The weight factor would concern me. Many greenhouse framing materials aren't designed structurally to bear any weight. Even if you use super light weight trays and cocoa coir media, the water weight combined with the plants and fruit weight would push the tensile strength of the typical greenhouse frame. Most greenhouses are built with light gauge steel tubing which isn't much stronger than a child's swing set. Most frames are only meant to hold up the plastic and possibly some snow load and provide some wind resistance and not much else. Even the older heavier gauge frames like i have on my greenhouses can barely support the wire trellis system i use for trellising my tomato plants and overhead irrigation. The only way to get past this issue would build a inner support frame which pokes at cost effectiveness. I Would tend to lean towards a ground based pipe support type system and if possible include a low growing secondary crop that can grow underneath the berry trays that can grow with the reduced light situation.
This is one of my main concerns with this project. Thankfully it is an older greenhouse and has some heavier gauge tubing. At least the load will get distributed throughout the frame....but that won't guarantee success. The modern greenhouses built for this type of growing method are certainly design for something like this. Retrofitting can be risky!
@@Bigelowbrook - i began using the old top rail pipe from chain link fencing to modify my bows. I Bent the centers of 20 foot lengths to the a-frame shape and used my original straight sections for legs because their weights and stresses are mostly straight up and down loads. Then i added extra braces that displace the loads outward to the posts mostly. And over time i added center posts wherever needed in the center sections. I'm on my 6th year with improvised support framing with no issues and frequent 3 foot snow loads in winter here in Maine.
Rob, check out the screw like pulleys used in overhead garage doors....this should give you the grip you need to use the SS cable. You probably already thought of it but if not consider adding some diagonal pipes to your hoop sections to create a truss. Have a great day.
I looked into the garage door pulleys...very expensive when you have to start getting dozens of them! I can print these out for less than a buck. Diagonal trusses are in the works...they'll be in video #3. ;-)
I thought about it. The wall thickness of .025" concerned me a bit. I might try to load some tough resin into my printer and see what it does. I think the set screws will crack it so I probably would have to have a couple of holes in the shim so they could pass through without crushing them.
Looking forward to seeing where you end up. Your last comment about the paint can was something I was wondering on how to get the system balanced so that one side is not heavier than the other. maybe there needs to be some sort of locking mechanism.
I've been wondering about how to keep it balanced. A lock or break system would help. I've thought about just hanging jugs of water as a counter balance. It's probably something I'll have to figure out once the system is running!
Hi Rob, I appreciate the update... I voted yes (1 of the 92%). I imagine you will have a flexible line to deliver water/nutrients. to the strawberries. Is this a point of discussion in a future video? I suppose you could do a twin pulley system stainless steel cable for the strength and paracord to "drive" the system. Cheers, Bill
Recommend helical para cord to avoid the run skipping out on you. More helical turns, more grip, needs set screw on side too so you could stack them for more/less friction.
@@PsychoticusRex hahahaha you can edit your post. Just tap the 3 dots to the right. and then destroy the evidence and delete second "correcting post". This bit was edited after the fact :) , Cheers, Bill
There should be two ways of doing this that I can see? modify your method with two chain sprocket and a chain to synchronise shafts or just go with cables and pulleys, just think negative feedback circuit but with steel cables instead, you need 8 pulleys 1 set of 4 pulleys like you where doing, the other set of 4 will connect in a X pattern so that each corner connect to the other platter both far and near. The cables pattern looking down from the top should look like a hourglass, two triangles touching, additional support cables could be added between theses two end, they would be just simple cross over cables one side to the other. I probably confused you, I'm not so great with written communications.
I wanted to make sure that the load was distributed on to each arch of the greenhouse so I went with this solution. With the X pattern going from one end to the other, I think that would just support the ends and not the entire troth? I also thought about chain but once you get into the sizes that can support weight the get very expensive/heavy. It would have made this much easier with chain!
