Bernina 217 Tension

[Beatnik]

Need some help.  I don't sew leather (mostly canvas) but this is the most knowledgeable forum group for Industrial Sewing Machines.  Great resource.  

I picked up a Bernina 217 (actually badged a Chandler) a couple months ago.  It's a really nice machine.  I installed a Servo Motor.  

I have not been able to get the stitch quality completely dialed in.  It is pretty close but the top tension feels really tight and the stitch still exhibits that the needle tension is too loose on the bottom of the fabric.  I have played around with the bottom tension and the bobbin tension feels 'spot on'.  Also the tread starts unraveling at the needle and eventually breaks during long runs through Sunbrella.  Pics attached. 

Any suggestions from the pros?

Thanks.

Mike in KY

[Constabulary]

looks like you are test sewing on 1 layer, I´d double the layer and try again.

[nylonRigging]

13 hours ago, Beatnik said:

Need some help.  I don't sew leather (mostly canvas) but this is the most knowledgeable forum group for Industrial Sewing Machines.  Great resource.  

I picked up a Bernina 217 (actually badged a Chandler) a couple months ago.  It's a really nice machine.  I installed a Servo Motor.  

I have not been able to get the stitch quality completely dialed in.  It is pretty close but the top tension feels really tight and the stitch still exhibits that the needle tension is too loose on the bottom of the fabric.  I have played around with the bottom tension and the bobbin tension feels 'spot on'.  Also the tread starts unraveling at the needle and eventually breaks during long runs through Sunbrella.  Pics attached. 

Any suggestions from the pros?

Thanks.

Mike in KY

 

Routing your top thread . Your not routing threw both the Tension assemblies are you  ? . you only use one of them for single needle . the 217 offered a double needle attachment and that is reason for there being 2 tensions  .

You said .." top thread feels real tight, but stitch still seems loose ". maybe you running to much bobbin tension ? . Or what 'Constabulary' said .. Double the layers, if only testing on a single layer.

For the fraying thread on the Needle . start by checking for burr on the Hook . Or a burr on needle plate or feed dog . Or maybe you got to small a needle hole for thread size . Or using to much tension and causing to much friction .
-

-

[DonInReno]

If you haven’t done it already, it’s always a good idea to change the needle to a new one - it would be a shame to tear the entire machine apart only to find a defect in the needle.   What size thread and needle are you using?