Renovating a Hardinge HLV-H

Thanks Lee :)

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How soon do you hope to start turning your first part ?

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Oh, I've been using it for a while now, just odds and sods (e.g. I trued up a prop-shaft bearing for my neighbour's yacht yesterday).

Now that I've sorted out the workshop, I hope to re-start the cnc conversion of the drill/mill and I've got a plan for a bed-top cnc add-on for the Hardinge similar to zepher9900's [ame="http://www.cnczone.com/forums/showthread.php?t=75106"] Feeler conversion [/ame]on cnczone; My brother wants me to make him some new wheels for his English wheel - it'll be a whole lot easier with a cnc lathe.

Bill, a fantastic job you've done! :clap: I was impressed enough at your mechanical refurbishment, but am blown away by your spindle control implementation. I'm planning on going down a different path with my Feeler, but that doesn't lessen my admiration for what you've done.

Randy

Aahh a mini Audit attachment, just needs a turret.

Kip, thanks for the kind words. If I didn't want the design copied, I would have posted photos like this. :heehee:

Randy

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Originally Posted by John S

...just needs a turret.

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Turret? We don't need no stinkin' turret! :nope:
[ame="http://www.youtube.com/watch?v=gQxNDtiku48"]YouTube - shay bushing 1[/ame]

Randy
(now I need to shut up before Bill thumps me for hijacking his thread)

Just thought I'd post a couple of pictures of my home-brew travelling steady


(just to bump this thread above Irving's ;))

bill,it looks fantastic got a feeling this is going to prove to be your number one lathe what about the spraying would you go down that route if you found another one or resort to brush roller going to paint mine not sure what way to go your looks the bizz but is it worth the heartache

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what about the spraying would you go down that route if you found another one or resort to brush roller

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I've got the hang of spraying now (well almost :)) I sprayed my first Haighton Mill (0011) and have the second one (0020) still to do (my olympic project :))

I suppose brush and roller would be OK, but I still prefer to spray paint.

Bill

what a job never tire of going thro the pages of progress this man is an old fashion tradesman,pity he didn,t put a few more up -B

:beer:

I've added a few bits and pieces since finishing the renovation, so I suppose I ought to just bring this thread up to date :

I have replaced the bearings in the cross-slide, top-slide and the collet closer and repaired the closer tube (to stop the closer wobbling madly). Replaced both drive belts.

I made a Hardinge style QC tool post for it (The Hardinge ones are impossible to find in this country) , a Metric banjo & bobbins (shaped to hold the large Myford 127T translation gear) and a close up steady to enable me to cut very small threads

To allow me to cut long pitch threads <8TPI without risking damage to the gear chain, I've added extra speed controls and switches on the threading lever. This enables me to set different spindle speeds for forward stop and reverse threading easing the forces on the gears as the dog clutch engages (see:Hardinge HLV-H threading-lever speed control.mpg - YouTube)

Very inspiring thread, I hope you don't mind if I pick your brains for my own Hardinge rebuild.

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Originally Posted by northumbrian

Very inspiring thread, I hope you don't mind if I pick your brains for my own Hardinge rebuild.

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No at all :) fire away.

Bill

Hello Bill,

I too have been inspired by your renovation and will also want to pick your brains when I start on rebuilding my own Hardinge. After two and a half years of searching I have finally managed to bag a HLV-H to call my very own. I am impatiently waiting for it's delivery on or around the 21st of this month. I do need to decide how I am going to power my lathe & initially thought of building a rotary converter. I do like the way you have powered yours but think I lack the required level electrical/electronic skill to emulate your work. My choice of rotary converter is based on the hope that it will be plug and play so I will not have to rewire the lathe. Were I more knowledgeable I would have followed closely in your footsteps. As I have not yet got my hands dirty on my machine I presently have only a couple of questions to ask you. DO you have the paint codes for the paint you used ( My lathe is presently green, but not for longhttp://www.mycncuk.com/forums/images/icons/icon11.png)? Secondly do you have any knowledge of and/or plans to build an electronic lead-screw? I ask this because I have seen a youtube video of the Babin Machine Tool electronic servo lead-screw and I want one but can't afford over five times what I paid for my lathe for it!