Just bit concerned about your safety, are those belts OK with UV and weathering, I know stainless steel cables are used in small aircraft and heavy medical equipment, don't know about trusting those belts in that environment? I shouldn't have watched this video, I keep trying thinking of different solution to this problem, kinda like a earworm. Thank you 😊
@@drmosfet I'm hoping the belts will be OK. The plastic covering for the greenhouse filters a lot of the UV. I've been thinking about also putting a safety cable on each section so if the belt breaks, the cable should catch the load. Even chains and cabling you buy tends to say 'not for overhead use' so everyone is trying to cover their butts!
you really should do the strength calculations first before you move on ... 1. the whole weight rests on your horizontal construction beams that are design only to keep the shape of your roofbeams under heavy weather conditions, not to carry extra weight. they are only secured with a simple bolt at each end. the weight distribution over the beam might make it bend, impairing its original purpose strength during storms f.e.. if there is space mont a bearing and axel on top of a construction beam instead of having it dangle underneath on 2 simple bolts. don't underestimate the weight of your basket, tge grow medium, the water, the plants and the inertia forces needed to get it all moving up and down. allow for a safety factor of at lesat 3. your axles shoud have enough stifness, i doubt your electricity conduit pipe is gonna hold up when everything starts shaking when in use during heavy winds.
Great idea Rob. Looking forward to the rest of the series. 👍👍
Hopefully I can get it to work! I still haven't figured out a few of the minor details. ;-)
Nice design journal providing your problem solving thought process through the various design iterations.👍
Well done sir! Really enjoyed riding along through your creative process and troubleshooting. Video format is a winner! Well wishes from Vermont.
On the bleeding edge, Rob. Love watching your content. Happy growing!
AMAZING, look forward to seeing the progress and as always thanks for sharing!!!!!
Great to see more details
The weight factor would concern me. Many greenhouse framing materials aren't designed structurally to bear any weight. Even if you use super light weight trays and cocoa coir media, the water weight combined with the plants and fruit weight would push the tensile strength of the typical greenhouse frame. Most greenhouses are built with light gauge steel tubing which isn't much stronger than a child's swing set. Most frames are only meant to hold up the plastic and possibly some snow load and provide some wind resistance and not much else. Even the older heavier gauge frames like i have on my greenhouses can barely support the wire trellis system i use for trellising my tomato plants and overhead irrigation. The only way to get past this issue would build a inner support frame which pokes at cost effectiveness. I Would tend to lean towards a ground based pipe support type system and if possible include a low growing secondary crop that can grow underneath the berry trays that can grow with the reduced light situation.
This is one of my main concerns with this project. Thankfully it is an older greenhouse and has some heavier gauge tubing. At least the load will get distributed throughout the frame....but that won't guarantee success. The modern greenhouses built for this type of growing method are certainly design for something like this. Retrofitting can be risky!
@@Bigelowbrook - i began using the old top rail pipe from chain link fencing to modify my bows. I Bent the centers of 20 foot lengths to the a-frame shape and used my original straight sections for legs because their weights and stresses are mostly straight up and down loads. Then i added extra braces that displace the loads outward to the posts mostly. And over time i added center posts wherever needed in the center sections. I'm on my 6th year with improvised support framing with no issues and frequent 3 foot snow loads in winter here in Maine.
Awesome video thanks for sharing
Rob, check out the screw like pulleys used in overhead garage doors....this should give you the grip you need to use the SS cable. You probably already thought of it but if not consider adding some diagonal pipes to your hoop sections to create a truss. Have a great day.
I looked into the garage door pulleys...very expensive when you have to start getting dozens of them! I can print these out for less than a buck. Diagonal trusses are in the works...they'll be in video #3. ;-)
@@Bigelowbrook ageeed... I was thinking you could print the pulley with the twist in it to save the cost. Have a great day!
3D print a C shaped tubular shim for the bearings/conduit. It works!
I thought about it. The wall thickness of .025" concerned me a bit. I might try to load some tough resin into my printer and see what it does. I think the set screws will crack it so I probably would have to have a couple of holes in the shim so they could pass through without crushing them.
