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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: What Did You Do Today 2020
12/01/2020 11:51:00
Posted by Andrew Johnston on 11/01/2020 11:37:47:

Over the last couple of days I've been machining the taper on the chimney former for my traction engines. Roughing was done at 180rpm, 50 thou DOC and 8 thou/rev, so quite modest for me. The chips were coming off dark blue though. FInish cuts were at 370rpm and 4 thou per rev, DOC as required, but generally 5 to 10 thou. Here's the setup for a finishing cut, about 15 minutes per pass:

finishing - former.jpg

I've been in discussion with a forum member, via PM, regarding the purchase of such a relatively large lump of steel. I mentioned that I got a rather odd finish, and promised to post a picture. So here it is:

The material purports to be EN1A. The general finish is so-so. It measures 3.3µm Ra, which is ok but not brilliant. Of course that doesn't matter for my application. The really odd thing is the darker bands every ¼" or so. I can't think of anything on the lathe that is repeating at that distance. Although the template is hand crafted I doubt my filing would produce such a regular pattern. That leaves the material. Each dark band is a bit shiny, which I associate with harder material when turning with inserts. I wonder if this is something to do with the extrusion or drawing process? As an aside, when roughing I had some problems with chatter. The chatter distance was short. an 1/8" or less, and at random places. One time next to the tailstock, next time in the middle. And the tool never chattered in the same place twice. Once I'd done a few roughing pases the chatter never re-appeared.

The former has tarnished overnight in the engine assembly area, sorry entrance hall, which seems to indicate EN1A.

Andrew

Maybe just changing feet while I open my mouth here, but...

I do not know that lathe at all, but is that a taper turning guide/attachment/mechanism hanging from the rear?

If not, how did you cut the taper - using a taper guide plate of some sort? What keeps the cross slide bearing up against the guide? Or does the lathe have a change gear set that drives saddle and cross slide synced somehow? I would presume the finish has something in whatever mechanism controlled the taper section..

Both feet firmly in mouth now..

Thread: soldering stainless steel
09/01/2020 09:56:10

Some liquid drain cleaners have a high phosphoric acid content - Might be available at your local hardware. Must admit I have never had success soft soldering SS of any grade. I have silver soldered a lot of SS with ease - made many an electric Slot Car chassis from SS Sheet and 'Piano-wire' - with moving pans so the car body could flex around the suspension, etc...

Thread: Precision 10MHz reference Oscillator.
23/12/2019 08:40:20

Thanks Chaps.

Dave, it was about a hundred hours of work, but took around 2 months. A lot of development work! The 5 to 10MHz doubler and subsequent amplifiers and splitters to generate 4 independent 10dBM 10MHz outputs took some doing to get clean signals, all harmonics better than -70dBc, etc.

The signal gen and DDS outputs are also around 10dBM, but not so clean - quite adequate as a signal for , say, receiver alignment or diagnostics, but lots of strong harmonics. The PLL (Si5351) essentially generates a square wave output up to 200MHz. I only have 2 switched low-pass filters, one at 80MHz, one at 200MHz. Likewise the DDS has switched Lo-pass at 30MHz and at 60MHz.

Had to seriously filter the 26MHz from the Si5351 PPL to the GPS - a 12 pole Cauer low-pass - to make sure the GPS clock is good 'n clean..

The display - a 7inch Nextion, is a treat - they are easy to use, and give a pro look to the unit - also, if you forget a switch or control in the front panel layout, you can just add it on the touch display! I use inkscape ( a freebie) to generate the imagery and transfer that to the display.

Interesting mind image that, Lions at the Dentist..

Robert -

Not sure I understand your question? I think you are asking why did I not just program the GPS Time Pulse output to output 10MHz? This gives a very accurate signal as well, since it is locked to the SAT reference, but unless you choose your GPS VERY carefully, you end up with signals that have very high jitter. You need to use a GPS intended for Time Pulse generation, and not all of those do it either. There were some GPS's ( the Jupiter, some 8 years old) that worked well this way and gave a stable, low jitter output, but that one is no longer available. The problem is that the GPS internal reference ( on most) is based on a 48MHz clock, and that does not divide down to 5 or 10MHz..the jitter on 10MHz is terrible, many 10's of ns. If you select say 8MHz, you get a jitter free signal ( well , a few ns.)

