Tunnel

First tunnel post

Slowly chugging away. Probably should have prepped the ground better. I’m pulling grass and weeds by hand because I want to isolate the Horse Vetch to either dig it out or spray it dead.

Grew in Bed 3 last Fall, 2024 and am growing in Bed 2 so far this year. I added plenty of goat manure to Bed 2 and it’s doing pretty well aside from Tatsoi with what was likely Flea Beetles.

Dried goat manure is approximately 1.35-1.00-3.00 (N-P-K) and the Salanova is picture perfect so I guess lettuce grown here likes a little Potassium.

I just started working on getting Bed 4 readied for growing and have Beans, Melons and Cuke seeds soaking. Bed 3 just needs a little manure added to grow in it.

Drip Irrigation

I’ve only watered twice this year and both times, I was transplanting starts. Things are finally starting to dry up a little so I need water and more drip line.

Drip is on the way. Bed 3 and 4 are seeded with beans/melons/cukes and I did enough rearranging of drip line to have a single line down each newly seeded bed. I have my controller set to run for 10 minutes at 8am, 10:30am, 1:00pm, 3pm, 5:30pm and 8pm.

Another roll of drip line will be here Tuesday – supposedly. Shipping schedule reliability has gone down here in rural flyover land. One of the many things that got worse and/or more expensive during covid and will never return to what it was because that’s just the way things work.

Added an accumulator aka expansion tank to the drip system to reduce pump cycling on/off. Went from 1 second on, 4 seconds off to 4 seconds on, 8 seconds off. It’s an improvement but could be better. I have a pressure gauge I need to install so I know what the water pressure is. Then the expansion tank gets charged with air to 3psi less than the pump shut off pressure.

Now that I think of it, I have a 25 psi pressure regulator and I’m not sure how that affects the pump cut off. Regulator is after the pump so pressure before regulator will be whatever pump will put out which I think is about 45 psi, then after regulator, 25 psi of course. Where is the accumulator or where should it be? Between pump and regulator so it can be set for 42 psi or whatever is 3 psi less than pump shut off.

25 psi is on the high side for drip. I have a 15 psi saved in my list on dripdepot.com and they also sell 10 psi and the flow rating of most dripper and micro-sprinklers is usually figured at 10 psi iirc. Either way, 15 psi is better than 25. What would be nice is an RV pump with adjustable regulator and they may make them but I doubt they go down to 10-15 psi.

Electrical

The conundrum. 24 vdc vs 12 vdc. The 24 vdc would be better because it means smaller wire due to half the amperage of 12vdc. I have one 24 vdc linear actuator but the rest will be 12 vdc because that’s what’s available. Network switch prefers 24 vdc but I think will run off of 12 vdc. Controller are the same, run best off 24 but will run off 9-28 vdc. Industrial automation stuff is generally 24 vdc. A quick search shows plenty of 24 vdc RV pumps but they’re pricey and tend to run higher pressures than 12 vdc.

Stick with 12 vdc I guess since the other big loads will be the linear actuators. Industrial automation components may generally be 24 vdc but they do have 12 vdc, just not as abundant but 12 vdc relays are abundant for automotive use. Solid State relays are hard to find in 12 vdc but I did find some and have tabs open to them on ebay. They basically last forever.

I do have a 12 to 24 vdc converter for the odd items that need it. That one 24 vdc linear actuator probably just doesn’t need to be in the tunnel. I’ll open/close the front room window with it when the temps get to that range when I want open by day and closed by night.

Ventilation

I don’t think I can make the bifold hangar type sides in one piece. That means two per side for total of four. Then there will be the two gable vents and I also need end doors to open/close automatically but I have no idea what type of doors they’ll be. I’ve seen commercial roll up doors which look good but are heavy and expensive.

Just deleted two paragraphs of me rambling and trying to decide what kind of door and think I settled on one but will need to find a pic and see how they work – brb. I’m back. A good thing to start with when researching is to find out what the hell it’s called. So far I have California style and swing up and over. Pic worth 1,00 words etc

That’s half way open of course. Big benefits especially for a self build. No tracks, one linear actuator per end, not lifting the full weight, could end up with a little sticking out when open creating a little roof of sorts. Need technical info like a good view of pivot point and arms, hinge point, hinge location, ratios etc. Tilt up canopy is another possible name. Seems like canopy door is the one that hangs out a little and tilt up goes back further on tracks so that it tucks all the way in.

Some videos.

DIY roll up tarp door (could overlap bldg more and have full height rails on outside to prevent blowing outward but he doesn’t have wind blowing outward like a tunnel will from other openings)

Couple of animations which may be right or may be totally wrong and just what they dreamed up as far as ratios

And a badass 38′ wide canopy door build