Squirt Build Tips
There are some idiosyncratic things to a Squirt build. Here’s some tips.
Squirt ducts are designed to print right side up without supports, except for the two mounting tabs. I print them with 100% infill.
I’ve seen some comments where people have said that props will slice up tpu ducts. I can’t vouch for anyone else’s prints, but here’s the wear and tear on mine, still going strong.
In the Thingiverse listing, the V2 duct is ‘squirt2duct’. A customer requested a version with more material at the prop line (on the outside of the duct), and that one is ‘squirt2duct_beefier’. Personally I don’t find it necessary but it’s there for you as an option.
I insert the 20mm standoffs in the duct and THEN screw them on to the frame. Pushing the ducts on to the standoffs when they’re already screwed to the frame can put undue stress on the carbon, especially the skinny cross brace.
The ducts can be slightly ovalized if you overtighten the standoff screws and twist the standoff. Loosen the screws once you mount it all up and let the duct relax into its shape, then tighten the screws just enough to bottom them out. Use Loctite rather than torque to keep them in place.
My preferred props are cut down HQ 4x4.3x3’s. As you can see above I’m trying out some fatter props, flies nice but motors get hot.
I designed the ducts to require some prop cutting, since a tight gap gives you more thrust. This is how I did it before I designed the prop cutter.
I cut two blades off and old prop, then gradually trim down the single blade ‘til it’s just right. Then I use it as a guide, with a little finishing on a file. Seems primitive but it works really well, and props come out surprisingly well balanced.
Stiffer props will bind and kick and you might get an uneven cut.
The solution is to cut the prop about 1mm too long, and gradually mill it down to length.
With a little patience you can get it almost perfect. It’s not necessary to get it this good, but I found that an approximately 1mm difference in the gap will rob you of up to 30g of thrust at half throttle.