So, most 'good' GPSDO's use an external, low drift reference oscillator, and since most of these are not at the GPS module reference frequency, you 'multiply' the ref osc up to the required freq ( 26MHz in my case) via a PLL synth.

Then there are two typical ways to determine the frequency offset- Use the ref osc to also feed a counter whose gate is controlled by the 1PPs from the GPS module ( this can have a few 10's on ns jitter as well...)

If the counter overflows a set value, the clock is too fast, and vise versa. That over/underflow then is integrated and creates a control voltage that drives the ref osc up or down in frequency. The integrator must have a long time constant, etc.

A alternative way is to use the data the GPS provides in the NAV-CLOCK message - Clock Bias ( essentially the amount of TIME the GPS is ahead or behind the GPS SAT Time) and the Clock drift rate ( normally in us/s or ns/s)

If behind time, we speed the clock up by increasing the clock control voltage. The amount we increase the clock control voltage per GPS cycle is dependent on the clock drift rate - a high drift demands a bigger voltage jump in each cycle - almost an inherent PID control loop. The Loop is actually an FFT/filter with a 32 second cycle time.

I implemented both the above concepts, and found the latter improved the clock bias from 7ppb to 3ppb over a 4 day period..

Sorry, too long a story with nothing to do with 'engineering' as exercised on this forum! ( except for the metal bashed box.)

Joe

22/12/2019 21:25:33

My Cesium Beam Frequency reference finally called it quits - the Cesium tube is dead. The unit has a very good quality, stable oven controlled 5MHz crystal oscillator, so I decided to build a GPS Disciplined Oscillator with it.

The 5MHz oscillator is used as reference for a Phase Locked Loop chip,which generates a 26MHz clock for a UBLOX , inexpensive, GPS module. A Nucleo STM processor module reads the NAV-CLOCK message from the GPS, and derives the 26MHz clock bias and drift values in relation to the Rubidium clock on the GPS satellite , and uses that info to generate a correction voltage to the 5MHz oscillator. When all locked, the oscillator shows a clock drift of +0.002 to -0.004 hertz from 5MHz over 24hours...Not bad.

Since the Phase locked loop chip I used has multiple independent outputs, I added a Signal generator function to the unit as well - 1MHZ to 200MHz in 1Hz steps..

I also double the 5MHz to 10MHZ, since all my other instruments require 10MHz as reference.

The Old Cesium beam unit - a good HP unit of old, weighed 17KG, the new unit weighs 2KG..

Quite a bit of metal bashing - The fun part of making boxes is in the corner bends - bend allowance, the K factor and bend deduction...

Joe

 

Top view - OCXO, Frequency doublers, Phase Locked Loop, Microprocessor..

top_open.jpg

Underside - PSU

underside_psu.jpg

Main Page display - Clock drift, bias and accuracy readings and a TOD clock.

front main page.jpg

Signal Generator page

front_setup page.jpg

Edited By Joseph Noci 1 on 22/12/2019 21:26:37 

-my usual poor English usage..

Edited By Joseph Noci 1 on 22/12/2019 21:30:11

Thread: What Did You Do Today 2019
22/12/2019 21:07:01

Spent some leisure time reading old Wireless World magazines, and then the thingy broke, so knocked up a new one out of polyprop..

t_roll_1.jpg

t_roll_2.jpg

Joe

Thread: Keyway Broaching
15/12/2019 17:01:08

I have broached quite a few bosses in aluminium, none as long as 70mm, and it takes a surprising amount of force. I would be reluctant to put that sort of force on the tailstock screw. Also, that load transfers into the tailstock body and lathe bed. I assume you have all the stepwise increment wedges for the broach as well. Whatever method you end up using, ensure that the force on the broad is really square-on and inline - a 5mm broach bends easily! Also, remove and clean out the chips regularly - 70mm is a long way to go!

