I'm trying to get my mother's Singer Touch & Sew Deluxe 645 to sew a straight stitch. I don't want to buy a manual since the machine rarely gets used and I have limited time to "fix"

Singer has most of their sewing machine manuals on their support site: https://www.singer.com/support . I don't see the 606 though. They do have the manuals for the 600 and 603 zig-zag Touch & Sew machines and the 604 straight stitch version. (Leave off the final 6 in the search box to see these manuals listed.) Since the Touch & Sew line didn't change much over time, these manuals may help.

Several sewing machine parts suppliers do have the 606 manual for sale. https://www.sewingpartsonline.com/instruction-manual-singer-606.aspx and http://www.sewingshop.com/singermodel606instructionmanual.aspx .

I do not have a source for the repair manual. Singer used to have parts diagrams available for their machines at singerco.com (on the Industrial machine page section). However, that site no longer works.

I hope that the above information helps.

Cindy Wells

The manual in belo link may help

https://www.manualslib.com/manual/1051312/Singer-Touch-And-Sew-639.html

Check for diagrams on the selector wheel and then adjust your stitch length. Do not set to tight as your thread will break

There is a sprung retainer to hold the bobbin case in place

try moving it with the stitch width set to #1

Go to the singer website--free pdf download
Go to the home page
Go to customer service--click on it--it will show a small menu--click on instruction manual
In the box put the model number (example 1748) & click search

try changing the needle--flat side goes to the back of machine
rethread the machine top & bobbin--make sure to use every thread guide
make sure bobbin is wound correctly & inserted correctly in the bobbin case
clean under the needle plate & in the bobbin area for lint or loose threads
if you don't have a manual try singer
Go to the singer website
Click on customer support--there will be a drop down menu
Choose instruction manual
In the box type the model number(example 758)
Click search

Instruction Manuals

Instruction Manual Singer 625

Try a new needle first failing that you may need to retime the machine, you can email me for an attachment of instructions [email protected]

Suggest you ask the seller of yr machine. It runs on computers... They can malfunction. Singers were the Best for decades. From treadle days into the '70's. When a repair guy told me Singer only made parts for 2 yrs post purchase.
I have both of my Grandmother's treadle machines, and their scissors. Would Not buy a Singer, now.