Member postings for Manofkent

Nigel

Many thanks for all this information which is very helpful.

It reminded me that my Harrison L5 lathe (now long gone) was powered by a 1.1kw motor and was plenty powerful enough - so a 1.5 kw will give me power to spare.

Now I just have to work out how to fit the motor in the lathe...

Thanks once again

John

Hi Nigel.

My ACL is now a Mach3 lathe. But when I got it the internal wiring had been well messed up - I think it had had a swarf conveyor fitted at some time, and then removed without care!

I still use one relay per Z and X axis limit switch as in the original - and these wired in series.

Here is a picture of the Motor plate.

The Parker SSD drive has blown quite a few resistors and a capacitor - not for the first time either.

So I was wondering - I can gat a replacement for about £350, or go AC with a VFD as discussed above.

Any advice gratefully received.

John

Thanks for your helpful replies.

Nigel - yes it is a Boxford ACL - although the rest of the cnc is now Mach3 .

Steve - amazing YouTube clip. Thanks.

I use the lathe (and my cnc mill) for small runs of parts and for one off designs. Neither machine is worked on an industrial scale.

I tend to run the X and Y axis quite slowly - because I prefer it that way and feel a little more in control.

I recently had some blind holes to tap (M8) and a spindle speed of 150 rpm was comfortable, but could be a little faster I guess.

Nigel - the spindle motor is an SEM one and weighs a ton. The issue really is whether to repair the DC drive boards or start again. The motor itself is old but OK.

John

Thanks Old Mart.

So I looked at some suitable drives on the inverter drive supermarket (that's a great resource by the way - thanks).

A suitable Parker drive says it varies down to 0.5hz which would in theory be about 70 rpm. Is it right to assume the motor power would be pretty well degraded at that level?. I guess there would be other issues such as heat.

Has anyone run a motor at 200 rpm ish from a VFD? , and if so how was it.

Thanks

John

I have a large Boxford CNC lathe. The spindle is driven by a massive DC motor.

The motor is showing its age, and I am looking at upgrade options.

One option is to replace it with an AC motor and VFD - but I have no experience with VFDs.

I have 3 phase power available, so would only need the drive for speed control.

My question please - what range of viable motor speeds can I expect through a VFD please? What are your experiences?

For the technical I would probably use a 4 pole 2hp motor.

Many thanks

John

Jack

On my ML10 the leadscrew will continue to rotate when the dog clutch is disengaged, but can be stopped by hand if needed. It does not have the power to take a cut with the saddle - to do this needs the dog clutch engaged.

One tip - with the dog clutch engaged and saddle disengaged you can still move the saddle automatically by holding the saddle move handle. Useful when making short cuts.

John

Ian

I have the same AEW Viceroy mill in my workshop.

It is a Brilliant mill.

I have run it from a static converter. The one I used was a really old 5hp model a bit over the top but no harm done. It worked really well. A static converter generates 2 phases, and uses the mill motor to generate the third. You just have to be sure not to wire the control switches to the third phase as they won't work. I did this, but simply just swapped the wires from the converter until it did.

This arrangement worked fine on my mill.

Now I run it from a rotary converter. This is only because I now have a cnc lathe, and it needs proper 3 phases as it does not directly drive a 3 phase motor..

This powers both the mill and the lathe perfectly well and I built it myself.

Hope this helps.

John

Hi Weary

Of course we must keep 2 meters apart.

What I meant was that it only takes a lovely new loco to appear, or a technical problem with an engine, for willing hands to gather round and forget the 2 meter requirement!

This aspect can be hard to police.

John

Writing as the OP, I would say this has been a much wider discussion than I expected!

Risk Assessments are important, and we do have one for Covid drawn up a few months ago.

However, as Paul Kemp says above my main concern was to comply with the new rules, made especially vital as they are no longer guidelines but law.

There is room for manoeuvre as they say in the number of groups of 6 we could have on a working day, but simple is best so we have agreed that we will not have a more than 6 in attendance on any running or working day, but we have now designated 2 separate working days each week to allow more people to come.

On the risk assessment I think Graham does have a point. Getting only 6 to turn up is easier perhaps than keeping them 2 meters apart.

John

Thanks to everyone for a lively discussion.

My main concern was that the new regieme will not be advisory like at present, but law.

The Southern fed rules (Thanks Bazyle) are interesting and helpful.

If I read them correctly there is a suggestion that working parties are working on the club's business and could be exempt, while running days etc are part of our hobby and have to comply with the new rules.

At Tiverton we are operating a policy of booking attendance beforehand. Running days will be split into two parts, to allow two groups of 6 on any one day.

A note will be sent to all members to advise of the new rules. What we really want to avoid are the circumstances where we have to turn a member away.

Discussions are ongoing about working parties.

John

Great news - well done Exeter.

In the West Country we have 2 new track projects ongoing - Exeter and Taunton who have acquired their own site.

At my club - Tiverton - we are pleased to have some members who are also involved in these projects - and we enjoy all the good news of their progress.

John

So yesterday new rules (laws this time I think) were announced.

Here at Tiverton Model Engineers the Committee are now considering how these apply to our club. We run all year round with no public running by the way.

It seems likely we can only allow 6 people on site at any one time. We are already operating a system of pre booking site visits which will continue.

We may split our formal running days into 2 parts if demand exists.

I would love to know how other clubs plan to navigate these rules.

Many thanks

John

Just to say I check in daily and greatly value this forum and its moderators.

Thanks

My 3hp lathe motor ran happily fir many years from a 2 hp rotary converter!

It is worth changing the wire to terminal connections around and see if that helps.

Also a 3 ph motor makes a horrible noise when wired in delta with only two of the phases connected!

John

Thanks all.

Looks like a taper turning anchor as you say. They were probably used in pairs whivh is why I have two of them.

Pity I don't have the rest of it!

here is a pic I found on google that looks very similar.

John

Hello

I have a couple of lathe fittings, which I think are from a Colchester lathe.

they look as if they attach to the bed somehow, and slide along it.

The tapered shaft is bored but not all the way through - so I guess it is for a handle rather than to lock it in place.

Any help would be greatly appreciated. I hope the pics help.

Many thanks

John

I have converted a couple of mills to CNC.

Nema 34 is probably the size to use, but you need a high torque motor as they have to hold the work as well as move it.

I would get ball screws and fit them.

I would drive the 3 axis indirectly, with a timing belt on pulleys between the motors and the lead screws.

My first conversion had a top speed of about 1500 rpm, and to be honest this was perfectly ok with hss tools.

To operate I recommend Mach3 or mach4.

For the saddle I suggest you rig up a counter balance to take the weight off. A spring or weight over a pulley would do the trick. Maybe even an old car spring?

Good luck. It looks a useful mill.

John

Hi

There should be two screws on the top of the boiler - 5 BA countersink if I recall correctly, that hold the regulator vakve body in place. If you undo these you might be able to move the regulator body sufficiently to see what is going on.

John

Hi

I presume you are using service motors fitted with encodes?

What encoder interface have you used?

John

Thanks Nigel.

Yes the Parker drive has those connections (and a load more - mostly on a 10v control circuit).

Your reply is most helpful. I thought I was losing my marbles trying to wire up this motor. I think the designation "Servo" took it to beyond my understanding.

I fabricated a new connection box cover. As you say, too small for some pretty thick cable.

Is there a way to tell if the thermal switch is still working. Were they normally closed or open do you recall?

Once again thanks. Your reply has been very helpful.

John