Suggestions for slowing down machine

[chrisash]

Very easy to get a friend with a lath to turn one up or local machine shop

[Constabulary]

16 hours ago, BDAZ said:

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

could you explain that please   What do wee need

[rockthecasbah121]

Any advice on taking this pulley off? I assumed all I had to do was loosen the set screw and slide it off, but it feels like I’m going to break my hex socket before it budges. Am I missing something else I need to do first?

[Scoutmom103]

I watched a you tube video, where someone changed the pully, and they used a specialty tool to remove the pully.  I think it was called a gear puller.  They are available at auto parts stores.  

[dikman]

Well, there's no keyway, but I'm not sure why it has what appears to be a sleeve between the shaft and the pulley, that's usually only done when the pulley is too big for the shaft. Have you tried removing the grub screw completely and twisting the pulley to see if it's screwed on? If you can't get the pulley off I wouldn't worry too much as from what you've said about using it if you buy one of the commercially available speed reducers (one with a BIG pulley and a small one) I'm sure that will solve your problem.

[rockthecasbah121]

 

5 minutes ago, dikman said:

Well, there's no keyway, but I'm not sure why it has what appears to be a sleeve between the shaft and the pulley, that's usually only done when the pulley is too big for the shaft. Have you tried removing the grub screw completely and twisting the pulley to see if it's screwed on? If you can't get the pulley off I wouldn't worry too much as from what you've said about using it if you buy one of the commercially available speed reducers (one with a BIG pulley and a small one) I'm sure that will solve your problem.

I’m thinking about leaving it on. The shaft size seems to be a strange one at 11/16”- I’m assuming I’d have to get that custom made. 

[dikman]

Probably a good idea . There have been times when I've been determined to remove/fix something that I should have left alone and I end up creating more work for myself! There are two basic styles of reducers available (have a look at the sponsors' sites here) - the box type, where the box frame mounts in place of the motor, which then mounts to the bottom of the box, and the reducer shaft and pulleys are mounted in the box, or the single-mounting type which has a heavy duty casting that screws to the bottom of the table and the pulley stack "hangs" off the side. Go for the one with the biggest pulley.

[BDAZ]

7 hours ago, Constabulary said:

could you explain that please   What do wee need

I did a thread on it a few years ago. You simply change the values on the resistors controlling the motor speed. Very simple circuit, since the speed controller is a variable resistor. I either added or removed resistance. I have been using is ever since and works like a champ. I won't be doing and sail making with this setup but great for very slow and accurate stitching.

Bob

 

 

[rockthecasbah121]

Ok- 3-6-9 pulley reducer ordered with 3 day shipping. I’ll let everyone know how it goes installing it and seeing how it works. 

[garypl]

23 hours ago, garypl said:

 

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

Bought a box speed reducer today from Cowboy Bob - $190.  Box mounts under table and motor mounts under the box.  Should slow down my machine so I can better control it!

[bullmoosepaddles]

@rockthecasbah121 Try a little WD40 or the like if you want to get the smaller pulley. My motor shaft does not have a key, it has a divot in the motor shaft that the Allen screw tightens into. Most good hardware stores have  bushings for adapting such differences.

The bushing in the link below is over priced. But it is what you would need in a shorter length. With no key way the Allen screw will just go through the key way spacing into the divot. 

https://www.ebay.com/itm/11-16-ID-X-3-4-OD-X-3-Shaft-Adapter-Motor-Pulley-Bore-Reducer-Bushing/372320001699?hash=item56b0005ea3:g:LJYAAOSwPYZU96se   

[bullmoosepaddles]

10 minutes ago, garypl said:

Bought a box speed reducer today from Cowboy Bob - $190.  Box mounts under table and motor mounts under the box.  Should slow down my machine so I can better control it!

Your new reducer sure beats the instillation of the cast ones.   

[garypl]

28 minutes ago, bullmoosepaddles said:

Your new reducer sure beats the instillation of the cast ones.   

