the AliX one

This is the usual far eastern headstock just an empty box with bearing pockets each side

This is the one with built in motor, note the large hollow housing between the plates and the left end has a large flange to allow motor to fit inside casting. Controls built into the back. Go search for it on google (images will find it)

Edited By JasonB on 02/05/2023 16:55:23

Pushing against the end of a 30 mm x 300 mm long workpiece is exerting a lot of levereage on the chuck.

It is probably at or near maximum capacity at 30 mm. Are you sing the appropriate jaws for the job?

A piece 300 mm long is only gripped in the jaws by a short length, so you could be distorting the workpiece as well as chuck comonents. Presumably your chuck is either a 80 mm or at most 100 mm?

Push too hard and you could do some damage to the chuck, at least, if yuou haven't already!.

Maybe you should repeat your tests with something a little smaller and shorter .

The reults might be a little more realistic for a minii lathe.

0.15 mm at 300 mm is almost 6 good old Imperial thous, so close up to the chuck with a smaller diameter arbor you may find a lot less .l

You must determine where the play is.

Within the chuck, the chuck / flange interface, or the spindle in the Headstock.

By exerting a lot of leverage, you may be straininbg the chuck minternals. There has to be clearance between each chuck jaw and the body; beteen each jaw and the scroll, and between the scroll and th chuck body.

Force each of those by excessive force and you will get a high reading.

You aspire to be an Engineer, not Mr Universe!

Until you find where the play is, you cannot solve the problem, even if the solutionn is to reject the lathe or the chuck.

Carry ouyt a few checks without using excess length or force, and give us the figures.

You may then get some comments which will help you decide what to do next

Howard

Looking at how professional machinests handle a say 300mm bar setup in any chuck, they tighten jaws, then check runout near chuck, in case of 4-Jaw if that set to near zero runout, they go to far end near tailstock and if it has now runout, they tap it in place, go back near chuck reset if necessary, go back to far end and retap it if necessary, a repeat process till satisfactory, important if stock is already near measurements to turn to.
I say this because this illustrates how you an manipulate a piece clamped in the chuck without adjustjing the jaws, which on top of that indicates to the function of the jaws clamping anything with enough lenght to matter and can be tapped right at far end, so the faws dont clamp perfect at lenght nessarly, even on most expensive heavy duty lathes..

The 2nd thing is if you start making/turning anything you wanted to make using the lathe as you got it, how does the results turned out to yor satisfaction measuring it, including your experience-? Are you happy with thos manufactured by you results-? One can theorise a lot about accuracy without making anything.

The 3rd thing is if you clamp the lathe down, you open another can of worms regarding the accuracy of flatness and strurdiness during temp changes of that base and how that will influence your lathe accuracy. You can bend the bed if not carefull to what you clamp it down to.

If the spindle has 2 lock nuts or a slitted nut, than it is probably fitted with contact angle bearing that can be adjusted. Unlock the nuts and adjust the play by locking the nut (just use your fingers, no tools). This will apply some preload on the bearings and will reduce/eliminate play.

When you measure play, place the indicator on the top of the head stock, not the bed. You don't want to measure bending of the bed or play because the head stock is not tightened to the bed or the chuck is lose.

Put a bar in the spindle, lock the spindle and measure the play close at the spindle. Measure the horizontal and vertical play. To measure play, you don't need a lot of force. 2 kg/4 lbs is more than enough.

You can also check the documentation about the type of bearings used in this lathe.

A picture of a slitted nut, my favourite for locking/preloading contact angle bearing shaft.

Edited By Huub on 02/05/2023 23:18:22

Adjustment of the nuts at the far end of the spindle to remove excess play is a standard adjustment that should not affect the warranty. It's possible one of the bearing races has seated a bit further into its recess, because it wasn't originally all the way home, or that the adjusters have come loose.

The correct setting depends whether you have ball or roller races on the lathe. probably the former.

See this search of the forum for threads on adjusting Mini Lathe Spindles.

www.google.com/search?q=minilathe+spindle+adjustment&sitesearch=model-engineer.co.uk

Neil

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Appears to also be offered in the E.U.

**LINK**

https://eur.vevor.com/metal-lathe-c_10121/vevor-mini-metal-lathe-machine-7-x-16-800w-precision-benchtop-power-metal-lathe-150-2500-rpm-continuously-variable-speed-with-3-9-3-jaw-metal-chuck-tool-box-for-processing-precision-parts-p_010746125015

MichaelG.

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Edit: __ Check the shiny picture of the motor

… I can’t see that having a hollow shaft 

Edited By Michael Gilligan on 03/05/2023 05:09:08

Just found Walmart listing for a BENTISM lathe, which appears to be the same: **LINK**

https://www.walmart.com/ip/BENTISM-Metal-Lathe-Power-Metal-Lathe-7-x16-150-2500-RPM-Continuously-Variable/1957903923?wmlspartner=wlpa&selectedSellerId=101078564

Item is listed but ‘out of stock’

Specification shows Lifespan: 3 Years

… My preconceived notions about machine tools are being trampled under the marching feet of progress !

MichaelG.

Thanks for all the answers. Much to think about and a few things to say, but not 'till tomorrow im afraid.

Just too busy with work and children right now.

(Howard... It's a 300mm job but I'm only putting pressure on the chuck itself. And very little force).

Cheers.

I’ve resisted so far but here is my comment, now.

It is vevor, so what do you expect?

Like ban good, vevor sell a lot of low specification products - likely some (or a lot) that are rejected by suppliers of better quality kit. Pot luck if the item is up to all specifications expected. Many don’t check them (and they are very likely the ones who say they are perfectly happy with their purchases from this seller.

My view? If you are not able to fix it, don’t buy it if you can’t afford to throw it away.

The likely typical response will be to offer a minimal partial refund. Good luck with anything else.

I have (fairly) recently bought two items with their name on the sticker. Neither worked to the specification and one arrived without a necessary part (which was clearly shown in the sales bumph). I was already aware, of course, that this might be the case and knew that I could probably get around the shortcomings relatively easily, or those shortcomings would not bother me for my particular application.

Buying cheap is not always the best way.

I mentioned the limited lifetime earlier in the thread but I think it only refers to the cast iron bed. Maybe like 'Mission Impossible' it then decomposes leaving the owner with and assortment of components lying on the bench

On a more serious note. The headstock casting looks to be a strong rigid structure (even better than the plain spindle version) which is good news, what does not inspire confidence though, is the small diameter of the motor itself. The radial depth available in small overall diameter and a hollow spindle does not leave a lot of room for the stator windings, rotor and magnets so I suspect the motor will be limited as regards torque.

The brushless motor, spindle and the bearings appear to be what would be described as as 'cassette' that installs in the bore of the headstock casting. Given the limited length and diameter available I think the bearings themselves are not going to be taper roller or deep groove types but more likely quite narrow section ballraces, how well they will perform as lathe headstock bearings we will have to wait and see.

Ian P

Good grief! That's a picture of a gib strip? Clearly, the thing's been thrown together by ignorant minions, employed by crooks and charlatans, and sold by deceitful people (I was going to say something much worse...). Fight to get your money back, and don't waste time on a heap of junk that may have many more problems waiting to reveal themselves!