Got me a lathe!

[6ply]

A / B / C / Z (DUNLOP) Power Twist V Belt Link Belting Nut Link T Link | eBay

Dunlop Premium V-link belting has low vibration and noise output, the link structure can dampen vibration caused by unbalanced pulleys or bearings. Power transmission and conveyor use. High horse power transmission.

www.ebay.co.uk

 

[DanClarke]

Get yourself some power twist link belt from eBay. It's not too expensive and it works. If it stretches over time, you can remove links.

Hi,
I sprang for the T-Link from China @ £48 for 1.5M.
But it is good to know the twist-link stuff also works, thanks!

 

[Keith 66]

Hilarious coincidence, Dan just popped round for a chin wag & cup of tea, Great hour wasted properly, then i mention Father in laws lathe that came from May & Baker, "I used to do work there" says Dan.... Turns out he knew my father in law, worse than that our respective inlaws lived next door to each other until my mother ln law went into a home. Thought he looked a bit familiar, Talk about a small world!

 

[DanClarke]

Hilarious coincidence, Dan just popped round for a chin wag & cup of tea, Great hour wasted properly, then i mention Father in laws lathe that came from May & Baker, "I used to do work there" says Dan.... Turns out he knew my father in law, worse than that our respective inlaws lived next door to each other until my mother ln law went into a home. Thought he looked a bit familiar, Talk about a small world!

Yes indeed. I felt that somehow I knew Keith's missus from somewhere but I did not make the connection till we discussed his late FIL's lathe and where he worked. Red face for me. My wife was in fits of giggles when I recounted the tale!

 

[DanClarke]

Lathe is all back together and is "sweet as"..... The missing RPM's have returned now a new smaller and non-slipping belt is on.
I was really impressed with Wych Bearings (no affiliation) I ordered 2 "most likely candidate" drive belts at 15:30 yesterday and they were on my doorstep by 10:30 this morning!

Control-box built as per @My Old Landy and a picture of one he shared elsewhere (plagiarism is flattery really....Honest!).
Mine is less profeshernul than wot Brian's is. Mainly because I is dull-witted and I been done has fingers like cow's teats.
Also, my drill wandered when cutting the holes out.
I need to determine where to site it, I don't fancy reaching "over" the spinning bits in an emergency.
All mini-lathes have the Emergency stop right on top of the headstock and they put their electronics inside it quite often.

 

[DanClarke]

Now working, only the tacho to mount (somewhere???) and wire in.
Amazed at how relatively quiet it is compared to the Chinese mini-lathe.

 

[striker]

I have a very similar set up on my lathe and mill, same vfd's. You can set the vfd to display RPM instead of frequency. Saves wiring up a tacho.

 

[MickeyW]

That's a lovely machine you have there Dan. I have one the same, but not as clean, and without quite as much tooling or the steadies.

 

[DanClarke]

I have a very similar set up on my lathe and mill, same vfd's. You can set the vfd to display RPM instead of frequency. Saves wiring up a tacho.

I thought that setting was only the RPM of the motor the VFD was driving. I want the RPM of the spindle and the workpiece I am cutting.

 

[DanClarke]

OK, I just went out there and by sheer good fortune I can mount the transducer flush on top of the headstock and up against the indexing assembly block with some JB Weld and the tip can protrude up close and personal to the back of the indexed backplate upon which I can mount a decent sized neodymium magnet. I will probably hot-glue the wiring to the headstock casing to make sure it keeps out of harm's way.
Sorted.

 

[striker]

I thought that setting was only the RPM of the motor the VFD was driving. I want the RPM of the spindle and the workpiece I am cutting.

Yeah I no longer use the lathe or mill gearing.. I just change speeds using the vfd. You can adjust the readout for the drive ratio, but this will change if you change gear.

 

[DanClarke]

Hi folks,
The trials and tribulations continue. :-)
Two RPM gizmo's have not worked (1st one went back), second one had the same failure but on looking at the reviews on Amazon I got the answer from a guy's review as he has had exactly the same issue as me.
Apparently the VFD emits some serious 3-phase EMI and the unshielded transducer cable picks it all up and makes the RPM doodad (technical term) display complete garbage.
I slapped a chunk of 2mm plate between the VFD and the transducer cable and the error rate dropped dramatically.
A shielding basket-weave sleeve is on its way to me for the transducer cable.