Once again thank you for for your great renovation blog.

Rodger

Hi Rodger,

Thanks for the kind words . :)

The paint I used was a standard automotive enamel. If I were to paint it again I would choose a different paint (perhaps a Sherwin Williams machine paint) The paint I have has held up well (resistant to coolant or oil) but it a little brittle and prone to chipping. The colour is a light/mid grey (perhaps edging toward blue-ish) that was a reasonably close match to the original base colour.

A rotary phase convert will work OK (please don't let a static converter fry that irreplaceable motor) and is probably a good choice if you have a few machines to power. However, the VFD does give some extra options*, and I would not hesitate to do the same conversion again.

I did look into an electronic lead screw. I like Paul Babin's version a lot; It keeps the lathe functioning as it should and doesn't try to do too much. However, last I heard from Paul is that he has no plans to make it available outside the US (I guess it makes it too difficult/expensive to support).

There is John Dammyer's excellent Electronic Lead Screw** DIY project in kit form. It was aimed at mini lathes but could be adapted for use on the HLV-H (might require a servo motor instead of the stepper currently used) . The Yahoo group is very active and John really gives excellent support.

I keep thinking about trying to make an ELS of my own (I've just bought a little Haighton Cadet, and am looking to make it cut metric screw threads) but, in the end, I just made myself a metric banjo and bought a set of Myford gears (Hardinge gears being almost unobtainable & expensive).

Let me know if you need any help, and start a blog so wee can see you progress :)

Regards,

Bill




*here's one I've just been showing to a guy on the Yahoo Hardinge group
Hardinge HLV-H threading-lever speed control.mpg - YouTube

**John's Yahoo group:
E-LeadScrew : Lathe Electronic Lead Screw R&D

Hello Bill,

I can only echo what other people have said about your rebuild. It has been a great read prior to the, hopefully soon, delivery of a KL-1 I'm negotiating to buy.

In the mean time I have been reading about your VFD conversion, including the information and drawings from the Yahoo Hardinge Group.
If I may, I had a couple of questions about the VFD that have been confusing me.

Yourself and some other people use a 240v to 480v transformer to power the VFD.
From the information I can find about the Siemens MM150 you use, it appears to be a 240VAC Single Phase input device, and looking through general component suppliers (RS), the only 480VAC input VFD's are 3 phase inputs, and the single phase input VFD's are 240VAC.

I wondered what the reason for the transformer is, since I assume that you are still only getting a single phase output from the transformer, just at 480v ?

I wouldn't have thought you could feed a 480VAC single phase into a FVD designed for a 480VAC 3 phase input, can you ?

Yours Confused !
Paul.

Hi Paul,

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the Siemens MM150 you use, it appears to be a 240VAC Single Phase input device,

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No. The Siemens MM150 VFD I am using is the 1.5kW 500v three phase input version. It is fed from the single phase 415vac output of a step up transformer.

All VFDs run on DC internally, so they do not really require more than one phase to work. High power ones have 3ph input because they need more current and it is easier (i.e. smaller, cheaper capacitors) to smooth the DC from a poly-phase input (like a single cylinder engine needs a bigger flywheel than a multi- cylinder engine) .

There is sufficient capacity in most VFDs to operate on a single phase input without causing any real problems (especially on a lathe with a low duty cycle operation).

Some VFDs have phase loss detection, which would prevent single phase operation, but most newer ones just sense DC bus ripple voltage so will operate fine on single phase input (they will still fault if excessively loaded).

Bill

Hi Bill,

Thanks for such a prompt reply.

That makes a lot more sense now.
I'm assuming that the risk is that since only one phase is being used to supply all the output power, that it is the rectifier diodes on the one input that risk being over-loaded - all the output power being derived from one phase set of rectifier diodes rather than three ?

Do you just leave two of the input phases disconnected ?

Using a 3 phase 415 input VFD makes the selection choice much larger and cheaper !

Many Thanks - I'll look into 415v 3ph VFD's now !

Regards
Paul.

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I'm assuming that the risk is that since only one phase is being used to supply all the output power, that it is the rectifier diodes on the one input that risk being over-loaded - all the output power being derived from one phase set of rectifier diodes rather than three ?

