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Member postings for Joseph Noci 1

Here is a list of all the postings Joseph Noci 1 has made in our forums. Click on a thread name to jump to the thread.

Thread: Harrison M300 single phase from new
15/07/2020 17:05:26
Posted by Bob Worsley on 15/07/2020 16:43:22:

Really not a good idea to run a three phase motor with a static converter in delta. Endless comments all over the web but principally because of circulating currents in the motor, excess heat.

 

Valid, if the machine is running for hours rather that the very intermittent hobby use..

  Mmm, all currents have to circulate in the windings to do any work, I would have thought...

The issue is maybe more one of imbalance of 3 phase currents due to the capacitors attached, and resulting phase imbalances - if this does bother you, for what is anyway intermittent use, you could balance them by selecting your capacitor values..

Rotary converters do work well, are very reliable, no electronics that let smoke out - no variable speeds, etc. Perhaps a little less green in power usage, but maybe greener when considering the total mnfr chain?.

Edited By Joseph Noci 1 on 15/07/2020 17:11:36

Thread: Emco servo conversion - compact 5 cnc
13/07/2020 14:54:33

Still nine fingers left then though...

Sam, what CAD/CAM software did you use to generate the cut file? Is the cut file G_Code?

I wonder how practical some live tooling would be on a setup like that? A third axis in Z bolting in place of the tool post with an ER spindle - would make the bolt head a lot easier on the machine!

Very nice setup - servos are certainly well tuned!

Nice job!

Joe

Thread: What Did You Do Today 2020
12/07/2020 14:49:46

Seems you might be able to -

Nextion editor on Mac

But not going to get into the Mac/Windows/Linux/Java thing...

12/07/2020 13:30:50

Hi Ian,

You should take a look at the Nextion displays - sizes from around 2inch up to 7inch - maybe more these days - a serial ( ttl level) interface, available with touch screen, 5v supply.

I use these extensively for non-dynamic graphics and text displays, esp suited to machine control, Radio panel display, etc.

You use a vendor supplied Screen page editor to create the structure of the display ( layout, placement of buttons, colour of buttons and colour change when activated, etc). To create the actual graphics you can use any graphics type editing package, photoshop, etc, I use a freebie - Inkscape - which is hugely suitable for this stuff. Save the graphic as a .png file, and load that into the screen editor mentioned, and define where it fits, how many screens you have, what is on each screen - create sliders, 'rotary' knobs and controls, etc. They just work...the image below has user buttons in the bottom row, and a screen brightness slider center below.

front main page.jpg

front_setup page.jpg

channel mode display.jpg

list of all channels.jpg

Thread: Anyone made Myfordboy's powered hacksaw?
28/06/2020 13:36:30
Posted by not done it yet on 28/06/2020 11:14:58:
Posted by Joseph Noci 1 on 28/06/2020 09:47:10

...

edit : won't that rearward protruding part of the blade smack the motor? Maybe you just have not cut it short yet..

Edited By Joseph Noci 1 on 28/06/2020 09:48:32

It’s already at the rearmost part of its stroke, Joe.

Moral is - open eyes, then engage brain, before opening mouth or typing...!

Joe

28/06/2020 09:47:10
Posted by IRT on 27/06/2020 23:19:19:

I finally finished the build today.

Now I just have to make it pretty.

That looks very nice! Very compact and certainly a lot lighter than mine! Please post a link to a video of it doing its thing..

Well done.

Joe

edit : won't that rearward protruding part of the blade smack the motor? Maybe you just have not cut it short yet..

Edited By Joseph Noci 1 on 28/06/2020 09:48:32

Thread: Omron VARISPEED CIMR-V7AZ21P5
21/06/2020 11:17:59

Yep, I would agree, that module probably done for - An internal short in the power module could put all sorts of power voltages out on pins where it should never be, and so the caps suffered.

Ditch it - not worth repairing - even with schematics..

 

And No, you cannot predict capacitor values or voltage ratings from their sizes - a 50v 100nF SMD ceramic cap can be the same size as a 10v 10uf ceramic cap, etc..

Joe

Edited By Joseph Noci 1 on 21/06/2020 11:18:55

21/06/2020 08:28:29

Mmm, only decent way is to have a schematic of sorts, or a parts list, or as a last resort, to try trace out a bit of the schematic from the PCB layout, to see where those caps fit into the scheme of things..

They are in parallel, and might be a snubber across some spiky voltage, or they may be across the incoming AC mains, as part of an EMC filter, etc, etc,...until you have some idea of where they fit, its a nogo.

Even if someone out there has an identical unit and can open it to see for you, those caps are SMD and they will NOT have values marked on them.

However, even if you find what they are, I strongly suspect they will be a few more blown bits aside from those caps!

SMD ceramic caps generally blow due to - mechanical internal short, due to either poor quality cap or the PCB flexing and micro-cracks develop; over-voltage; or way to high ripple current. If any of the latter two, then I am sure some more bits also are blown..

