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ben-s
04-05-2007, 06:21 PM
Here is a CAD drawing of my idea for a leadscrew driven syringe.
I think that the basic design is adaptable to virtually any size syringe.
It's based on standard size steppers, syringes and threaded rod.

I think the most expensive part would be the baseplate, but it's design is such that could easily (and fairly cheaply) be lasercut and CNC bent.

That aside, the rest could be built with basic tools - a drill press, a saw, a tap and die set and screwdrivers.

The leadscrew nut block could be machined for greater accuracy, but I doubt that this would be necessary. The backlash adjustment on that part may not even be needed in the actual event, as it's not going to be frequently reversing.

It's a bit oversize on the length, to allow the syringe to be removed for filling, exchange when it wears, or to change chemistry.

Any thoughts?

Photo Engineer
04-05-2007, 06:29 PM
Looks good to me, but you may need a clip to hold the plunger so that you can fill the syringe when mounted by running it in reverse. Otherwise, how would you fill it and then place a filled syringe in the mount?

PE

ben-s
04-05-2007, 06:42 PM
Ah... yes :p
missed that one.

I was aiming for as little plumbing as humanly possible - I was intending to fill the syringe off the machine.

What do you think to adding a quick release for the syringe?
Somewhat like this:

I'd need to add a stepped bush or collar that slips over the syringe to stop it wobbling all over the place.

ben-s
04-05-2007, 06:53 PM
Added the syringe collar:

Photo Engineer
04-05-2007, 08:50 PM
Ben;

The mod looks perfect to me.

Now, the outlet can be on-center or off-center. If intended for upright delivery, either is ok, but if intended for horizontal delivery, the outlet must be on the bottom side of the syringe to allow filling.

Do you agree? If so, this will take a custom syringe as seen in the web site referred to above.

PE

Photo Engineer
04-05-2007, 10:10 PM
Guys;

I just saw a device called a syringe rack. It was being shown on TV and is a device used by chefs to make items that have to be injected into ice water, hot water or hot oil. The rack that I saw held 12 syringes and was operated manually by a block of wood.

Looks neat, inexpensive and doable.

PE

MattKing
04-06-2007, 03:05 AM
Guys;

I just saw a device called a syringe rack. It was being shown on TV and is a device used by chefs to make items that have to be injected into ice water, hot water or hot oil. The rack that I saw held 12 syringes and was operated manually by a block of wood.

Looks neat, inexpensive and doable.

PE

Is this the George Foreman emulsion maker - available only through this special TV offer:D .

(Sorry, I just couldn't resist)

By the way, this and the other thread about automated emulsion making are fascinating, even if you are like me, and therefore absolutely unlikely to ever try any of this yourself.

Matt

ben-s
04-06-2007, 09:47 AM
Ben;

The mod looks perfect to me.

Now, the outlet can be on-center or off-center. If intended for upright delivery, either is ok, but if intended for horizontal delivery, the outlet must be on the bottom side of the syringe to allow filling.

Do you agree? If so, this will take a custom syringe as seen in the web site referred to above.

PE

Thanks :)
I just drew the syringe as a standard concentric type as it was easier, but I believe I can get hold of off centre syringes, if hotizontal mounting is the order of the day, but I'm working on a concept sketch of a system where 4 of these are attached vertically to a square bar.
This arrangement could then be attached to an ordinary clamp stand over a hotplate stirrer, or fit onto the lid of a machine.

I'll have another play later on. It's HIE and velvia-with-a-polariser weather now though... I'm going out

PeterB
04-07-2007, 04:36 AM
Wow ! I have found this thread very interesting indeed for quite a few reasons.
Firstly I am an Electrical Engineer and Computer Programmer. Secondly, one of the many things I do for a living is to develop automation and control systems using (amongst other things) PCs and Data Acquisition systems. The final and obvious reason is that I am an APUGger.

I like the idea of designing an "open source" mechanical, fluidic, electrical and software system. It could even be beneficial to begin drafting up some requirement specifications for such a system - one that can be edited by anybody interested in contibuting.

PE, do you have any draft or working drawings/sketches that show a possible system as a whole ? (or a system which is sufficiently 'similar') ?

regards
Peter

Photo Engineer
04-07-2007, 10:37 AM
Peter;

I could do that from memory, but I'm considering the ramifications of postng something like that due to the fact that I have too much information on confidential items. I have to edit my memory so that I can satisfy you and not disclose too much. We are treading pretty close here.

I may diagram one single delivery system and leave out details to obscure some of the fine points.

PE

rmazzullo
04-07-2007, 10:11 PM
Just another idea for discussion. This is more than likely overkill, but it might generate other ideas.

