Each installation is different. The baffle isn't made and adjusted for the stove, it is fabricated and adjusted for the
chimney. (and resistance of connector pipe)
Set the plate on the rear brick retainers.
Angle iron can be used on the plate as shown in the baffle thread, but not necessary. It keeps the side bricks in place very well.
Angle upwards toward the lower top bend.
Final adjustment can be made by sliding bricks forward and back to adjust baffle height at front. Newer stoves have one piece angle iron down the sides making it infinitely adjustable. Older stoves with brick clips may need notching of bricks for correct height. Others will have a second course of bricks requiring a different size plate. The second set was added in the 1977 prints but not all fabricators used the design. It was to increase firebox temperatures more than protect the sides, so they are not necessary if you don't have them.
The baffle thread here gives details of the correct smoke space (square inch area) of exhaust travel.
https://www.hearth.com/talk/threads...d-fisher-more-heat-less-smoke-under-25.74710/
This thread was written for the single door stoves that never had a factory baffle plate, but can be added to any Bear Series or Fireplace Series stove.
Notch the corners as shown on the thread to avoid corner stagnation. This is a tested design from Fisher research and development used on the later stoves after 1980 to reduce smoke emissions. I adapted the design to the single door stoves, I didn't design it.
There are no exact measurements for baffle plates. Some stoves were made wider, Series I will have one course of brick, Series II may have two. The Model III is a different dimension, and too many variations of other models to make a standard size baffle to fit each model. As stated in the baffle thread, make a cardboard template and set in place in your stove. As your needed angle changes, so does the baffle size. When your template is the right size for the angle and smoke space, make one to match with steel and set in place. I have gone to peoples homes to make a template, made the baffle and returned to install it with their stove going. It's that easy to install once made to the correct size.
