Singer class 7 double needle has a issue

[1985]

Hi to all, 

I am quite new to forums, so hope this will reach any one who may help please,

A few years ago I got hold of a couple  Singer class 7 one was a  7-33 and the other a double needle Singer class 7, I think ,

I now decided to take a good look at the Double needle one, and check its functions, as its been under cover in my garage waiting to be worked on, but I only have limited knowledge with sewing machines, I need to call upon people with a lot more experience in this field than I. 

 After placing  oil on all moving parts again as I have done through the year`  there seams to be an issue, or a few I think"

When turning the hand wheel, there`s a point where its stiff then loosens up, then I noticed a few things under close inspection, There is a scraping shiny mark on the Cam thread take up in the grooved area about a inch long , And at the back of the machine is the another shiny scrape mark on the Connection feed forked . But it was about 7 mm in length and 2 mm in width but seems to of nearly gone now after me rotating the wheel, trying to find out the issue`s, but I will still show as it may be significant to some one. These two issues obviously must be rubbing at them points,and I don`t know why,

The other issues is on the needle assembly thread take up leaver , I notice when slowly turning the hand wheel round there`s a certain point the thread take up leaver stays stationary even though every thing else is rotating,

The Cam thread take up will rotate about a inch before the needle assembly take up leaver moves again, this will happen at the point where the shuttle hooks would be passing the scarf of the needles, just as the shuttle hooks grab the loops from the needles, So I don`t know whether that is normal, for non movement at that point of the needle take up leaver,

Also I had just noticed that both sides of the Driver shuttles start to rub up close to the plate above as they move to a certain point ,I will show in the photos pointing with screw driver showing a gap then showing there`s no gap at a certain point,where I feel it slightly may rub,

So first two photos are showing the long mark in the cam thread take up,

third photo shows shiny part of metal where on the connection feed forked 

Next two photos show the gap then no gap on the shuttle drivers,

And the last two photos show the double needle Singer class 7  I think, if any one knows what class it may be it would be nice to know

 

 

 

 

[1985]

I just noticed photos when entered topic never went in order sorry.

[CowboyBob]

It looks like a 7-38,the wear your looking at is normal,the takeup doesn't move @ that point so the thread can be picked up by the hook.Oil everything on it that moves & there are places when you spin it it might get alittle harder to turn like when the feet lift do to the action against the pressure foot spring.

[1985]

On 1/8/2024 at 12:01 PM, CowboyBob said:

It looks like a 7-38,the wear your looking at is normal,the takeup doesn't move @ that point so the thread can be picked up by the hook.Oil everything on it that moves & there are places when you spin it it might get alittle harder to turn like when the feet lift do to the action against the pressure foot spring.

Thank you,Cowboy Bob

Yes !!  all makes sense,cant find pics of the 7-38 I was starting to think it might of been a ADLER because I have not seen a 7 class with that plate at front of it like mine yet ,the serial number is AD 046017 

So after you pointed stuff out to my questions , logically and mechanically thinking now after reading your reply` the bolt was applying more pressure to the pressure foot spring, So I had to release the down wards pressure on the pressure foot spring, by going anticlockwise on the bolt , Which would at that point place less pressure to the pressure foot ,that eases pressure on the material ( between )the pressure foot, and feed dog.

I also realize now when adjusting the pressure bar spring to have (more) pressure to the pressure foot. the hand wheel is stiffer when rotating , even before the pressure foot makes contact with material, So this is why force and friction on all parts play a big part to the stiffness as well, so very important that I oil the moving parts frequently,as you state.

So over a period of time the friction made between two services if left dry , will wear causing parts to become looser, the tolerance level is acceptable within certain parts to the sewing machine, but in others sections of the sewing machine it would be unacceptable I guess.

Why don`t sewing machines not have high speed sealed high temp greased bearings in certain places to ease friction? 

So I also noticed that both shuttle horns that showing in the pics where gaps closing up  at a certain point on its oscillation  rotation at there certain point they both look as if they ( jilt / move ) slightly up or down in the timing basket, when they move towards me.entering under the cast of the machine base ,is that normal ?

I also noticed if I grab hold of the basket and push inwards towards the back of machine and then forwards there`s about 0.5 mm movement and it is not where the basket joins to the bar as that is pinned tight, should I adjust to make sure there`s no back and forth movement, or should it be left with some,? 

 

 

 

 

Edited January 11, 2024 by 1985

[CowboyBob]

15 hours ago, 1985 said:

So I also noticed that both shuttle horns that showing in the pics where gaps closing up  at a certain point on its oscillation  rotation at there certain point they both look as if they ( jilt / move ) slightly up or down in the timing basket, when they move towards me.entering under the cast of the machine base ,is that normal ? Yes,it might not hurt to take the screw out that holds the horseshoe spring & the there's a ring behind it that get dirt & thread between it & clean it out.And be sure the oil the race where the shuttle rides against often.

