Arriving Soon.
- Thread starter DannyC
- Start date
DannyC
0
I didn't let the blue smoke out and the jury-rigged VFD & Motor worked fine. 
However, it's not a working machine because the final drive belt (the T-link one) just slips as soon as any load is placed on the system. As everything is driven off the spindle through gears any application of traverse of cross-feed stops the spindle, but the motor and all of the belts keep on trucking. So it is the T-link belt slipping. I will try and take it off and see if it is toast or just oil/grease contaminated.
However, it's not a working machine because the final drive belt (the T-link one) just slips as soon as any load is placed on the system.
As everything is driven off the spindle through gears any application of traverse of cross-feed stops the spindle, but the motor and all of the belts keep on trucking. So it is the T-link belt slipping. I will try and take it off and see if it is toast or just oil/grease contaminated.
DannyC
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Update:
The T-Link belt that drives the spindle is probably OK, but I have ordered a Chinesium one anyway (£48).
There is/was an issue where the bull-wheel and pulley were not properly connected and only "stiction" was imparting drive to the spindle.
I worked the mechanism backwards & forwards a few times and it fully engaged and all "feed functions then worked without stalling the driveline.
I checked the speed of the lathe chuck against the gearbox label RPM’s and they were pretty good (527 when it should have been 540 RPM).
I put a piece of 40mm round bar into the chuck and checked the run-out of the 3-jaw chuck (<5 thou’).
The very fine feed (0.0015”) per revolution produced a lovely smooth surface on a traverse (turning the bar down in diameter) and similarly on a facing cut with a cross-feed.
I then tried something a little more aggressive and that’s when the next problem appeared. The NEW belt from Motor to first drive pulley began to slip and the lathe stalled.
I am not sure I can tighten the belt any further as I seem to be at the end of the slots of the motor mount or there is no force I can apply that moves it any further.
I pulled the loose new belt off using a pry-bar and a rubber wedge and slipped the old belt on in its place (same issue).
I’m going to hoick it all out again and see if I can improve the belt fit by moving the motor further over (if there is in fact room in the mounting slots in the frame).
Then force the new belt on (wedge & pry-bar again). That isn't good for the belt, but needs must!
The T-Link belt that drives the spindle is probably OK, but I have ordered a Chinesium one anyway (£48).
There is/was an issue where the bull-wheel and pulley were not properly connected and only "stiction" was imparting drive to the spindle.
I worked the mechanism backwards & forwards a few times and it fully engaged and all "feed functions then worked without stalling the driveline.
I checked the speed of the lathe chuck against the gearbox label RPM’s and they were pretty good (527 when it should have been 540 RPM).
I put a piece of 40mm round bar into the chuck and checked the run-out of the 3-jaw chuck (<5 thou’).
The very fine feed (0.0015”) per revolution produced a lovely smooth surface on a traverse (turning the bar down in diameter) and similarly on a facing cut with a cross-feed.
I then tried something a little more aggressive and that’s when the next problem appeared. The NEW belt from Motor to first drive pulley began to slip and the lathe stalled.
I am not sure I can tighten the belt any further as I seem to be at the end of the slots of the motor mount or there is no force I can apply that moves it any further.
I pulled the loose new belt off using a pry-bar and a rubber wedge and slipped the old belt on in its place (same issue).
I’m going to hoick it all out again and see if I can improve the belt fit by moving the motor further over (if there is in fact room in the mounting slots in the frame).
Then force the new belt on (wedge & pry-bar again). That isn't good for the belt, but needs must!
It sounds like you need something firmed up, but I'd advise not go crazy trying to eliminate all slip.
That's one of the desireable things about a belt drive lathe - It WILL slip if you jam or crash it, without necessarily breaking something.
Gear head lathes are convenient, and great for hogging off material, but the scrap yards are full of sad stories of crashes with them.
That's one of the desireable things about a belt drive lathe - It WILL slip if you jam or crash it, without necessarily breaking something.
Gear head lathes are convenient, and great for hogging off material, but the scrap yards are full of sad stories of crashes with them.
