Seed Injector Improvement


#1

My first post, so apologies to the admins if I was wrong to start a new thread.

In the interest of open source I just thought I would throw out an idea. It seems there are issues with the seed injector design with clogging. Has anyone considered just installing a solenoid (or similar) into the seed injector so that it can blow out any debris or stuck seeds? There is a water line already installed in the UTM?
Alternatively the supplying vacuum could be switched to supplying compressed air. A venturi could be used to generate the vacuum and simply switch to an ‘eject’ setting to blow it out?


#2

That seems like the most sensible thing to do. I know FarmBot requires a lot of attention and maintenance, but having to clean the nozzle after planting a couple of seeds would be a bit much.

I thought maybe having a claw (almost like toy cranes at fairs) could replace a loud vacuum pump altogether, though I’m not sure how effective it could grab seeds. The seed bin would have to be really full for the claw to plunge in and successfully grab some seeds.


#3

I think that there may be a requirement for more than one seeder. I can’t quite see a single seeding attachment handling carrot, pumpkin, and chard seeds.

The vacuum is going to have real issues with beet and chard seeds, as the are so irregular. We may have to (gasp) do some things by hand. I DO like @albino’s idea of the air pump / venture for seeds that vacuum WILL work for. One “nice” side effect of that is that when creating the initial hole, the seeder could be “blowing” lightly, so that it is not plugged. Alternately, you would need another tool for creating the hole. How are you doing this at present? Also, how are you covering the seed after planting?

I am trying to think of some alternative ways to handle the seeding process.


#4

Instead of having a seed bin and vacuum pump, what about using a seed canister with a valve and cranking mechanism on the bottom?

Something like a coffee bean dispenser:

Maybe not as large, but something that can rest in the tool bay and be attached to the UTM.

  • Seeds can stay in the tool bay, because they are in a dry environment.
  • It eliminates the needs for a vacuum pump (at least for the current Seeder tool, but may still be useful to have anyways for other future tools). Seeds can be dispensed by gravity alone in its simplest form, or be forced out by some kind of rotating mechanism pushing out seeds like a gumball machine.
  • The risk of plugging the nozzle is decreased, because even if the nozzle gets plugged by dirt, if you’re forcing out seeds with a mechanism, the nozzle is cleared (provided the mechanism is strong enough).
  • There is a potential way of better controlling the amount of seeds planted per location. Simply crank the mechanism multiple times for more seeds.
  • FarmBot could read the tool to see if it has enough seeds for the next sequence.
  • It could be combined with the vacuum pump to create a hybrid between the current Seeder tool and this idea.

If only I knew how to make CAD drawings…


#5

Sounds like a good direction. You could have a single hopper, with separate (screw on) bottom ends for different seed sizes (or multiple hoppers, with one per seed type, but that could start adding up.). Looking at the way FarmBot seeds now (in the video), it is dropping the seed into a pre-existing hole. I assume that there is a tool that makes those holes. (They may been using the seeding tool, which would explain why it was getting plugged. I would look at a separate tool, and eliminate the potential for ground contact completely.)

It would be interesting to look at the crank mechanism. Coffee beans are pretty tough. Lettuce seeds (among others): not so much.


#6

I was thinking this same thing. With a small hobby servo to push the seed. I was thinking something with a disk. Large planting implements us vaccum to hold the seed in the disks. It is more accurate from what i have been told. The also blow the seed down to the trench. So small hoppers would work. This leads to less travel of the robot head. The only time it would need to move to the tool bay was to switch hoppers. One can get rilly crazy with this. The seed can be measured and the the planting nozel can be adjusted using vaccum. Mdingena a sketch is all I need I could help you out.


#7

We have a push seeder and you just change out disc for different seed sizes . Would be less wear on gantry. Works for furrows .


#8

Can you elaborate?


#9

Yes please do. Are you talking about a EarthWay seeder?


#10


Most push seeders and pole seeders use the same kind of basic idea. In fact a pole seeder is like double coffee bean dispenser mechanism operated straight up and down and more letting the seed move with gravity.

Yes changing the rotating disc in a push seeder changes the space in the disc that will take seed that is the same you do in a pole seeder except design for working on one axis.

There are examples around of the basic mechanical design of the bamboo seeder scaled down to the to very small seeds like lettuce seeds. These mechanisms are fairly much has to be made to match the seed size or have changeable parts.

For planting with variable sized seeds without having to change mechanics normally ends up being the vibrating trough of some design.
https://www.google.com.au/patents/US2609123
Yes this is something that was patented back in 1952 with many variations all of those patents are well and truly expired now.
Most likely there will be a need for more than 1 seeder solution.

All vacuum based seeder have issues with clogging. Even if they don’t come in-contact with the ground not all seeds will be in good condition so you will get fragments of seeds entering the machine and blocking places. Same issue that happens with inject printers with badly recycled ink seeds are always like this. Even with pole seeders you do have to dissemble and clean. So how ever a seeder is design the most critical parts is tolerance to contamination and cleanability and min damage to seeds.

