# Got Milk? - NO need help



## MachinePop (Aug 30, 2012)

Building a goat milking machine but having trouble getting beyond the Protech 
gearmotor and the SCR (specs below). 

My issue: the Minarik SCR MM23001c seems to need/require additional 
components to function properly.  I bought the Protech and Minarik from 
surpluscenter.com. The gearmotor was actually cheaper than the Minarik SCR. 

The Minarik SCR needs a line fuse pg.18.  
Minarik drives require an external fuse for protection. Use fast acting fuses 
rated for 250 VAC or higher, approximately 150% of the maximum armature 
current.

and line filter pg 69, 

If the exact line filter is not available, the specifications are as 
follow:

L= (1.73 + 0.03) milliHenries.
C = (0.27 + 0.54) microFarads (X); 0.0055 microFarads (Y)
R = 330Kohms.
Rated current: 1.4 times maximum DC motor current.
Filter type: Balanced 2-section.


http://media.countrylivinggrainmills.com/wp-content/uploads/2012/04/DC-Drive-Card.pdf

Can anyone recommend a line fuse and line filter for me to use besides the 
Minarik brand, or can someone recommend a different SCR that I could use that 
would be easier to install, or at least comes with line fuse? My concerns is 
that I am going to end up spending more money than necessary to get my current 
SCR to function properly with the gearmotor below.

Gear Motor:
Protech 250 RPM 125 VDC RA gearmotor
Amp: 0.5, 1/12 HP

Thanks


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## Tony Wells (Aug 30, 2012)

Tyco Electronics is the distributor for this product line:

http://www.cor.com/Series/DC/DA/

And one of those, even the 3 amp should do the job. It's primarily a compliance to CE standards requirement anyway. I'm sure you could find many suitable filter modules on ebay.

As far as a line fuse, you will need to buy a few bits and build a simple enclosure with a surface mounted AGC style or similar fuse. Should be straightforward. Make sure you fuse the hot side rather than the neutral.


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## jgedde (Aug 30, 2012)

I wouldn't worry about a line filter unless you plan on marketing this machine.  It's to meet the CE (conducted emissions) requirements of CE (European Community).  Without it, you may hear noise if your listening to an AM radio while milking but that's about it.

The fuse, however, must be there.  Fuse selection is a non-trivial activity - although it sounds easy.  I would do exactly as they say and use a fuse 150% of the armature current.  You can't know what that current is without measuring it during actual operation.  So, I would put a 3 or 5A fast blow fuse (glass cartridge type - 3AG) in there for now to protect the controller until you get everything working to your liking.

John




MachinePop said:


> Building a goat milking machine but having trouble getting beyond the Protech
> gearmotor and the SCR (specs below).
> 
> My issue: the Minarik SCR MM23001c seems to need/require additional
> ...


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## jumps4 (Aug 30, 2012)

we may want to get the goats opinion on thisanic:anic:
seriously do you have any pics i'm just wondering how this all works on the mechanical side
steve


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## roygpa (Aug 30, 2012)

I sure hope that you are milking goats to make cheese that you intend to sell to people here? Maybe?
I can't say that I ever tried goat's milk cheese, but would be willing to give it a try. )

Roy


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## Tony Wells (Aug 30, 2012)

Froneck said:


> If your looking for a different DC Motor speed control you need to define your requirements. First it not an SCR. You want an Adjustable DC Motor speed control. An SCR is a Silicon Control Rectifier. If it used a Transistor then you would be looking for a Transistor not a speed control. You want a speed control, do you plan on using DC motors in the future? Is the Motor series or shunt wound? DC speed controls are usually cheaper than AC. This control has a lot of features such as acceleration and deceleration adjustments etc. Are these needed too?
> 
> Frank




Frank, please read the OP again. He has already purchased the hardware. It is an SCR based DC motor controller. The specifications he has recommend a line filter and a line fuse. That's all he's asking for help with. If you can help him locate those, fine. Otherwise,  you're not helping, but adding information that is not needed and is off topic. It's my recommendation that the line filter is not mandatory,agreeing with John, but Tyco, as I mentioned does sell the type he needs if he chooses to go ahead with it. A fuse on the "line" or supply, is most definitely recommended, and there are a few ways this can be accomplished. If you have recommendations on a small enclosure that would house the fuse safely, I'm sure he'd be glad to see specifics on what you think he should do. 

Stay on topic.


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## Tony Wells (Aug 30, 2012)

Frank, he's only interested in exploring other options if his already in-hand system proves to be more difficult to install than he anticipated. It is not, especially considering the lack of the need for a line filter, which we all agree upon. Therefore, when the original situation is cleared up, all he needs is a way to provide fuse protection for what he already has bought.

And SCR (Thyristor) based DC motor controllers are as common as dirt. It is the proper type for his application. He already bought it, so let's help him put it to work.