From the PCB tracking, it does seem they are on the mains input or rectified DC output side - try to trace out the interconnections around them, also give some photos of the other side of the board in that area, so we can see what other parts are in the vicinity.

Joe

Thread: Experimental Vibration Analysis of a WM280 Lathe
19/06/2020 11:25:34

My accurate Clock reference - generates a 10MHz clock, typical accuracy to 10-13.

Uses an 'old' HP voltage controlled ovenised crystal oscillator, with a phase locked loop, locked in essence to the GPS 1PPS signal, with a many tap IIR filter to help. The oscillator is from a defunct HP Cesium Beam standard - the Cesium tube now dead..

The GPS time can then be set to UTC, and then the 1PPS synchronized to UTC, derived from the stable crystal clock. Generally to better than 0.1 PPT...with jitter seemingly better than 1PPB - I cannot measure to better than than 1PPT, so...

With a Nucleo of course..

Waaayyy of topic now...

Joe

front main page.jpg

top_open.jpg

Thread: My Morgan SCARA coming together
18/06/2020 18:14:24

Neil, a 'tad' is slightly understating, no?..

I am keen to be able to fit a laser head of sorts, but that is another field on its own. A fibre laser would be nice as the weight is remote, with only the fiber and lens at the end of the arms, but the fibre laser is rather limited in application with certain materials - wood and many plastics are a no go, pvc, acrylic, etc. I did try one of those chinese '5 watt' blue laser heads - absolute junk - if that was 200mW it was a lot...and the control electronics was useless - pulse control was very poor so raster engraving was mediocre. There are a lot of those type lasers from Ebay, Ali-xyz, etc, but the specs are impossible to believe..

So, any ideas for a good (light weight) engraving laser are welcome!

No idea what sort of laser is needed for SLS, but the idea is interesting - when the machine is sort of working I may try the SLS route.

Thanks for the good words chaps!

Joe

18/06/2020 12:10:49

WARNING - Those opposed to over-engineering should avoid reading this lot...

This project started as a challenge, rather than any need for a 3D printer. It has been almost a year and slowly it is starting to come alive - although I still find no need for a 3D printer...

Anyway, a challenge it is - Polar co-ordinate world to work in, with inverse kinematics and some fun math..And I don't leave it there - the Hot end is an induction heated one, the heat part is currently being worked on on the bench in an attempt to see how often I can blow it up in one day...

Also, the extruder drive train will ( hopefully..) be a brushless (RC) motor drive - so am also developing a Step/Direction input brushless motor servo drive. The reason for the induction heater and brushless motor drive is to try get the entire hot end / extruder below 150grams, 200grams max. I also want the extruder to be at the hot end, no Bowden tube, etc. So a lot of fun still to be had.

In the meantime, the actual SCARA arms, the drive servos/stepper, powers supplies, Nucleo brain, etc ias all together, and my good Wife is software-ing it - I have to fit a spring loaded pen to the hot-end end, so she can draw some calibration verification squares and circles to start.

Some photos - beware, the qty of pics matches the engineering effort..

The electrical/electronics box, ready for tig welding

ready to tig elec box.jpg

Some tigging done..

box tigged.jpg

Re-winding an old Amplifiers toroidal txfmr to suit my voltage needs:

winding transformer.jpg

All Wound:

wound transformer.jpg

Trial wiring before stripping and painting:

start of trial wiring.jpg

Ready to strip and paint:

ready to paint.jpg

Painted:

painted.jpg

Starting to test things:

test starts.jpg

Electrical box wired - Extruder control and induction heater still to go in at lower right.

electrical box.jpg

SCARA Arms servos:

servo drives.jpg

Z Axis Stepper drive and leadscrew:

z stepper drive.jpg

Next installment when the thing moves about and draws stuff...

Joe

Thread: Experimental Vibration Analysis of a WM280 Lathe
18/06/2020 11:27:29

Too little time, too many distractions, and insufficient discipline.

Dave

Thank God for that! I think, post career, that all those elements are what keeps up healthy, alive, alert and the brain active. ( sorry, what were we discussing...?dont know)

on your issue with the GPS signal..

My clock-analyser project stuck when I realised it depended on a good GPS signal. My unit doesn't work reliably indoors and having to take clocks outside for testing is a bust.

- I had a similar issue with a 'mobile' GPS stabilised reference oscillator - I made a sort of 'signal repeater' - I used an active GPS antenna, fed it 5v via two 10uh inductors using an SMA T connector - the antenna on one end of the T, the 5V on another, and then a 2nd , non active antenna, on the 3rd end of the T.

Place the active antenna outside with good sky view, and place the 2nd antenna with its business end on top of the antenna you wish to get the signal into. My antenna each had 6meter cables, so was easy to locate - Worked a charm.

Dave, if interested PM me your email and I can send you all I have on the Miklos system - lots of PDF's and photos of setups, quite interesting.

18/06/2020 08:45:44

Michael,

Yes, I found that as well, but his web site is gone, and he does not answer his email anymore. The manual gives interesting insight, but how to obtain his software - it was inexpensive.

