Advice on a Recently Purchased Claes 8346-30 Patcher Sewing Machine

[Cumberland Highpower]

15 hours ago, ya2daup said:

Well it appears that I have bigger issues. I got it threaded up and the top thread doesn't want to pickup the bobbin thread. I put in an empty shuttle and cycled it with the bobbin holder door open and it appears that the machine is WAY out of time. The fact that the back cover was off when I purchased it seems a bit dubious. I'm mechanically inclined but with such little information available about these machines I'm not sure where to start. I can post videos if anyone is willing to help troubleshoot. I'd happily pay for some online tutelage.

Are you certain you're using the right needles?  A needle too short or too long can give you the illusion of being out of time. Might sound like a silly suggestion but sometimes could be the case?   Just look over the mechanisms, you should be able to "see" what the problem is with a little careful analysis. 

Edited July 11 by Cumberland Highpower

[ya2daup]

19 hours ago, friquant said:

What is the minimum speed of the servo motor on your consew? It's easy to find a "digital" servo motor with a minimum speed as low as 200 rpm, which with a 45mm motor pulley gave me 111 stitches per minute with an 80mm hand wheel pulley. Your setup may be slower if your handwheel is larger than 80mm. If you want slower than that, they you either need a speed reducer, or an "analog" servo, or both.

My Consew's servo has a min of 400 rpm and I have the smaller pulley installed. If anything a needle positioner would be nice on this machine. As for the Claes I think I'll get a speed reducer to really slow it down.

 

6 hours ago, kgg said:

I am wondering what you mean by " up to max thickness "?????

In my opinion Patchers are not meant for boot soles. The max sewing thickness of that machine is less then a 1/2" at 12mm (15/32").

I assume you meant Claes 8346-30.

Here is a good manual that you can download ( https://www.manualslib.com/manual/3027579/Claes-8346.html?page=3#manual)

kgg

Yup, thanks for the correction on model number. For some reason I've been transposing the 3 and the 4 ever since I first read about this model. I can't find a way to change the title or I would...

I'm sure you're right about boot soles. I don't really have any goals with the machine other than to be able to get into tight places for boot and backpack repairs. If it did soles that would be a bonus but not a deal breaker. 

Thanks for the link, that manual seems to be posted on a few websites. I also have a document with drawings of individual components but that one is in German. I've seen posts regarding a mechanics manual but I can't seem to find one posted online.

 

8 hours ago, Cumberland Highpower said:

Sewing machines are simple machines and anything can be fixed.  It's probably just a timing or adjustment problem rather than a parts one.  

I don't think that machine can handle much sole work, if any?  I think most buy them for things like sewing patches on jackets and shoe upper repair work in 4/5oz or less shoe leather.

Positioner on a shoe patcher might be not worth the effort, you'd be better off just to set it up to run slow.   Positioners are more for speedy production machines and a patcher isn't really one. Slow sewing design w/small bobbin.

Hopefully you're right on the adjustment. We'll see what everyone thinks after looking at the video.

No worries on the sole work, just brainstorming what things I may attempt to repair.

Yup, I think slowing the machine down to a crawl would beneficial than a positioner.

 

2 hours ago, Cumberland Highpower said:

Are you certain you're using the right needles?  A needle too short or too long can give you the illusion of being out of time. Might sound like a silly suggestion but sometimes could be the case?   Just look over the mechanisms, you should be able to "see" what the problem is with a little careful analysis. 

It came with a couple dozen 88 needles, I didn't see any 81s in the batch.

Here's the uploaded video. Along with the needle timing I'm also concerned about the horizontal play in the main shaft. You can hear it "clunk" into place every rotation.

Here's the Youtube link, hopefully it's good enough: 

 

 

Edited July 11 by ya2daup

[Northmount]

1 hour ago, ya2daup said:

Yup, thanks for the correction on model number. For some reason I've been transposing the 3 and the 4 ever since I first read about this model. I can't find a way to change the title or I would...

I'll fix the title in a few minutes.

[friquant]

I can see that the timing is off, as it moves too far clockwise / not far enough counterclockise to drag the thread around the bobbin. (Even if it did manage to pick up the thread in the first place) 

 I have not been able to find a service manual for this machine. As @Cumberland Highpower said: "Just look over the mechanisms, you should be able to "see" what the problem is with a little careful analysis."

I would start by removing/opening covers. See if you can trace the movement of the hook all the way back to the main shaft. That is, figure out which shafts, rods, gears, cams, and/or arms are involved in making the hook turn. At least of of those members will be adjustable in a way that allows you to change the hook timing. Feel free to post additional videos as you make progress.

Once you figure out what to adjust to effect a timing change, try setting the hook so that in its clockwise swing the point of the hook only goes about 5mm past the needle before the hook turns around to go counterclockwise. I expect that will put you in the ballpark where it will actually sew.

Edited July 13 by friquant

[Constabulary]

Looks like a model from the 1980 which is slightly different to the latest model. IIRC the blade spring on the rear is a different one on the latest model but thats the only major difference I recall. Right now I have a very similar machine here and can take some pictures if you need assistance.

