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chrisp
26th August 2008, 01:14 PM
I've been dabbling in woodwork for about as long as I can remember and I've been progressively accumulating tools and machinery along the way. I've got to the point where I could pick up most WoodSmith magazine projects and follow the instructions to the letter without having to improvise for the lack of machinery.

So, overall, I'm pretty pleased with my machinery collection but noticed that when I mention to a new acquaintance that one of my hobbies is woodwork their response is usually something like "Oh, so you have a lathe?". I usually answer truthfully "Um, no, I don't have a lathe, but..." and try to explain that there other aspects to woodworking than just wood turning. However, most of the time it is a loosing battle and I'm usually left feeling that I've made a misleading statement - how can I possibly claim to be a real woodworker and not own a lathe? :?

It seems that the time of redemption and fulfillment is near...

My work was closing down a woodworking section and I managed to pick up a secondhand lathe. All I need to do is get it working and I'll be able to rightfully claim membership of the "real" woodworking brigade

So what did I end up buying? Well, to be completely honest, I'm not completely sure. It is a Woodfast lathe but I don't know which model. The only identifiable number that might be a model number is "LBL2400-77" stamped near the end of the bed. From what I have measured, it has a 6" centre height and is about 1000mm between centres. Head headstock is fixed but it has an outboard section that presently has a 280mm sanding disk and a table with mitre gauge. The spindle threads are 30 x 3.5 - RH on the inboard, LH on the outboard. It has four speeds (belt change) and an indexing arrangement built in to the headstock pulley (15 degree stops). The only major problem is that the motor is 3-phase and I don't have 3-phase power at home

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After sorting out the box of bits and pieces that came with the lathe, I found that I managed to pick up a few accessories as well.

It came with lathe chisels...

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The usual assortment to tools and bits and pieces (but no face plate or chuck).

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Metal spinning tools...

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And a couple of stray socket firmer chisels (I am pleased with these).

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The Motor Issue
The lathe has a three-phase motor and thought I'd sort out what to do with the motor. As I see it, I have two possible options: replace the motor with a single phase unit, or convert it to VSD. Initial inspection shows the motor mounted on a flat hinged flap. Replacing the motor with another unit would be relatively straight forward.

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However, those in the know tell me it would be much better to convert it to variable speed drive (VSD). So the next question is whether the 3-phase motor is wired as a star or delta. Hopefully the motor is wired as a 415V star so that I can be convert it to 240V delta to be suitable for a single-phase powered VSD controller. The name plate on the motor didn't provide any hints so I have to remove the motor to check. After scribing lines on the motor mount plate so I could reinstall the motor back to the same position, I removed the motor.

Having removed the motor, I could see that there is another plate on the top of the junction box. The motor is not only wired in star, but is link configurable to converting to 240V delta - sometimes one does get lucky.

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The conversion process to straight forward. The motor was originally wired as a 415V star...

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and by moving three links it is now it is converted to a 240V delta...

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I cleaned the dust off the motor and put the cover back on and I'll set it aside until I sort out a VSD.

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Replacing the Headstock Bearings
The lathe hasn't been used for many years so While the motor was out I thought I'd check the headstock bearings. When turning the spindle by hand, the spindle seemed to turn reasonably smoothly but not perfectly smoothly and there was a scraping noise. Maybe it is just dry bearings? I figured I had nothing to loose so I removed the spindle and visually inspected the bearings before deciding to repack them or replace them.

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I found that the grease was like treacle. I tried a few drops of oil just to see if a bit of light lubrication was going to help but in the end I decided I might as well remove the bearing completely and replace them.

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The front (inboard) bearing is a press fit to the spindle. I thought I'd try an out an old trick and see if I could use the lathe to press out it's own bearings. After removing the spindle, I placed it backwards against the headstock and bought the tail stock up to press on the end of the spindle.

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I was interested to see if I could get enough force on the spindle to press it off the bearing or would the tail stock slip? After winding up a fair bit of pressure, I was presently surprised to detect some movement - and it was between the spindle and the bearing - and not the tail stock slipping on the bed. After pressing the bearing of about 50mm the interference fit finished and the bearing could be slid by hand, well, up to a couple of burrs on the spindle where the grub screws for the pulley sit on the spindle. Just a point to note: the way I pressed the bearing off transferred the force through the actual balls on the bearing. i.e. I was applying pressure to the outer race to press the inner race off the shaft. My understanding is that this can "spot" the bearings and render them unusable.

