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

[ya2daup]

Good afternoon all,

First off, thank you all for the years of information on this site. I recently created a login and this is my first post but I've been quietly soaking up the wealth of advice for over a year.

I just picked up a Claes 8436-30 for a great price and would appreciate some help getting it tuned up and ready to go. Everything seems to rotate smoothly and corrosion is at a minimum. I haven't tried sewing with it yet but am hopeful that it'll take off without much effort.

I found a couple other posts about these machines and found them helpful, but would appreciate a bit more info. Also, my documentation is in German and would appreciate it if anyone could help me track down the user and maintenance manuals. 

It looks like it was either set up with a motor at one time or darn close to it. Can anyone recommend what size servo motor I should put on it. And how imortant is a speed reducer and needle positioning sensor?

@shoepatcher, @Constabulary. Sorry for the tag but you two seemed to have a lot of great input on the other posts I saw.

I'm attaching photos of the machine and the hardware it came with. Thanks in advance for your help

 

Edited July 11 by Northmount
Title corrected

[friquant]

 

On 7/9/2025 at 4:55 PM, ya2daup said:

Can anyone recommend what size servo motor I should put on it. And how important is a speed reducer and needle positioning sensor?

What materials do you anticipate sewing, and how thick?

With your other sewing machines, which would you rather have: A. Slow gentle startup, or B. The convenience of a needle positioner?

It seems that there are two camps of servo motors. With an analog servo motor you supposedly get slow gentle startup, but not necessarily support for needle positioners.  With a digital servo motor you get decent support for needle positioners but you get a jerky startup. Some have reported that their needle positioners did not work when they added a speed reducer. 

If your servo motor has a standard 15mm cylindrical shaft with a woodruff key in it, you can buy an aftermarket 45mm pulley (75mm is standard) for about $10 to get some speed reduction. 

 

 

[ya2daup]

2 hours ago, friquant said:

 

What materials do you anticipate sewing, and how thick?

With your other sewing machines, which would you rather have: A. Slow gentle startup, or B. The convenience of a needle positioner?

It seems that there are two camps of servo motors. With an analog servo motor you supposedly get slow gentle startup, but not necessarily support for needle positioners.  With a digital servo motor you get decent support for needle positioners but you get a jerky startup. Some have reported that their needle positioners did not work when they added a speed reducer. 

If your servo motor has a standard 15mm cylindrical shaft with a woodruff key in it, you can buy an aftermarket 45mm pulley (75mm is standard) for about $10 to get some speed reduction. 

 

 

Thank you for your reply.

Materials/intended use: I'm using it for general repairs and small batch fabrication. Anything from lighter weight materials up to max thickness leather and boot soles. So I would prioritize control and accuracy over speed.

I also have a Consew 206RB-5, I swapped out the clutch motor for a servo with the smaller pulley last fall (I did not get a needle positioning sensor). I went back and looked at the product listing and it doesn't mention whether or not it's digital or analog, only that it's a 750W Brushless Servo Motor. It does seem a bit jerky at startup and even on the lowest setting there are times I wished it moved a bit slower.

*EDIT* On second thought, is analog vs digital as simple as a dial controller vs a digital display? If so, the one I have is digital.

Edited July 11 by ya2daup

[friquant]

1 hour ago, ya2daup said:

is analog vs digital as simple as a dial controller vs a digital display

In practice, yes. What I really mean by this distinction is whether they have a minimum speed or not, and the ones with a digital display seem to have a minimum speed. They're either not moving at all, or they are moving at least at their minimum speed.

And by analog, I mean you can ease into the gas pedal and start out at a crawl.

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.

I don't work with thick leather, so I will let others chime in regarding whether you will need a speed reducer in order to stitch the thick materials you are targeting.

 

Edited July 11 by friquant

[ya2daup]

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.

[friquant]

Yes, do post videos. 
Have you done timing on your RB5?

[ya2daup]

24 minutes ago, friquant said:

Yes, do post videos. 
Have you done timing on your RB5?

Thankfully I haven't had to adjust the Consew, it runs like a dream. The pickup timing on the Claes appears to be way off and there's also some odd play in the main shaft running from the pully over to the head. I'll post a couple videos tomorrow. Thanks again.

[Northmount]

8 hours ago, ya2daup said:

Thankfully I haven't had to adjust the Consew, it runs like a dream. The pickup timing on the Claes appears to be way off and there's also some odd play in the main shaft running from the pully over to the head. I'll post a couple videos tomorrow. Thanks again.

Post the video on YouTube and link to it here. Need more than 5 seconds that fits file size restrictions here. 

[Cumberland Highpower]

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.

[kgg]

13 hours ago, ya2daup said:

Anything from lighter weight materials up to max thickness leather and boot soles.

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").

On 7/9/2025 at 8:55 PM, ya2daup said:

Claes 8436-30

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