Adler 20-7 Project

[VanRhodes]

I picked this Adler 20-7 up about a year ago but havent been able to spend as much time and money on it as I would have liked to so the rebuild has been taking longer than expected, but its progressing steadily. Cleaning it up and removing decades of grease and dust took its fair share of time even though it was relatively easy when done with chemically pure gasoline.

One thing that was weird with this machine was the fact that it was feeding in the opposite direction, I dont know if its been modified or if there was some mistake made when they swapped the shuttle race for a Singer made unit instead of the original Adler. This had me quite confused for a while and I figured I might as well try to remove the cover plate from the stitch regulator and see if it would feed the other way when I move the regulator to the top, much like you would to put a normal machine in reverse. Luckily for me, it did so this seems to have solved this issue for me.

I have temporarily rigged it up to the original table as I have failed to find a good retailer that has unit stands at a reasonable pricing. The local retailers in sweden are asking a little to much for a stand in my opinion and college sewing is refusing to ship stands outside of the UK. So for the time being, its still on this old, oversized stand.

I have some issues with the cam not staying in its position despite being pinned and screwed on there, perhaps the shaft has taken some damage during its years in use. I fixed the screw with loctite wich held it quite well in place for a time but I recently noticed it had began shifting a little causing additional skipped stitches. Any tips or trix to remedy this would be greatly apprechiated, otherwise I am considering having someone weld it in place.

Below follows some more pictures of it in its current state. Visible in these images are the temporarily mounted Jack servo motor wich is actually quite capable of running the machine. Also visible is the timing belt and cogs that I ordered and will modify to fit the motor and machine for a 10:1 ratio, this will make the machine more than manageable when sewing. AndreNL was nice enough to ship me new feed dogs that works very well and offer more contact against whats being sewn(Sorry about not having shipped the smaller one back yet, will do it soonest possible)

http://s3.postimg.org/gmkwoljub/adler20_7_20140816_2.jpg

http://s12.postimg.org/3z2m0gl3x/adler20_7_20140816_3.jpg

http://s27.postimg.org/ocup4ap7n/adler20_7_20140816_4.jpg

http://s3.postimg.org/bhoakpwab/adler20_7_20140816_5.jpg

http://s21.postimg.org/k4nddwp87/adler20_7_20140816_9.jpg

Here's a few pictures of the 3d printed prototypes for the new presser feet that I will have a buddy machine for me. They should suit my sewing better than whats on there now.

http://s14.postimg.org/6fpev8t4x/adler20_7_20140816_6.jpg

http://s21.postimg.org/k0tjxnjqv/adler20_7_20140816_7.jpg

http://s1.postimg.org/har8s25lr/adler20_7_20140816_8.jpg

[Constabulary]

The feeding in different direction is normal as you have a gear reduction (German "ADLER slang": Rädervorgelege) installed and this changes the direction. But you can change the rotation direction on your motor.

[VanRhodes]

Yeah, I am aware of what you are saying but that wasnt the issue at hand here. The feeding direction was opposite of the shuttle rotation/tensioning of the thread via the take up lever so to speak. Its hard to properly explain it, but the cycle of operation isnt identical if you spin it forward or reverse, if you rotate it in the wrong direction and try to form a stitch the take up lever will try to apply tension to the stitch before the thread has passed around the shuttle, thus tearing the thread.

[Constabulary]

Hey VanRhodes - I just stumbled over this auction on Ebay Germany.

http://www.ebay.de/itm/131278201857

seems these are Adler 20 parts as far as I can tell. I though this could be a great deal for you if you bid on it.

If the seller will not ship to Sweden tell him to send the items to my address and I can forward them to you - just for the case...

[VanRhodes]

Thanks for the heads up Constabulary! Greatly apprechiated!

[VanRhodes]

I've been having some sporadic issues with skipped stitches ever since I got the machine running and sewing. I partly managed to remedy this by futher tighting the cam to the drive shaft and by adjusting the needle to shuttle hook distance. However, I have long been of the impression that the hook is way to far advanced in its cycle in relation to the needle as you can see in the picture below.

The normal way to fix this would be to adjust the height of the needle bar(wich I cant, its already as high as I can get it) or adjust the rotation of the hook around its axiz(wich I cant, since the drive shaft and shuttle carrier are both pinned), but since I have an extra hook I figured what the heck, I'll just shorten the hook by about 2mm and to see if it works better. Below is a before picture with the area to be grinded off is marked in red so you can see how much I took of the hook. I have the hook installed and will do some more test sewing over the coming days to see if it did anything to help with the problem but this far its been working pretty good.

[VanRhodes]

Here's a comparison picture to show the difference with the newly modified hook compared to the original, un-modified hook(1st picture, last post).

http://s18.postimg.org/wpjhjexw9/hookneedle1.jpg

http://s13.postimg.org/ezbozxwlz/hookneedle2.jpg

Its quite a difference as you can tell, wich also leads us to the next set of pictures comparing the distance between the hook and the needle when needle is at its lowest position. With the original, un-modified hook I somethings had the issue that is illustrated in the first picture where the hook traps the thick thread on its left side, between the hook and the needle not allowing it to loop in front of the hook as the needle begins traveling upwards. With the shortened hook I believe I wont be running in to this issue as its got plenty of clearance now.

Original un-modified hook at the lowest point for the needle: http://s29.postimg.org/99g3w44p3/original_hook.jpg

Modified shorter hook at the lowest point for the needle: http://s30.postimg.org/6gry9gar5/needle_lowest.jpg

[VanRhodes]

As always my updates are few and far apart but last night I finally managed to meet up with a buddy who could help me machine the first set of timing gears to fit the machine. The small 12 tooth for the motor had its hole widened to fit the 13mm shaft and we also added a slot for the key. Perfect fit! The large 60 tooth wheel was also widened up to 17.5mm diameter and we added the four 6.5mm holes that will be used to couple it with a 27-tooth cog that will be machined next time, the 4 holes will also be used to attach the larger balance wheel that I will have to manufacture. Its kinda hard to see but we shaved off about 0.75mm on top of each tooth on the large 60-tooth cog so that each tooth would have a small ridge on each end to help keep the belt in place.