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A little bit of careful filing to remove the burrs and a little more pressing the bearing was off.

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The rear (outboard side) bearing was removed using the spindle in a similar manner. This bearing is a neat fit and pressed out quite easily.

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The next photo shows the spindle and the two bearings. The rear bearing is a single race ball bearing unit with a shield only on one side (6206Z) and the front bearing is a double row angular ball bearing open unit (3206 or 5206) Checking the bearing showed that the rear bearing was quite okay but the front bearing was the noisy one. Since new bearings are cheap ($9 + $28), I thought I'd just replace both bearing rather than reuse the rear bearing.

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The next stage is to clean the old grease out of the headstock and grease nipples and start the reassembly process. I'm a little worried that I'll reassemble the headstock without the belt in place.

I expect I'll have the head stock reassembled this coming weekend and after that I'll start investigating VSD units to see what I can find.

I'll post some follow ups as I make progress.

hughie
26th August 2008, 02:03 PM
Good pick up :2tsup: and welcome to the club of the addicted.....:U

Would'nt be too concerned over the 3phase as you can get a inverter for it very easily and in doing so have a VSD set up. Failing that pick up a single phase motor and re fit the pulley to it. I would look at 1kw which equates to around 1.5hp or so,plenty of power for that lathe I would think

ss_11000
26th August 2008, 03:28 PM
we have them lathes at school. they are great!

good pick up mate:2tsup:

Stryker223
26th August 2008, 04:43 PM
Outstanding Chrisp!!!!!
No problem swapping out the three phase motor to a single phase and you have one fine lathe there!!!!

chrisp
26th August 2008, 05:07 PM
Thanks for the comments on the lathe. I was wondering if it was a reasonable unit or not as I only got to see it for a few minutes before placing an offer.

Regarding the motor, I've made a couple of phone calls and I can get a new VSD for $340+gst for 0.75 kW or $382+gst for a 1.5 kW unit. It looks like fitting a VSD to the existing motor could be a goer.

I'll get the headstock back together first and see how the bank balance is holding up before purchasing a VSD. Hmm, I wonder if I could borrow the motor from my bandsaw to give the lathe ago? :rolleyes:

Chris

RETIRED
26th August 2008, 05:12 PM
I'm a little worried that I'll reassemble the headstock without the belt in place.Put 2 belts in while you have it dismantled.
They very rarely break but they always do it when you need it most.:wink::D
PS. Welcome to the Black Arts side of things.

jefferson
26th August 2008, 07:06 PM
Crisp,

You need to be very careful about what you say on this forum about "what constitutes woodworking".

There are many among us that make furniture. Tables, chairs, display cases and even kitchens. Heaven forbid, but it pays the rent. And keeps the missus happy.

Some of the others just turn. And even among those that turn, some just turn spindles (some for a living like ) while others just turn bowls and platters, or lidded boxes or pens. Dark siders beware.

Recently, I stuck my woodworking foot into turning. An eye-opening for sure, being one that is use to moving wood into the machine, not the other way around. (Hand planes and chisels excepted).

I wouldn't denigrate what you can do without a lathe. I agree that an good all-round woodworker should turn and do so regularly. Split turnings, exquisite turned table legs etc are skills that should be acquired. But don't go thinking that your efforts as a woodworker are second-rate because you might not have a lathe.

Truth be told, the lathe is just one small part of the equipment and skills that makes a good general/ all-round woodworker. Don't say that too loud in the company of turners though! Myself, I've got the bug for lidded boxes and the cabinets that SWMBO desires are on the back burner.

So, a word of caution. Watch those buggers out there that specialise in turning. They are a quite different breed of woodworkers - and I luv 'em!

Jeff

tea lady
26th August 2008, 07:33 PM
Great lathe pick up there.:2tsup: All my admiration goes to those who can fix up their own stuff. I am a learna turna, and am now gunna learn some furnitcha making. Maybe I'll be a woodworker one day too.:D

Cliff Rogers
26th August 2008, 08:04 PM
Another one bites the dust. :D

I dreamed of owning a Woodfast for years before I saw my fist Vicmarc, good pickup. :2tsup:

joe greiner
26th August 2008, 09:24 PM
Put 2 belts in while you have it dismantled.
They very rarely break but they always do it when you need it most.:wink::D


Everybody: Write that on a piece of tape, and affix it to your headstocks. And/or, how about a Sticky for Woodturning - General?