Must remember we are speaking of a dynamic balancing tool here - not at all what Dave is chasing - this tool does not do vibration analysis in the true term - just enough to do balancing.

Vibration analysis with a view to machine reliability analysis is a life's work and a handful of dissertations all on its own!

You may know the SA Rooivalk Helicopter...I had a 'small' team ( 9 people..!) working on developing a real time vib. analysis strap-on system to predicate lifetime and service interval requirements on its rotor gearbox. That was interesting - digging out the few hundred hertz gear-teeth vibrations from the wapping of the rotor blades from a few rpm to maybe 500rpm, the turbine reduction box noise, etc....There were more than a handful of TMS 320 series DSP's,...And a few maths geeks far smarter than I was on the subject!

18/06/2020 07:26:38
Posted by SillyOldDuffer on 17/06/2020 19:02:54:

Off searching for Miklos T Koncz now.

Ta,

Dave

Dave, seems Miklos has disappeared. Cannot find any trace of him or his doings anymore. Maybe I can help you out with his kit if you are interested....PM me..

Joe

Thread: Equatorial Platform Build
17/06/2020 21:25:23

Nice Neil! Quite amazing how model making is changing - so many technologies and disciplines are becoming easily accessible , each of which just open up new ways of doing things, which in turn enable the next level up.... You are certainly getting your monies worth wrt the 3D printer!

Keen to see this mount assembled and driving..

Joe

Thread: Experimental Vibration Analysis of a WM280 Lathe
17/06/2020 21:17:48

Yep, thats the technology of the day, back then - used many variants of those when we did the MIL-STD-810 environmental qualification tests on avionic boxes - used to close the vibration loop on the electromagnetic shakers.

Those sensors were expensive for sure! And the Charge amplifiers likewise.

The one in the photos still works, in my draw, with its charge amp..

accel1.jpg

accel2.jpg

17/06/2020 18:06:45

Can't find my circa 2016 post on the vibration analyzer/balancer I built up ....Anyway, used software from Miklos T Koncz , a Hungarian. Built up the accelerometer sensors using ( now a bit old..) Free scale MMA7260 3 axis analogue output devices, into the laptop sound card, with an optical rotation position sensors.

Works very well indeed - used it to balance spindles etc, up to 25K rpm.

Might have a go and instrument the lathe...

balancer sensors and control box.jpg

Accelerometer modules

accelero modules.jpg

Sensor selection control box

control box.jpg

Balancing a 20Krpm spindle on a sensitive drill press.

Red arrow is the balancing 'weight' - a small strip off adhesive aluminium tape. White circle is rpm and position center.

balancing.jpg

Accelerometer super-glued to support arm to measure lateral acceleration.

balancing1.jpg

Thread: Reciprocating mass instead of flywheel?
16/06/2020 10:57:49
Posted by JasonB on 16/06/2020 10:33:21:

2nd one down is what you need

Posts crossed, I don't see the need for a crank on a filing or sawing machine and like above shows TDC would be when piston is at one end of stroke, BDC at other

Edited By JasonB on 16/06/2020 10:40:54

As I said, that is a double acting cylinder with NO CRANK. Obviously such a mechanism works fine - the motion is generated linearly from the start - there is in fact no TDC or BDC - the motion changes direction when the appropriate valve is actuated.

If PGK drops the thought of a crank in his mechanism and uses a double acting cylinder, then , well, nothing to discuss..

16/06/2020 10:48:14
Posted by Neil Wyatt on 16/06/2020 10:43:34:

Final thought,

Various multi-cylinder designs work without flywheels, anything will rotate continuously if it doesn't have dead spots.

The real function of the flywheel is to smooth the motion, this is why water power was still preferred to steam for spinning yarn in the early days and also what led to the invention of the governor.

Mine and feed pumps have no need for smooth, constant delivery of power so don't have flywheels.

What about steam locomotives? They don't have flywheels but use the massive momentum of the whole machine to smooth their motion. There were some notoriously unbalanced locos that used to sway or hammer the tracks due to poor balance.

Much lighter steam cars had flywheels, as did road locomotives that usually had to function as stationary sources of power. Steam wag(g)ons were bigger and heavier and usually had multi-cylinder engines.

The real answer, I suspect, is that adding a reciprocating mass (a) creates challenges in tuning it to match different engine speeds and (b) requires a level of extra complexity that could be used to add a second set of cylinders.

Neil

Still do not agree!

They certainly have flywheels! The Linear motion is converted to rotary by the very wheel on which the loco runs, and so as the loco moves, its massive momentum forces the wheel to turn, forcing the crank to move...The loco, its, weight and momentum, and the coupled rotary to linear motion is precisely what a flywheel is, no?

Joe

16/06/2020 10:44:11
Posted by Neil Wyatt on 16/06/2020 10:35:15:
Posted by John Haine on 16/06/2020 10:23:17:

Flywheels store kinetic energy, wouldn't a pendulum be better?

How about a pendulum that swings right round into a complete circle.

We could call it a pendwheel

Neil

Or an angularly-disadvantaged flywheel..

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