Automation Project Idea, need some suggestions, Pancake Maker

edlikestoboogie

I want to start a weekend project of making an automatic pancake maker using one of these: double sided griddles:

http://www.target.com/gp/detail.html/180-8914246-2011931?asin=B00008PC98&AFID=Froogle_df&LNM=|B00008PC98&CPNG=appliances&ci_src=14110944&ci_sku=B00008PC98&ref=tgt_adv_XSG10001

The idea of this project if for me to start learning how to use stepper motors and get me introduced to industrial automation.

My idea is to use two steppers, one to open and close the griddle, and another stepper to flip the unit along the axis at the midpoint of the unit. I also want to use a solenoid valve to dispense the batter. Is this design sound? and does anyone have suggestions for a novice? Like what steppers to use. Please recommend me a plug and play stepper controller/driver board and some SPIN code to drive it quickly without hassle.

Thank you, and I hope to get some awesome suggestions.

edlikestoboogie

Keep in mind, money is not really an issue, or at least its not as important as speed/ease of use. I would like to finish this project in the shortest time possible.

Leon

You need to select suitable stepper motors first, before deciding on a driver board.

edlikestoboogie

Any suggestions Leon, on a stepper motor that can handle the torque to open this thing, and to rotate it?

Leon

You need to determine how much torque you need by some measurements and calculations - all standard design stuff.

T Chap

Easy to use, and will handle the all power you need:

Gecko G212 bipolar stepper driver.

Then find a Nema 23 size bi polar stepper.

Unless you have another solution, use some cheap acme threaded rod from Mcmaster.com, 1/4-16 1-start acme threads, and get some Delrin nuts here:

[url] http://www.dumpstercnc.com[/url]

bill190

I should think there would be a problem with the batter if gravity fed. Different consistencies would flow at different rates. And an almost empty dispenser would flow more slowly than a full container.

There is probably a "food service" name for a device which would dispense an exact amount of fluid, but I have no idea what you would call that.

However I was just poking around looking for some laboratory related stuff the other day and came across gizmos called "dosing pumps" or "dosing meters" which would be used in the medical field.

I tried switching that wording around a bit to "dispensing pump" and came up with some interesting stuff...
http://www.google.com/#hl=en&safe=off&q=dispensing+pump&aq=f&aqi=g-c1g1g-m8&aql=&oq=&gs_rfai=&pbx=1&fp=2c55ee91c591a154

RichK

While working with servos and stuff, you could find some way to drive this:

http://www.amazon.com/Norpro-Stainless-Pancake-Dispenser-Holder/dp/B0007Z1NJU/ref=sr_1_3?ie=UTF8&s=home-garden&qid=1282846346&sr=1-3

to make consistent size pancakes. Then you need an arm that swings overhead, more servos and some kind of sensor to detect batter level. It's not really a fluid so I'm not sure how that would work. Probably just count them after it gets loaded. Maybe a camera to monitor how well the dispensing went.

How are you going to unload the cooked ones? Invert it completely? I checked and my wife cooks them by timer but she needs to adjust the time based on the batter and if anything is in them. Apparently chocolate chip ones cook faster. Who knew?

An interesting project.

edlikestoboogie

T Chap: Yeah I was thinking of using CNC parts, I assume it will give me all the torque I need.

Bill 190: My last project used peristaltic pumps to dispense exact (to the mL) amounts of chemicals into a reservoir. Unfortunately I think pancake batter is too viscous for peristaltic pumps, I may be wrong, please let me know if you see a suitable "dispensing pump" or "metering pump" or something similar that could handle pancake batter, that would be a much simpler solution that anything gravity fed, but for now, as a proof of concept I might just go with gravity feed from a funnel, with a big enough solenoid valve.

RichK: I plan on unloading the pancakes by simply inverting it like you said, I hope this works, assuming the griddle is using a non-stick surface, I assume all griddles are made with such surfaces, the pancake should slip right off right? I haven't made pancakes in ages, as a homework assignment I should make some . I usually avoid the stuff because of the excess carbs.

edlikestoboogie

I just looked on youtube of other people making pancakes, and i feel like I shouldn't rely on the non-stick surface of the griddle to do its job and allow me to easily drop the pancake. I may have to use a parallax servo I have laying around to spray some PAM or similar lubricant on the griddle, that shouldn't be a problem, again I haven't cooked anything in ages, I should practice.