I also noticed if I grab hold of the basket and push inwards towards the back of machine and then forwards there`s about 0.5 mm movement and it is not where the basket joins to the bar as that is pinned tight, should I adjust to make sure there`s no back and forth movement, or should it be left with some,?  I don't understand ,can you take a pic of this?

 

[1985]

Okay `sorry Bob, let me try to explain it in a better way ` as I am possibly not using the correct names for the parts in question, I will show a pic front on with screwdriver touching to what I call the basket, it oscillates the two shuttles,may be you could give a correct name as I can`t seem to find its known name for that piece, So ill just keep calling it a basket until stand corrected,

The basket is connected to a bar or rod from the rear end part of the basket, they are connect by the rod entering into the stem from the rear of the basket,  

They have been pinned together which means when the bar or rod moves the basket oscillates at the same time,as they are connected with a pin .so when the basket oscillates also do the two shuttles, .

And my question was ,

When I grab the basket then push on it towards the hand wheel` and then pull back to the front there`s about 0.5 mm movement , I here it knock underneath at the far rear towards the hand wheel ,does this 0.5 mm movement need to be adjusted some where underneath at the back to where the other end of the rod is connected  so there`s ends up with no 0.5 mm movement. 

I also here a knocking noise when it moves 0.5 mm the noise is coming from underneath at the rear of the machine ,I think it might be where the other end of the bar or rod may be connected to the connected rod,  but don`t quote me on it being called connecting rod lol. 

So here is a pic of what I call the basket and another pic where I am pointing at the rear section of the basket and to where its pinned to the bar or rod.

There was also no play where the pin is joined so its not a loose pin.

Ps take no notice of the screw driver with the brown handle it was just left in the back ground,

Hopefully I have 

Edited January 12, 2024 by Northmount
moved post from the quoted box

[Northmount]

2 hours ago, 1985 said:

Okay `sorry Bob, let me try to explain it in a better way

Please post your info outside of the quoted box (usually below) so it become obvious it is a new post not quoted.  It gets confusing to users when new info is added to quoted text.

[1985]

Sorry ` my bad, not 100% sure some times , just getting use to forums, 

[CowboyBob]

Yes,there is a bolt with a tapered head on it that is at the end of the rod.Turn machine & watch on the rightside underneath you'll see where the rod comes down to make the hook shaft go back & forth.You just need to tighten it alittle & will have to hold the head of the screw when you tighten the locknut it so it doesn't get too tight.

[1985]

23 hours ago, CowboyBob said:

Yes,there is a bolt with a tapered head on it that is at the end of the rod.Turn machine & watch on the rightside underneath you'll see where the rod comes down to make the hook shaft go back & forth.You just need to tighten it alittle & will have to hold the head of the screw when you tighten the locknut it so it doesn't get too tight.

Brilliant Bob a Thank you ,

I know exactly what you are are on about, I really do appreciate you taking the time and having the patience to give your knowledge and experience to my questions, it really helped me out to understand the machine better . and it also may help others who may check this out.

I suppose every one can remember how daunting messing with there first sewing machine not knowing whether they will adjust something out of sink, if they had not had any training first or some one not watching every move to advice them,

 I have studded and watched hundredths of hours on footage to do with sewing machine, but since having bad reactions to COVID jabs and getting brain fog with speech issues for months and then getting COVID a few times my memory suffers from brain fog allot, its almost like short term memory loss to things I try to remember, so I have to film or photo most stuff for reference now,

Anyway`s I need to possibly at some point strip this Singer double needle class 7 down for a good clean as its starting to patina with fine rust in places I can`t get to easy with out taking bits apart and there`s loads of gunk in hidden places, But I am worried I might mess up the timing set buy the factory, but I think the factory have place a screw in the front cam joining the bar .

 

So this is my thinking on how the parts control certain areas ,

From what I gather now if I split the machines workings into 3 sections in my mind it makes it easier to see whats doing what, if correct starting from the hand wheel crank bar that runs through the head of the casting,

Section 1) The crank bar is where everything is timed by, moving from the back to the front CAM that has a connecting bit that moves in the cam groove` this connection bit also joined to the moving parts on the out side that controls the needle thread lifter ,and the foot bar that is having pressure from above by the spring foot pressure bar at the same time. And at the front of the cam there`s a joining piece that moves the needle bar clamp up and down, which moves the needle bar that hold the needle, few!! .

Section 2) The back end of the crank bar rotates moving a forked piece back and forth,the forked piece also has a forked piece at the bottom that`s connected to a bar , that bar is rocked back and forth ,witch intern moves the  shuttle hook holder I call the basket,

Section 3) Then staying with the underneath at the rear end joined onto the forked bar there`s a connected bit that goes to another bar, that moves the feed dogs, Have I missed anything out,in principle

I don`t want to mess up the original factory timing , I also not sure should the needle bar be at its highest or lowest point when starting to dismantle everything or does it not matter,

And what should I (not) dismantle with out marking its original position first ,

I really need advice here from you guy`s on the does and don`ts that need to be done or not when stripping the machine down in the near future,please,