fibersport

Again, I'm not looking to maintain the slow speed, only to have a slow ramp up speed,

It's a Pfaff 545. I already have a servo motor on it but it's a few years old and probably a low end one. I'm not looking to sew at that speed, I just don't want to have the motor start turning at a high speed for the first few stitiches. I built a speed reducer that is about a 5:1 ratio which really helps, I'm just looking to see if I can make it any better in terms of a slow ramp up speed. The higher the max speed setting on mine, the less control I have on my ramp up speed. It's like anything else, the less you spend the less you get, so my less expensive servo motor gives me less control.

Yes, that's the one. I'm still on the fence over the digital and analog motors, or do I just sit tight and live with what I have - decisions decisions ..... I really think all would be fine, I just need to dive in and spend more time sewing, if only my job didn't require that I be there every day! Thanks again for your input Wiz -

Got some interesting information tonight from Reliable. I was told that the Quietsew 6000SM has a minimum speed of 500 rpm. Different pulleys are able to be installed as well but the needle positioner will not work with different size pulleys. I guess the benefit of the 6000sm might be the controllable startup speed. It would be interesting to find out the minimum speed of the Consew 550 (and clones).

Great find and really nice looking CJ too! Since the RB-5 is still being made, couldn't you just buy a new feed dog and plate? It sure would be easier, and I'm one for doing everything myself. By the way, I'm giving you a Jeep wave, I've got an '84 CJ that will be getting new seat covers soon as my first real sewing project!

Exactly. I built a speed reducer and would loose some benefit using a 60mm pulley. However, I would try the motor without a speed reducer first to see how I like it. If it's not right, I can add my speed reducer and or look for a smaller pulley.

From what I can find, the original pulley on the Reliable/Sailrite motor is 60mm, I am currently running a 45 or 50mm pulley. Sailrite specifies that you should not run their motor with their "Monster pulley", not sure if it's because of weight or diameter. I do know that the Sailrite motor comes with a small diameter toothed pulley so I would think going with a smaller grooved pulley would work as well.

Has anyone installed a smaller drive pulley on a digital servo motor and if so, were there any issues?

GerryR - as they say (not that I would), many ways to skin a cat. I think your method would be great for a system that is run full time as it sounds very robust, it sounds like it would be at home in an industrial environment. Right now, I don't have the time to devote to yet another project putting everything together for the drive system - I like to tinker but I'm more mechanical than electronic, but still I like your approach.

Gump - that's what I'm looking for, however my eye's aren't that good, I would probably sew through my finger! Your comment reminded me of a video I once saw of someone changing a fan belt on an old VW beetle with a screwdriver when it was running. I've been doing some reading up on the Sailrite Workhorse, they too say that you can basically go stitch by stitch when starting up or in intricate areas. Any idea what the minimum speed might be of your motor, I can only find range and a maximum but not a minimum. Maybe because you can't really measure the minimum as it's ramp speed is variable so they just say it starts out at 0?

Uwe - great information and really am impressed with your home built unit. As for the Efka - way too rich for my blood. The Teknik would be a very interesting way to put together a great system but right now I already have way too many projects! Kgg - good information, thanks, I'll put it all in my memory bank as I continue my quest.

Gump - I caught the start up speed setting in a video on setting the parameters on the Sewquiet 6000, zero disables the slow start but it didn't say what the highest number is nor what the different settings actually do. With my current set up, it's either zero or 500 rpm at the motor. On your sewquiet, can you slow the stitch down just by feathering the treadle?

Keep in mind that I am not concerned with the minimum speed, what I am looking for is a ramp up speed, or actually time. As I have said, I have a speed reducer installed. My minimum motor speed is 500, my final output speed is about 109. I have an app on my phone that uses the camera light to act as a strobe to tell you what the rpm is, both my phone app and calculations are in agreement with my measurement of the pulleys and machine handwheel. I am looking for the slowest ramp up speed between the analog and digital servo motors.

No it didn't. I bought it some years back to upgrade from a clutch motor on my old Singer. I'm really hesitating to buy another digital controlled motor that looks a lot like what I already have. From what I'm reading, the Reliable motor is a 12 coil motor which should give me better start up torque and what looks like a stronger physical designed motor. It seems the Reliable and the Sailrite are the same motors except for price. The brush motor that Wizcrafts talks about looks like its a tried and true motor, just more old school in terms of servo motors. Those reasons are why I'm looking to find someone that has one of these motors, to basically compare actual experiences rather than just reading about them.

