Member postings for Joseph Noci 1

I second most of what you said Dave. But I still believe the method is not bad. No good in a production setup maybe, but the FB2 is a hobby machine.

I spend a fair time in the workshop, but the FB2 and the lathes work maybe 5-8 hours/week and I find I adjust the backlash on the FB2 maybe every three or four years.

On the lathe the backlash is ignored anyway - as you say, with DRO it matters little. The FB2 also has DRO, but baclash on XY is important to me there. It helps prevent issues with normal/climb milling trying to pull the opposite axis into the cut.

Nuts can be obtained from EMCO Austria still - pricey I guess.

7075 does not wear cutters much worse than any of the other Al grades really - it's all related to cutting speeds and feeds, and lubricant. Carbide drills in 7075 wear when speeds are high and no cooling occurs - the Al adheres and forces grow, chipping the cutting edge. There is around 0.2% Si and Cr in 7075, where its 'toughness' is derived, but I would not say it is abrasive. Be careful of choice of bronze - some are very hard - try for a high lead bronze perhaps.

But maybe we are being over-fussy here - the Z axis movement is very small generally, and much more infrequent WRT X and Y. Wear in Z is rather slow, if things are set up correctly and lubricated - As Graham indicated, no wear or required adjustment for 26 years, mine even longer. Any of the harder Al grades would probably be fine, as would probably be any bronze or brass even. The wear action is so slow...And as Graham also indicated, backlash should easily be taken up by the weight of the head anyway - if not, then the gib strip screws and slide block pinch bolts are probably way to tight.

Was the upper half of the nut, the part above the compression slits, still attached to the lower half, ie, was it only that the threads are stripped from the upper half, or had the upper half parted from the lower half?

Are there signs of rubbing tween leadscrew and the crimp nut interior ( item 4 below) at all? If not it should be impossible for item 4 to unscrew, unless the z nut somehow rotates- that could occur if item 22 is not well tightened..

Do you recall what the hole in the side of the nut, where item 22 impinges, looks like at the moment? Has it elongated vertically? If so, then all the head weight is on item 4, compressing the z nut slits all the time and wearing the upper thread half prematurely. However, that that should even more prevent item 4 from unscrewing as it is under tension all the time. Or has the hole elongated horizontally? If so, the nut would turn a little each time Z is wound, and that would cause loosening of item 4

Still not sure I understand - I know the nut well, so understand how it works, but fail to understand how if the lower half's threads are not stripped that the head would still not move. Was the leadscrew turning while the head remained stationary? If so then the lock-screw in the side of the slide block into the Z nut was not preventing the z-nut from turning. Or would the leadscrew not turn, ie, jammed?

If the upper half threads are stripped while the lower half are good, then the compression nut on top of the slide block was probably way overtightened - a number of times...

The design works and works well if not abused, so it should work for you as well!

I frequent various EMCO ( lathe and Mill) groups ( groups.io, etc) and no-one has complained of the Z nut design being unfit for task..

How 'partially' stripped? If the head would not move while the leadscrew turns, then the nut is stripped properly..How did you 'fix' this by boring out stripped threads?

I have 3 FB2's - One is cnc'd with ballscrews, but the other two have the original Z nuts in, one still OK after 32 years, the other after 21 years.

I do however have a spare set of XYZ nuts, obtained from EMCO 2 years ago - they still have stock..

The Z nut is a simple one to make though - if you can find a piece of 7075 aluminium bar stock that will work just fine.

The thread will need a inner pointing tool ground , but that is not to difficult I would think.The thread is quite short in that nut so the tool need not be very long. When I obtained the second FB2 (pre-owned) , it was imperial and I purchased metric leadscrews and nuts and dials (2001) and swapped out so I have a set of new imperial screws and nuts in the cupboard...I did investigate shipping costs to the UK for another fellow interested in some other FB2 parts, and from Namibia it was horrendous - near 170 pounds to the greater London area!

I use HIKVISION cameras a fair bit - camping lodge water-hole viewing, home perimeter watch, etc. The DS-2CD2012WD ( 4mm lens) is a small camera that works very well at night, self IR illumination up to around 30meters - 12V DC and a LAN cable to your PC with their software and you can view, record, etc. I am sure you have HIKVISION in the UK - around $60 on ebay. They also have WiFi cameras of similar ilk - need only supply +12v, if you have a WiFi router in your home for your internet, etc, then that is more convenient - there are around twice the price though...

There are wildlife cameras ( https://www.wildviewcameras.co.uk, etc - ) from a number of 'outdoor' shops, but those cams are generally above £100 ( plus!)