Josh Large planting implements define large. If you are talking about planting a complete field most are basic mechanical designs of hole at bottom of hopper that the seed goes into the hole moves drops seed and hole move back to get another seed by some means. No vacuum. If you talking about a person planting out trays of plants then you find vacuum. You have to remember when someone is planting out trays of plants as long as greater than 95 percent of segments in a tray ends up with a seed in it the process is called a success. When planting seed trays you have a tolerated rate of failure either due to seed or due to not putting seed in that location in the first place. The machines for planting out fields with crops are design to the 99.9 percent or higher odds that a seed will be placed where intended because 5 percent of a field without crop would be someone fired. So there is a very big difference is large planting set-ups between tray and field.

Seeds can stay in the tool bay, because they are in a dry environment.
This is could be wrong. http://howtosaveseeds.com/store.php there are guides to long term seed handling. Properly dried seed that are Desiccation-Tolerant you freeze once properly dry and Desiccation-Intolerant seed you put in fridge for storage between plantings. This is one of the issues is technically seeds cannot be left in the machine long term between plantings they need to be put away and stored correctly.


#11

Thank you that was very informative. I was not thinking the seed would be left in the hopper long term. From my understanding in a conversation with a technician, larger implements( field sized planters) us a vaccume on the plates that distribute the seed. I also found that small seeds are invested in something like a paper mesh ball. This way the planters can handle the seed. I am just starting to learn about seeds and how mechanical planting is performed. The bamboo push planter looks awesome. Thank you for the information.


#12

EarthWay seeder is a scaled down commercial behind tracker seeder with a vertical disc design. If you find like a Jang TD-1 is horizontal disc disc design. Vertical disc does solve a set of problems and cause a set of problems.
https://www.youtube.com/watch?v=yNkM13eWHeQ this is a Jang TD-1 video. Vertical operations items like the Earth-way vertical disc or a pole seeder normally self clear in case of picking up 2 seeds and getting partly jammed. Horizontals have a habit of just getting wedged. This does not matter if it a single row like a Jang TD-1 or a tractor behind machine multi rows wide.

These are all we have X size hole so only X amount of seed fits.


#13

From my understanding in a conversation with a technician, larger implements( field sized planters) us a vaccume on the plates that distribute the seed.

I was not exactly right because I refer to the large field sized planters as vaccume assisted. Field sized planters you have either horizontal or vertical disc and the disc picks up the seed. In all the field sized planters I have worked with if it has a vacuum it to make sure seed comes out of disc not to pull seed onto disc. All the field sized planters I have handled with vaccume you can disable the vaccume and it will still plant just you have to check on it more regularly for blockages on disc. Maybe there is a different design out there that I have not handled. Yes suck on one side of disc is basically the the same as blow on the other end result seed goes down pipe to hole everything is good. Yes I have handle some with air blowers sending air to the discs again prevent same problem clogging. Universal battle of seed planters is avoid clogging. Automated cleaning is part of a good seed planter design nothing in the current planter design include auto cleaning.

So its vaccume off the plates that distribute the seed in the ones I know. Gravity gets seeds onto the plates in all the designs I have handled.

Josh paper mesh ball would be what is called a seed pellet, Clay, paper and many other materials are used.


Common process onion pelleting if it done wrong you will have a complete failure of a germination rate as seeds could have been bashed to death. Yes the pellet coating is fairly much dirt. If you planter cannot tolerate grime and broken off fragments you are in trouble. Yes pellets can get shattered and broken so creating fragments that what to stick in planter. I don’t know of any good method for diy making seed pellets.

Now https://milecreekfarm.com/2012/03/30/building-a-vacuum-seeder/ items like this I call a vacuum seeder as these remove the vacuum they no longer work.


#14

oiaohm can I just say it’s a delight to have you on this forum? I know virtually nothing about farming, yet I’ve wanted to have a little place in my garden to grow my own food. You are simply a great source of knowledge!

I think having larger seeds will be better to have an injector handle them. Because the smaller the particles, the more chance there is that they clog up the mechanics. Onion coating them increases the individual size of the seeds. If I understood correctly (I had to watch without sound) it also provides some nutrients (when they add ‘chemicals’).

While thinking about this idea, I thought about paintball hoppers. Sometimes they are “agitated” which means they don’t rely only on gravity, but they have a little rotating device that forces the balls out. But this device needs to be gentle, because it can chop up the paintballs in your hopper otherwise and create a big mess.

The problem here is that paintballs are obviously a lot larger than seeds. A solution would be to use Seed Balls, or the Onion Coating method you showed above, but apply more layers to increase the size. I think the cost of seeds will rise a lot though.

Bottom line is, the vacuum approach of the current FarmBot has many points to improve on. It’s a matter of finding a cost-efficient way of achieving that. I’m looking forward to following this thread and see what we can come up with.


#15


mdingena the core to a single shot paint ball gun is basically the same idea as the pole planter or disc planter.

