Searching for 29 inch channel balance for 15 218

I'm not sure what you may have, but it sounds like it'll have to be specially made. To confirm, can you send us a picture of the top and bottom ends of your balance, as well as a picture of whatever clip is attached to the end of the cord? Can you also give me the width and height of the metal channel and whatever number is printed on it? Finally, how many did you need?

To be safe, I'd also like to see a picture of your pivot shoe.

Ah yes, it's just as I suspected. We should be able to help, though. I still need you to tell me the width and height of the original metal channel as well as the number printed on it. 

Just to be on the safe side, I'd also like to know the width, height, and depth of the pivot shoe, and a picture of the pivot bar that goes into it. 

It looks like you sent us pictures of the clip at the end of the balance cord. That's not the pivot bar. I apologize for the confusion. The pivot bar is the piece of metal at the two bottom corners of the sash that go into the pivot shoe. I'd need a picture of one of yours out of the window.

Thank you! I think that information will do just fine. Based on the size of your pivot bar, I think you will need our 15-212 pivot shoe in addition to the balance we will need to specially make. You mentioned before that there are no markings on your balance, in which case we will need the weight of the sash that is supports. That will let us calculate the proper spring strength.

Hmm... I'm sorry to keep you waiting on this. We've been looking all over, but we haven't been able to find this style balance that can support a 25 pound sash. These max out at 20 pounds, which is just not strong enough for your sash. This has been really puzzling. 

I hate to ask you for more photos, but would it be possible to see one picture of the inner ribbed metal channel balance? Specifically, I'd like to see opposite side where the springs fit into. You showed the back side where the spring sits in in you first post, so we just need the other side of that. There may be a stamp there, which would be a huge clue and get us on the right track.

Thank you! That's everything we needed. I will email you a special balance link for 6 of these right now.

I'm sorry to hear you're having trouble. I'm actually shocked this didn't work; the 28TG stamp you gave us was only used for this kind of balance. Or so I believed. Have you tried installing it without using the covers? See if that helps. If not let me know.