If you have a decent Security product supplier nearby I would pay them a visit. ( https://www.argos.co.uk / https://www.gardenersworld.com/, etc)

All fixed and all working fine from my end - only difference is I see now I remain logged in from day to day - used to be auto-logged out a short while after having closed the site on my browser.

I wish the forum well with the Mortons move!

Edited By Joseph Noci 1 on 10/06/2022 11:54:08

And from 14H00 today the MEW site comes back with a 'not-secure' certificate and is blacklisted by Chrome and Norton antivirus...can only access the site in 'unsafe' mode, ie, virus check is disabled on this site now - also had to re-enter my logon info...in unsafe mode...

Reports as :

This server could not prove that it is www.model-engineer.co.uk; its security certificate is from *.mortons.co.uk. This may be caused by a misconfiguration or an attacker intercepting your connection.

obviously not an attacker, but certainly misconfigured.

Also makes it difficult to post anything, as Norton rejects the effort until I tell it to ignore the danger..

Edited By Joseph Noci 1 on 08/06/2022 14:23:24

Why is that? Are they scarce because of environmental issues in your country? There appear to be many sources for 9v NiMH rechargeable blocks..

Michael,

That tool does everything mine does, and a lot more! If I were still mucking around building my house I would ditch mine and get one of those. I think the Drywall reference is for our American friend's peace of mind - I have found on numerous older reviews the American have regularly asked if it works with drywall - since that is the primary construction method there I guess.

Here are some reviews that show it's ability against brick and concrete as well. ( Forgive the patronising video - not my doing..)

**LINK**

**LINK**

The dielectric constant of the materials do play a role in the detection capability, and drywall tends to be air or foam etc in the cavity and the detection signal is less masked compared to when in concrete/brickwork, so the unit is perceived to be more sensitive - meaning that a 'conventional' detector would probably battle to localise the detection area due to the heightened sensitivity. The self calibration of the unit held against the drywall would correct for that I guess.. A the risk of placing myself in the line of fire, I would recommend that unit - if you can live with the size in your application.

Waayyy to sharp for anything more than 10amps....

I have an oldish Bosch - PDO Multi and it works well, even does a good job of detecting wood 20mm inside a wall...! I have found sensor orientation has some influence on the center of detection - hold the unit vertical battery down gives a sense centre that is approx 15mm lower than if the unit is vertical battery up - the average of the two seems always to work..Left / right position is good, irrespective of unit held up or down.

Live cable sense very good, dead cable sensed in metal detect mode and depends on cable thickness - 2X14 gauge copper wires detect easily at 30mm below plastered wall. 50mm panel-pin head detects @ 25mm.

The PDO is no longer available and Bosch intimates the GMS120 is its successor - I would go for that.

Bosh PDO Multi Manual

Bosch GMS-120

Windy mentioned earlier issue with detection when tig welding at low amp - most of the inexpensive helmets do not work reliably at low amps - 40 and down, esp in the sub 25 amp region - with TIG - they work better with MIG and stick at those sorts of amps but the TIG arc is very small and rather shielded by the TIG cup - the helmet detectors then fail to detect, or do so some seconds after the event, and clear the lens during welding when the arc is shielded as the TIG cup is rotated, etc - that results in Brighteyes....

I use an ESAB Sentinel-A50 - works very well even down to 4 amps - welding Beer cans together...Eyes are worth more than any helmet.

If you can stabilise the job decently, a auto-dark helmet is not really needed by weekend welders for MIG - you can place the torch nozzle correctly and close the hood and press the trigger - enough light thereafter to see what you need. Production welding is easier with auto-dark. Stick welds - I would go for auto-dark else its a bit of a hit and miss affair - although I would maybe consider spending the decent helmet money, plus a little, on a small MIG machine rather, and use a flip helmet to save the spent money...

Edited By Joseph Noci 1 on 03/06/2022 16:17:44

Sorry Chris, No such thing in JHB, or anywhere near, I fear...There are not even any machine suppliers of the kind you have in the UK either ( ARC, etc) . There are large machine tool companies, all easily googled, and 'Ardendorff' - real crappy type tools supplier, from cement mixers to lathes, welders, etc, but really low quality stuff. There are no model supplies - metals and such...there are a number of 'hobby' shops, but all are model trains - small stuff, HO scale, etc, Radio control models - a good shop in JHB -Aerial Concepts - etc.

The only modelling club worth 'something' is the Centurion Society Of Model Engineers - located at 193 Kwikkie Cres, Zwartkop, Centurion, Pretoria direction - google for contact info - the members may have a better idea of sources on interest. No modelling club in JHB - a good one in Petermaritzburg - a bit far..

