Thread: Hembrug lathe on the way.

Hi Pete, how did you get around the voltage change on the Aciera motor, or are you running a 415 motor on 240? If so do you use the 29Hz trick?

Okay synopsis is, single phase, single speed motor + vfd, no problems. Most of the motors I have lying around are out of woodworking equipment and are 2880, but ill look about for a 1440 motor. Thanks everyone for going over this topic again ill now move onto the other problems the machine no doubt will present.

Ralph

Originally Posted by caskwarrior

Okay synopsis is, single phase, single speed motor + vfd, no problems. Most of the motors I have lying around are out of woodworking equipment and are 2880, but ill look about for a 1440 motor. Thanks everyone for going over this topic again ill now move onto the other problems the machine no doubt will present.

Ralph

Single speed *3 PHASE* motor plus VFD. Not single phase motor.

PDW

Sorry that was a slip, I only have 3 phase motors anyway.

Originally Posted by RayG

Hi Pete, how did you get around the voltage change on the Aciera motor, or are you running a 415 motor on 240? If so do you use the 29Hz trick?

Good question Ray, this was a while ago now and I can't recall the specifics, but I must have found the star point. I always run the motors on their appropriate voltage in delta.

I do remember taking a motor to a rewinder and getting them to dig out the star point for me, and I have a sneaking suspicion it was this one. Normally I'm able to dig them out without too many problems, and have on every other motor, albeit sometimes not easily, but I do remember taking this one apart, digging around and thinking it was all getting ugly. The two speed motors are a lot "busier" in there than standard motors and while I'll have a go at most things, there's also a time to admit it's time to call in experts on some jobs. The more I think about it the more I think it must have been this motor as I remember them having a whinge about it when I picked it up.

It's not exactly free to have the above work done. But this is Sydney, and you can't get anyone to answer the phone for less than a hundred bucks! They had to dig pretty deep as I understand it, then re-bake the whole package, so it was probably a good call on my part to take it in.

Originally Posted by caskwarrior

Okay synopsis is, single phase, single speed motor + vfd, no problems. Most of the motors I have lying around are out of woodworking equipment and are 2880, but ill look about for a 1440 motor. Thanks everyone for going over this topic again ill now move onto the other problems the machine no doubt will present.

Ralph

Yes other than that slip about it being single phase, that's correct. I'm not saying you can't run a two speed motor through one VFD, but I think you're opening a can of worms there that might be best left alone. As I mentioned, there's a heck of a lot going on with these motor drives besides being a single to 3 phase conversion, and at the end of the day that's the most minor of points, despite the fact it's why many of us first begin using them.

Here's a couple of photos I found of the control panel and the internals of that motor. Being a Swiss machine you can imagine the motor was typically over-built! There's two spindles on that machine, hence the "Main Spindle" and "High Speed" labels. The high speed is in fact a completely seperate motor attached to my high speed head. I have a lead with a plug on it and plug it in to the control panel when I have that head on the machine.

Aciera 2 speed motor.jpgAciera Control Panel.jpg

Originally Posted by caskwarrior

Sorry that was a slip, I only have 3 phase motors anyway.

No worries, just better to keep the details straight.

FWIW I've found an Aussie company that can/will make 2 speed 3 phase motors. I'm going to get pricing etc off of them next week.

I'll make sure I'm sitting down when I open the email.

PDW

I moved it in over the weekend, just have to find time to start cleaning it, see what needs work, the gibs still have some meat at least. I have all the original 'standard' accessories, changewheels, thread dial drive plate and face plate, travelling steady but no fixed steady, the QCTP is an interesting design too.20170211_133601[1].jpg20170211_133615[1].jpg20170211_133617[1].jpg20170211_133619[1].jpg20170211_133624[1].jpg

I see that your lathe has the mechanism to allow belt pulley changes. Does your spindle only have one pulley?

I have a different rotary tool holder completely...one that rotates in the vertical plane.

Greg

I saw that vertical tiny turret toolpost in the manual, it looked quite interesting, ill post the ppage from the manual here. And mine has a matching pair of 4 speed pulleys.

The vertical toolpost is very robust, but strikes me more like a mini turret type set-up. My lathe also came equipped with two tailstocks, although the lever action one looked unused.

Since the motronics drive that I had provided only one pulley I went down the servo route, but those parts are still on my shelf. (Its future home is only a month from lock-up, so it is coming north soon.)

Greg

Originally Posted by Greg Q

The vertical toolpost is very robust, but strikes me more like a mini turret type set-up. My lathe also came equipped with two tailstocks, although the lever action one looked unused.

Since the motronics drive that I had provided only one pulley I went down the servo route, but those parts are still on my shelf. (Its future home is only a month from lock-up, so it is coming north soon.)

Greg

Welcome back. Good to hear that beautiful Hembrug that I keep eyeing off when I visit Phil's is scheduled for resurrection. With additional brain surgery no less. The electronic lead screw, servo driven spindle, you realise you are only a hop skip and jump away from full CNC?

Ray

Hiya Ray...

I don't think I will do anything with the leadscrew now that I think about it. But the servo drive has to be done. Michael G got me some acme rod from McMasters a few years ago and I think ther's a big chunk of leadscrew rod in there if I recall correctly.

The CNC caper is something that I was teying to avoid, but it looks like I need to make a cnc foam cutter quickly, so maybe after all of the house stuff is done I will retrofit a milling machine. Of course I will have to make a cnc router first. Sigh.

The house is taking sooooooo long. We started construction almost a year behind schedule and have just slipped further and further behind from there. I haven't been to MEL in over a year now, so a visit is long overdue. I am looking at a supertanker in Singapore harbour as I write thinking that's about how much Black Label I owe Phil by now.

GQ

Originally Posted by Greg Q

... but it looks like I need to make a cnc foam cutter quickly...

PM me as I have literally kgs of NiChrome wire here (around 5.8ohm/m ) and I'll never use that much.
Same goes for anyone else who wants to make a hot wire cutter.
There was a thread about the sophisticated one I made here but all the pics have gone //metalworkforums.com/f65/t1514...-foam-castings. Without them it just reads like another precision project.

Michael

Greg if you had access to it I would really appreciate a few photos of the lever action tailstock, I would be very keen to replicate one. On another note it came with a qctp morse taper toolholder, what is the purpose of these, why would you want to hold anything with a mt shank off center? Is there some obvious use case im missing?