For more torque, I need what?.....

[Beanwood]

I'm stil playing with my Brother LZ1-B651.

It does 12mm zigzag, and it is not designed to sew big thick and heavy stuff.... However I need to close off 'loose ends' of webbing, and that works really well by zigzag stitching them onto another piece of webbing .

From time to time though it get's stuck, so I need to increase the torque somehow, as well as slow the speed.

I've made and installed a 6" to 2" speed reducer, and it's now slow enough, but still doesn't have the punch I need to push through several layers of webbing.

It has the original clutch motor, so I'm inclined to think installing a servo motor is the way to go - is that right or am I wasting my time? If it's right, is there much difference between a 3/4p or 1hp motor?

I'm UK based, so will need to go with something from over here, rather than the forum sponsors/contributors.

 

[Constabulary]

Make sure the V-Belts are tight enough and do not slip. But anyway - servo motors are the best option nowadays.

I run my Singer 111G156 with a 750W servo and small pulley and with a 1:3 speed reducer and it punches trough 10mm thick Mil Spec cotton webbing at slow speed - just saying...

Back then I bought my JACK servo from College Sewing in the UK.

Edited February 3, 2023 by Constabulary

[Beanwood]

25 minutes ago, Constabulary said:

Make sure the V-Belts are tight enough and do not slip. But anyway - servo motors are the best option nowadays.

I run my Singer 111G156 with a 750W servo and small pulley and with a 1:3 speed reducer and it punches trough 10mm thick Mil Spec cotton webbing at slow speed - just saying...

Back then I bought my JACK servo from College Sewing in the UK.

Perfect  thanks - I'm just musing on adding that £140 to my order, and didn't want to commit that cash until someone confirmed I'm not talking rubbish 

I guess I was just trying to be cheap, and go for the 550W ...

[cynthiab]

If your LZ1 is a Chinese clone of the sailrite LZ1, the working parts/castings are very weak. I have hade to replace a ton of parts in mine ( with sailrite parts) so that when I tighten a screw it dosent strip out ( I'm not that strong) or when I sew through tough stuff the mechanics don't snap. 

Just my experience... 

[Beanwood]

Thanks @cynthiab no it's not a clone - it probably predates the Sailrite by quite a few years, and is Japanese made, so is tough as old boots.

 

[dikman]

To be honest I'm not sure that you would notice that much difference between a 550w and 750w motor if you use a speed reducer too. Having said that, if the price difference isn't too great by all means get the 750w.

Speed reducers - you can get very slow speed, with gobs of torque, by varying the pulleys in the reducer, but at the expense of top speed. On one of my machines I fitted an 8" pulley in place of the handwheel, a 2'" on the motor and between them a reducer running a 1 3/4" and a 4". A bit extreme, perhaps, but I could get 1 stitch every 2 1/2 seconds! My favourite method, if possible, is to replace the handwheel with a large pulley and a small one on the motor, I find this is a fairly simple method to use.

[DonInReno]

A 3:1 reducer and servo motor is a good combination.   I’ve had a small servo with 3:1 on a standard size hand wheel and wished it would sew a slightly slower on the low end so went to a 7:1 reducer and that was a little too much.  I really like larger handwheels and think it’s just perfect combined with a 3:1 and small pulley on the servo.  

[Michiel]

20 hours ago, Beanwood said:

I'm stil playing with my Brother LZ1-B651

Is this similar to the brother LZ-B652? (The early sailrite)

That is a very nice zig zag machine

With most zig zag machines the hook is too early at the left sticht and late at the right stitch

the hook of this machine goes a little bit faster when making the right stitch and slower on the left one (you can see the mechanisme at work on the underside of the machine)

its very helpful with this 12 mm stich

it doesnot have the walking foot

but i know this machine and the new original sailrite:

the vintage brother has much more quality

 

Edited February 4, 2023 by Michiel

[Beanwood]

2 hours ago, Michiel said:

Is this similar to the brother LZ-B652? (The early sailrite)

That is a very nice zig zag machine

With most zig zag machines the hook is too early at the left sticht and late at the right stitch

the hook of this machine goes a little bit faster when making the right stitch and slower on the left one (you can see the mechanisme at work on the underside of the machine)

its very helpful with this 12 mm stich

it doesnot have the walking foot

but i know this machine and the new original sailrite:

the vintage brother has much more quality

 

Thanks @Michiel - I mistyped in my original post - it's actually a TZ1- B651 - very similar indeed to the B652.

As you say - no walking foot unfortunately, but it's very solid, and parts are still readily available.

 

[Beanwood]

7 hours ago, DonInReno said:

 I really like larger handwheels and think it’s just perfect combined with a 3:1 and small pulley on the servo.  

Looks like I'm on the right track then. How do I get a larger handwheel - is it literally just finding a larger pulley, and usnig that as a wheel

 

[Beanwood]

10 hours ago, dikman said:

To be honest I'm not sure that you would notice that much difference between a 550w and 750w motor if you use a speed reducer too. Having said that, if the price difference isn't too great by all means get the 750w.