For Tooling ( I am in Namibia) I normally get from Skok Tooling in JHB - a big company, not street visitor friendly, KNUTH machine tools, likewise a big company, not hobby style at all. there is also 600SA - Harrison, Colchester lathes( big stuff), etc, , Eason Vertex ( rotary tables, Vises, etc) - All supplying industry, big manuals, CNC and so on. Mostly, I get my tooling abroad - UK, germany, USA and China...

Not much for the general hobby line I fear..

Joe

Agree!! I could not have said it any better!

A bit off-beat maybe... I designed an Omni-directional Airspeed sensor (OAS) that sits atop the standpipe above the main rotor on the SAAF Rooivalk 'copter. A 350mm horizontal tube 10mm OD, with pitot holes in the tips at opposing leading edge, feeding two pressure sensors. The tube spins ( like the "copter rotor..) and if standing still with no wind, the differential pressure measurement is nil. Any wind ( from wind or motion) creates differential pressure in a sinusoid voltage, which is proportional to airspeed. A optical encoder disc fixed to the vertical spinning shaft gives position of the spinning tube relative the the sinusoid, and from this is derived wind direction. The device was calibrated in the Wind Tunnel at the CSIR...

I still have the prototype which I use on the ground when we go fly our UAV in the desert - to derive landing approach for wind direction and speed...

Joe

EDIT - we had a 20meter rail with a winch towed carriage in the lab - the OAS was mounted to the carriage and the winch would wind the OAS along the track - from 0m/s to 10m/s within 15meters. Carriage speed and OAS data was logged and a calibration curve for the sensor derived. We were generally within 3% of the wind tunnel cal results..Air cons were turned off during the runs...

edit-2 fix a typo or two..

Edited By Joseph Noci 1 on 25/05/2022 20:41:40

This question is important...The steppers all (except the OP) are referring to are 'run off the mill' , ie, low voltage 'high' current. A motor plate rating of say 3V / 1,5A means apply 3volts to get 1.5amps flowing. John indicates a voltage of 24 or 48 volts ( why the two? - probably because the motors can be wired series or parallel - 4 or 8 wire motor-)

However, the issue is the 24/48volts - if that IS the namplate voltage for winding rated current, then the stepper controller will need to have a much higher input voltage to ensure di/dt constraints are met. One normally applies anywhere from 12v to 60v to the stepper driver to drive 'normal' 3v or 5v type steppers. The same relationship applies if the stepper is a 24v or whatever motor. A 24v winding will also demand lower current ( field strength is related to number of turns in the winding and teh current thru said winding), but the resistance is greater and also inductance, so a higher voltage is needed to get the current flowing fast...

Running such a motor from a 24v stepper driver will lead to tears...

As usual, lots of speculation with insufficient data input -

post the namplate specs of the motor or a link to its spec sheet...volts, amps, inductance...

Very nice work as usual Graham. I was not aware of your trials and do wish you well.

Difficult to lose the Super-11...I trust you will always have a place for the FB-2 though..

From the machining marks on the Clutch upper body it seems the process was carried out under CNC control? As usual, a complex piece done well! Keen to see it come together.

Joe

How will you process the 'few' images Michael? I build drones ( fixed wing) that Surveyors use for land survey - fitted with reasonable ( 25mpxel) cameras and 50mm lenses - we fly with autopilot, a ladder track over the area taking photos that have left/right/forward overlap of 40 to 60%. We used Agisoft software to process - creating full 3D imagery, full dimensions, volumes, etc. Used a lot by local mines to determine stockpile volumes versus mined 'hole' volume, etc. Camera sensor size/pixels, lens focal length, etc all play a role in ground resolution - so not sure what you are after - We have obtained very good results - 10cm ground accuracy to 2sigma - with simple cameras Canon Powershot - pocket camera - 350grams, with a pentax fixed focus 50mm lense. FLight height above ground should be better controlled if sub 10cm ground resolution is needed...since I don't know what you need, I cannot comment!

Wow! Looks like an accident in the waiting...

Those elements are typical of types using in small baking ovens - two vertical at the oven rear wall, with a blower through them over the bake.

I hope that wiring is high temp silicone at least but still that dries and the insulation becomes brittle with heat and time and will fret away...with all that loose untrunked wiring that is a killer..But back the the questions...

No way that will run off single phase: If those elements are the typical 200mm diameter type, they are abt 3 to 4KW .

Sort of ties in with the '5elements in the box statement' and that the spec was for a 20KW oven - more or less..

Assume the motor is 1KW. 21KW is 90amps form 220VAC single phase....No need to discuss further I guess..Plugging this into the local mains will turn the whole village into a heater as it burns down, as I am sure when the breakers trip, Car battery cable jumpers will be used to bypass the breakers...