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True, but since the rectifier diodes are usually integrated with the rest of the power devices, there's virtually no cost to the manufacturer to make the devices very robust (i.e. to use the same spec devices for the smallest and largest power VFD in a range).

The only real issue is ripple current heating in the capacitors.

Bill

Bill I am curious as to how you designed the mounting of the wheels to the side wall of the stand such that the weight could be securely carried, as I would not have thought the steel sheet was rigid enough. Have you put a large backing plate in behind the sides and underneath to spread the load? Would very much like to see a photo of the innards of your design, as I would like to do the same assuming it is all very secure...thanks, Adam

Hi Adam,

Sorry for somewhat delayed reply , I haven't been back here for a while :-)

The Hardinge stand is made of 4-5mm plate steel near the corener bend it is easily strong enough to take the 700kg load .

However, the lathe is extremely unstable on those wheels and I removed them ater positioning , never to be refitted.

I've recently received a really good question from a PM forum member regarding the HLV-H VFD conversion that I completed ten years ago. I t asks what i would do different now .

I thought it might be worth posting my answer here for other's to see and comment on.

Switch or not to switch?

In 2009, new VFDs were very expensive so , I bought my VFD from eBay (3ph ones then were cheap!) .It was a conventional switched output VFD and so it tends to lack power at lower output frequencies, leaving me little option but to switch motor windings.

There have been suggestions that there is no need to switch motor speeds, if one used a modern sensor-less vector type VFD. These VFDs can compensate at low frequencies and provide much more torque. I have not tried one , so I can't be certain but: The Hardinge motor has a 3:1 speed change and that is asking a lot of the VFD (in 'low' speed it would be only putting out 17Hz) and motor.

It is notable that when Hardinge produced an all electric vary speed HLV-H they up graded the motor to 5hp .

I remain a switcher :-)

When to switch motor speeds?

There is at least one forum member that will tell you that VFDs are happy to be switched under load . I strongly disagree, and so ,as it happens, do Siemens and every VFD maker whose manual I have read!

I played around trying to make the VFD 'catch' the spinning motor, to allow seamless speed changes, after powering down swapping contactors. In the end , that proved unreliable, so the stop /switch/ start logic was used.

When I started the conversion , I had been building electronics devices for years and wanted to get away from microprocessors and complex logic, which is why I chose to use simple relay logic.

It turned out to be quite complex relay logic and made the machine somewhat 'clunky', so IF I were to do the SAME conversion, I think I'd now wrap the logic up in a PIC micro-controller and use solid-state output to drive the contactors.

However , I have been thinking about different ways to do the conversion: Someone on this forum suggested two VFDs ,one for each speed.

The two windings are separate and, provided the other VFD is disabled, each VFD could be optimised to drive its 'motor'. I have a couple of spare Siemens VFDs (one for the speed jack) and intend to try this at some point. I may be able to get the 'flying motor catch' to work with this setup.

Bigger VFD and more power ?

Something that has come up recently, in relation to milling machines , is that the VFD tends to limit the maximum motor power : Motors are very robust and can easily produce far more than their plate rating for short periods if the current is available. A bigger than 1.5hp VFD (and transformer) could be easily used and would provide more power , but I can't say I've ever needed extra power on the lathe.


Transformer to voltage doubler?

In most of the conversions (240v 1ph to 415v 3ph) I have used a step-up transformer to get the higher voltage single phase for the VFD. In a couple I have used a capacitor voltage doubler. In one factional Hp device all it required was a simple wire link inside the VFD . For my brother's mill conversion I built a large 4kW unit with a couple of large high voltage caps (from a dead VFD) that is nice and compact and has been working fine for a couple of years.

There are VFDs available now with a capacitor doubler inside , so perhaps that's the way to go rather than a difficult to find transformer?

What else?

One thing I would suggest is a VFD with braking resister option (do not confuse this with dc injection braking); The spinning motor and gubbins generate a lot of volts when the VFD tries to slow them down , this power has to be dumped somewhere and without a braking resister , the bus voltage will rise causing the VFD to give up with an over-voltage fault (requiring a reset) . I managed, to get the braking time down to something usable but would be better with a BR.