First for me and brand new ( to me :) ) WW2 ships Lathe.

[Hood]

It just seems weird, I would have expected it to be the other way if I am honest, 1 turn of pulley is 2.25 of spindle at 1000rpm gear.

 

[Hood]

Ok so if it is definitely that way then I did things wrong by dividing the pulley, I should have multiplied.

 

[Pete.]

Wolly, I think you're set in back gear. Move the top right lever to the right and do your check again. If my guess is right your input pulley will turn 1.2 turns for each turn of the spindle.

 

[W.olly]

Ok lets see.

First thing is, are we definite that when in 1000rpm gear the pulley turns 2.25 times to 1 spindle rev?

i am glad your not to close to me otherwise you would around here and wobbling my head ha ha

i just found the high gear for 1000rpm. that give a turn of 1 .25 time to give one full rev of the spindle.

i checked and checked, its not easy the reading on this lathe speeds setting plaque.

 

[W.olly]

Wolly, I think you're set in back gear. Move the top right lever to the right and do your check again. If my guess is right your input pulley will turn 1.2 turns for each turn of the spindle.

if you mean reverse then nope as the chuck rotates anticlockwise.

i miss placed as gear as above.

 

[W.olly]

i just put it in the calc above or here again as is

Belts - Pulley Diameters vs. Speed

The pulley laws - driver and driven - diameter and rpm

www.engineeringtoolbox.com

pulley 1 100mm with 1455rpm
pulley 2 160mm and 882rpm...............so X by 1.25 to give 1136rpm.

 

[Pete.]

i just found the high gear for 1000rpm. that give a turn of 1 .25 time to give one full rev of the spindle.

That makes sense if you read the bottom of the lever position chart it seems to say that those are the speeds you'll get with the input pulley doing 1200RPM. 600 or 1200 suggests that maybe the machine originally had a 2 speed motor.

So here is what I would do. Slowest speed on the chart is 25RPM figure out what size pulley you need to achieve that at say 30hz on your motor and let the VFD speed control sort everything out.

 

[W.olly]

That makes sense if you read the bottom of the lever position chart it seems to say that those are the speeds you'll get with the input pulley doing 1200RPM. 600 or 1200 suggests that maybe the machine originally had a 2 speed motor.

So here is what I would do. Slowest speed on the chart is 25RPM figure out what size pulley you need to achieve that at say 30hz on your motor and let the VFD speed control sort everything out.

i need to understand that now, the hz thing lol.

 

[Hood]

Do you have a clear picture of the speed plate?, had a quick look back and could only see one but when I blow it up it is a bit blurry.
It does look, like @Pete. says, that it might be a 2 speed motor as the speeds for each lever position shows two speeds unless there is a back gear.
Seeing the plate clearly may help.

 

[W.olly]

how is that kida

 

[Hood]

Nah, speed plate, that is the feed plate

 

[Hood]

This one.

 

[W.olly]

 

[Pete.]

i need to understand that now, the hz thing lol.

Well your motor runs at 50hz but you can safely slow it down to 30hz or up way past 100hz (I've gone down into the low 20's withut any problems). That will make your 1455rpm motor turn at 875rpm at 30hz.

I make it 110mm.

 

[Hood]

Aye, so as @Pete. says it has 600 and 1200 at the bottom so that is a two speed motor.

 

[W.olly]

Do you have a clear picture of the speed plate?, had a quick look back and could only see one but when I blow it up it is a bit blurry.
It does look, like @Pete. says, that it might be a 2 speed motor as the speeds for each lever position shows two speeds unless there is a back gear.
Seeing the plate clearly may help.

Aye, so as @Pete. says it has 600 and 1200 at the bottom so that is a two speed motor.

unless you can read German you know what markings mean on these lathes ha ha

So shall i just get a 100mm motor pulley and use the VFD to set speeds while its in 1000rpm setting, or better to use the gears ?

 

[Pete.]

A 100mm pulley would be fine you would use the gears to select the appropriate range and just fine tune the speed on the VFD. Personally I would use the gear that makes the machine run the quietest.

 

[Hood]

At the bottom it says 600 oder 1200 and in each speed it says *** oder *** so that seems to tie in with either 600 or 1200
In fact I have just looked up and oder means or so that all ties in.

 

[W.olly]

my giddy aunt, that was hard work. head is banging now. got my shopping list for pulley bush and belts all ready

thanks guys, man hug coming your ways

 

[MattF]

man hug coming your ways

Thank god I didn't chime in.