Joe

Thread: Amplifier Repairs..
04/12/2019 14:57:35

Me upset??? You need to try harder than that..Or just start a discussion of oxygen-free Copper speaker cables and their beneficial addition to the system's sound...

If pedantism rules, then I would agree with the cold interpretation of quality existing only if it is measurable. I have however seen products manufactured and passing muster under the manufacturers ISO9000 accreditation, only to fail miserably in the lack of 'good workmanship' - The ISO accreditation allows for many sins to be committed at the artisan level, as such systems often fail to dictate the criteria artisans apply in the daily application of their 'art'.

If a 12mm hole is required to be within plus/minus 2mm of a drill point, and the hole diameter may lie between 10.5 and 13.5mm, that does not mean the Worker should not measure where the hole should be, that he should not center-pop the point, or that he should grab blindfolded for the nearest size drill - failing to do any of these, just because the process allows him to, just breeds bad practice for future use.

Perhaps we mix good workmanship and quality up somewhat in means and definition thereof, but I do believe that anyone with self-pride, and an interest in how he does things, an interest in the product, etc, would plainly see the difference between good and poor workmanship. The observer might not notice that the product is also good or bad 'quality' - Quality is not visible, no matter how you may wish it was. The quality process only managed to ensure that the correct part number component was fitted in the correct hole, and the soldering iron was at the correct temperature when the legs were soldered, and the solder was the correct ( lead-free!) stuff. How well the artisan did the soldering job is up to the artisan, not the QA process...If the dry joint passes inspection, then the artisan failed..

Sometimes good workmanship gets in the way of profits - the old 'time is money' saga, so neatly dressing wires where its not needed, sanding smooth the angled-ground marks on the casting ( within sound limits..), etc, may be a waste of time, money, or whatever, but unless outlawed by the Boss, I believe it speaks to the mindset of the worker/artisan.

Attention to detail, cleanliness in application, neatness of work, none of which can be easily specified in a quality process, are all , in my opinion, essential elements in making a good worker, and a good product.

I'm not sure we have an addiction to quality as such - I think nostalgia is also a culprit in our thinking though.

When you want to purchase a jersey in the high street shop ( I'm lucky here, I have no high street... let alone shops..) you may rub the wool between your fingers ( while rubbing the shop assistant up the wrong way as well) -to judge the 'quality'

While wool quality is measured by strength, staple length, fineness and consistency ( among other things), you would not determine any of this while rubbing the jersey...however, if you 'rubbed' a Cashmere weave and then a jersey made from local 'farm' wool, you could be forgiven for thinking the Cashmere jersey is a far better quality. You may (probably) also be forgiven for thinking it's wool..it is in fact hair, from the Kashmir goat.

Measurable quality, I believe, is a phenomena that exist almost only in the engineers mind - the rest of the population have there own definitions! But workmanship can be seen and felt - which is what most of the 'better in the old days' nostalgia relies on for survival.

Back to the subject though -

I am not sure that we should lump 'Hi-Fidelity' listening in the same basket as the Stomp-boxes, combo amps, and general equipment as used by those rock and roll ruffians. Yes, Hi-Fi ( not that crap with 4liter speakers, a combined CDplayer, Tuner, 'amplifier, USB music player, all up 2 kg weight..) should be the piece of wire with gain.

But that is not what the Bands or gig players want. I would not want the amp to add unpredictable bad sounding distortion, or for it to 'modify' the sound in unpredictable fashion, at odd moments. However, each ego demands that the sound exiting the amp at the end if his guitar must be 'unique'; must sound 'good' to his ears, etc. So the amp must be able to be abused, trans-sounded, more slappy, etc. How would you describe the amps being 'brighter' in 'quality terms' ?? Sort of - the frequencies between 3khz and 4.795khz are boosted by 7.956dB, while the frequencies between 5Khz and 9Khz are raised 3,9dB and those below 2KHz are reduced by 4dB per decade....And the sound Mixer fellow will say ...Huh??, you mean brighter??

