Recent content by jrmichler

So far, so good. Now I need to see a diagram of the hull with and without your sponsons. Search terms personal watercraft hull design found numerous images. At least one of those should be good enough to show your concept by screenshotting and loading into MS Paint.

Welcome to PF. Your diagrams only show a slotted object sliding over a T-rail. That's not enough for me to help you. Before I can express any opinion on the value of your ideas, I need more information. 1) Are you attaching to an existing bracket? How is that bracket attached? What are the...

High school physics has everything you need except for fluid dynamics. Fluid dynamics is a third year engineering course. Lots of fun reading in between. Which leads to what @Baluncore said. I would have liked to say something similar, but his words are much better than anything I would...

Any valves should be bellows sealed to eliminate leaks past the valve stem. The image below is of a Swagelok bellows sealed flow regulating valve: The above valve is not the right valve for a shutoff application. It is the first diagram that I found in a quick search that clearly shows how...

Google Street View dated August 2023 of that address shows: 106 is the door on the far left. The door in the middle is 102-104. There are several patents assigned to Aerogel Technologies, LLC of Boston, MA. The most recent application was filed in 2023 and published June 2025. Boston is...

Swagelok is a manufacturer of top quality tube fittings. Check them out: https://products.swagelok.com/en/all-products/fittings/tube-fittings-adapters/c/154?clp=true. They have a contact page with a Technical Product Information category.

Welcome to PF. The surface color could be a lead / antimony / tin oxide. Are you sure that the lead is ruined? Did a measurable amount disappear? Molten lead has a vapor pressure, so it evaporates. I searched vapor pressure molten lead, and found this in the Wikipedia article on lead: The...

Not as good as This Street and That Street, but accurate:

Photo of me after a four mile run at minus 32 deg F this morning. Frosty on the outside, warm on the inside. The ice buildup on my eyelashes is only a problem when it gets heavy enough to pull my eyes shut. Cell phone camera.

Some points to consider before you get too excited: 1) Thermal cycling also kills motor/generators. I once headed a motor reliability project. The primary cause of failure was thermal cycling. If the energy storage is underground or inside a thermally insulated structure, thermal cycling...

A four bar linkage can generate a figure 8 path. There are four bar simulations online to save you the time to create your own. This one took about five minutes to find and get it to generate a sloppy figure 8. Some additional tinkering can get a much better figure 8. I leave that as an...

Quote from Section 6 in the Duplomatic PDF: – It is necessary to vent the air from the delivery connection before operating it the first time. Another quote from Section 6: The minimum suction pressure allowed is -0,3 bar relative. The maximum vacuum on the suction side is 0.3 bar of vacuum...

The extreme case of a clamp not conforming to the shaft would be two flat pieces clamped to the shaft as in the diagram below. Two bolts, each with clamp force F. The free body diagram (FBD) is on the right. The total normal force for each clamp piece is 2F. The maximum tangential force for...

Thermal mass flow sensors measure mass flow, normally of a gas such as air. The output has units of mass per time, such as kg/sec. Thermal flux sensors measure heat flow. The output has units of power per area, such as watts/cm##^2##. A good explanation is in the Thermogage User's Guide...

When I was a grad student teaching assistant in the early 1990's, I assigned a design problem for the gears and bearings class. The assignment: Design a brake disk for the Mini Baja Speed 45 MPH Gross weight 500 lbs It needs to make one stop from full speed Use materials from your textbook...