Lockdown Ideas and Distractions

Arrrghhh... no pictures!
I've been doing more videos on my Youtube channel "Del Cat"... (it's not monetized, no damned adverts to wait through). I've had some good reaction and even done one video in response to a specific question.

I've been toying with the idea of making a wind tunnel to measure the drag of arrows. It would be a vertical pipe with a fan at the bottom drawing the air through. The arrow would be suspended from its point by a fine thread which would connect via a lever which pressed down onto my digital grain/gram scales. Switching on the airflow should in theory increase the apparent weight of the arrow as the airflow pulls it down due to the drag.
The main problem is getting a fan with sufficient airflow, but then I thought of my dust extractor!
It's spec says 183 cubic metres per hour air flow. Now it's just a matter of some arithmetic to convert that into feet per second (fps) of air flow through a 60mm drain pipe. Unfortunately it comes out to about 52fps which is much slower than a flight arrow (~200fps or more).
On closer examination of the fan assembly from the dust extractor I found the air inlet is only 30mm diameter which is half the diameter of my drain pipe and thus 1/4 of its cross sectional area... ha, now if I make the pipe 30mm diameter, that would increase the air speed to about 200fps.
There are nice commercial dust extractor fans which shift 100 cubic metres an hour, but they are about £90 , rather big and probably noisy... not worth it for something I'll prob' only ever use once... not enough room in the garage for a decent wind tunnel really.... I could doubtless fill a large barn with stuff given half a chance.
Of course this is all rough calculation back of an envelope stuff (other writing surfaces are also available, although backs of fag packets have now been largely superseded).
There are many problems with wind tunnel design, even a crude one, but there is tons of stuff online for anyone interested. One obvious problem is that as the pipe diameter gets smaller the arrow can hit the side and the diameter of the arrow starts to become a bigger factor in blocking the airflow than its genuine drag. Still it may provide useful comparisons between similar diameter arrows with different tapers, points or fletchings... ah, that gives me an idea... a relatively short vesion could just test fletch configurations, drag vs area of fletch!

Anyhow, no rush to leap in doing it yet as I have another distraction... I bought myself a blues harmonica! The rest of the family are V musical but I'm not, I can sing, but if someone harmonises I get immediately phase locked into their notes!
I'd been given one as a kid one Christmas, and we had to call out who had given us what present so that we could all write our "thank you letters " when the excitement had died down. When my Dad asked who gave me the mouthorgan, I gleefully replied "'Our Monica!" (It was from Uncle Morris and Aunty Monica)
I had no idea how to play it and of course in those days, if you wanted to learn it would be from a book or a record if you were lucky. Nowadays with the wonders of Youtube it's easy to find a tutorial that suits your aspirations. Within a few hours of the blues harp arriving (see I already have the lingo!) I could make a reasonable sound and even managed a rather lumpy jam with my Son on his guitar. It took me a good 20 minutes to get the grin off my face.

I hope you are all finding stuff to do, keeping safe and refraining from drinking disinfectant.