My pennies worth..

J

04/12/2019 06:33:56

Danny, of which series is the Valvstate 2000? I know the Valvestate 20 series, and the various models in the 200 series, but not any 2000's..

Did you get the parts from DigiKey? I obtain a lot of electronic parts for our wildlife tracking collars from them and the Declaration of use is standard with most American component suppliers - including Mouser USA, but not Mouser UK..

Interesting names the amps get - 'ValveState' and Peavey's 'TransTube'...

Nice Guitar Neil!

J

03/12/2019 12:02:09

Huh????

I have repaired many a 'Fender' and 'Marshall' of recent 'vintage' ( Peavey as well) and can only say that digging around in those was never a 'pleasure' - Most who buy today's Fender's and other makes of similar ilk, do spend a fair amount on them, so I would have thought that the manufacturer could up the build quality in keeping with the name - their customers could afford it..

early this year I repaired a Fender BassBreaker 30R (4xEL84 in the output) . Needed to replace 2 of the EL84 valve bases - and one EL84 that I broke(!) - removing the spring clip that pulls the valve into the base, two valves just fell out of the base! The first caught me by surprise and fell onto the speaker magnet...The valve base contacts did not contact the valve pins anymore...The 30R is a new amp, very recent mnfr..made in China.

Why was I removing the valves to start with - I always do that first, so that I can remove the amp chassis from the cabinet without inadvertantly breaking a valve....

The Sales pitch Mesa applied is nothing new - go read a little on the Fender web site and see their version of the speed control knobs..

Marshall's language follows suit, and so does that of all 'good' amp vendors.

Marshall does, however, also make some very nice amps - particularly the HandWired series, and the 1974X, which has no PCB, is point to point wired, and very neat and easy to work on. Sounds great too!

J

03/12/2019 09:17:33

For Brain Food I repair musical equipment for our local Music Shop - A nice one came in yesterday. Very nicely made by Mesa Engineering, Hand Assembled in California! Was a pleasure to work on. A simple repair - a large 3.3uf 600v polypro capacitor had broken one leg - it was the only cap not bonded to the PCB, and being a good combo/base amp, the vibration took its toll.

A really nice sound, hard to distinguish from really good Fender and Marshall bits of old..2 x 6L6's in the output, a nice 50watts.

The metal chassis has every open seem tig welded, every edge and corner de-burred and smooth. Every wire nicely laced and tied.

Thought this did not happen anymore in the real world.

amp front.jpg

amp upsydown.jpg

made in usa.jpg

measeng.jpg

Thread: More evidence that the world has gone mad!
03/12/2019 09:02:46
Posted by Tony Pratt 1 on 03/12/2019 08:54:43:

The lunatics are running the asylum

Tony

And only those without are mad..

Joe

Thread: EMCO Rotary / Indexing table
01/12/2019 20:23:56

Hello Raphael.

I have some zipped BMP image files of the FB2 manual, in which the rotary table is well described.

The images are not great, but are legible/usable.

PM me with your email and I will email them to you.

The 'Lock pin' you speak of is used to 'pin' the rotary table in fixed indexes - if I remember correctly - in 15degree increments, in the perimeter of the rotary table. If using the index discs or dividing plates, that lever is pulled out and rotated to the disable position, so that you can index incrementally. The other two levers are to lock the table in position while machining.

To turn the table freely, loosen and back off the Cap Screw seen near the worm shaft exiting the table block. Then rotate the worm away from the table gear by rotating the dividing plate counter-clockwise.