You could have a long thin stainless steel rod (say 1/8th inch diameter) pointed at one end, traveling coaxially (telescoping) inside a larger stainless steel tube (1/4" inner diameter) submerged in the emulsion mix. The larger diameter tube is swaged, or somehow reduced in diameter on the submerged end, so the thin rod inside will not pass through the end of the larger tube. The pointed end acts as needle valve, and the ingredient is introduced at the side near the top of the larger tube, under pressure. The top end of the thin rod protrudes from the top of the larger diameter tube, and is acted on by a servo (I keep thinking model airplane types, but there must be an industrial strength commercial version that does the same thing) so you can vary the length of the needle valve that retracts and for how long very smoothly and consistently. Once you have the exact "delivery profile" figured out, it could be repeated from run to run. I have to figure out how to seal the delivery tube at the top (or servo) end so the added ingredient doesn't come out of the top, yet allows the rod to move up or down relatively freely. It might be easier to have two small diameter tubes welded side by side, with the ingredient in one tube, and the needle valve riding in the other, and joined at the bottom. There would be a hole on the side of the delivery tube, where the needle valve would slide past in varying amounts. What would have to be worked out is the shape of the ingredient discharge at the end of the delivery tube.

Additionally, you could have two (or more) of these delivery tubes running very close to, but on opposite sides of a small turbine mixer (I haven't figured that part out yet)submerged and carrying different ingredients and the motor driving the turbine could be a hobbyists Moto-tool. For short duration mixing the Mototool should be ok, as the Mototool's speed runs up to about 20,000 rpms. You could even vary the speed of the moto-tool right along with the delivery rate and amount of the ingredients, and track the results in realtime with your monitoring electrodes...all done via a PC. You could have the mixer, mototool, delivery tubes and servo mechanisms on a small lab stand, perched above the mixing vessel. You could have a fast mixer delivering and mixing ingredients in a local area of the vessel, and a second, slower mixer submerged directly opposite in the same container, to mix everything together.

I have no idea if this will destroy the emulsion, or make it super-homogenized and destroy it, or make it better. Something tells me that this latest fit of madness can and will do all three at any given time, depending on any number or combination of factors, and / or how those factors are implemented. If I knew some sort of mathematical CAD program, I could probably model different physical / rate of delivery arrangements to get the best result for a given container shape (square or round bottom), but I do not. I will have to perform this experiment and find out. For all I know, all this gadget could be good for is making mayonaise.

If anyone has any thoughts, please feel free to contribute.

Thanks,

Bob Mazzullo

Photo Engineer
04-07-2007, 10:59 PM
I've seen a lot of good ideas here, but the problem is, a good dose of actual emulsion making will go a long way in understanding the process.

I'm trying to come up with a way of describing an addition method that will work, but the simplest is just a syringe and the next up is a burette, and then above that is a peristaltic pump. Each moves upwards in complexity and cost. Any of these can be accurate and repeatable.

PE

rmazzullo
04-08-2007, 02:09 AM
Hello PE,

I agree with you completely, and know that I really have to do the work to understand what is going on. I will admit that I do get a bit carried away with the "thought exercises" though.

I am hoping the Mees and James, and the Haist books will help explain more of what is happening, and how the technology has progressed.

Thanks,

Bob Mazzullo

epatsellis
04-08-2007, 05:57 AM
just as an aside...

As part of a part time business, I design, repair and retrofit CNC routers. Instead of the pic/AVR approach, why not use one of the many off the shelf 6 axis s/w packages out there? They are run on pc class machines, and use step/direction interfaces directly from the parallel port, if anyone is interested, email me for links. it's relatively trivial to program in G code, and the ability to have coordinated moves is quite likely the easiest apporach to getting consistency. FWIW, the pricing ranges from free to ~$150 or so.

erie

PeterB
04-08-2007, 10:38 AM
Peter;

I could do that from memory, but I'm considering the ramifications of postng something like that due to the fact that I have too much information on confidential items. I have to edit my memory so that I can satisfy you and not disclose too much. We are treading pretty close here.

I may diagram one single delivery system and leave out details to obscure some of the fine points.

PE

Hi PE,

After typing this reply, I have realised that you began another thread on automated emulsion making here (http://www.apug.org/forums/forum205/38064-automated-emulsion-making-more-modern-formulas.html#post451083). I'll let you decide which thread you want to put any reply to.

Obviously you have thought about how much info you are comfortable revealing without upsetting Kodak, and what I have written below seeks to address your comment: "I have too much information on confidential items. I have to edit my memory so that I can satisfy you and not disclose too much. We are treading pretty close here."

Make the descriptions generic enough so that you don't reveal any of Kodak's IP. Alternatively, you can always be specific with info that is already in the public domain, and processes for which patents have expired. You have highlighted an interesting dilemma here, do Kodak's secrets go with them to the grave ? Given that Kodak no longer manufacture B&W papers, perhaps they would be open to the idea of publishing their trade secrets which don't relate to their colour papers, or their film emulsions - I mean what do they have to lose ?