Last remaining "issue(?)" is the temperature of the primary drive shaft bearings (where the shaft goes through the two flanges of cast-iron where the oiler buttons are.
They feel a bit "warm" to me, but I have no idea if they are expected to be warm. When does warm become "too hot", at what temp? I will measure with an infrared probe.
I don't expect them to be stone cold because there is bound to be some friction.
Perhaps I have the cone-pulley belt too tight? Nothing in the manual about specific level of tension adjustment or even about belt replacement at all.
Of course I can slacken the belt a bit and see if the belt doesn't slip and the bearing stays cool I suppose.
Anyways, the lathe does work in all respects/features so I am very happy with my purchase, just chasing down these last few niggles.

Dan.

Edit:
I slackened the drive belt a bit. It doesn't slip under firm hand pressure load on the spindle backplate. After 10 mins the temp at the oiler on the bearing flange was c. 31°C.

 

[not done it yet]

I looked at your vid of VFD operation.

The VFD should be safely mounted in a suitable enclosure. It is all documented in the installation manual. It should also be protected from air-borne particles - particularly electrically conductive ones. Turning cast iron can make a lot of dust!

You are seen fiddling close to mains voltage conductors that only have a single layer of insulation! There should always be two layers of insulation if it can be touched.

RF emissions can (and should be) reduced by use of screened cabling on the output side. I expect that is also mentioned in the manual.

 

[dave h 2]

Dan,
NDIT beat me to it.
The VFD is is a component and not a finished product so they can miss out the filters etc that would be required if it was. Makes them attractively cheap, but some are so bad they have been prevented from entering the country in bulk. Earthed steel box required + shielded cables. These have also been known the mess up the DRO readings.
As it is if you have that in an unheated space you may get condensation on it when cold weather becomes warm which could make life momentarily interesting if you switch it on.

 

[DanClarke]

I looked at your vid of VFD operation.

The VFD should be safely mounted in a suitable enclosure. It is all documented in the installation manual. It should also be protected from air-borne particles - particularly electrically conductive ones. Turning cast iron can make a lot of dust!

You are seen fiddling close to mains voltage conductors that only have a single layer of insulation! There should always be two layers of insulation if it can be touched.

RF emissions can (and should be) reduced by use of screened cabling on the output side. I expect that is also mentioned in the manual.

Thanks @not done it yet .... Sadly, the supplier neglected to provide either of these pearls of wisdom in their double-sided single folded sheet "manual".
I shall do my level best NOT to get into any intimate contact with Mr. Volt or Mr. Amp.
It is what it is.....cheap and probably quite nasty.

 

[Seadog]

Hi folks,
The trials and tribulations continue. :-)
Two RPM gizmo's have not worked (1st one went back), second one had the same failure but on looking at the reviews on Amazon I got the answer from a guy's review as he has had exactly the same issue as me.
Apparently the VFD emits some serious 3-phase EMI and the unshielded transducer cable picks it all up and makes the RPM doodad (technical term) display complete garbage.
I slapped a chunk of 2mm plate between the VFD and the transducer cable and the error rate dropped dramatically.
A shielding basket-weave sleeve is on its way to me for the transducer cable.

Last remaining "issue(?)" is the temperature of the primary drive shaft bearings (where the shaft goes through the two flanges of cast-iron where the oiler buttons are.
They feel a bit "warm" to me, but I have no idea if they are expected to be warm. When does warm become "too hot", at what temp? I will measure with an infrared probe.
I don't expect them to be stone cold because there is bound to be some friction.
Perhaps I have the cone-pulley belt too tight? Nothing in the manual about specific level of tension adjustment or even about belt replacement at all.
Of course I can slacken the belt a bit and see if the belt doesn't slip and the bearing stays cool I suppose.
Anyways, the lathe does work in all respects/features so I am very happy with my purchase, just chasing down these last few niggles.

Dan.

Edit:
I slackened the drive belt a bit. It doesn't slip under firm hand pressure load on the spindle backplate. After 10 mins the temp at the oiler on the bearing flange was c. 31°C.

I had problems where one stopped working after about 5 years. Reversing the polarity of the magnet sorted it.

 

[DanClarke]

Thanks @dave h 2 yes it is lacking in levels of isolation.
The single phase mains input lacks double insulation of the final conductor tails.
Similarly the 3-phase output tails only get double(and then triple insulated) when they enter the routing conduit that then goes through the back of the lathes cabinet and to the motor.
Yes, it is largely unheated in there but so far there have been no condensation issues. I shall beware.
Some screening braid for the sensor is on its way and should be here today.

 

[DanClarke]

I had problems where one stopped working after about 5 years. Reversing the polarity of the magnet sorted it.

Yes, the item is polarity sensitive for sure. Like Santa it prefers the North Pole.

 

[Seadog]

Yes, but it worked fine for 5 years, then one morning it thought, I'm changing sex

 

[slim_boy_fat]

then one morning it thought, I'm changing sex

Jumping on the "I now identify as..." bandwagon?