Looking forward to seeing where you end up. Your last comment about the paint can was something I was wondering on how to get the system balanced so that one side is not heavier than the other. maybe there needs to be some sort of locking mechanism.
I've been wondering about how to keep it balanced. A lock or break system would help. I've thought about just hanging jugs of water as a counter balance. It's probably something I'll have to figure out once the system is running!
Hi Rob,
I appreciate the update... I voted yes (1 of the 92%). I imagine you will have a flexible line to deliver water/nutrients. to the strawberries. Is this a point of discussion in a future video?
I suppose you could do a twin pulley system stainless steel cable for the strength and paracord to "drive" the system. Cheers,
Bill
yes, I"m planning on flexible line....I haven't figured that part out yet. ;-)
Recommend helical para cord to avoid the run skipping out on you. More helical turns, more grip, needs set screw on side too so you could stack them for more/less friction.
Argh, helical pulley, using paracord.
@@PsychoticusRex hahahaha you can edit your post. Just tap the 3 dots to the right. and then destroy the evidence and delete second "correcting post". This bit was edited after the fact :) , Cheers,
Bill
@@williamwalter8554 shame teaches better than competence. ;)
That is a lot of weight to hang from a structure. Is the greenhouse itself sturdy enough to handle it?
nice
There should be two ways of doing this that I can see? modify your method with two chain sprocket and a chain to synchronise shafts or just go with cables and pulleys, just think negative feedback circuit but with steel cables instead, you need 8 pulleys 1 set of 4 pulleys like you where doing, the other set of 4 will connect in a X pattern so that each corner connect to the other platter both far and near. The cables pattern looking down from the top should look like a hourglass, two triangles touching, additional support cables could be added between theses two end, they would be just simple cross over cables one side to the other. I probably confused you, I'm not so great with written communications.
I wanted to make sure that the load was distributed on to each arch of the greenhouse so I went with this solution. With the X pattern going from one end to the other, I think that would just support the ends and not the entire troth? I also thought about chain but once you get into the sizes that can support weight the get very expensive/heavy. It would have made this much easier with chain!
Just bit concerned about your safety, are those belts OK with UV and weathering, I know stainless steel cables are used in small aircraft and heavy medical equipment, don't know about trusting those belts in that environment?
I shouldn't have watched this video, I keep trying thinking of different solution to this problem, kinda like a earworm. Thank you 😊
@@drmosfet I'm hoping the belts will be OK. The plastic covering for the greenhouse filters a lot of the UV. I've been thinking about also putting a safety cable on each section so if the belt breaks, the cable should catch the load. Even chains and cabling you buy tends to say 'not for overhead use' so everyone is trying to cover their butts!
Wow, what printer do you have?
I have several printers, but these parts are printed on an Anycubic Photon S using Siraya Tech non-brittle resin.
@@Bigelowbrook The printed parts seem very good and strong. I presume that's the reason you chose a resin printer or something like PLA?
@@heckyes the resin printers are far more accurate and there is a better choice of materials with the resin
I'd do it the lazy way (and open up for a big failure), i.e just having the pipes set and throwing some ropes over them.
you really should do the strength calculations first before you move on ... 1. the whole weight rests on your horizontal construction beams that are design only to keep the shape of your roofbeams under heavy weather conditions, not to carry extra weight. they are only secured with a simple bolt at each end. the weight distribution over the beam might make it bend, impairing its original purpose strength during storms f.e.. if there is space mont a bearing and axel on top of a construction beam instead of having it dangle underneath on 2 simple bolts. don't underestimate the weight of your basket, tge grow medium, the water, the plants and the inertia forces needed to get it all moving up and down. allow for a safety factor of at lesat 3. your axles shoud have enough stifness, i doubt your electricity conduit pipe is gonna hold up when everything starts shaking when in use during heavy winds.
I agree. The weight has been one of my biggest concerns about this entire project. I'll cover some weight calculations in a future video. thanks!