Thanks, Ian ().

Joe

Vernonv
27th August 2008, 10:51 AM
That looks like a great lathe ... very sturdy and "industrial" looking ... good score.

uidaa
27th August 2008, 01:53 PM
Good Stuff! I wish I had one for long times!

chrisp
2nd December 2008, 04:28 PM
Well it's been awhile but there has been some progress.

I've got the headstock back together with new bearings. It all went back together reasonably easy. I used the tail stock to press the new bearing on with the pulley and a few spacers used to support the bearing while it was pressed on.

I even tried 's suggestion of fitting two belts but I had to remove one as I couldn't find any space to keep the spare out of the way.

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I've also partially sort out a variable speed drive for the lathe. I'll post some details in a separate post.

chrisp
2nd December 2008, 04:47 PM
Converting the lathe to a variable speed.

The lathe was fitted with a 3-phase motor (and I don't have 3-phase power) so the question was whether to replace the motor with a single-phase unit or to fit a variable frequency drive (VFD). As indicated in an earlier post, the motor was originally wired internally as a 415V star wind and could easily be configured to a 240V delta wind. On the face of it, this motor is quite amenable for use with VFD with a single phase power supply.

What follows is my step by step account of rewiring the lathe and initial trial fitting of a VFD.

The first issue I tackled was the supply cord and the cable entry to the lathe. The original cord entered via a cut-off cable gland that acted as bushing for the cable. This arrangement lacks any form of sensible cord restraint. Also, the supply cord was a 3-phase cord and I would need to replace it with a single-phase cord.

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The easiest way to provide an acceptable form of cord entry and restraint is to use a cable gland. The next three photos show the new cable gland - with an adapter to fit the hole in the lathe, how the gland is fitted inside the lathe, and the new power cord passing through the new gland.

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Rather than make up a new power cord from scratch, I find it easier to buy an extension cord an cut the socket off. In the photos tha follow you can see the new yellow supply cord.

The next photo shows the VFD and the 3-phase motor out of the lathe. The VFD I chose was an Omron model 3G3JX-AE015 (list price $382 + gst) which is rated to be suitable for a 2 HP / 1.5 kW motor (the unit has a actual rating of 2.9 kVA). I also considered a smaller model 3G3JX-AE007 (1 HP / 0.75 kW motor, 1.6kVA rating, list price $339 + gst) which would have been perfectly adequate of the motor. In the end I chose the larger model as it was in stock at the time. BTW, it is quite possible to get better prices than the list prices.

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I started wiring from the motor. First I removed the terminal box cover from the motor.

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I fitted a cable gland to the terminal box cover. This also required a adapter to make the gland fit the thread on the motor.

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The new motor cable was threaded through the gland.

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There are lots of different ways to remove the sheath from flex, but I'll show you the way I usually do it. Firstly, think pinch-and-rip. Using combination pliers, pinch to sheath close to the edge to avoid pinching any of the inside wires. Squeeze the pliers tight and rip the pinched piece of sheath from the cable. You should end up with something like the third photo in this set.

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Repeat the pinch-and rip several times around the cable.

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and slide off the remaining sheath. This particular job looks a little rough.

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Using side cutters, I can tidy up the job.

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and it now looks much better. Note, there are no nicks or cuts on the inside wires.

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Doing the above, I was a big hamstrung using pliers and a camera at the same time. On the other end of the cable, I just stripped it as I normally would (sans camera) and this end didn't need tidying up.

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On to the actual wiring of the motor. The first thing to do is check that enough sheath has been stripped.

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In this case the motor is fitted with brass studs for the terminals. While it is fitted with a set of washers with upturned lugs that are designed to hold bare flex, it is much better to use lugs instead.

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Next part is to strip the insulation from the wires. Again, there are many methods, but in this instance I just used side cutters. The idea is not to cut the insulation, but to grip it with the cutting edge and tear it off. What is not shown in the photo is that I use my little finger to hold the cutters open while the other three finders hold it closed. The idea is to maintain a controlled opening in the cutters so that they hang on to the insulation but don't close on to the copper conductors.