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## jumps4 (Aug 30, 2012)

something must have scared him off he never posted again
that was only his second time posting here i hope he was just busy and not forced away
steve


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## MachinePop (Aug 30, 2012)

Not scared but someones got to work around here.

Okay with further research I found these possible comparable drives to the Minarik.

KB Electronics - KBMM series: seems to come with fuse holders but requires HP resistor - pg 8,10
http://www.kbelectronics.com/manuals/kbmm_smt_manual.pdf

Dart Controls - 125DV-C:  seems to be all in one- pg 11
http://www.dartcontrols.com/catalogs/125DSeries.pdf

Baldor - BC141:  seems to come with fuse holders but requires HP resistor - pg 6, 12
http://www.baldor.com/downloads/manuals/_downloads/704-711.pdf

Bodine - 0865 - pass on this one, looks like the problem I already have.

Graham - s1000 - also looks like it could fit the bill. pg -5
http://www.grahammotorsandcontrols.com/products/manuals/s1000.pdf 

Anyone familar or can recommend one of these that might work.

Also I waiting to here back from Surplus Center regarding why they recommended this drive outside that they carried it.

Thanks


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## jumps4 (Aug 30, 2012)

oh good your back 
steve


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## Tony Wells (Aug 30, 2012)

Soooooo Pop, what exactly do you want to do? Abandon your current controller in favor of a new one, or proceed with the one you have? Seems to me that you aren't far away from a workable system with what you have. Your call, and we will help all we can.


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## MachinePop (Aug 31, 2012)

Well I am just trying look at my options. At this point I am leaning more towards return the current SCR and purchasing one where I don't have to be overly concerned with my ability to wire the damn thing. Being that I don't have much experience in wiring circuit boards. I can return my current SCR within 30 days. So I am weighing the possiblities, I have alot of work to do on all of this. So I am trying to simplify were I can.


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## Tony Wells (Aug 31, 2012)

For a very basic controller, and an economic one, I suggest looking at Boston Gear's Ratiopax line. I have one that is set up to drive a 90VDC PM motor on a 90 degree reducer. Works like a charm. No fancy bells and whistles like accel/decel or braking, but for just a simple drive, it would be hard to beat. They don't get any simpler. It has a fuse on it's own, and it's only connections are power in and motor out.

http://www.bostongear.com/products/electric/ratiopax.html

That's the general info page, but there are a couple on ebay right now. Or you could locate one of many power transmission suppliers that are Boston distributors.


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## jumps4 (Aug 31, 2012)

i know i'm late with this but is this motor going to need variable speed or just something to drive it at it's fixed speed.
if its always going to run the fixed speed why not just a rectifier it's 125 volt add a fuse and be done with it.


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## jumps4 (Aug 31, 2012)

if you do need to control the speed plug it into a harbor freight router speed control will work fine costs very little and reverse is a matter of the right switch to reverse the motor polarity
this motor is .5 amp 1/12 hp not a real problem to power
just a thought to save some money
the rectifier is $1.96 free shipping way oversized up to 1000v 35amp
http://www.ebay.com/itm/1x-35A-1000...454?pt=LH_DefaultDomain_0&hash=item3a7789529e
steve


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## MachinePop (Aug 31, 2012)

I need a chassis style driver, not sure if the Boston gear provides that capability. I want to enclose the entire unit. 

Harbor frieght is like going to Costco on payday. All they need to do is sell hot dogs.


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## jumps4 (Aug 31, 2012)

pop
are you going to adjust the speed?
steve


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## jumps4 (Aug 31, 2012)

just trying to help
steve


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## MachinePop (Aug 31, 2012)

Hey I have one of those router switches laying around, can't pass up a great deal. I think I will plug it in and give it a try. That might solve the the problem. I will give it a test run tomorrow and let you know. I do need to solve this because I need to get on with machining a extension for the gear shaft.


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## Tony Wells (Aug 31, 2012)

Well, the ratiopax is a self contained unit, enclosed. It's not large, if you need to protect it from the elements, or need it in a larger enclosure along with other things.


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## MachinePop (Aug 31, 2012)

Steve if I am understanding you correctly I can plug the corded gear motor into the harbor frieght switch and give it a whirl? Or do I need to plug it after resolving the SCR issue?


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## jumps4 (Aug 31, 2012)

NO POP dont try that. you need the rectifier to make it "dc" before it hooks to the motor
dont try that pop!
you may need to find a friend with electrical ability or hire an electrican this 125v dc or ac will kill you
steve


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## MachinePop (Aug 31, 2012)

Hey, Hey just took me a moment to think about it all. I am going to return the other SCR, and look for something that better suits my level of understanding, and or ask a couple of buds who used to do this kindof stuff I think.


