Is the horizontal spool pin just for exotic and fragile thread or any thread on a spool? I am having difficulty with top tension, I am using a spool of King Tut 40 wt. thread and the top tension will not behave. I have tried everything and the spool pin is the only thing that is left. I have adjusted the bobbin its perfect and the top tension is also perfect I have cleaned the machine I have loosened the quilt top. I can find anything else to try. I have checked the threading and flossing I have changed the needle, I cant thing of anything else to try. Any suggestions would be apprecited.