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Also, keep the face of the cutters at right angles to the cable or else it will either work out, or work in to, the cutting edge and the cutters are pulled. If done right, you shouldn't cut or damage any strands of the wire.

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The next step is to crimp on the lugs. If you haven't got any climpers, get yourself a reasonably good pair. The really cheap don't do a very good job. One test of the crimpers is to try and pull the cable out of the lug. If the cable pulls free from the lug before it breaks the crimpers are no good.

It is important to thing about the current path when making connections. For example, the screw for the earth wire has two washers. It is tempting to place one washer above the lug and one below. However, this would result in the current path being via the lug-washer-motor. It is better to place the lug directly against the metal of the motor (and have both washers above the lug). The screw (and washer/s) aren't really intended to be part of the current path, rather they are intended to clamp the lug to the body of the motor.

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The three wires for the three-phase connection are wired in a similar manner.

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With the wiring at the motor completed, the cover is reinstalled and the cable gland tightened.

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Using a multimeter, I do a few basic checks on my wiring. Firstly, I check the earth connection by measuring the resistance from the earth wire to some exposed metal on the motor. Do this in a couple of spots. The reading is about 0.3 ohm which is quite good and I know my multimeter leads will read about 0.2 ohm on their own.

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While I'm using the multimeter, it is also a good idea to do a (very) basic insulation check to make sure that the internal connections aren't inadvertently touching the inside of the cover, to that a motor winding has broken down. Measuring between one of the actives and the body gives an open-circuit reading (which is good).

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I'm happy with the wiring of the motor so now it is on the wiring it to the VFD. In this case, I'm just want to try the VFD out to check that it is going to work and that the motor is still okay (I've never seem this motor operating). I fully expect to rewire the VFD again when it is physically mounted into the lathe.

The cover of the VFD is attached by a single screw and a couple of clips.

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The motor connections are at the bottom of the unit labeled U/T1, V/T2 and W/T3. There is also an earth connection at this end.

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As I not sure whether this is a protective earth or a shield earth, I wired a another earth wire off this point to take it back to the supply cable just in case this earth isn't intended to be used as a protective earth.

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Similarly, at the top of the VFD, there are the terminals for the incoming single phase supply. The 240Vac is wired to the "N" (neutrual, light blue) and the "L1" (active, brown) with the earth wired to the earth connection (and I've looped to the output side as well).

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The wiring of the VFD is now complete and the cover can be reinstalled. You may have noticed that I have the 3-pin supply plug insight at all times while working on the wiring. This is a good habit to get into when working on electrical equipment so that you know that the equipment is unplugged.

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As I'm happy with the wiring of the motor and I don't think I need to change anything in it's wiring I reinstall the motor back into the lathe.

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After rechecking the earthing with a multimeter I give the system it's initial power-up. Note: I've left the belt off as I don't know which way the motor is going to run.

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I pressed the "Run" button and the motor slowly spun/ramped up to speed. It works! And the motor direction is correct! If the motor was running the wrong way, it can be reversed by swapping any two of the three motor actives; or the VFD and be configured to reverse the direction.

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Having sorted the electrics, I still need to sort out where to mount the VFD. One possible location is in the cavity above the motor.

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There seems to be three option for mounting the VFD:


Mount it so the the front of the VFD just protrudes through metal cover of the lathe. This would allow the controls to be reached without opening the cover. This would take a bit of work as the top of the VFD isn't rectangular.
Mount the VFD totally enclosed within the lathe and wire up remote switches and potentiometer to allow the on/off and speed to the controlled remotely from the VFD.
Mount the VFD totally enclosed within the lathe and insatll a remote control panel which can be purchased as an option for the VFD.


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The other matter I need to sort is the main switch. In the temporary setup I wired above I didn't install a mains switch. In the final set up I'll reinstall a mains switch. The lathe originally had two switches: an isolator and a magnetic contactor. The magnetic contactor requires 415V to operate so I can't use it. The isolator could be used as a mains switch but I'm a little concerned that it is old and the location isn't the best as the drive belt runs directly behind it (the cables may rub against the belt?).

