Member postings for Kevin McCartney

Dave

Thanks for taking the time to reply. I have checked all terminal connections and they're tight. The switch over socket is wall mounted. I have rattled, pulled and twisted the cable between the VFD and socket but the symptoms are the same. I haven't tried the multimeter yet but will next weekend.

Since your reply another fault code has appeared on the E500 - E.LF but only when connected to the lathe! This is an open circuit on phase U.V.W load side.

I'm wondering if I have two gremlins - a faulty motor on the lathe and an intermittent fault in the switch box (on/off switch or speed potentiometer) for the VFD?

Kevin

Hi

Wondering if anyone can help diagnose a problem with my inverter. It is a Mitsubishi E500 and has worked flawlessly for 10 years or so. I have it connected to a large 4 pin socket so that I can swap it between my lathe and mill.

It now only works very intermittently. When I power it on fans start as they always have with 0.00Hz on the display. When I lift the lever to start either machine the motor buzzes loudly the hertz figure increases but the motor doesn't start. If left buzzing it will "trip" and show OL on the display. This behaviour is replicated when connected to either the lathe or mill which makes me think I can rule out the machine motors as being faulty. Nothing has been disturbed or changed recently.

There are two links below to short clips of the motor noise and the inverter display.

Any assistance would be appreciated, thank you.

Kevin

https://youtube.com/shorts/Vl1CJuadBUk?feature=share

https://youtube.com/shorts/mcxUKomEvmY?feature=share

Thanks for the replies. As it's working nicely I'll leave it alone, I thought if I could add the feed rates to match my lathe it would finish it the project nicely but for my use it is an unnecessary addition (patter!).

Kevin

Another quick question - maybe someone can point me in the correct direction?

My ELS has been running perfectly and tonight I've successfully updated it to v1.3.01 - the main reason being that I was keen to have the buttons disabled whilst running, as an accidental reversal during running would shatter my PLA gearing.

Another addition with this release is support for different gearing - if your lathe has separate lead screw and feed shafts. Mine is a Colchester student and I would like to customise this function so that the feed rate displayed is true to the carriage movement.

I can't find the file to customise, can anyone point me in the right direction - and even better can you give me the values required for a Student??

Kevin

Well.....after the comments from my last post regarding NEMA selection I've had a busy couple of weeks fitting an electronic leadscrew conversion to my roundhead Student. It is now fully fitted and I'm glad to say so far it is behaving perfectly.

I'm certainly not re-inventing the wheel here and all of the credit for software development etc belongs to James Clough. The information available and Youtube videos from Clough42 are first class - it was more the selection, and placement of components that was the challenge for me and this is probably most likely to be of interest to others on the forum.

I chose a NEMA 24 4NM servo motor and driver kit from stepper online, Omron encoder and 3D printed all of the pulleys.

The pulleys took a bit of trial and error to get right but I think they'll be strong enough. I used a pulley generator on Thingiverse and inserted the Colchester spline centre using Tinkercad. All pulleys printed at 40% infill.

I chose to drive the encoder 1:1 with 60T GT2 10mm wide pulleys. I am driving the leadscrew with a 3:1 24T - 72T HTD 5mm pitch 15mm wide pulley.

Clough42 uses a die cast box from Bud industries for the control box. I couldn't find one in the UK (and didn't think to get one from from Mouser US when I placed the order for the LaunchXL) but found that a Hammond one available in the UK has exactly the same dimensions although the corner radiuses are slightly different. I can live with that. I 3D printed the lid and printed the control button information on a laser label.

After much deliberation I went with a 36v switching PSU for the servo motor and got a din mount 5v PSU for the LaunchXL and enclosure fan. Component layout below:

It took ages to decide on where to place the motor but in the end I placed it between the main drive belts. This meant there was absolutely no modification of the lathe needed. It fits nicely with loads of adjustment available.

The encoder was slightly easier but care had to be taken to keep it inside the cover

Finished power box below. I thought the box was going to be overkill size wise but I'm glad I left some breathing space!

Control box sits nicely next to the vid control

I really enjoyed the project and am pleased with the results and consider the outlay worthwhile. Although I have most change gears it was a pain swapping them over and it is now nice to be able to select surfacing and facing speeds at the press of a button.

I hope everyone here is able to stay safe and well during the COVID-19 lockdown and hopefully get to make the most of some workshop time.

Kevin

Thank you for all of your replies and information.

I have gone for a hybrid NEMA 24 4Nm hybrid kit from omc-stepperonline, shipping from Germany. Maybe a little overkill, but the physical difference between the 23 and 24 doesn't make a lot of difference to the location preferred - if the jump up to a 34 had been required for more torque I would have needed to rethink the fitting location.

The PSU discussion is interesting - Cough42 uses a switched mode with some spare capacity over the needed spec. This seems to work although I realise a hefty linear one is probably better in the long run.

Watch this space....

Kevin

Hi

Another lurker here with only a couple of previous posts. I enjoy logging on most evenings and have learned so much just by reading through the forum.

I have a 1955 Colchester Student Roundhead with no gearbox. It performs well and although I have a full set of gears, changing them is a pain in the neck. I have studied Clough42's ELS project and have ordered some components for a build. I am fairly confident as I have successfully completed many arduino projects in the past.

If anyone can help my questions (so far) are: what size Nema Hybrid servo motor would be suitable for my lathe? I think some Students had 3HP motors, mine has an original 1.5HP as I think some were supplied with lower power for college use - I don't know if this info will help. Certainly 1.5 HP has always been enough for the jobs I have undertaken.

I have taken measurements of motors and made up templates - a NEMA 23 3Nm would fit nicely. Would this provide enough torque? I intend belt driving and gearing 3:1.

A larger NEMA 34 would be a squeeze in the location preferred as I don't really want to butcher the original end cover, although a shorter 4Nm may fit.

Clough42 mentions 3ph steppers although many of the ones I've seen are 2ph - is this a consideration or does the supplied driver box take care of this?

Any help gratefully received.

Kevin

A shame - I got my first lathe tools there. Keith was really helpful the morning I went and spent time explaining a couple of things to me. I'll also miss seeing the Border Terrier crashed out sleeping in his basket at the front window!

Hi, I've been lurking here for a while. I have had a 1955 Colchester Student Roundhead for 18 months now and have enjoyed making small parts for my motorbike - stand bushes and petrol tap levers amongst other pieces. I have an interest in renovating old Hyflo aquarium pumps. Looks like a milling machine will be my next purchase....