Just bought a Fortis lathe

[GraemeVW]

Most VFDs will offer braking options, including coast to stop, moderate braking and very aggressive braking, possibly with a braking resistor. Be careful if the chuck screws on!

That sounds like a good reason to go that route anyway then. I tend to do alot of my turning by light cuts and repeated measuring. Having to wait for the spindle to run down all the time may get tiresome.

Edit, is the amount of brake a setting? I assume i couldnt decide each time i stop it how quickly i wanted it to stop.

The clutch and brake set up on the drummond was good for those 'oh s**t' moments when you want everything to stop asap! But wouldn't want the lathe to stop that way every time I switch off.

Hmmm, maybe I really should look at some kind of physical clutch and brake set up.

 

[GraemeVW]

Seems this wouldn't have had a very powerful motor to start with.

If I really want the clutch and brake, maybe I could use an industrial sewing machine motor like my drummond does.

If I get a 3 phase one, I could still use a vfd. Then I have variable speed, settable spin down, clutch and brake.

Need to check the hp ratings of these kind of motors though, may not be enough for this.

 

[MattF]

I have a little drummond lathe.

Which model?

 

[GraemeVW]

Which model?

1902 flat bed running off a 1940s? Singer sewing machine motor through some kind of 3 speed gearbox.

 

[GraemeVW]

Got the motor out.
Although obviously not the original, it's 1/2hp. Sound about right?

It's a thermoguard and has this odd (exposed!!) Switch set up. A thermal cut out switch?

It's 1425rpm so don't know why it would be too fast?

 

[MattF]

1902 flat bed running off a 1940s? Singer sewing machine motor through some kind of 3 speed gearbox.
View attachment 398426

Nice. The first incarnation of that model.

 

[GraemeVW]

Nice. The first incarnation of that model.

Yep, it's super early!

 

[Jelly_Sheffield]

Yep, have dogs, could turn my own tapers. Hadn't thought about that. Not done that before but see no reason why I couldn't.

I may be teaching granny to suck eggs, but...

The trick is to put a sample piece which has the correct taper between the centers and set the angle of the top slide using a DTI or Dial Gauge so as you traverse it consistently reads zero.

The beauty of turning between centers being that you can take things out and put them in with no loss of concentricity.

Most VFDs will offer braking options, including coast to stop, moderate braking and very aggressive braking, possibly with a braking resistor. Be careful if the chuck screws on!

Definitely worth downloading the manual for any VFD you're planning to buy to see what options are available and how easy it is to program for that speaking for myself there's a certain amount of price premium that's worth it for good documentation that allows for a straightforward setup process.

In an ideal world you'd want one with distinct "functional stop" and "E-Stop" inputs, and complementary programming options, that way you can have a red momentary pushbutton which gracefully slows down over a couple of seconds, and a separate red mushroom button which applies full DC braking then cuts the power until reset.

 

[GraemeVW]

I have another project to finish before I get too involved in this lathe, but I just can't help myself!

This is why its coming apart before being used. It's grim!
Took the carriage off and the apron is full of sticky grease and there is swarf hiding in there too.

I think I'll probably break it down into chunks, then sort out the cabinet, then the bed, then do each chunk in turn. If I just blow the whole thing to components in one go I'll forget where it all goes!

It does seem pretty simple though, even if I don't quite understand what's going on in the apron yet.

 

[GraemeVW]

I may be teaching granny to suck eggs, but...

The trick is to put a sample piece which has the correct taper between the centers and set the angle of the top slide using a DTI or Dial Gauge so as you traverse it consistently reads zero.

The beauty of turning between centers being that you can take things out and put them in with no loss of concentricity.


Definitely worth downloading the manual for any VFD you're planning to buy to see what options are available and how easy it is to program for that speaking for myself there's a certain amount of price premium that's worth it for good documentation that allows for a straightforward setup process.

Not teaching me to suck eggs at all. I'm a machining novice really. Been doing plain turning, fed by hand, for a few years as that's all I've ever needed to do. Anything else is new territory.
Without what you just explained I'd probably have set the tailstock over and done the taper that way. Bit ive never tried tapers before, tjats just the first thing that would have come to mind.

 

[Jelly_Sheffield]

When you take the apron apart it's worth looking out for a sheer-pin or other deliberately engineered weak spot (not being familiar with the lathe, it could equally be in the gearbox assembly or not have one at all).