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Please note:
The above was just a temporary rig up to check that the VFD and the motor would work together. In a later installment I'll show how to earth the body of the lathe and the electrical fittings.

In case anyone was wondering, mounting the VFD on the outside surface of the lathe isn't an option as the terminals on the VFD don't provide adequate insulation nor cord anchorage. The VFD here is intended to be mounted within another enclosure the protect the wirings.

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INVENTOR
2nd December 2008, 05:54 PM
Chrisp, good post, haven't read every word, can you say where you bought your OMRON unit. And is it designed for 'constant' torque loads or otherwise?
Also is the 'IP' rating OK (eg dust getting into the unit).

Appreciate any info.

new_guy90
2nd December 2008, 08:04 PM
wow you got a good buy. cool getting the metal spinning gear, that could come in handy :2tsup:

Robomanic
2nd December 2008, 09:32 PM
Great post - perfect encouragement for those of us who do these kind of things when we get the chance :2tsup:

Plan on doing any spinning with it? That is yet another thing on the list to try one day.

chrisp
3rd December 2008, 12:06 AM
Chrisp, good post, haven't read every word, can you say where you bought your OMRON unit. And is it designed for 'constant' torque loads or otherwise?
Also is the 'IP' rating OK (eg dust getting into the unit).

Appreciate any info.

Inventor,

I'm not surprised you haven't read every word - it was a rather verbose post :rolleyes:

I purchased the controller direct from Omron. They seem very good to deal with and happy to get stock from interstate the next day.

The unit can be configured for several different V/f characteristics - the default characteristic is constant torque, but there is also a couple of reduced torque options and a torque boost option. The JX is the baseline model. The next models up, MX and RX series, may have more options again.

The specifications give the IP rating as IP20. The -AE015 model I purchased is force-cooled and that was one reason I was considering the smaller unit (-AE007) which is convection cooled. I figure if dust is a problem, I can remount it in the cabinet on the tailstock end of the lathe. Also, I suspect the fan wouldn't be required when using this smaller motor so I might get away with removing the fan. The other thing was I was surprised how clean the enclosure in the lathe was - maybe the dust wouldn't be a problem? (Here's hoping)

I priced a remote control panel for the JX - list price $60 but delivery is 2 weeks as it will have to come from Japan. I didn't price the MX or RX equivalents but these could be better value as they come with a removable control panel as standard.

TTIT
3rd December 2008, 12:07 AM
Excellent post Chris :2tsup: A mate of mine has an old Woodfast that needs the same treatment and he is hesitant about fitting the VFD. Your post makes it look so easy I think it should convince him.

Ed Reiss
3rd December 2008, 01:08 AM
Wow Chrisp.....your doing an excellent restoration there and a good WIP....gonna' have a mighty nice lathe when done!!:2tsup::2tsup::2tsup:

artme
3rd December 2008, 05:29 AM
You´ve don e well Chrisp!!:2tsup::2tsup::2tsup:

A neat set of detailed tutorials on your repairs and conversions too.:2tsup::2tsup::2tsup:

CameronPotter
3rd December 2008, 08:20 AM
Jealous... :grumble:

Nice pick up and thanks for detailing the procedures!

Cheers

Cam

INVENTOR
3rd December 2008, 08:43 AM
Thanks for the information, you have been very helpful with your time, I am sure many will benefit.

Good luck with the lathe, its looking good.

Manuka Jock
3rd December 2008, 01:45 PM
Chrisp ,
Good score , and excellent refurbishment work :2tsup:
Is the remote speed control a magnetic one , and is it digital button job , or speed dial one ?

Now that you have this new toy mate , its time for some update photos on the 'shed thread' (http://www.woodworkforums.ubeaut.com.au/showthread.php?p=854138#post854138) :U

chrisp
3rd December 2008, 02:03 PM
Chrisp ,
Good score , and excellent refurbishment work :2tsup:
Is the remote speed control a magnetic one , and is it digital button job , or speed dial one ?

Now that you have this new toy mate , its time for some update photos on the 'shed thread' (http://www.woodworkforums.ubeaut.com.au/showthread.php?p=854138#post854138) :U

Manuka,

The remote control panel is functions exactly the same as that on the front of the unit in the photo - it has both up/down buttons (I think you can set up to 16 preset speeds) and the dial as well. If you look carefully at the pictures for the front of the VFD, there is a network style connector (behind a rubber cover) that is used to connect to the remote panel. I've attached a PDF with the dimensions of the panel.