Thanks Constabulary but I already built a speed reducer. It does bring the overall speed down nicely but it's the ramp up speed that I'm looking to slow down. My current motor starts at about 500 rpm, I have brought the machine rotation down to about 100 rpm which is nice and slow but it literally goes from 0 to 100 with no ramp up. My current motor also has a digital control so unless it can be reprogrammed, there is no way I can adjust the start up speed. One other thing, using a speed reducer means I can't use a needle positioner due to the rpm differences of the different pulleys involved - although not having one isn't that big of an issue with me. I'm just trying to see if there is a difference in ramp up speed between the two motors that I think I've narrowed things down to.

There have been many good comments on my original question. After doing more research and actual testing, it seems that my biggest problem is the ramp up speed of my Goldstar servo motor. With that said, I'm really leaning towards just replacing it with a better motor. The two that seem to be popular are the Consew CSM550 (or equivalent) and the Reliable 6000sm (or equivalent). I know Wizcrafts has the analog type motor and Uwe has the digital type and I value both of their knowledge and opinions. The price is minimal between the two types although the digital model can use a needle positioner, which might be a nice option but not required. Brush wear is not an issue for me as I would probably never wear a set out. I guess my question really is which one has a slower ramp up speed?

I ordered the same pulley combination, got them off of ebay, they came direct from the C country and cost something like $15 for both. I would have liked to go bigger on th large one but had a tough time finding one that was cheap.

I used that pulley calculator too just to see what speed I would be getting. I also downloaced an app on my phone to use it to measure speed, while probably not perfect, it worked consistently. My pulleys are, measure on the OD of the pulley, 50, 120, 42 and about 80mm on the machine. My measured motor speed was 502, my machine speed was about 106 which matches up really close to the pulley calculator. That gives me about 1.7 stitches per second. I would like to be able to get slower than that, thinking it's the servo motor start-up speed that's keeping things faster than I would like.

Tastech - a picture of the speed reducer I made is on the second page of the link that Burkhardt posted.

Perhaps I should have worded my question along the lines of a slow ramp up in speed from 0 rpm to whatever maximum might be. I do realize that 0 rpm is stopped but one has to start somewhere, and I know what revolutions per minute means - and really why would anyone want to sew at 1 rpm? Wizcrafts you seem to understand my initial question, starting at 200 or 300 rpm is what I have but not what I want. It's that initial start up speed that I'm trying to lower. A clutch type motor could be made to start up slow by slipping it but I don't sew enough to be able to master that technique even though I've driven vehicles with clutches for decades, slipping a clutch on a sewing machine just eludes me! Thanks for all the suggestions and comments, nice to have a great brain trust from which to tap in to once in a while.

Are there any servo motors that actually have a zero speed startup? I bought from a supplier a few years ago but it doesn't start at zero, the controller says 200 I think, not sure if that is truly 200 rpm or not but it isn't zero. I see conflicting specs on some of them saying the speed range is 0-4500 - but will it actually start at 0 rpm?

You can get complete tension assemblies for around $10 US and up on ebay. The servo motor will help but put a 40 or 45mm pulley on the motor to really make a difference. I also built a speed reducer for mine which helped slow down the start up speed even more. The post is titled Questions re: DIY box style speed reducer 1 2 .My speed reducer design is on the second page. It still isn't as slow as i want it but I think it's a limitation of my servo motor. I sent you a private message regading the manuals.

You figured it out. Actually I believe one of the manuals covers the exact issue, the solution is to spread the two parts apart with a screwdriver. You don't want to spread them too much or they could break, however once you spread them and the bobbin holds tight, you should be good for years. Have you been able to find an owners manual? They can be found on-line with a little searching. I have also found that downloading the manuals for the 1245 are beneficial, especially when trying to set timing and such.

As long as you have a little clearance between the wheel and the belt when not winding a bobbin, you're fine. I picked up a 545 a few months ago, if you need any help feel free to contact me either with a post or a private message. I'm just getting into sewing as a hobby, these are great machines, parts can be pricey though. One last thing, add a drop of oil in each hole on the bobbin winder, it will seep in and get it running even better. Be sure to give teh machine a good cleaning and lube as well. Greg

Does that machine have a safety clutch? When I bought my Pfaff I too thought the timing was way off, until I started ,looking deeper into it and found the safety clutch had tripped. I didn't realize that a simple jam would trip it - glad to know it works.