DannyC
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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.
Control-box built as per someone else's picture (plagiarism is flattery really....Honest!).
Mine is less profeshernul than wot the one I copied is. Mainly because I is dull-witted and I 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 motor control electronics inside it quite often.
I might try and get this on the wall above and to the left of the headstock. We will see.
The missing RPM's have returned now a new smaller and non-slipping belt is on.Control-box built as per someone else's picture (plagiarism is flattery really....Honest!).
Mine is less profeshernul than wot the one I copied is. Mainly because I is dull-witted and I 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 motor control electronics inside it quite often.
I might try and get this on the wall above and to the left of the headstock. We will see.
DannyC
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The new belt (smaller of the 2 that I selected) was a pretty snug fit and I managed the job all on my own by putting one foot on the motor and shifting all my weight to that leg while I did one bolt up a bit.Hey we both had a good day by the sound of it ?
Well all but Rita who probably got roped in to provide some ballast whilst you tighten the bolts up
Paul
Swapped my weight to the other end of the motor and repeated the same thing. Then got off and did all 4 bolts up nice and tight.
It was a struggle putting it back in the cabinet (it is too wide to get through the door of the compartment so you have to hold it at 45° and do some fancy rotating nonsense while holding a 60 pound lump.
I am really feeling it now
But it really is a very different experience to the Chinesium machine.
One oddity that is common between this machine and many others is that the direction you set the leadscrew for traversing right to left for turning down material in the chuck has to be reversed when you want to do a facing operation. It can be alarming when the cross-slide starts coming outwards towards you instead of going across the face of the work.
Not long ago, I had to do something like this, inside the base of a small horizontal mill - I needed to change to a different motor, which meant pulling out the original motor (heavy), and its articulated mount (also heavy), which was intricately connected to the variable speed drive, drilling mount for the new motor, and then re-installing and adjusting it all (multiple belts, re-routed wiring, etc.) - All at arm's length, crouching / kneeling, and reaching through a 16" square opening.
I felt it for a week ......... At least.
I do feel your pain, but you're welcome to it - I've had enough, recently.
DannyC
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A big disappointment was the Tachometer for the lathe spindle.
I tried everything I could think of to improve it, but it just would not give reliable and stable results. So it has been returned to the seller.
A new "mains-powered" one has been ordered in its place. Hopefully, this one will work. If not...back it goes too!
I tried everything I could think of to improve it, but it just would not give reliable and stable results. So it has been returned to the seller.
A new "mains-powered" one has been ordered in its place. Hopefully, this one will work. If not...back it goes too!
DannyC
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I am doing a little "Happy Dance" because the lathe rev-counter is working 100%.
The item bought from Amazon came in a box with "Zero/Zilch/Denada" info as to "how".
I've been struggling all day with ferrite noise suppressors etc. etc. all to no avail. :-(
Then I did a google search online and up popped an e-bay link to a similar product to mine (AC powered) but it offered 2 variants. Unshielded sensor, or "Shielded Sensor". Now I just added a shield to my sensor yesterday and it made NO difference. But, when reading this e-bay seller ad it became clear that for usage where there is possibly RFI/EMI from a VFD you should buy their shielded version and attach the sensor shield NOT TO EARTH but to the -ve terminal of the sensor connection to the tacho.
Boom! and I am a very happy man.
because the lathe rev-counter is working 100%.The item bought from Amazon came in a box with "Zero/Zilch/Denada" info as to "how".
I've been struggling all day with ferrite noise suppressors etc. etc. all to no avail. :-(
Then I did a google search online and up popped an e-bay link to a similar product to mine (AC powered) but it offered 2 variants. Unshielded sensor, or "Shielded Sensor". Now I just added a shield to my sensor yesterday and it made NO difference. But, when reading this e-bay seller ad it became clear that for usage where there is possibly RFI/EMI from a VFD you should buy their shielded version and attach the sensor shield NOT TO EARTH but to the -ve terminal of the sensor connection to the tacho.
Boom! and I am a very happy man.