Joe

fix typo

Edited By Joseph Noci 1 on 01/12/2019 20:25:17

Thread: Extending router shanks
13/11/2019 20:18:24

Just be VERY careful! A 6mm cutter in a 8mm adapter leaves only 1mm wall. Those cutters spin upward of 20K RPM, even up to 35K+ RPM. Any TIR in the bored 1/4 inch hole, or the quality of fit will result in notable forces at those RPM's. The type of steel you would use for the adapter also bears consideration. There are considerable side forces on the cutter when pushing through the wood, and at those RPM's, with that supporting wall thickness...

Maybe make the adapter with an 8mm stub into the router, and a 10 or 12mm extension to take the cutter..All with little or no TIR.

Joe

Edited By Joseph Noci 1 on 13/11/2019 20:20:27

Thread: Grinding wheel 'washers'
08/10/2019 06:46:13

Thin Gasket sheet from your local motor-spares supply works very well - I use around 0.6mm material. In my town, around £3 for a half square meter. Use the rest on your model engines..

Joe

Thread: Small Metric Screws
03/10/2019 22:16:12

I have a number of times imported a variety of types of tiny fasteners from these chaps in West Sussex. - Not in the last 3 years though..

**LINK**

Speak to Steve Craven - +44 (0) 1342 717582

Joe

 

Edited By Joseph Noci 1 on 03/10/2019 22:16:32

Thread: New lathe?
02/10/2019 12:45:19

John, you will be surprised how easy it is, esp in a mnfr environment where pressured by time..

I had abt 60 short Ali inserts to make - each had a mm12 thread through, abt 9mm long - you get into the swing of it, drill, retract, swap drill for tap, tap, retract, swap tap for drill, move tailstock out the way, bring in parting tool, part off and repeat. And when you are focused on the cutting edge(s), and you know where to put you hands on things without looking, you swing that arm to push the tailstock back, once a little more enthusiastically than needed, ...and it carries on sliding on a nicely lubed bed..and falls off the end...onto the handwheel...Yes, some lathes don't have a stop at that end, the V10P was one of them...

Joe

02/10/2019 10:36:14

Definitely the better choice - vastly superior - I have a 40 year old V10P, and a new 14D (much later version of the Super-11) . Both superb, while the V10 is my go-to lathe every day..

However, check as best you can for wear - esp the bed near the chuck - sometimes a lot of backlash in the cross slide leadscrew indicates a lot of use as well. If you can get to the machine, nip up the cross slide gibs while working the cross slide back and forth - if the slide is loose near the middle 1/3  and very tight in others ( normally 2/3 towards end of travel either way) , then its normally a good indicator of having worked very hard...

Spares are not to easy to come by, esp things like cross slides, etc. You may even find a new bed, but thats not worth the money then..Leadscrews and nuts are still available. Some handwheels too. If you are not into big models, nicely restored, that Super-11 will be your last lathe purchase!

Edit - to add - Also, put the drive gear train in 'neutral' - select 'between' gears, so the spindle is free. do the 'ear-bone' sound test while spinning  the chuck by hand slowly, listening to the bearing spot at the chuck end. You will hear any not-so-nice bearing rumble quite easily. ( use a 200-300mm long solid screwdriver, tip to the bearing spot on the headstock- behind the chuck- and screwdriver handle firm against your skull at the ear hole..) - Or, if you are a doctor and have a stethoscope...Reason to do this is that the bearings are so far un-obtainable in original spec...I have a Super-11 in restoration and cannot get bearings for any money..

 

Joe

 

 

 

Edited By Joseph Noci 1 on 02/10/2019 10:36:45

Edited By Joseph Noci 1 on 02/10/2019 10:42:31

Thread: Filter Design Wizard
30/09/2019 11:01:23

Nice Neil! Interesting how many 'enabling' hobbies we all seem to have. ( Not a fan of that word, though..)

I'm pretty sure you don't need to log in to use the Analog Devices calculator.

Not necessary to log in, but I had to register on site first to be able to use it - as it can store your files in their 'cloud' - (Yuk!) -

KiwiB - On the Linkwitz - here's a spreadsheet calculator - you probably have it if you are playing with this stuff..

