Singer 251-3 Sewing machine.

  • Thanks, Pierre.

    Thinking that this machine running so fast is a common problem, I thought that maybe singer made alternative flywheels that could be swapped out. Don’t think so.

    Then I thought that maybe using a lathe to cut another flywheel, either out of stacked plywood or aluminum, and replacing the existing one with a larger diameter might be doable.

    0_1490805258529_Capture flywheel.JPG
    The belt rides over the t4 screws

    I have no idea if this is much more difficult than adding a jackshaft, because I have done neither.

    I see that other people have this problem too. See here:

  • Does anyone have sheet gasket (cork)?

  • I can likely acquire some. How thick do we need?

    Also… The advantage of a jack-shaft is that it gives you a much wider range of ratios to play with. If we machine a new pulley for the handwheel (which is a super cool idea…) we are limited by what will leave adequate walls for the v-belt. We likely don’t want to change the diameter of the part where the stitch lengths are marked… So we can maybe do a 10% speed change there. V-Belt grips on the sidewalls, so we can’t remove too much sidewall.

    The jackshaft could easily cut speed to 1/4 current speed. Could even use a pair of stepped pulleys to have a couple of speeds available.

    Other option is to change out the pulley at the motor end. I bet that is a simple princess auto part.

  • Thanks, Pierre. I was looking to replace the top gasket in that machine. Not sure the thickness, but just about anything under 2 mm should work.

  • Re step-down pulley system, see:

    Talks about replacing clutch motor with servo type (seems expensive) then walks through pulley system step-down.

    Also here:

    However, if you look here:

    at the 4:08 mark of the video, it talks about the lubrication system. The automatic lube of the machine requires it to run at nearly full speed in order for the pump to work to lube the top of the machine. So after stepping it down, we should make sure that the oil still drips through that little window.

    So this may be a better option to consider here:

    where he merely lengthens the arm of the motor control (not sure how/if that would work on our singer) in order to fine-tune the speed control, without gearing it/slowing it down.

    I will have a look tonight when I am there.


  • The other thing you might try is … Sewing with it as designed on some scrap material for about fifteen minutes or so. I found it super intimidating and hard to control at first, then realised that it is very much like switching from my pickup to my van… The gas pedal on the van is much less stiff and more sensitive than the truck (and the power to mass ratio favours the van greatly) but it is actually not that hard to not burn up tires and grass once you drive it a bit… I have found references to some people putting a foam wedge under the pedal to make it stiffer on these machines.

  • @Lawrence a cam might work to create more pedal travel. That might make finding the starting point easier

  • I bet part of the reason the leather video is belting down is to gain torque. Sometimes with a thick stack of leather you really have to stab it to get the needle through. Adjusting the pedal travel might be better for now.

    I now have a roll of 1/16"x10"x26" cork gasket material. I’ll leave it by the sewing machine next time I’m in.

  • Thank you for the gasket material, Pierre

  • I used the machine last night for a small leather project and to get a feel for it. i have also texted Rudy to get his feedback on the set-up. I will write a synopsis of any issues that we have found and post it here. For now, it does no harm to adjust the clutch sensitivity as noted in the video I posted above, “a better control of speed of a sewing machine, part II”. Then if we decide we want to further this by trying a cam as Grant suggested, above, then we can consider that too.

  • Okay, so Rudy and I have had a talk about this machine. Basically, Rudy points out that this is not really a heavy-duty machine as it does not have a walking foot. It was probably designed to do light, straight work fast, like draperies or something like that with long, straight stitching. So it is fast but does not do thick. In this way it is “heavy-duty” in terms of durability of parts, etc, but not in terms of the materials that it can sew. The speed of the machine and it being suited to long straight seams does make it a bit difficult to use for smaller projects. We discussed that it should have a needle guard for safety. Something like this:

    Will help to keep people from running over their own fingers when the speed gets away from them. Oops, that one is built-in to the foot, so maybe this would be a suitable add-on:
    Maybe I could bend one of these myself out of wire.

    Hope this helps.

  • When I used the machine last I found that the oil was not dripping down through the little window in the front of the machine, even when I ran it fast. I do not know how oil pumps work in these machines, but I understand from the instructions that the oil is always supposed to be moving through the window. I checked the oil level and it seems to be fine, so there may be something wrong with the pump. The oil pump looks like this:


  • Design Lab

    Hi @Lawrence ! Amber is coming in to open house and is wondering about working on that sewing machine - if you are around, come by and let’s get her setup?

  • Sure, Vaughn, just need to find time this week. Tuesday sounds like it could be good. What would be a good time?

  • Design Lab

    She plans to come in weds nights through tje summer and work on some leather, clay and laser etched buttons. If you can make it for a weds let me know, but no presh - just wanted to do a proper hand off on that machine. Thank you for all you’ve done to get that old.machine back in action.

  • Design Lab

    Also, the leather machine worked beautifully for her last weds. Thanks for that too!

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