I bought a David III earlier this year (my first floor loom). With the help of the "technical department" (that would be my husband!) we got it assembled and working. I love the David and have been working my way through the plain weave lessons with great enthusiasm. I have been able to "fiddle" using the various tips I've picked up from videos, etc to try to get the 2-1/2 sheds Jane describes. When I was using plain weave I was able to get a big enough shed to get by, but I recently started the Two Stripe Twill lesson at the start of Season 4, which involves changing treadling to include 3/1 tie ups as well as 2/2. It seems each time I change the treadling, I lose my shed opening and have to start re-adjusting. My questions are:

- when the tensolve cord is attached to the treadle, some cords are taut and some are quite loose. Is that OK? I've tried shortening some to see if it helps my shed but that may not be helping.
- I've found one of the best ways to increase my shed is to screw the nut that's on the lamm for each harness counterclockwise as that raises the shed in the reed. My current problem is two of nuts are now at the point where I can't turn them anymore or they will come off the screw, yet my shed is still "out of whack".
-I saw in a Louet video that you can adjust (shorten) the tensolve cord attached to the springs in the castle to increase your shed. I've tried that adjustment but it didn't seem to make much/any difference.

I've learned how to adjust/lower the beater so the treads are at the bottom o the reed when you want them to be, so that part of the shed is fine. I also don't leave my lease sticks in so that's not contributing to the problem.

Any advice/assistance would be appreciated.

I'm attaching link to a PDF that JST has put together - https://janestaffordtextiles.com/knowledge-base/david-lll-shed/

You can download it on your device and have it handy while you troubleshoot the problem with your David lll shed. Let us know if this helps.

Louet has a good YouTube video (David 3 Harness Adjustments and More) that is pretty good (helped me).

I’m in a similar position. Just finished S3E8 and some sheds were very narrow. The bottom rests on the race, it is the top shed that is not very high - though all threads are even. PW is never an issue. It is the other combos (eg. 134/23).
Also, some shed combos were sticky and I would have to step on the treadle twice to get it open.
How do I get the top shed to flow higher through the reed?
The harnesses are the correct distance from the castle as per all the videos out there. Lease sticks out. Beater even. I am not weaving too close to the dent. If I raise the harnesses using the lamm screw that will whack out the castle distance and the decreasing heights suggested.
As Patricia noted above, my treadle cords are a mix of taut and limp. Is that important?

I wonder if tightening the springs under the storage tray might help keep the shafts that are not supposed to be pulled down when you treadle from falling a little (or a lot).
I had to make that adjustment when I was weaving the scarves from one of the 8 shaft episodes last year where the treadles were tied up to 6-7 shafts and the ones that weren't tied to those treadles fell down anyway. Tightening the springs kept them up where they should have stayed.

I did relax the extra tension before I warped and wove the next time.

Based on the feedback I received from the original post, I found that when I adjusted all the nuts down to the eyebolt , I could then use the eye-bolt adjustments on the individual harnesses to get a good shed on my threads. I agree that it does affect the spacing on the harnesses, but I haven't seen a negative effect because of the new spacing, and the adjustments have given me a 2 - 1/2 inch shed.

Update from me. I just warped up for classic 13/24 PW but thought I would give the Jane Shed Adjustment a go. Even though up till now PW has not been a problem.
Held down all the lamm cords, screwed the nuts way down. I had to loosen Shaft 2 some as it was too low. Also, my 24 treadle #2 was too high so moved that down 1 texsolv hole. The shed is wide and the lower shed sits on the race. I think the upper shed is a tad higher than before. I measured the shed and it is 2", about the same.
I wonder if I should lower the beater? Would that give me more shed space? I have it as instructed at 8.5cm from cross bar.