I think it will be a neater solution.  Bob says I probably will not have to cut out the slot in the table.   I’ll post results after I get it installed.

Gary

[DonInReno]

3 hours ago, rockthecasbah121 said:

I assumed all I had to do was loosen the set screw and slide it off, but it feels like I’m going to break my hex socket before it budges.

If you need to loosen that set screw (or any tight screw) I'll first use a screwdriver bit that fits and give it a hammer smack - often times that's all it takes to get a stiff screw to let loose.  If that doesn't work I'll heat it with a torch just until a little water starts to boil off and no more.  200 degrees is hot enough to loosen any glue or thread locker if present, and expand the parts just a tiny amount without damaging anything. If that doesn't work I'll cool it with canned air turned upside down to get the really cool liquid (usually r134 refrigerant), reheat with the torch and then smack the screw with a driver bit and hammer.  That usually takes care of it.  If the screw strips out you drill it out with a drill bit just smaller than the threads - it takes all the pressure off  the threads and an easy out or triangle file jammed into the hole turns it out easily.  

[rockthecasbah121]

After about four hours, the new pulley is on. My bobbin winder may not fit back on afterwards, but that’s ok. I will need to cut out some additional room for the belt and also get a new belt for the motor to fit around the largest wheel- the one it came with left it slightly too loose. 

Right now I have the motor going to the 6 inch pulley and the sewing machine going to the 3 inch. Anyone have any idea what that reduction on speed ends up being? Even in this configuration, it’s a lot more manageable. 

[dikman]

Well, according to my maths (and I was never any good at maths!) you've got a 2:1 reduction, i.e. running at half the speed it was before. Once you can use that big pulley you should notice a big improvement.

[rockthecasbah121]

Two new belts later and the machines speed and power are perfect!

my wife has OK’ed the speed for sewing collars. One last question on a problem she is having. She is used to the machine automatically raising the needle to the position to remove the item and release the bobbin thread. I know there is an attachment to do this on Juki’s. Can I use this attachment with the pulley adjustment or can I adjust the timing so that it releases the bobbin thread at the highest point of the needle?

[brmax]

It may be two different task your decribing that can be done. I believe the first she could be refering to is the “ needle positioning “ this is a electronic motor setting, be it servo motor or older clutch type with great electronics. 

The second is an attachment your mentioning; there is the presser foot that can raise with your knee on a cushioned lever and or by hand near the needle, with another lever.

The electronic needle positioning may only work correctly with the reducer if a reduction ratio is limited to 3 to 1, this has been talked about in post somewhat. So it may not work. 

 

Good day

Floyd

[dikman]

As Floyd said, you're referring to a needle positioning system. Servo motors often have it as an option, a sensing device that can be attached to the side of the handwheel. The motor can be set so that the needle stops down or up when you take your foot off the pedal. When I fitted a speed reducer my NPS wouldn't work due to the electronics not coping with the changed ratios caused by the extra pulleys in the drive train. Didn't bother me though as I found it a nuisance and unnecessary for slow speed sewing in leather.

[Davidmadd]

Just out of interest I've just posted a reply to someone who has just set up a speed reducer.  In case you cant find that reply I mentioned that due to my complete lack of sewing skills I wanted a really slow and easily controlled machine and have used a 250W DC motor.  It needs a 24V DC power supply and a 24V DC Motor speed controller.  A potentiometer then easily controls the speed from 0 to max revs.  I found a spring loaded arm potentiometer and connected a presser foot lift pedal to it.  It works great on my 31K15 and 31K47 but my 111W154 needed a larger sewing machine handwheel and pulley for best result.  I can now do single stitches, start, stop or put my foot down and get a decent speed when needed.  The motor, power supply, controller and foot pedal are far less bulky and industrial looking than the standard clutch motor and this has worked for me.  I have now acquired  larger slightly equipment and will soon by driving my 132K6 and 45K by DC power.

Hope this helps, Regards  David - Plymouth, UK