Thanks Alan and John,
In the past I have had mixed results using plastic RC tanks. This one will fit and I can push it all the way back against the Rear Bulkhead to keep the weight further back. Especially as all tubes exit forward. On a horizontal plane does the uniflow tube remain on the tank horizontal center line for its entire length? or does it angle up or down? Is a solid oiece of tube inserted between the clunk and the feed tube so the clunk does not fold back on it's self? And dosn't the clunk get hung up on the uniflow tube? I thought I saw years ago a scheme where the uniflow tube was also flexible and was attached to the pickup via a slip arrangement so they both moved in unison. I guess these are the reasons I've had mixed results with clunk tanks. Is there a part number for this tank, so it would be easier to find online?
The Uniflow tube is a solid tube, initially set up on the centerline of the tank. The location of the uniflow being the outermost hole in the stopper precludes interfering with the clunk. It also allows the uniflows height to be adjusted by rotating the uniflow line itself, and is easy to do without taking the tank out of the plane, or disassembling it. You change the apparent height by raising or lowering the end of the uniflow inside the tank.
If you desire, a short legnth of solid plastic, or copper tubing can be placed in the pick up line, so it won't be able to flop forward in a hard landing, or minor crash. I've found the use of the sintered bronze filter,m as a clunk, seems to do a great job of both filtering the fuel, and reducing possible problems with fuel pick up. Virtually all the fuel is gone from the inside of the tank, when the engine quits, and I get little, or usually no surging as the tank is running out of fuel.
The RC tanks I like to use are made by Sullivan, and in the case we're talking about here, is the RST-8. RST relates to the type of tank, the 8 refers to the capacity. The diagram I posted was based on a smaller tank, so to use the larger 8 oz tank, the front view of the tank would be shown with the wider dimension being the to of the tank.
I've used this method of constructing uniflow clunk tanks for over 15 years, and it works great for me. I really like being able to adjust the apparent height so easily.
Others build their uniflows with a clunk on both the uniflow, and the pick up line, or connect things up so the uniflow follows the pickup. It can be made to work, but I do not believe you wind up with the best uniflow tank this way. First, there are two lines that must be flexible enough to allow relatively free movement. Next, the end of the uniflow moving with the pickup, sees varying heights, and pressure differences as both the uniflow, and the pick up move arround. In a hard tank, the unilow does not move around, it stays fixed, and establishes the height of the tank. I think that is why some have problems setting up an RC plastic tank for uniflow in our CL models.