I'm thinking of making up a post (with something like a microphone goose neck?) to mount the remote control on so that it is near the head stock. A friend of mine who is in to lathes told me it is good to have the controls near the headstock when parting off spindle work.

Yep, the photos in the shed thread are somewhat old - there is also some pictures of my new work bench in another thread somewhere. I'd take some new photos but the shed is unbelievably (okay, okay, "believably") messy at the moment :B

Chris

Vernonv
3rd December 2008, 02:23 PM
Hi Chris,
Great WIP, with excellent detail and photos (I especially like the cable stripping info -great little trick :2tsup:) ... although I fear some people may be having kaniptions in regard to your unathorised use of eletrickery magic.:U

Manuka Jock
3rd December 2008, 02:36 PM
Sometimes , the headstock control can be in a dangerous place .
Leaning over , or behind the workpiece , faceplate turning being one example , is dicey .
There are some controls that can be attached to the lathe bed , away from danger.
My DVR has the digital buttons on the headstock , I am thinking of finding out about a magnetic dial one to have on the bed.

When I get me machine out of storage that is .......:doh:

INVENTOR
3rd December 2008, 05:03 PM
Chrisp, Manuka Jock is right. Manufacturers put the switches there cause its easy. 'just' OK for the start button??? but no good as the only stop button.

Think about having a remote control box ( magnetic base perhaps) that you can move to the end of the lathe. AND a well adjusted knee stop bar, running along the front of the lathe ( similar to the bigger Vicmarc lathes) but adjust it so you don't trip it off when you lean against the lathe. that's the problem with some lathes. Then you have the best of both worlds and you keep both hands free, which is sometimes critial.

I am sure with your knowledge you could set up some stop/start buttons etc (relay if required) you can source cheap good quality stop /start mechs if you look around.

Its amazing how many times you start and stop the lathe so taking the time to set it up correct is worth it.

chrisp
4th December 2008, 12:06 AM
There are some controls that can be attached to the lathe bed , away from danger.
My DVR has the digital buttons on the headstock , I am thinking of finding out about a magnetic dial one to have on the bed.


Chrisp, Manuka Jock is right. Manufacturers put the switches there cause its easy. 'just' OK for the start button??? but no good as the only stop button.

Manuka Jock & Inventor,

Thank you for your advice. Thinking back, I think I've misquoted what my friend suggested - and I think what you have posted is correct - I need a hands-free way to shut the lathe down such as a knee or foot operated switch so that, for instance, spindle work can be steadied/caught with one hand while it is parted off with the other.

Please correct me if I'm wrong, but I think what you are suggesting is that the remote control panel could be mounted on a magnetic base like one of those used with a dial gauge. This would allow the main controls (on/off and speed) to be placed in some convenient location to suit the work being done. In addition, there should be a hands-free way to shut the lathe down such as a knee bar, foot switch, mushroom stop button, or all of the above.

I don't think it will be too hard to rig up the extra stop switches, electrically anyway, as the VFD has emergency stop connections that can be wired up to external switches - all low voltage and low current (i.e. it's a "soft" shutdown function).

Chris

Manuka Jock
4th December 2008, 01:16 AM
Manuka Jock & Inventor,
I think what you are suggesting is that the remote control panel could be mounted on a magnetic base like one of those used with a dial gauge. This would allow the main controls (on/off and speed) to be placed in some convenient location to suit the work being done. In addition, there should be a hands-free way to shut the lathe down such as a knee bar, foot switch, mushroom stop button, or all of the above.
Chris

Chris ,
Not just the on/off switch , but the speed control too.
And not for convenience , that is secondary. Safety is the main concern .
When you have a method of changing speed with the lathe going , like any variable speed one , and you are fine tuning it often at times , especially when roughing down ,for balance and vibration etc , then the movable control needs to be in a place that keeps you hands out of harm's way , rather that reaching over , past ,or behind the spinning work piece.

