Job Specific Sewing Machines

[Evo160K]

10 hours ago, jimi said:

I think that cone of thread on the floor is for refilling the bobbins Al, you can see it in the first picture.

Jimi, so you don't think the spool is automatically feeding the "bobbin"?

[dikman]

Mark, I see no reason why that wouldn't work, but if it was me I'd be looking at some way of attaching a pulley to that handwheel, that way you'll have a choice of pulleys for the motor and can use standard belts. Have a look at second-hand/used machinery places and see if you can find a cheap pulley (that's how I found one of mine, I saw it and thought "that looks like it might be useful" - and it was!). The shaft size won't matter because you'll be modifying it. I used a pulley off a car airconditioning unit by drilling and tapping the handwheel on one of my machines, like Bob suggested.

[Wizcrafts]

On 2/21/2019 at 3:24 PM, Evo160K said:

Is that lower spool of thread continuously feeding the bobbin?  Isn't that' sort of the holy grail of sewing?

You are confusing a 2 thread bag closer that forms a type 401 chainstitch that uses loopers to interlink two threads on the bottom with a type 301 lockstitch machine that has a bobbin. Chainstitch machines don't have bobbins, just loopers. Most are type 101 single thread type with a looper on the bottom. This stitch is fairly easy to unravel. A type 401 chainstitch is not easy to open.

Many people through out the history of sewing machines have tried in vain to create an endless bobbin. The various chainstitch systems were what they settled upon. The endless bobbin system lives in the same place as the Pegasus

[jimi]

5 hours ago, Evo160K said:

Jimi, so you don't think the spool is automatically feeding the "bobbin"?

I think this is how it goes Al.

[Mark842]

8 hours ago, dikman said:

Mark, I see no reason why that wouldn't work, but if it was me I'd be looking at some way of attaching a pulley to that handwheel, that way you'll have a choice of pulleys for the motor and can use standard belts. Have a look at second-hand/used machinery places and see if you can find a cheap pulley (that's how I found one of mine, I saw it and thought "that looks like it might be useful" - and it was!). The shaft size won't matter because you'll be modifying it. I used a pulley off a car airconditioning unit by drilling and tapping the handwheel on one of my machines, like Bob suggested.

Actually just found this on eBay

https://www.ebay.com/itm/AMEC-BK85H-SINGLE-GROOVE-QD-PULLEY-W-BUSHING-CHOOSE-YOUR-SIZE/323479315865?hash=item4b50dea599:m:mCYWodtYMYTO5XFlFXlLEDQ:sc:USPSPriority!84015!US!-1:rk:5:pf:0

and I'm thinking it would work. I'm trying to get my pea brain around the pulley sizes for speed control and torque. I already have a spare speed reducer pulley sitting here from the leather machine co. The place selling this pulley has them available with an 8.25" O.D. and  5" O.D.. I'm inclined to go with the 5" thinking the 8" might be too slow. I'm just judging this from using my Cobra 4 as I currently have the speed control set as fast it will go and while it is an OK speed for some stuff like belts I wish it could be a little faster...the joys of production work. All this being said, I don't even know how much I will use the Singer 7. I have a problem with just liking cool old machines!

Edited February 23, 2019 by Mark842

[Bugstruck]

On 2/23/2019 at 12:58 AM, Wizcrafts said:

You are confusing a 2 thread bag closer that forms a type 401 chainstitch that uses loopers to interlink two threads on the bottom with a type 301 lockstitch machine that has a bobbin. Chainstitch machines don't have bobbins, just loopers. Most are type 101 single thread type with a looper on the bottom. This stitch is fairly easy to unravel. A type 401 chainstitch is not easy to open.

Many people through out the history of sewing machines have tried in vain to create an endless bobbin. The various chainstitch systems were what they settled upon. The endless bobbin system lives in the same place as the Pegasus

Unless I'm completely missing something that 301 lockstitch and continuous bobbin feed thread path is fully achievable. Blows my mind nobody has figured it out yet. Not really a challenge compared to all the other machinery technology  hurdles that have been long been cleared. Push the bobbin on a horizontal hook to the floor, then engineer the path.  Barely difficult. Drive the hook from the side is the easy solution. With a gear under the hook and bobbin (as they all are now) it is rather more problematic but also achievable. Thread has to run the hook gear centerline in that instance, so a fight but surmountable. 

[Bugstruck]

Well that's what three glasses of wine will do. Wiz is correct, my idea won't let the stitch form as the upper thread won't loop the core thread (bobbin). Hey, I was brilliant for about 30 seconds, in my mind only. LMAO now, at myselt.

[Wizcrafts]

1 hour ago, Bugstruck said:

Well that's what three glasses of wine will do. Wiz is correct, my idea won't let the stitch form as the upper thread won't loop the core thread (bobbin). Hey, I was brilliant for about 30 seconds, in my mind only. LMAO now, at myselt.

And so another Hobbit learns a lesson.