If it does have one, you can then measure it and stock up on, (or make) a couple of spares to keep in a ziplock bag in the cabinet just in case.

 

[GraemeVW]

When you take the apron apart it's worth looking out for a sheer-pin or other deliberately engineered weak spot (not being familiar with the lathe, it could equally be in the gearbox assembly or not have one at all).

If it does have one, you can then measure it and stock up on, (or make) a couple of spares to keep in a ziplock bag in the cabinet just in case.

Thanks, ill keep my eyes open.

 

[Jelly_Sheffield]

Not teaching me to suck eggs at all. I'm a machining novice really. Been doing plain turning, fed by hand, for a few years as that's all I've ever needed to do. Anything else is new territory.
Without what you just explained I'd probably have set the tailstock over and done the taper that way. Bit ive never tried tapers before, tjats just the first thing that would have come to mind.

I don't have the facility to set my tailstock over on my lathe (it originally sold with a full length taper attachment, which sadly disappeared before it reached my hands) so it never occurs to me to do it anymore and I have to use the top slide.

Depending on your lathe and the length of taper to be turned, setting the tailstock over can be easier and/or more accurate, but you can still use the DTI and known good taper trick (putting the indicator baseon the carriage rather than top-slide) to set the angle in a (relatively) stress free way...

If you turn a known good cylinder between centers first before setting the tailstock over you can also use that to execute the same trick in reverse too, which saves a lot of frustration and rude words.

 

[GraemeVW]

Minging

Are those spiral wound covers you see on some lathes retro fittable to other lathes?

 

[Jelly_Sheffield]

Minging

View attachment 398437

Are those spiral wound covers you see on some lathes retro fittable to other lathes?

Yes, cheaply available via Ali-Express in a wide range of sizes.

My hands have asked I recommend you wear gloves when putting them on (bad memories), it's effectively a big spring made out of very thin sheet steel and the cheapest possible supplier doesn't spring for deburring as standard.

There's also accordion type covers and a type which works like those retractable barriers they use in public buildings sold by UK suppliers for PUWER98 retrofit purposes... But they're £££ for what they are compared to the spiral ones.

 

[GraemeVW]

Yummy

Still, looks like no broken teeth. And at least the grease means no rust.
Hopefully it didn't make grinding paste either.

Considering these gears are open to the outside world, how should they be lubricated? Left dry?
I have some dry Molly spray I could use too.
There are nipples to grease the shafts though.

 

[GraemeVW]

Yes, cheaply available via Ali-Express in a wide range of sizes.

My hands have asked I recommend you wear gloves when putting them on (bad memories), it's effectively a big spring made out of very thin sheet steel and the cheapest possible supplier doesn't spring for deburring as standard.

There's also accordion type covers and a type which works like those retractable barriers they use in public buildings sold by UK suppliers for PUWER98 retrofit purposes... But they're £££ for what they are compared to the spiral ones.

Fantastic. A worthwhile upgrade I think.
I'll wear gloves!

 

[GraemeVW]

When you take the apron apart it's worth looking out for a sheer-pin or other deliberately engineered weak spot (not being familiar with the lathe, it could equally be in the gearbox assembly or not have one at all).

If it does have one, you can then measure it and stock up on, (or make) a couple of spares to keep in a ziplock bag in the cabinet just in case.

The tumbler (not sure how this comes off yet) has an aluminium gear. The weak point?

 

[Jelly_Sheffield]

The tumbler (not sure how this comes off yet) has an aluminium gear. The weak point?View attachment 398440

Probably a home-made replacement for a chipped one.

Even in aluminium gears are complicated and expensive enough to make that it would be a silly choice of sacrificial part.

Given the age of the design it's very possible there is no sacrificial part in there... But if you do spot one in there it's worth keeping a spare.

 

[6ply]

Fantastic. A worthwhile upgrade I think.
I'll wear gloves!

Or for the really cheap, some claim to have used these.

1pc 90cm plastic Appearing Cane steel elastic rod magic tricks wand telescopic magic props Halloween toy stage - AliExpress 26

Smarter Shopping, Better Living! Aliexpress.com

a.aliexpress.com

Being cheap myself I did give it a try and couldn't get it to work. Mind you, makes a decent weapon.