anhingus

interesting idea. a problem, though - the product description suggests this is an eyeball application. you would probably need temp monitoring.

to handle variations in batter viscosity, you might be interested in a turbidity meter, basically an opamp in constant current mode shining a light toward a photocell. put a sample of batter in an amount of water, shake well, get output voltage from the photocell and use a lookup table to control device heating process in terms of power on/off.

for rotation, consider a low rpm motor with a limit switch, lid lifting the same.
project shouldn't require stepper precision. assembly code speed is not required - femtobasic or propbasic would do just fine.

in line with the peristaltic pump comment, in a sewer works, the thick stuff [don't ask] is moved by an augur. would think batter, stepper motor, and archimedes screw type dispenser would be a cool app for a microcontroller.

the real failsafe thing to worry about, considering mention of wife, is to guarantee lid lock and release mechanism. a misfired demo could ruin years of accumulated attaboys.

i like the idea, i do! this could do well in one of the prop contests.

PJAllen

Ed, you could take this completely over the top with a brush that whisks the surface with some melted butter (shwip, shwip, shwip). That'd be awesome.

PJAllen

Further automate and standard by using "Batter Blaster" (pancake batter in whipped-cream cans, with that nozzle), mounts in a holder and gets bopped with a linear solenoid.

I'm totally munched-out at this point.

http://www.batterblaster.com/

Post edit -- And, if you bust your ***, you could get in on that contest ($1000), too. A sure winner!

edlikestoboogie

That intro jingle for batterblast.com is hilarious. but all kidding aside, I'm just looking to get a plain old pancake cooked and dropped reliably, if I can do that I can justifiably put "industrial automation" on my C.V.

Hey PJ Allen:

What kind of solenoid should I use to press a spray can nozzle?, could you recommend me one?

I am not really interested in contests right now.

PJAllen

A solenoid (some of us have taken to calling solenoids "linear solenoids" as opposed to "rotary solenoids".) Wiki that.
Those nozzles let loose with a laterally-applied force, not by pushing them in. You could try and force the nozzle with the can stationary, but you could get more leverage, requiring less force, by clamping the nozzle and rocking the opposite end (see dwg.)

[Hey, I'm just the "idea man."]

I still say go with butter instead of Pam, but it's your show.

PJAllen

Got to thinking -- you don't need a fancy solenoid. Use a cam on a servo or a motor. See attached.
[Sorry, but cannot add attachments via Edit.]

Searider

Search Amazon for Batter Dispenser. There seem to be many different models but most work the same way. a valve on the bottom opens up to allow the batter to flow.


You could maintain the batter level with a liquid level sensor. With a constant batter level in the dispenser, you should be able to get consistant batter applications using time.

The larger batter hopper that feeds the dispenser could have an agitator in it to help maintain the concistancy of the batter between top-offs of the dispenser.

edlikestoboogie

PJ Allen: What you showed me with the servo is pretty much what I was originally thinking.

And yes, I think I will go with the batter dispenser, using another parallax servo to actuate it. Would it be a crazy idea to buy one of those mini desktop fridges that use those peltier coolers, to keep the batter refridgerated when the unit isn't in use? I don't know exactly how those things work, but I'm just throwing it out there, if anyone would like to argue against it, please do.

Searider

You bring up a whole new design criteria about Food Safety. I think you will need to put some serious thought into this. You could operate the system in a simi-batch mode. Meaning that you mix a certain amount of batter and then run the system continuously until the batter is used (say an hour of production) then take it all apart for cleaning. If you expect to run this continuously for long periods of time, or "on Demand" over a long time, then you will have issue with bacteria growth that will take more to solve than a Peltier cooler.

PJAllen

Peltier-cooled bacteria and gunked up hoppers and all that lot -- barf out. Why not just change out a can?

I'll be impressed to see an unmanned, autonomous pancake flipper, even if it requires user input: ladling batter onto its plate.

bill190

I'm no Julia Child. As proof of this, I will say I have even burned boiled chicken! (Smoke detector woke me up when dinner was ready.)

Anyway I once came up with the idea of making a large bowl of pancake batter, and keep it in the fridge. Then I could easily make pancakes every day...

As I recall, that bowl of pancake batter became quite nasty looking after just a few days.

And I have a waffle iron. And when I spray that no stick stuff on, smoke goes all over the house and sets off the smoke detectors. I now make waffles outside, then no problem with the smoke.