Suggestions for slowing down machine

[rockthecasbah121]

My wife and I own a dog collar business, and although we don't typically work with leather, our collars are relatively thick and we recently upgraded to an industrial machine after breaking numerous home machines.

We now have a Juki DDL-5550 with a servo motor. It goes through our collars with little effort, but we're having trouble controlling the speed. Even with the servo motor on the lowest setting and the pedal adjusted to not fully pull down the motor lever, the machine continues to take off of us when we're doing small runs (we have stitch lines that are only 2 inches in max length but have to go through two layers of collar). 

I've looked in to two possible alternatives- the reliable 6000SM which claims to be able to do one stitch at a time by tapping the pedal, and a superior 3-6-9 speed reducer pulley. Both items are pretty expensive, so I'd like some opinions on either one before I move forward. Is there one I should choose over the other? Should I go for both? Is there any issue with attaching the reducer pulley to a servo motor I should consider?

[Mark842]

Can't speak for the reliable 6000 but I have the superior 3-6-9 on three different machines. I can move the needle slower than you would possibly need to. Keep in mind you will need to pick up a belt and reposition your servo motor a little bit so you can line everything up

[keithski122]

You may be able to lengthen the arm that controls the motor and/or the pedal (not the joining rod), this should make the machine more controlable.I added an extra 3 inchs to both on my machine.

[Northmount]

Add a set of speed reducing pulleys.  You will have great torque and very slow speed if you size them right.  Can purchase a set, or build your own depending on your abilities and time.  There are lots of posts about using speed reducers here if you care to search for them.

Tom

[rockthecasbah121]

55 minutes ago, Mark842 said:

Can't speak for the reliable 6000 but I have the superior 3-6-9 on three different machines. I can move the needle slower than you would possibly need to. Keep in mind you will need to pick up a belt and reposition your servo motor a little bit so you can line everything up

Do you have any issues with the machine not coming to a quick stop with the pulleys being used? 

[rockthecasbah121]

32 minutes ago, keithski122 said:

You may be able to lengthen the arm that controls the motor and/or the pedal (not the joining rod), this should make the machine more controlable.I added an extra 3 inchs to both on my machine.

That's an interesting solution I had not thought of. I'll take a look at my motor when I get home to get an idea of how easy/hard it would be to replace. Do you notice any low torque issues when using this method? I know at the slowest speed I can get my machine to with very little pedal compression, I sometimes have to give the flywheel a nudge to get it going. 

[DrmCa]

Get a smaller pulley for the motor. Your servo probably came with the 3" pulley.

[keithski122]

Machine will act the same as before.All I did was use short lengths of angle to lengthen the arms.It all leverage and arcs.......the pedal has to move further between min and max making control beween the two less sensitive.

[Mark842]

2 hours ago, rockthecasbah121 said:

Do you have any issues with the machine not coming to a quick stop with the pulleys being used? 

No.

[dikman]

A decent speed reducer is probably the way to go if you already have a servo fitted. Couple that with the smallest pulley you can fit on the motor and you should get it to go much slower and have increased torque. You can make your own, but it's a fair bit of messing around.

I'm surprised that, being a servo, you can't get a slower speed out of it.

[rockthecasbah121]

2 hours ago, DrmCa said:

Get a smaller pulley for the motor. Your servo probably came with the 3" pulley.

Just measured and it does have the 3" pulley on the motor. What's the smallest size you can go down to? Looks like the interior bore is 5/8 inch. Is there a site most people get their pulleys from? 

[BDAZ]

I found on my machine that by changing the resistors in the speed controller, I can dramatically lower the maximum speed and have no problem getting a stitch every couple of seconds. 

Bob

[bullmoosepaddles]

I bought a 40 mm (1.57") pulley for my Consew Rb1 from  eBay. It was like $12. I have the old style 3 to 1 reducer which I also bought used off eBay for $60. If I were to buy one today it would be the one on the right in the posted link. It bolts exactly where your motor does now, your existing motor bolts to the bottom of it. It allows you to tilt the machine as you always have for service and maintenance. While it is more expensive, in my opinion it is worth every dime.

 http://www.cowboysew.com/product911.htm This link shows all three of the normal types of reducer. I would suggest the box type. 

[DonInReno]

If you are somewhat handy I'd suggest putting together a reducer from off the shelf pulleys for the least cost solution:  10" pulley $17, 1-3/4" pulley $7, 5/8" keyed shafting $12, pillow block bearing $10, two new belts $10.

Otherwise a factory built reducer would be the next least cost.

Napa auto parts and other auto part stores stock 3L light duty belts - a 38" belt would simply be # 3L380 but an auto parts place will charge you $12 or so.  An eBay search will show 3L belts for as little as $2 ea.

 

[Gregg From Keystone Sewing]

     If you are using up to a V69 thread and happy with the performance of a Juki DDL-5550N, and you are trying to bang out these dog collars...a full function under underbed trimmer machine may be in order.

     A new Juki with auto presser foot lift under bed trimmer needle positioner automatic back tack and servo motor than can be programmed for certain repetitive functions with great control.   A machine like that cannot do anything more or less than your current machine, but has what would be called labor saving devices and in the case of dog collars can really do a lot to move you forward at really an economical price.  Many folks here on leather worker may explain that you need to go big as in speed reducers and such, but the correct machine is really what you are after.  And by the way never get rid of your Juki DDL-5550N.  It's the best back up machine you can get no matter what motor is on there.