And to make life easier , cranking up a dial switch is a lot less annoying that a digital push button panel , 5 rpm at a time , such as the one on my DVR.
I'm not too up on electronics , but if it was possible to set the digital pad speed to a general speed range for that part of the job , and then use the dial to increase or decrease either side of that a bit , that would be great .
Though if there is a dial that could swing from 100 - 3500 rpm in one go that would suit mine to a tee.

INVENTOR
4th December 2008, 08:21 AM
Chrisp, I think you have the idea, put your controls in an adaptable box with a strong magnetic on the back. If you ever do hollow forms etc then you can place it at the tailstock end of the lathe ( or even on the back of the lathe) assuming you will leave the lathe out from the wall. As that is where you might be standing.
When you think about it even a start button near the headstock is 'silly' as you need to reach past the 'line of fire'. Better to start the machine with your hands and body out of the way of the chuck etc.

A good foot switch is not cheap and 'questionable' compared to other ideas. I think if you added the moveable control box and if possible a long knee stop you would be cover all bases and have a very nice working step up.

At the expense of getting DVR users upset. 'WHAT WERE THEY THINKING?' The Nova's are a good lathe and then they go and add that %&^$ control panel. Clearly not the best idea.
I know long time Nova owners who won't upgrade to the DVR because of it. Not due to lack of money.

Good luck, you seem to be on top of it well and truly, great to see.

tea lady
4th December 2008, 09:27 AM
Great thread.:cool: Careful where you put the magnet mount on the head stock. I have a memory of Skew saying something about a mysterious problem caused by a magnetic thing put near the pulley or something. :hmm:

Manuka Jock
4th December 2008, 09:33 AM
The idea is to put the remote controls away from the headstock , out of the danger zone

CameronPotter
4th December 2008, 09:37 AM
a mysterious problem caused by a magnetic thing

Luckily this can all be fixed by the judicious use of a foilie...:wink:

chrisp
4th December 2008, 09:38 AM
Great thread.:cool: Careful where you put the magnet mount on the head stock. I have a memory of Skew saying something about a mysterious problem caused by a magnetic thing put near the pulley or something. :hmm:

Ah, sounds like induction heating. I wonder how close Skew's magnet was to the pulley?

I do very much appreciate all the comments and suggestions. Typical of me, things tend to happen in bursts with quite long lulls in between the bursts.

I think I will go with the remote control panel idea (and I must get my order in - 2 weeks delivery time) and I have a think about how I might set up the extra switches around the lathe, and what type of switches to use. I don't expect I'll get much more done on the lathe this side of Christmas.

Chris

tea lady
4th December 2008, 09:44 AM
Ah, sounds like induction heating. I wonder how close Skew's magnet was to the pulley?


Chris I think it was something to do with the magnet pulling something off gradually. :shrug:

chrisp
27th May 2009, 06:22 PM
It has been awhile...

Continuing the story, when I last left it, it was essentially a wiring mock up to check that the motor and variable speed drive would work together. Now that I'm happy it is all going to work, it is time to start the real wiring. I've cut all the mock up wiring from the controller, rather than unscrewing it, as the stubs of cable will help to confirm the correct locations for each wire.

The original switch gear is shown in the next two photos

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The lathe with the original switch gear removed and the panel removed to show the proposed location for the VSD.

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Electronic devices don't like having metal shaving in them, so rather than using the VSD as a template, the mounting hole locations were measured and marked on to masking tape.

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Screws for mounting the VSD were captivated to the back panel with shake proof washers and nuts. This was done to make it easier to installed and removed the VSD it will be be done many times during the wiring. The VSD will be secured to this screws with another set of nuts later.

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Check that the mounting screws are in the correct place.

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The VSD was removed and another hole drilled through the back panel. This hole will become the main earth point.

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It is very important to remove all the paint around this hole to provide a good earth contact on to the body of the lathe. I used a Dremel type tool with a grinding stone.

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The earth screw is, in this case, a 4mm screw with a star washer and nut.

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This are installed to the earth point - with the star washer to the bare metal. These are then tightened up.

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All the earth connections of the various parts will brought back to this point. I've shown a few crimp lugs on this terminal so you can start to get an idea of the earthing arrangement.

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Looking ahead a bit, some of you maybe wondering how I'd be able to adjust the speed when the VSD is installed. The VSD is capable of being controlled by an external control panel shown here.