Speed reducers - you can get very slow speed, with gobs of torque, by varying the pulleys in the reducer, but at the expense of top speed. On one of my machines I fitted an 8" pulley in place of the handwheel, a 2'" on the motor and between them a reducer running a 1 3/4" and a 4". A bit extreme, perhaps, but I could get 1 stitch every 2 1/2 seconds! My favourite method, if possible, is to replace the handwheel with a large pulley and a small one on the motor, I find this is a fairly simple method to use

Great - 550w is a fair bit cheaper, but wth @Constabulary having the 750w on the same sort of combination I'm sorely tempted to spend the extra.

1 stitch every 2 1/2 seconds !!!!! Crazy slow..I'd probably forget what I was doing befoe I got to the end of a run.

 

[DonInReno]

5 hours ago, Beanwood said:

Looks like I'm on the right track then. How do I get a larger handwheel - is it literally just finding a larger pulley, and usnig that as a wheel

 

Many machines have a 1/2” shaft so a pulley or larger factory handwheel from another machine with 1/2” bore can often be easily attached.

The downside to an oversized factory part are the limited choice and cost - $150 and up for the few that I looked up.   It’s a matter of searching through heavy duty machines that have about the size of handwheel you want and tracking down the part number and contacting replacement parts department.

The “monster” pulley that Sailrite markets is available from numerous sources for $100 to $150, but it requires using an “xl” clogged timing belt.  It’s a nice wheel, however it does make a noise that some find objectionable.  15mm clogged pulleys for the servo are available in steel from Sailrite or aluminum on Amazon.  The belts are available in a wide variety of sizes and are sold in one cog increments - xl belts also come in multiple widths so you’ll want one that matches.  You’d have to cobble together a few clogged pulleys for a reducer since I don’t think anyone makes a 3:1 reducer.

Pulleys on the other hand are definitely the lowest cost option.    Cheap aluminum pulleys like are used on swamp coolers can be had for $10.   Just make sure it fits a 1/2” belt at most.   3/8” pulleys are less common and many are just a 1/2” pulley and also work with 3/8”.

The main problem with a pulley is it looks like a pulley and feels like a pulley when hand turning it.  In the first picture this hand crank wheel would look at home on an old Singer, and have a good feel once it’s smoothed out.    I’ll machine a belt groove in the center, remove the handle, polish the outer rim and smooth out spokes.  None of that is all that difficult, but if you don’t have a friend with a metal lathe it would be prohibitively expensive to have a machinist cut the groove.

The second picture is a handwheel from a Singer 29-4.   It has a nice size to have a belt groove cut in the rim, but it’s too dished to work well unless the hub with set screws is cut off and a new hub silver soldered to the other side.

Some older machines like the Singer 144 use a stamped steel pulley as the handwheel, but the two new steel pulleys I’ve had aren’t all that straight and it would drive me nuts seeing them wobble.

[dikman]

10 hours ago, Beanwood said:

Great - 550w is a fair bit cheaper, but wth @Constabulary having the 750w on the same sort of combination I'm sorely tempted to spend the extra.

1 stitch every 2 1/2 seconds !!!!! Crazy slow..I'd probably forget what I was doing befoe I got to the end of a run.

 

Yeah, too slow to be really practical, but I was curious how it would work. I removed the reducer and just used the 8"/2" combination, it's on my Pfaff 335 with a generic 550w motor and it's more than adequate.

Don, that wheel will look great when it's finished and cleaned up. Make sure you post a photo.

[Beanwood]

22 hours ago, DonInReno said:

The main problem with a pulley is it looks like a pulley and feels like a pulley when hand turning it.  In the first picture this hand crank wheel would look at home on an old Singer, and have a good feel once it’s smoothed out.    I’ll machine a belt groove in the center, remove the handle, polish the outer rim and smooth out spokes.  None of that is all that difficult, but if you don’t have a friend with a metal lathe it would be prohibitively expensive to have a machinist cut the groove.

The second picture is a handwheel from a Singer 29-4.   It has a nice size to have a belt groove cut in the rim, but it’s too dished to work well unless the hub with set screws is cut off and a new hub silver soldered to the other side.

I really like the look of that as a solution!

I'm sure I can find someone to machine the groove, but I think I'll struggle more to find a handwheel like that in the first place.

[DonInReno]

This type of cast iron pulley isn’t a bad place to start - they aren’t as smoothly shaped as a custom part, but it just bolts on and is fairly cheap.  This lightly used 6” made by Browning is on eBay in the US for less than $30US delivered - there must be similar pulleys made in the UK.

At least in the US, many non-sewing pulleys sold for 3L (3/8”) belts are actually made for A belts (1/2”), but are close enough that they work for either size.   The B size belts are 5/8” wide and don’t work at all.

For some reason, no matter what size handwheel you think will work best, once it’s on you will wish it was a little larger or smaller - 5” to 6” is a good place to start. Lol