Some time (years) ago I translated a 8346 mechanics manual from German to English for one of our members (seems I had a lot of spare time back then 😊) but I have to look for it in my records. I´ll send you a PM if I find it.

BTW some of the parts I see in the pictures obviously do not belong to this machine. FI the Singer class 15 bobbins and the bobbin cases.

Edited July 13 by Constabulary

[ya2daup]

On 7/12/2025 at 6:50 PM, friquant said:

I can see that the timing is off, as it moves too far clockwise / not far enough counterclockise to drag the thread around the bobbin. (Even if it did manage to pick up the thread in the first place) 

 I have not been able to find a service manual for this machine. As @Cumberland Highpower said: "Just look over the mechanisms, you should be able to "see" what the problem is with a little careful analysis."

I would start by removing/opening covers. See if you can trace the movement of the hook all the way back to the main shaft. That is, figure out which shafts, rods, gears, cams, and/or arms are involved in making the hook turn. At least of of those members will be adjustable in a way that allows you to change the hook timing. Feel free to post additional videos as you make progress.

Once you figure out what to adjust to effect a timing change, try setting the hook so that in its clockwise swing the point of the hook only goes about 5mm past the needle before the hook turns around to go counterclockwise. I expect that will put you in the ballpark where it will actually sew.

Success! I was able to remove the cover underneath the shuttle assembly (not sure if that's the correct terminology) and move it around until it started picking up the bobbin thread. I did some test sewing and it appears to be working well! Any thoughts on the horizontal play in the main shaft that is connected to the motor pulley? At the top of the cycle it moves about 1/4 inch and then "clunks" back into place as it continues the cycle. I can't think of any reason why it would do this and want to make sure using it like this isn't going to cause undue wear.

Once I'm confident that it's operating correctly I can start work on the motor, trundle and speed reducer.

On 7/13/2025 at 1:58 AM, Constabulary said:

Looks like a model from the 1980 which is slightly different to the latest model. IIRC the blade spring on the rear is a different one on the latest model but thats the only major difference I recall. Right now I have a very similar machine here and can take some pictures if you need assistance.

Some time (years) ago I translated a 8346 mechanics manual from German to English for one of our members (seems I had a lot of spare time back then 😊) but I have to look for it in my records. I´ll send you a PM if I find it.

BTW some of the parts I see in the pictures obviously do not belong to this machine. FI the Singer class 15 bobbins and the bobbin cases.

I do believe you're correct on the age. The serial number ends in 86, which I believe is the manufacturing year.

I did see that old post about you having an english translation for the mechanics manual. I didn't realize you did the translation yourself. I'm sure they were very appreciative! If you can locate it I would be very grateful if you would send me a copy.

The old owner removed the motor and trundle connections so any pictures of that setup would also be greatly appreciated.

 

[friquant]

13 hours ago, ya2daup said:

Any thoughts on the horizontal play in the main shaft that is connected to the motor pulley?

Are you saying the main shaft moves horizontally (and takes the handwheel with it)? Send a video maybe.

You might try preventing the horizontal movement to see if the machine can still turn without binding up. If it binds up without the horizontal movement, then maybe the horizontal movement is by design.

Also check to see if there are any screws loose near the main shaft whose job it might be to keep the shaft in place. On domestic machines I've seen C-clips used to prevent horizontal movement of the hook shaft. If a C-clip were missing, there would be a groove cut in the shaft but nothing in it.

[ya2daup]

1 hour ago, friquant said:

Are you saying the main shaft moves horizontally (and takes the handwheel with it)? Send a video maybe.

You might try preventing the horizontal movement to see if the machine can still turn without binding up. If it binds up without the horizontal movement, then maybe the horizontal movement is by design.

Also check to see if there are any screws loose near the main shaft whose job it might be to keep the shaft in place. On domestic machines I've seen C-clips used to prevent horizontal movement of the hook shaft. If a C-clip were missing, there would be a groove cut in the shaft but nothing in it.

If you look at the second half of my video above it shows the movement I'm speaking of, but I'm happy to take another video. Oddly enough the hand wheel doesn't move, the motor pully and the whole shaft, all the way out to the sewing head, moves. I'll find something to act as a shim and see what impeding the movement does. Let me know if you would like a separate video. Much appreciated.

[ya2daup]

On 7/13/2025 at 1:58 AM, Constabulary said:

BTW some of the parts I see in the pictures obviously do not belong to this machine. FI the Singer class 15 bobbins and the bobbin cases.

Thanks for the spare bobbin identification, I knew it didn't go with the machine and they're smaller than what's on my Consew. Unless anyone reading this thread want's them for cheap I'll list them on ebay. I also think the bobbin winder came from a different machine, I wouldn't think there would be much of a secondary market for that.

[friquant]

4 hours ago, ya2daup said:

Oddly enough the hand wheel doesn't move, the motor pully and the whole shaft, all the way out to the sewing head, moves.

Forgot that you have two hand wheels! Or one giant handwheel and two motor pulleys (one on the motor, one one the patcher). This is going to mess up my terminology notes for sure 🤷‍♂️

From your video, I'm not sure if that lateral motion is a problem, a feature, or neither. Is there anything along the main shaft that looks like it's intended to impede this lateral motion?