Clearly your manual process does not disclose IP, otherwise you wouldn't be running workshops on it. So document that process and we'll automate it for you, and hopefully we may come up with a different way to do it that doesn't infringe on a Kodak patent. (if our 'automated' way happened to do things in a similar way to a non-patented but secret Kodak proess, then that's tough bickies for Kodak !)

regards
Peter




One could argue that

rmazzullo
04-08-2007, 01:21 PM
Hello all,

This question is not intended to divert this discussion from the topic too far but...

Out of curiosity, does anyone know if 35mm film leader usually used for motion picture work, is supplied with or without a subbing layer? I do not know if the sprocket spacing is the same as on 35mm still camera film, but I did a google search and found sources in clear acetate and polyester, in 1000 (one thousand) foot rolls.

You know where I am going with this. I was just curious about the potential. That's all.

Thanks,

Bob Mazzullo

Photo Engineer
04-09-2007, 01:47 PM
Here is my description of a fully automated precise delivery system....

I will describe only one system.

First, imagine that you wish to deliver 0.2 molar Silver Nitrate for 1 minute and then hold and then deliver 2.0 molar Silver Nitrate for 10 minutes.

This design will include 2 jars, one of Silver Nitrate at 2.0 molar and another jar of distilled water. It will include 2 pumps and associated pipes and automatic valves.

Ok, first, the Ag and water jars will have to have recycle lines and valving so that the pumps will be up to speed when delivery starts, so here goes.

1. Start Ag at 1/9th the rate needed and water at 9x silver and set for recycle.

2. At time zero divert both to the reactor thereby providing 0.2 molar Ag solution and at 1 minute shut off the Ag and allow the DW flow at 1/9th higher speed to push the exact amount of Ag into the reactor at exactly the same rate as previously for the entire combined flow, then shut off DW entirely.

3. Hold as desired while Ag is in recycle and the recycle ramps up or down to the proper rate for the next addition. DW is OFF.

4. At time zero, start Ag at full flow and DW in recycle at same flow. Pump Ag for the time required and then shut it off while DW is turned on to run to the reactor pushing the correct amount of Ag into the reactor.

This is done to prevent line volume from distorting delivery volume. The total exact volume must be delivered if automated. Any error will result in formula fluctuations or waste of Ag solution.

This system will also allow for ramped flow rates and ramped concentrations which gives the system described very great flexibility. It also leads to great complexity and an interesting problem for the programmer.

So, you guys considering automating delivery should be aware that when a formula calls for 20 ml of Ag solution in 1 minute, they mean exactly that, no more and no less. Variations will cause fluctuations in the resultant formula. Here is an example of a system that will carry out this accurate delivery.

Now, multiply this by the need for running salt (in control) or two salts (one in control and one not), dopants, antifoggants, gelatin, auxiliary materials such as stabilzers, acids and bases, and you get an idea of the complexity of the systems involved.

No, I'm not trying to discourage you and no, you don't need the above for a home system. What you do need is a system that can fill a jar and deliver it fully to the reactor in a specified time. And, you need this capability for every item you wish to deliver in a precise manner. I'm merely showing you one way I know it can be done.

Now, you run with it.

PE

rmazzullo
04-09-2007, 02:59 PM
PE,

If you are able to (within the limitations you mentioned before) can you please shed more details on the purpose of recycling?

I am thinking this is to mix the required proportions to get the desired solution strength ahead of the timed injection into the reactor, but something tells me this may not be the case.

Thanks,

Bob Mazzullo

Photo Engineer
04-09-2007, 03:03 PM
No, recycling is to get the pumps moving at the right speed before delivery starts and so as not to waste solution. If the pumps are not running at the right speed, then the delivery rate will ramp up with pump speed and delivery will not be at the right flow rate / unit time unless the flow is started prior to real delivery but is recycled back into the originating vessel. There is no mixing of DW and Ag before flow commences. Plumbing is designed to insure that.

PE

wirehead
04-09-2007, 04:25 PM
So, you guys considering automating delivery should be aware that when a formula calls for 20 ml of Ag solution in 1 minute, they mean exactly that, no more and no less. Variations will cause fluctuations in the resultant formula. Here is an example of a system that will carry out this accurate delivery.

Now, multiply this by the need for running salt (in control) or two salts (one in control and one not), dopants, antifoggants, gelatin, auxiliary materials such as stabilzers, acids and bases, and you get an idea of the complexity of the systems involved.

No, I'm not trying to discourage you and no, you don't need the above for a home system. What you do need is a system that can fill a jar and deliver it fully to the reactor in a specified time. And, you need this capability for every item you wish to deliver in a precise manner. I'm merely showing you one way I know it can be done.

Now, you run with it.

PE

So basicly our semi-automatic-amateur-setup would replace a fairly small number of containers of chemicals only at the maximum concentration with a larger number of auto-syringes? In our case, you'd have two syringes, one with 0.2 molar silver nitrate and one with 2 molar silver nitrate?