Knee lift versus pedal lift.

[toxo]

I'm liking my LS341/2750 clone more and more. I'm hating the pedal lift with a vengeance though. One of my "benches" is an old Singer table with the motor and knee lift still in situ. Yes, I determined to rob the knee lift for the new machine but when I got under it yesterday I found the rods went through the oil tray instead of individual pillow blocks. So I'll be off to the engineers very soon. I've found the pedal lift to be very hard so I'll probably install a spring somewhere to assist the knee.

If anyone wants the clutch motor they can have it for free. It was a bit whiney when I got it a few years ago so I replaced the bearings so it purrs now. Make a good motor for a project.

[kgg]

3 hours ago, toxo said:

I've found the pedal lift to be very hard so I'll probably install a spring somewhere to assist the knee.

I find that a bit odd. I just checked my Techsew 2750 and the only thing I can see that would cause the lifting to be hard would be an incorrectly placed, overly strong spring that returns the lift to a natural down position on the lever system or the screw on the pivot point is tighten to tight. Any chance of a photo showing how your lift is now setup.

kgg

Edited September 3, 2024 by kgg

[toxo]

1 hour ago, kgg said:

I find that a bit odd. I just checked my Techsew 2750 and the only thing I can see that would cause the lifting to be hard would be an incorrectly placed, overly strong spring that returns the lift to a natural down position on the lever system or the screw on the pivot point is tighten to tight. Any chance of a photo showing how your lift is now setup.

kgg

I moved the wire rope to the furthest back hole.

The fulcrum screw was a bitch to undo but I got it. It wasn't that.

I unscrewed the top P/F tension screw to the max.

All done has made it a bit lighter but juddery where it's binding on something. The angle of the rope going through the table is not excessive. I think it might just need wearing in. It's perfectly usable especially now that it's a bit easier, will be even better when I install the knee lift.

This is my first new machine and discounting the old Durkopp 239, the first with the elliptical feed dogs. My Adler 69 is an excellent machine but the linear feed dogs sometimes made it challenging where I asked too much of it. This new machine is working like it's supposed to with no dramas at all. I look forward to using it now. Just have to sort out the needle positioner and along with the knee lift I'll be an even happier bunny.

[kgg]

11 minutes ago, toxo said:

Just have to sort out the needle positioner and along with the knee lift I'll be an even happier bunny.

I did have to adjust the arm on the head side of one machine where the lever actually does the lifting as it was binding there slightly.

kgg

[toxo]

Had another go at the needle positioner yesterday and I think I've got it to stop down. Don't mind wheeling it up so I'll leave it there.

Sourced a longer shaft for the knee lift. Had to keep it at 11mm in order to keep the knuckles which meant having to order two 12mm pillow blocks/bearings cos I could find any 11mm. Not a problem cos they have set screws to clamp the shaft. Hopefully will get here today or tomorrow.

[kgg]

1 hour ago, toxo said:

Sourced a longer shaft for the knee lift.

Looking forward to seeing your arrangement. I assuming you are going to tie to the existing presser lift lever.

kgg

[toxo]

 

5 hours ago, kgg said:

Looking forward to seeing your arrangement. I assuming you are going to tie to the existing presser lift lever.

kgg

 

Pics not very good, video even worse but it shows the necessary. I tried to wrap the cable around the bolt in nan effort to leave everything in place so it could all be reinstated in the future but it's already got slightly loose so I'll have to do that bit again but it does work.

[kgg]

19 hours ago, toxo said:

I tried to wrap the cable around the bolt in nan effort to leave everything in place so it could all be reinstated in the future but it's already got slightly loose so I'll have to do that bit again but it does work.

As a couple of suggestions to tighten up the cable:

i) add two nuts and large flat washers to the threaded bolt to sandwich the cable.

ii) I had a machine that had a half moon pulley on the end of the knee lift shaft that the lifting cable went into. I can't remember the make or model but here is a sketch of sort of what I remember but using a small wheel pulley.

kgg

Edited September 6, 2024 by kgg

[toxo]

2 hours ago, kgg said:

As a couple of suggestions to tighten up the cable:

i) add two nuts and large flat washers to the threaded bolt to sandwich the cable.

ii) I had a machine that had a half moon pulley on the end of the knee lift shaft that the lifting cable went into. I can't remember the make or model but here is a sketch of sort of what I remember but using a small wheel pulley.

kgg

Great minds think alike. 

Can't access photos from phone for some reason. 

Edited September 6, 2024 by toxo
pic insert.

[kgg]

23 minutes ago, toxo said:

Great minds think alike. 

If the cable slips again just make a complete wrap of the cable around the bolt. I don like KISS solutions.

kgg

[toxo]

1 minute ago, kgg said:

If the cable slips again just make a complete wrap of the cable around the bolt. I don like KISS solutions.

kgg

Trust me, it won't slip. Turned out the bolt was too long. A more direct pull had the end of the bolt hitting the table and I wasn't about to dismantle it again. It works fine as it is and needle down as well, yes! Time to make something. I can feel a Hobo patchwork bag coming on.