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## MachinePop (Aug 31, 2012)

Getting down and dirty with this now. Upon further review, I think Tony is onto something with the Bostongear Ratiopax. Since I was going to need to have an external control anyway, eventhough the Radiopax is bigger than what I was originally thinking, it actually would work quite nicely.

Now which one, I did send a request to Bostongear for assistance in matching. However I would like to get input from here, maybe Tony.

Bostongear Ratiopax general specs: pg 2
http://www.industrialmagza.com/pdf/boston/varspeeddrives/manuals/ratiopax-MGZ.pdf

Protech Gearmotor specs:
Speed: 250 rpm
Voltage: 125 DC
Amp: 0.5 Amp
Power: 1/12 HP
Torque: 10in - lbs
Gear ration: 10:1
Rotation: Reversible 
Duty: Continous
Comes with IEC 320 C19 connector on 25" cord

Thank and much obliged


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## Tony Wells (Aug 31, 2012)

No doubt, Boston will give you good, solid information. I'll look it over also and see if my recommendation matches theirs. Do you need reversing with this motor?


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## jumps4 (Sep 1, 2012)

the unit in the pdf is only good to 90v unless you hook it up to 220v instead of 110v (it would run but not full speed) 

i didnt know if you were going to power this off 220ac but if so you will also have to watch you dont turn the unit up to high because it will put out 180v dc and burn up the motor (125v dc)
steve


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## MachinePop (Sep 3, 2012)

First no I don't need reverse. Also as suggested, I am consulting with my bud who is an electrical engineer to have him go over the specification of my DC motor and make sure that I am getting the proper components for it to operate safely.

More to follow.

Thanks


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## Bill Gruby (Sep 3, 2012)

Machinepop;

 I have a KB Penta Power KBIC-120 Variable Speed unit on hane. You will have to get the Resistor as I don't have one. let me know if you can use it. 

"Billy G" )


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## MachinePop (Sep 3, 2012)

okay after consulting with my friend, he pointed out that the Protech gearmotors voltage is 125 DC and looking at all the SCR that I was reviewing went 115v to 0-90dc or 230v to 0-180dc. Not 115v to 0 -180dc.

The question is what would be the downside of running the gearmotor at the lower 90dc, so as I could plug it into normal house current? 

Would the motor turn at all or would it turn with limited torque? I am not sure of the answer. At this point with safety first always in mind I need to get theses questions answered before proceeding. 

I writing to the Surplus Center to inquire why there tech said I could use normal house current to run this gearmotor.

Thanks


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## Tony Wells (Sep 3, 2012)

Only downside is you won't have the top rated motor speed. 90 VDC will be 90/125th of the rated RPM. Unless you need top speed, it will be fine.


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## MachinePop (Sep 4, 2012)

Okay with that being said, the maxium RPM of 250 would be reduced to 180 RPM being that the percentage of reduction is 72% in regards to 90/125. If this is the case then I can move forward.

Now I can review this KB that was so graciously offered.


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## Tony Wells (Sep 4, 2012)

After thinking about my previous reply, I believe that I was wrong in what I said. Using 90 volts instead of 125 will not reduce the speed as much as reduce the power of the motor. That said, if there was a light load, you would not have a problem with it at all. Since it is geared down so much, you might never notice.


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## MachinePop (Sep 4, 2012)

How would you define a light load. And is there a way to calculate the power reduction with no load? So as to get a baseline as to what power it would have.


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## Tony Wells (Sep 4, 2012)

It would be the same percentage that we discussed on the speed. Your motor is 1/12 hp, with a given gear reduction. The torque even such a small motor can transmit through a reducer can be surprising, so it might be enough. Having no idea of what you want to drive with it, and how, it's hard to say if it would really hinder you.


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## MachinePop (Sep 4, 2012)

My drawing is awful so I shall attempt to explain. The gearmotors shaft will be used to drive a rod into a diaphragm. The piston like movement creates the suction, which is connected to the teat cups. So the importance is that once suctions is attained it needs to be maintained.


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## Tony Wells (Sep 4, 2012)

Well, I have never milked a goat, but have a few cows, so I have some idea of the forces required for doing what you are, and there should be more than plenty of muscle for that. Of course, the stroke length of the crank that drives the rod operating the diaphragm as well as the diameter of the diaphragm really controls how much vacuum you can draw with it, I'd say plenty. I assume you have a releasable check valve involved here somewhere?


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## MachinePop (Sep 4, 2012)

Yes there is a check valve release. My concern is with the reduce power it may limit the number of teat cups I can operate and any one time. Also I put this question to KB electronics I am hoping to get a response soon.


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## MachinePop (Sep 4, 2012)

I got a response from KB electronics. Basically he said that I could use their SCR the effect would be that I would see as you said a reduction in RPM's.


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