This is the thing the same basic design does not matter if it a gun or planter or coffee dispensator is used over and over again because it fairly dependable. So yes it can be scaled down or up.

Onion coating can be done with a wide range of materials adding nutrients does not have to be chemicals as such. Onion coating is a variation on Seed balls. Layer coating of Onion coating gives some structural strength consistency that random constructed seed balls can be lacking. So you don’t just want to make any random type of seed ball when you are going to be mechanically handling you want a uniformed structural strength so you can have a machine that will not break them yet use so much force to move them.

Non uniformed shaped seeds turn them into some form of seed balls can be mandated to be able to use them in a mechanical planter.
There is are three issues with seed balls

  1. Seed balls shelf life is reduced due to the coating process increasing the moisture content of the seed. So seeds that fully dry could be frozen can only be put in fridge after been seed balled. Also the coating at times can break down if they get dried. So you don’t want more seed balls than you are wanting to use.
  2. Can have poor germination rates if they are incorrectly made compared to the raw seed itself.
  3. Cost they are most expensive.
    Ideal would be a dependable system on site to make seed ball seeds on demand. Its not that we can avoid seed balls but we really don’t want large stocks of seed balls with home gardens. Home gardeners can take multi season to plant out a full seed packet. Seeds ball are basically you get/make them you plant them all.

The one thing about paint balls that is simple to forget they are all built to the same basic strength this is how you can have a rotating device that is gentle enough not to break them. If paint balls were/are random consistency you would have big trouble. Yes bad batches of paint balls have random consistency and make a huge mess of agitated style paint ball guns.

Having larger seeds by turning them into seed balls will not help a vacuum style injector the current design has. Why coating gives something to fracture off and jam into the vacuum injector so blocking the vacuum and making it not work and is more likely to fracture off than the shell of the seed that is current problem. The issue with coating is you cannot coat a seed too much or they will not grow. Same issue here with digging a seed in too deep when putting too thick of coating on. Something to remember longer seed is expose to vacuum the more likely a fragment is going to break off. So part of the issue with the current seeder is too much travel time so the seed is exposed to vacuum for too long so it going to get jammed up for sure by broken off seed shell forget anything else. So at a min on gantry seed holders would be worth attempting that would slow down clogging a bit. Excess travel time is bad for power usage and for items like seeds depending on handling method excess time is bad.

Also I don’t see a dibbler or trench tool in the current design use by farmbot. This is also part of basic action of a planter.

  1. make hole(dibbler or trenching tool)
  2. drop seed in hole
  3. cover hole.
    Current design attempts to do all 3 in one step this is not done normally because it cause trouble. Even the basic hand held pole planter if you look how it works does make hole then drop seed as second steps and the person using does the third. There is a min number of steps to-do the job planting go less then them you will have trouble. The basics of a mechanical planter were worked out in the industrial revolution.

I highly like the idea of a farmbot just the current design still needs a lot of work in places. Lessons of general farming are not in the machine yet. I have covered fairly much all the basic theory of a planter. The hard part is design working versions. Its really simple to design failed designs.

I have planted some horible seeds like Buffel Grass. It a seed type that will jam almost every seed planter design known to man and it cannot be coated so I got to know planters way more than I wanted to.


#16

I work in food production. For spicing things on an assembly line, we use a hopper with an auger in the bottom of the funnel. As a container stops beneath the hopper, the auger turns slightly allowing a specific amount of spice to be released. Could this concept work on a micro scale? I don’t know if you could calibrate it down to a single seed but surely very few seeds. We see virtually no clogging as, by its nature, and auger is constantly unclogging itself.


#17

This is a fine solution, I think! Also easy to implement on the universal tool mount. A canister with seeds and an auger in the center that dispenses very small amounts of seeds simply by rotating.

Then, on the same tool, it’d be possible to attach a spike that creates a hole for the seeds. The gantry could first push down to create a hole, then come back up, slightly reposition so that the auger is above the hole and then crank the auger to drop seeds.

Can we also come up with something that covers the hole with dirt again?


#18

My first thought on hole covering would be a tool with a small blade like a hoe on the end. The covering action would need to be designed to lower the gantry to one side of the hole just under the soil level and slide toward the hole. Then lift, move to the other side of the hole just below soil level and slide toward the hole covering the hole. You’d run your entire seeding sequence then, once complete, you’d run a covering sequence. However, I’m not above getting out there with the back of a rake and dragging the whole plot. :wink:


#19

How do you plan to manufacture the said device? 3d printing? There are limitation on what sizes the printers can get down to. But we need to start somewhere. Then when we hit limitations we will need to go from there. What size seed should we start with?


#20

The only issue here is the unbalanced torque on the Z access arm.

You would be better to have a pair of opposed blades/paddles that move towards each other. Admittedly, the distribution of the soil around the hole may not be exactly even, but this would apply less lateral torque.

It may also be possible to bury the seed by watering the hole.