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Back to the earthing. It is very important to be convinced that the earth connection is good. Using a multimeter, I check the resistance between the earth screw and the tail stock. I choose the tail stock as it was about the furthest bit of metal on the lathe. This will be about the worst resistance measurement I should get.

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The earth resistance reads o.3 ohm (acceptable), but I know the multimeter leads contribute a fair bit of this. Shorting the multimeter leads together gives me a measurement of the lead resistance. In this case it also reads about 0.3 ohm.

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Therefore, my real earth resistance is about 0 ohm (or about 0.1 ohm give or take). You should be able to achieve earth resistance of 0.5 ohm or lower. If the reading (corrected for the leads) is above 0.5 ohm, you should review the earthing arrangement.

The earth resistance needs to be low so that in the event of a fault, the fault current will be high and trip the circuit breakers, or blow the fuse, promptly.

I'm happy that I've got a good earth contact to the body of the lathe. I've placed a sticker near the earth screw to indicate that this will be the central earth point in this machine.

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I rewire the motor side of the VSD. Note that the earth is taken to the earth screw.

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The mains side of the VSD is slightly more complicated. The active and neutral go straight to the VSD. The earth from the cable to connected to a lug. A separate wire is used to connect the earth terminal on the VSD to another lug.

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These two earths are taken back to the main earth (rather than daisy chained).

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It is important to constrain the wiring too. The wiring is constrained with cable ties to prevent the cable coming adrift if the wires break.

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So far, the wiring has the mains coming in and going directly to the VSD. We'll need a mains switch as well - and also an earth to the panel on which the switch is mounted. I've added another earth cable from the central earth for this purpose.

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The loop of yellow cable will be cut and a switch installed. I'm using a industrial switch. As the mounting block doesn't have cable entries in the rear, I'll drill my own and install cable glands.

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I've install the panel back on the lathe. [I'll deal with the extra holes later.]

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The yellow cable has been cut and fed through the cable glands.

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The mounting block has been attached to the plate.

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The rear of the plate shows (a) how the glands come though one of the large holes; and (b) the earth connection to this plate. Again, the paint was removed and a star washer used.

EDIT: The front panel is earth using a separate, dedicated, screw rather than doubling up and using, for example, one of the screws holding the switch in place. This is done so that the earth isn't accidentally left unconnected when doing work on the machine, and also, screws though plastic (i.e. the mounting block) can't be relied on to maintain sufficient tension on the screw to maintain a good earth contact.

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The active and neutral are wired through the switch. Note this is a 3-pole switch intended for 3-phase. I'm only using two poles. Tighten all the screws - including the unused terminals. Very important: DON'T ever switch the earth!

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The earth connection is tightly twisted together. It is this twisting that makes the main contact between this wires.

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This twisted joint was folded and a 2-screw BP connector installed. It is important to check that the screw actually presses on the wire. These aren't my preferred type of connector for this type of connection. Screw terminals that have the screw pressing directly on to flex or not the best. Normally I would use a crimp joiner.

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Tape up the earth connection and install the switch to the mounting block.

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Behind the panel, Tighten the cable glands - these form the cable restraint to prevent the connections from receiving mechanical forces that may be applied to the cable. Cable tie the cables together to keep everything neat and tidy and out of harms way.

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With the panel installed, check that the cables are well out of harms way. These photos, looking up the past the motor, show the cable sitting well away from the moving parts, and no sign of cables or wiring near the belt.

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The bulk of the mains wiring is now done but there are a few things still to be done:



Cover the holes
Install the remote control panel
Install some axillary / emergency stops
safety test


More soon...

Cliff Rogers
27th May 2009, 06:44 PM
:2tsup:

Hardenfast
27th May 2009, 07:12 PM
Excellent post. Probably something that only someone with electrical experience should/would attempt, but a very detailed and informative explanation of 415v > 240v conversion, as well as changing bearings etc. Many thanks!
I also have an old Woodfast 415 volt lathe which would benefit from this process, but I think I'll just sell it as it is and point prospective purchasers to this thread. :;

Wayne

powderpost
27th May 2009, 07:58 PM
An excellent lathe. I have one I bought in 1981. The bearings and belt are as good as the day I bought it, in spite of a hell of a lot of work. Changing the belt speed is a pita.
Jim