You might want to read Bill Pentz' site in regards to ducting. The tighter the turn, the more it will make your air stream slow down. Generally speaking, 90 degree turns are bad news. Use a pair of 45 degree elbows, or if you can find them, long sweep 90s. Yes pine comes off in LONG strands from the planer. Then again in my experience so does oak. Pine however is pitchy, especially when green, and the shavings can, if they aren't moving fast enough, clump up. If your airflow isn't moving fast enough to keep the system from jamming while planing / jointing pine, odds are excellent you aren't pulling enough air through the system to get the fine particles you want to collect anyway.
My suggestions to fix this problem, and the problem that this points out which isn't really the pine are...
#1. Age / dry your pine / fir to insure no warping / twisting, and keep the stickiness of the pitch down. Mind you pine / fir does jam up blades and bits pretty good, keep those clean too!
#2. Minimize the best you can, any bends at all in the system. Make your runs as straight as physically possible.
#3. Eliminate any tight 90 bends, they kill DC system performance. Go with long sweep 90s, or a pair of 45s spaced by a couple of inches to help keep air speed up.
#4. Eliminate where you can, any corrugated flex hose. I will explain the last two in a minute...
#5. If you have a filter bag, give serious consideration, budget allowing of course, to replacing it with a 1 micron or better filtering pleated canister filter. You will have MUCH greater surface area for the DC to breathe through, which means the DC itself will breathe freer, elminiating restriction and flowing better.
Think about airflow, like cars on a road, to take a very tight 90 degree turn, or drive over a washboard road without totalling your car, you need to slow WAY down. The same is true with air. You want, as much as possible to reduce the restrictions in your air flow... To more or less keep those cars moving at as close to their maximum speed as possible.
I am curious, you mention a HF 1.5 HP DC. I am aware of a 1 HP model, the small portable single bagger, and a 2HP model, the upright with the ring and an upper and lower bag. When did they sell a 1.5 HP?
Due to the amount of pitch in pine, I would also recommend against burning it in a fireplace or wood stove. That pitch will build up in the chimney and become a fire hazard itself unless you keep that chimney clean all the time... Yes it burns fast, and hot, which is one of the things that makes pine scrap a great thing to take to the beach for bonfires, but again, the pitch makes it somewhat dangerous for indoor heating...