**LINK**

But to simulate I have not seen anything specific to this application. However, I DO recommend LT_Spice - free and not difficult with many examples and many Tuts.

The spreadsheet helps with the data does do most of what you may need though?

Joe

30/09/2019 07:49:49

Yep, I use that one quite a bit, but must say I almost prefer the Texas Instruments one - both very good .

**LINK**

I dabble a lot in building Ham Radios, and use op-amp filters in the audio chain, esp. for direct conversion receivers, where the filters should be low noise with LOTS of gain.

Use LT_Spice for simulation - very good.

However, the BEST filter design program ever was Texas Inst. Filter-Pro vers 2. That no longer exists -

Ver 3.1 is available, but it is so full of bugs - poor.

The replacement TI version is, like the AD one, all on line, which personally I hate. Means you have to register, have to be online, etc. Suppose that's the trend these days ( Fusion, etc..). There are MANY very useful little 'calculator' programs, esp in the RF and AF field, and most of them have moved to .php programs that have to run from the website, online. So, back to the good old calculator and brain cells most of the time..!

I suppose I also have an aversion to providing my personal info on website after website..

high-pass filter for my bass guitar - Sound like a contradiction in terms...

What PCB CAD do you use and where did you get the PCB made?

Joe

 

 

Edited By Joseph Noci 1 on 30/09/2019 07:51:14

Thread: Anyone made Myfordboy's powered hacksaw?
13/09/2019 07:12:58
Posted by Ian Thomson 2 on 12/09/2019 19:40:20:

It looks good!

Are you please with the accuracy of it?

I am expecting to take far more than 2 weeks with my build.

Hi Ian.

Yes, I am very happy with it. Cuts straight in stoke as well as vertically. However, that was achieved by having good adjustment capability in the saw frame - the frame is all bolted construction, so that the forward and rear vertical struts can be adjusted in vertical angle, independently , allowing the blade to track perpendicularly to the saw vice, and in a vertical manner. The entire saw can also rotate a few degrees clock/anti-clock on the base to ensure a square cut as well. Welding up the blade frame would imply putting the adjustment mechanism in some other part of the machine somehow.

The Myfordboy saw has a very short stroke, which is ok when cutting large material, occupying a large length of the blade all the time. I have two crank pin position that are easily changed - 15 seconds or so - that give a mid length and a full length stroke - the mid length caters for material up to 80mm diameter, the full lenght for material to 40mm diameter.

I also first made a hydraulic lift mechanism to lift the blade on return - it worked very well, but I found by proper implementation of the crank center of rotation in vertical relation to the blade frame con-rod attachment position, it was very easy to get blade lift on the return stoke - the rising crank pin ( the 'big-end' on the forward return stroke pushes the frame up, and the falling crank pin on power stroke pulls the frame down, ie, the blade is pulled into the work.

Take a look from around 55sec into the video - you can see the frame up and down motion quite nicely - all the way into maybe 1.5 minutes into the video.

Hacksaw Video

Clive Foster said:

If you want a quick build might be worth looking into replacing the built up from hexagon bar slide system with one of the linear rail and bearing block systems that can be got quite inexpensively these days.

I had also hoped this would work since it would save some DIY pains - I made a test frame and gantry and it worked ok - was noisy - the little balls in the slide block did not like a 100 strokes/min at all; even 60/min was not nice..I had my doubts though, and that noise translated into ball failure after about 3 hours of running at 100 strokes/min - lubrication was a bit difficult as the slide block has a wiper to keep grit out of the balls, and it would wipe away most of any lube applied. The blocks and rails I used were SKF ( damn expensive!) , the rail is a 40mm wide 20mm high rail, and I used two long blocks - 75mm long each.

I tend to runthe saw at 80 to 120 strokes/min all the time - anything slower is frustrating!

Joe

 

EDIT - eliminating errant emoji's!

 

Edited By Joseph Noci 1 on 13/09/2019 07:15:41

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