Edited July 6, 2018 by Gregg From Keystone Sewing

[rockthecasbah121]

1 hour ago, bullmoosepaddles said:

I bought a 40 mm (1.57") pulley for my Consew Rb1 from  eBay. It was like $12. I have the old style 3 to 1 reducer which I also bought used off eBay for $60. If I were to buy one today it would be the one on the right in the posted link. It bolts exactly where your motor does now, your existing motor bolts to the bottom of it. It allows you to tilt the machine as you always have for service and maintenance. While it is more expensive, in my opinion it is worth every dime.

 http://www.cowboysew.com/product911.htm This link shows all three of the normal types of reducer. I would suggest the box type. 

Do you know how much it costs? It looks like you can’t buy it through the site but have to call them. 

35 minutes ago, Gregg From Keystone Sewing said:

     If you are using up to a V69 thread and happy with the performance of a Juki DDL-5550N, and you are trying to bang out these dog collars...a full function under underbed trimmer machine may be in order.

     A new Juki with auto presser foot lift under bed trimmer needle positioner automatic back tack and servo motor than can be programmed for certain repetitive functions with great control.   A machine like that cannot do anything more or less than your current machine, but has what would be called labor saving devices and in the case of dog collars can really do a lot to move you forward at really an economical price.  Many folks here on leather worker may explain that you need to go big as in speed reducers and such, but the correct machine is really what you are after.  And by the way never get rid of your Juki DDL-5550N.  It's the best back up machine you can get no matter what motor is on there.

We looked at some of the programmable machines- but my wife is OCD and was not OK with the stitch quality. She is used to her machine that has a one stitch button on it, hence the need to slow down our current machine. 

[bullmoosepaddles]

@rockthecasbah121Not sure what Cowboy gets for them. Several years ago they were sold on eBay by a small company who marketed their own product.   

Edited July 6, 2018 by bullmoosepaddles

[garypl]

 

3 minutes ago, bullmoosepaddles said:

@rockthecasbah121Not sure what Cowboy gets for them. Several years ago they were sold on eBay by a small company who marketed their own product.   

I saw a box type speed reducer sold on eBay for $210

[rockthecasbah121]

My machine has a family FESM 550s Servo motor in it. When I looked it up, the only thing I can find is that it has an amco shaft. Are all amco shafts 3/4 bore? It looks like this pulley will probably work on my machine if so and reduce the rpm by half:

https://www.amazon.com/Industrial-Sewing-Machine-Motor-Pulley/dp/B01CXNRK6S/ref=pd_aw_sim_201_1?_encoding=UTF8&psc=1&refRID=42421DT2Y031XF8H0A0M&th=1

[trash treasure]

Have you checked that shaft with a caliper?   It might be 20mm, not 3/4" .

[dikman]

Most servos are made in China and it's highly likely that they will have metric shafts so you should check the diameter as tt said. Pulleys can be picked up on ebay pretty cheap, but most that I have seen use a keyway and a nut on the end of the shaft to retain them, just make sure that's what your shaft uses.

I still don't understand why you can't get it to go slower, as the model you quote should be adjustable down to 0rpm according to the specs I saw.

[rockthecasbah121]

7 minutes ago, dikman said:

Most servos are made in China and it's highly likely that they will have metric shafts so you should check the diameter as tt said. Pulleys can be picked up on ebay pretty cheap, but most that I have seen use a keyway and a nut on the end of the shaft to retain them, just make sure that's what your shaft uses.

I still don't understand why you can't get it to go slower, as the model you quote should be adjustable down to 0rpm according to the specs I saw.

The “0” setting does not spin the shaft at all- I’m assuming this is to facilitate hand cranking? The next slowest setting is 350 rpm, but when we do our thickest runs which are only 7-12 stitches long, it needs more torque to get started and then takes off on us. This is probably something that could be overcome by practice, but my wife would rather just get rid of the machine rather than mess up a bunch of collars. 

[bullmoosepaddles]

@rockthecasbah121My Consew did the same thing. When I turned the rpm up enough to punch through the leather I was sewing. On the first few stitches it gained momentum and then did a sprint more than I could control on short runs, 1 to 1.5 inches in length. I typically sew at 5 spi, that is not a lot of reaction time.

A speed reducer will make your wife a happy lady. It did for me and mine.  

If you don't have an inexpensive set of calipers, Harbor Freight is your friend. 

Edited July 6, 2018 by bullmoosepaddles
added content

[rockthecasbah121]

1 hour ago, bullmoosepaddles said:

@rockthecasbah121My Consew did the same thing. When I turned the rpm up enough to punch through the leather I was sewing. On the first few stitches it gained momentum and then did a sprint more than I could control on short runs, 1 to 1.5 inches in length. I typically sew at 5 spi, that is not a lot of reaction time.

A speed reducer will make your wife a happy lady. It did for me and mine.  

If you don't have an inexpensive set of calipers, Harbor Freight is your friend. 

I'm going to get a caliper tonight and confirm the size of my current pulley and then try and find a 1.5" or smaller one to attach to the motor. If that doesn't work, I'll move on to a pre-made speed reducer. No returns on this machine, so I've got to make it work for my wife. 

[bullmoosepaddles]

@rockthecasbah121Your shaft is .750 3/4, or .787 if 20 mm. You won't find a smaller pulley for that diameter shaft. There has to be enough material left to provide strength, place for the key way and home for the grub screw to lock it to the shaft. Happy hunting.