25-01-2024, 11:03 AM
Hi,
It's ages since I posted so here's an update on my Lorch lathe; better late than never and it's a modification I carried out quite a few years ago.
I became fed up of the flat leather drive belts with their constant clicking and slippage so gave it a great deal of thought coming up with an alternative solution. I had converted my restored Graduate woodturning lathe to 3 phase variable speed with forward and reverse using an Huanyan 3hp VFD (2.2kw). I had been allowed to bring home two 1.5hp 3 phase inverter rated motors from work these being used for test purposes; they are top quality Brook Motors; all I had to do was to ask. I'm not an electrician so connecting the VFD and adjusting its pages of parameters I eventually succeeded.
My head was buzzing with ideas; would it be possible to run both these motors on different lathes from the one VFD? Best way to find out was to try although I DON'T RECOMMEND A NOVICE TO ELECTRICITY TO TRY THIS; mains electricity will kill so easily with just one simple mistake.
I dreamt up a switching arrangement where I could run only one lathe at a time; I had an high power 3 phase rotary switch which took care of the power but it was the signal connections that hugely frustrated me. I spent many hours experimenting; at times the motors had a mind of their own. Eventually I found out running power and signal cables alongside each other was very bad news due to "cross talk" between cables hence the signals were all over the place. I rearranged the cable runs separating them but with research I found I needed CAT 5 cabling for the signal cables which later I upgraded to CAT 6. Both motors being identical twins simplified the job a great deal; only one set of VFD parameters to deal with.
Onto the actual belt drive problem; the leather flat belts kept slipping driving me mad so could I convert to Poly V drive? Short answer is YES. I welded a new motor mounting platform topping it with 18mm thick plywood keeping the belt length as short as possible. The only modification I did to the lathe was to drill one hole in the suds tray keeping the lathe almost untouched. Obviously I had to remove the headstock mandrel to install the new Poly V belt and to align and adjust the motor for belt tension; this was the easy part; I'd bought a new Poly V drive pulley with locking insert so installing the new pulley to the motor shaft was no problem.
Then came the fun with the wiring connections. Having sorted out the switching between the Graduate & Lorch I ended up successfully running both lathes from the one VFD; this was all new to me but I do like to experiment with ideas I dream up.
The new Poly V drive works very well indeed even though the original flat belt headstock pulley is used; it's a neat modification with extremely little damage caused to the lathe; the remote signal switching was the most difficult to sort out but the lathe is a joy to run. This modification spanned many weeks of frustration but has been worth it and in the end I'm delighted my idea proved a success.
I still keep very busy and have just completed the restoration of an Howard Bulldog petrol rotavator it around 70 years old but now back doing a good job rotavating our mountain.
I'm currently making new tines for the rotavator; if only our dire weather was better I could do so much more.
Kind regards, Col.
It's ages since I posted so here's an update on my Lorch lathe; better late than never and it's a modification I carried out quite a few years ago.
I became fed up of the flat leather drive belts with their constant clicking and slippage so gave it a great deal of thought coming up with an alternative solution. I had converted my restored Graduate woodturning lathe to 3 phase variable speed with forward and reverse using an Huanyan 3hp VFD (2.2kw). I had been allowed to bring home two 1.5hp 3 phase inverter rated motors from work these being used for test purposes; they are top quality Brook Motors; all I had to do was to ask. I'm not an electrician so connecting the VFD and adjusting its pages of parameters I eventually succeeded.
My head was buzzing with ideas; would it be possible to run both these motors on different lathes from the one VFD? Best way to find out was to try although I DON'T RECOMMEND A NOVICE TO ELECTRICITY TO TRY THIS; mains electricity will kill so easily with just one simple mistake.
I dreamt up a switching arrangement where I could run only one lathe at a time; I had an high power 3 phase rotary switch which took care of the power but it was the signal connections that hugely frustrated me. I spent many hours experimenting; at times the motors had a mind of their own. Eventually I found out running power and signal cables alongside each other was very bad news due to "cross talk" between cables hence the signals were all over the place. I rearranged the cable runs separating them but with research I found I needed CAT 5 cabling for the signal cables which later I upgraded to CAT 6. Both motors being identical twins simplified the job a great deal; only one set of VFD parameters to deal with.
Onto the actual belt drive problem; the leather flat belts kept slipping driving me mad so could I convert to Poly V drive? Short answer is YES. I welded a new motor mounting platform topping it with 18mm thick plywood keeping the belt length as short as possible. The only modification I did to the lathe was to drill one hole in the suds tray keeping the lathe almost untouched. Obviously I had to remove the headstock mandrel to install the new Poly V belt and to align and adjust the motor for belt tension; this was the easy part; I'd bought a new Poly V drive pulley with locking insert so installing the new pulley to the motor shaft was no problem.
Then came the fun with the wiring connections. Having sorted out the switching between the Graduate & Lorch I ended up successfully running both lathes from the one VFD; this was all new to me but I do like to experiment with ideas I dream up.
The new Poly V drive works very well indeed even though the original flat belt headstock pulley is used; it's a neat modification with extremely little damage caused to the lathe; the remote signal switching was the most difficult to sort out but the lathe is a joy to run. This modification spanned many weeks of frustration but has been worth it and in the end I'm delighted my idea proved a success.
I still keep very busy and have just completed the restoration of an Howard Bulldog petrol rotavator it around 70 years old but now back doing a good job rotavating our mountain.
I'm currently making new tines for the rotavator; if only our dire weather was better I could do so much more.
Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
