EVS on Durden wood lathe.

[Drillit]

As a matter of general interest, I mentioned a little time ago, that I would post details of an EVS system
that I had retro fitted to my Durden lathe (Top Turn Series 400). The major reason behind my decision was that the lowest speed
was 350 and the highest 3500, via 4 step pulley belt change. I found that the low speed was too fast for large
pieces, particularly on the outboard. So I approached an electrical engineer friend, who could install an EVS system that he made
from scratch. The upgradeinvolved changing the motor to a3 phase, 240V,1.1 Kw, 4 pole, 1425 rpm motor and adding a 1.5 Kw ac inveter, giving the motor a variable speed capability.
The inverter converts a 1 phase, 240V, 50Hz input supply to a 3 phase, variable voltage, variable freaquency supply to control the new motor, which produces 7.5 Nm of torque.
The pulley step 1 - 24.5 rpm to 350 rpm with a torue multiplier of 4. Step 2 63 to 900 with a TM of 1.6. Step 3 126 to 1800 with a TM of .8 and Step 4 - 245 rpm to 3500 rpm with a TM of .4.
It has a Motor Thermal overload protection, inverter cooling fan and inverter braking resistor protection. The speed control box is fixed to the headstockbyway of magnets. I also had included
(as previously) a foot control that I have found to be excellent. The only slight drawback is that the speed controlbox does not give a read outof the spindle speed. To overcome this, I have taped
some silver paper at the spindle and I can get a speed read out from a digital tachometer, if needs be. I hope that this information is not too technical, because that is not my forte.
I have enclosed some pictures so that, my explanation is better understood. The all up cost with a new motor was $1100.00. I, of course, gave the old motor (which worked fine) to my friend. Drillit.273793273794 Havent bothered with lathe photos but electronics box is fixed on and housed at the tailstock end. Happy to answer any questions, I hope. :B

[BobL]

. The all up cost with a new motor was $1100.00.
That sounds very expensive.

My VFD upgrade cost ~$200
http://www.woodworkforums.com/attachments/f245/251072d1358926169-bobls-shed-fit-latheww.jpg

Second hand 3phase 1450 rpm 1HP motor $30; 1.5kW VSD $120; an e-switch, a longer belt, a 10k pot and a couple of switches <$40; and a $15 for a 70 mm diam piece of ally for a new pulley.
Used 3Phase motors are very cheap, I have bought a bout a dozen and the most I have paid is $70. I even picked up a 5HP motor in mint condition for $35.
Have since removed original motor and switch.

[Drillit]

That sounds very expensive.

My VFD upgrade cost ~$200


Second hand 3phase 1450 rpm 1HP motor $30; 1.5kW VSD $120; an e-switch, a longer belt, a 10k pot and a couple of switches <$40; and a $15 for a 70 mm diam piece of ally for a new pulley.
Used 3Phase motors are very cheap, I have bought a bout a dozen and the most I have paid is $70. I even picked up a 5HP motor in mint condition for $35.
Have since removed original motor and switch.

Hello BobL, You did well. The main thing for me was the low speed minimum with bulky wood. All fixed. You have the technical electrical skills, I dont. But I think the price was fair. Thanks for input, Drillit.

[BobL]

Hello BobL, You did well. The main thing for me was the low speed minimum with bulky wood. All fixed. You have the technical electrical skills, I dont. But I think the price was fair. Thanks for input, Drillit.

Whoops - I forgot about that. Having just had a sparky around to do a bit of work on the house that explains a fair bit.

[Paul39]

Drillit,

Very nice! The slow speed is wonderful. I think you will find the lack of a spindle speed readout won't bother you much.

The more you turn the more you will find that for a given chunk of timber: this pulley, speed about there, and off we go. When the lathe stops rocking back and forth, up the speed.

Here's to many happy hours in front of the Durdan.

[Drillit]

Paul,
Many thanks. It sure has made a difference. It is a wonderful lathe, that I fortunate enouigh to get at a bargain price because a Ladies College didnt really want it any more. Took up too much space, they said.
I dont really think that they cared about the price as it was replaced with a $20K CNC. I offered to tutor some students if they were interested - but the answer was students dont seem to be interested.
Anyways it came with set of P&N chisels basically unused, like the lathe, outboard and extractor system. The new package is about $5500 - I bought for $800. As my mentor said - find of the century. Drillit.






Drillit,

Very nice! The slow speed is wonderful. I think you will find the lack of a spindle speed readout won't bother you much.

The more you turn the more you will find that for a given chunk of timber: this pulley, speed about there, and off we go. When the lathe stops rocking back and forth, up the speed.

Here's to many happy hours in front of the Durdan.

[RETIRED]

I bought for $800Ned Kelly is alive and well.:D

[Drillit]

,
As a matter of interest when they told me the price (basically take it or leave it), I went over to H & F who I knew had one on the floor to make sure that I was buying the top model.
That was confirmed. I quickly rang back and the rest is history. The interesting part was disassembling on site, moving and re-assembling at home. It is so heavy. Anyways, just
another story. The good part is that when I sold my old kit I finished up in front and so that paid for the EVS upgrade. As for Ned K, he is now buried at Greta? and I am still
upright to-day. Ha Ha. :D Drillit.





Ned Kelly is alive and well.:D