Motor For Adler 105-8 Clone

[AEH]

Just wanted to give you an idea of how it looks when my Jack motor is running at 200 rpm and how slow the needles goes up and down. Event an 500 and 1200 rpm it is still relatively slow stitching.

Hi Constabulary,

Very instructive video, and fine set up. I would like to avoid a speed reducer, both for the cost (it will probably be very expensive to have one made here in Norway, if I even could find someone to do it) and the construction of the table stand may be a problem when it comes to fitting it. You saying that the motor runs as low as 200rpm makes it more attractive, but if I still have to buy a speed reducer and a new table stand ...

Need to think about that one. Thanks anyway,

Arvid

[Constabulary]

@ mikesc

well, that explaines a lot - sounds a little bit like the situation in Greece. We don´t live in a perfect world - thats how it goes.

But thats all a different story lets get back to topic

@ vanrhodes

thanks for the lesson in math - it never was my favorite!

@ AEH

I can ask the guy who makes the speed reducer for me if he can make some more.I actually thought about a bigger 50mm / 200mm speed reducer for my Singer 133K. I will probably get a better price if I order more.

When I look at your stand - there should be a hole in the right leg where once the shaft for the treadle pulley was - if you know what I mean.

So this is perfect for adding a speed reducer. Pretty much the same situation as on my stand but I have a flange bolted on the leg.

[mikesc]

VanRhodes..to get the ratios you need to divide the pulley circumferences, ( which is also, co-incidentally, the distance traveled by a point on the belt per revolution of each pulley that it is on ) not their diameters..although the figures for the ratios are close to dividing by diameters, but, to do so is not as precise..( But it is so close as to be "good enough for jazz" )

to get the circumference of each pulley you use

C = 2πr,

Then divide the bigger circumference of each pulley "pair", by the smaller circumference of each pulley "pair"..

So if on Constabulary's slowest speed of 200rpm ( You used 1200 , but I'm sure that 2 was shown on the control box, I think 2 on the display means 200rpm ? )..Constabulary ?

Diameter 150 gives circumference of 471.3 ( I'm rounding to nearest decimal point )..diameter of 40 gives circumference of 125.7

ratio of 471.3/125.7 = 3.74 ( nearest decimal point 3.75 ) so "transferred" rpm of 200/3.75=53.3 rpm ( "rounded" again )

then the second "reducer stage applies..

Diameter 150 gives circumference of 471.3 ( I'm rounding to nearest decimal point )..diameter of 50 gives circumference of 157.1 ( rounded )

ratio of 471.3/157.1 = 2.99 or 3.00 ( rounded to 3.00 ) so transferred RPM of 53.3 / 3.00 = 17.76 rpm ( "rounded" again )

which seems to be about what the machine is running at ( measured by watching the needle motion ) on the video..I counted 3 "up and downs" ( would have made 3 stitches ) in 21 seconds,

or about 18 rpm ..which would be great

Or I could be wrong..as has been known to happen, on more than one occasion

@ AEH

I can ask the guy who makes the speed reducer for me if he can make some more.I actually thought about a bigger 50mm / 200mm speed reducer for my Singer 133K. I will probably get a better price if I order more.

You could have a lot of interest in that..

Edited November 11, 2014 by mikesc

[VanRhodes]

Mikesc: Thanks for the lesson in math, I knew I missed something! Although we did end up with pretty much the same ratios as mine were only 0.01 off in both cases.

[mikesc]

To tell the truth..In my head I did it your way ..

At school ( which was many decades ago ) I used to get into heaps of trouble in maths for not "showing my working out"..teacher couldn't see how I was "getting to the answers"..my point was always "What does it matter if when I got there it was right"..( 0.01 is as near to "right as it gets ..eh

So , I also learned how to "show all the working out" to "keep teachers happy/quiet"..and in case I ever became an engineer..

I didn't...( Artist / Designer for over 40 years now ) but due to teachers, I also have a head full of this kind of stuff ..

[VanRhodes]

Haha, just like me. I delivered the answers required but did not bother to show my entire process in getting there and just like you, I have also worked as an artist of sorts(3D-artist) and currently designer and pattern constructor.

[Constabulary]

@ AEH

I forgot to mention that College Sewing has not smaller pulleys fort the Jack Servos. The Jacks have pulleys with 13mm straight bore and College Sewing only has pulleys with 15mm straight bore as far as I remember.

@mikesc

You could have a lot of interest in that..

No problem but don´t forget that shipping comes on top.

Depends on how heavy they are - registered airmail all over the world is just about 10€ for a package up to 1Kg.

The one I would order will be for a 10mm V-belt, has a 200mm and 50mm pulley, 2 ball bearings and they will fit on a 15mm shaft. So this is the reducer pulley only w/o any mount or flange.

If some one needs a certain shaft I of course will ask for it too. But thats it - everything else would be too complicated

They guys is now on holidays for 10 days so it will take at least 14 days to get a quote.

So if some one is interested please send me a PN and I will try to get a quote for reducer pulleys and shaft (if needed).

[Northmount]

Hey guys, When calculating ratios, pulley diameter or circumference will work out to the same answer, if you carry enough decimal places. The 2 pi cancels out in your calculation, leaving just the diameter. (2 pi divided by 2 pi = 1) You would also get the same answer using radius. No advanced math required.

Now if you are calculating belt speeds or linear velocity at the rim of the pulley, then you need to use circumference and the pulley speed.

Tom

[mikesc]

So..Tom..did you get chewed out at school for not showing how you reached the answer(s) ?

Now if you are calculating belt speeds or linear velocity at the rim of the pulley, then you need to use circumference and the pulley speed.

Without using a reducer..and based upon observing the clutch driven Juki DLU 490 ( textile sewing machine not normally used for leather ) I bought last month and have just finished getting in running order again..

I'd say the linear velocity is a multiple of bats out of hell.. it seems real eager to eat fingers when you put your foot down other than really gently ..even with a small pulley.

[Northmount]

I'd say the linear velocity is a multiple of bats out of hell.. it seems real eager to eat fingers when you put your foot down other than really gently ..even with a small pulley.

That's why there's now a servo on one machine instead of a clutch motor, and a servo plus speed reducer on the other. Had tried just a smaller pulley on the clutch motor, but wasn't adequate at all. Sure makes life easier now, especially going around corners!

When I got into high school, math was no longer a problem. Suddenly became easy to make 100% on the exams. Teacher started using my papers for the answer key. Makes a real difference when you have good teachers that know what they are teaching.

Tom