Changing pulley on a Family Sew motor

[kgg]

23 minutes ago, CowboyBob said:

14mm

For those who are not metric 14mm is .2875 mm smaller then 9/16 inch.

kgg

[mikesc]

Or..14MM = 35/64 ths of an inch...metric is so simple compared to fractions.

[kgg]

not really but close enough:

35/64 ths =.546875 inches while 14mm=.551181 inches

[SARK9]

The decimal inch, divided into a million parts, was so simple before the political expedience of the metric overlords. No really, decimal is decimal. This is the penalty we all must endure as a concession for preferring Greenwich for the location of the Prime Meridian. 

The real fun begins when we start trying to get us peasants to relate to SI time, and reveal the rubbish one must endure when attempting to name these new *units of time* something which can successfully describe a naturally variable seasonal cycle. 10 month year vs. lunar cycle, etc. Nature is so inconvenient. I find myself armed with the numbers .03937 and 25.4 in the calculator memory and go on down the road.

*ON TOPIC NOTE:*  The Consew motors have a shaft diameter of 15mm., or 0.59055",  which 19/32nds (0.59375")approximates for all practical sewing needs. Pedants can take full advantage of the "decimal sized" reamers offered by most industrial supply houses. I make all my own pulleys to suit, and lathe bore them with miniature boring bars. Concentricity, you know.

 

-DC

Edited June 9, 2019 by SARK9

[mikesc]

The decimal inch was indeed simple enough, but it comes with that attached "baggage" of the 12 inches to a foot , 3 feet to a yard..and 660 feet, 220 yards, 40 rods, or 10 chains to a furlong..and 8 furlongs to a mile..

I learned ( and had to calculate in both at school..long division and algebra ( all kinds ) in "imperial measures" ) can think and work in both..but prefer metric..for all the sensible logical reasons..

For people on the right hand side of the pond..the "Jack" servo motors sold by College Sewing..also had 13mm shafts..which can make getting pulleys "off the shelf" that fit a bit awkward..I say had, because nowadays I get mine from china and they come with 15mm, maybe the later, more recent Jack ones do too, or not ?

Old thread ( one of many ) on the subject of Servo motors..There are many many, more on pulley speed reducer systems ( bought and self made ) ..and "tuning" Servo motors..

https://leatherworker.net/forum/topic/67110-will-the-150-chinese-servo-motors-from-ebay-work-on-an-old-adler-68/

note..I'm jealous of people who have lathes..I must build a bigger atelier ..I sorely miss my old one, which was big enough to fit all the 9 houses in my cul-de sac lane here in..

Edited June 9, 2019 by Wizcrafts
Fixed link by editing the source code

[kgg]

The accuracy of either Imperial or Metric are equal. It only becomes a problem when trying to go from one system to another as it is near impossible. I like the Imperial system and to this day hate, hate, hate the Metric system. When Canada "seen the light" and went Metric all the construction designs were done in Imperial and then just converted to Metric. It was bad enough having to contend with US Gallon (3.8 litres) being less by about 20 percent then the Imperial Gallon (4.54litres). To this day I have to convert in my head what things are in Imperial to get a sense of size/speed/distance/weight particularly at the supermarket where say meat is priced by the pound and sold in Kilo's. Confusing, maybe just me.

kgg

[mikesc]

The problem with Imperial,is that it is inconsistent, it changes it's base multiplier or divider depending on "the size"..or "the thing"..

1000 thou' per inch..or 8 eighths or ( "this many" "whatevers" per inch ) ... and then it changes again when going from (12 )inches to a foot ,and again when it goes from feet ( 3 ) to a yard ( 220 ) yards to a furlong, not to mention (40 ) rods per furlong..( which means that a rod is 5 and half yards..or 16 and half feet , or 198 inches ).. and 1760 yards per mile..No logical progression at all, measurements that do not relate to each other by any common denominator..apart from that of one inch ( which used* to be based upon an "average" man's thumb from the joint to the tip..Mine ( because I'm big..is one and one half inches ), someone else's measurement there is different again..

Btw..Both the USA and Canada use currencies which ( no-one living in those "non metric" countries has any problem with :) ) are divided by 100..and neither has 12 dollar bills, or 36 dollar bills etc..The attachment to "imperial" is just that, an attachment to a measuring system imposed by the British Empire..and even the British currency went metric ( I grew up with their old guineas, pounds, crowns , half-crowns, two shilling pieces, shillings, sixpence, three penny bits, pennies, halfpennies, farthings etc ...nightmare for most people to "make change" without a piece of paper and a pencil to calculate it, and even then getting "short changed" was an every day occurrence, which many did not do deliberately, nor notice if they were on the receiving end, unless their mental arithmetic ability was above that of the average person ) ..The weights and volumes were on different bases again..and as you note, the gallon varies depending on where you are..

Metric base 10 ) is consistent , easy to calculate, and the same base is used for currency, weight, volume, everything, only one thing for children to learn..how to divide or multiply by 10..

*People are getting bigger with each generation , in all countries, due to better overall nutrition, more food, imperial is even less relevant to current humans than it was before, where not all people in all countries were of equal size, they still are not..

Europe is entirely metric..and is a bigger market than North America, so change to being supplied in metric will happen..even if as a result of Brexit the UK were to revert to imperial, the numbers are in favour of metric worldwide..even India is moving steadily towards metric, they currently use both, what they manufacture marked in inches and metric sizes, like plumbing supplies is primarily for the USA market..China and Russia are already using metric , again they manufacture and mark some things in imperial "equivalents" for the USA ..

You'd avoid all these "shims" and "reaming out to fit" and "adjusting" if everyone went metric..your money already is.. :)

Edited June 9, 2019 by mikesc

[dikman]

Mike, that link goes to "example domain". Your French keyboard giving you problems again?

[mikesc]

After I posted it..Tom fixed it..( apparently it wasn't working when I initially posted it..I hadn't noticed ) I haven't touched, nor tried it since, Tom's edit..
But ..here it is again..working and tested ..


https://leatherworker.net/forum/topic/67110-will-the-150-chinese-servo-motors-from-ebay-work-on-an-old-adler-68/


It's not the keyboard* that gives me problems with links and other HTML code :) ..it is that I have to add the HTML link code and any other HTML code like quotes manually,..You, if you are logged in can do it by clicking.. But if I log in , the site here crashes my browser FF after a short time because it uses "push scripts" that my tweaked browser rejects..when it does the scripts repeat until I get a crash..I could fix it at my end, but I'd have to recode some add ons that I use ( in particular some that I wrote ) , and it isn't a priority ATM..My add ons ( and those of many other devs, some of which I also use ) won't work on new Firefox ( which uses the same system as Chrome and Edge ) ..I ( and many others ) prefer to keep my ( our ) system(s) secure and "tweakable" than to have it ( them ) running the new "locked down" Googly tainted Firefox..It makes FF as vulnerable as Chrome or Edge to the same exploits written to attack their now shared add on system..

* The keyboard , and running a hybrid French English Linux system which thinks some words are incorrectly spelled gives me more typos that I have to correct..as you have noticed :)

I noticed Wiz posted whilst I was typing ..thanks Wiz :)..my edit window on my original post was long past when I read dikman's post..

Edited June 9, 2019 by mikesc

[Wizcrafts]

I edited the actual source code and fixed the link. It's an HTML thang.