Magnetic Solenoid
 

Recently a company donated a bunch of magnetic solenoids to our team. They are 12V 2.5A working load. The stroke length is 1.5 inches. I know you can make a custom circuit on but can you make one for a solenoid such that the current draw is only 500mA? The next thing I am curious about is since the stroke is 1.5 inches could you set up a mechanism that only allows the stroke to be one inch? Would these things make the magnetic solenoids legal?

Thanks for the help

Re: Magnetic Solenoid
 

Well, we don't know what the rules would be for next year...

But for this year, most likely no because you can't modify your solenoids beyond what R30 allows which does not mention shortening the stroke of a solenoid

Re: Magnetic Solenoid
 

It's an interesting solenoid where you can remove the piston. If you would like I can upload a picture. I don't want to undermine the rules at all but since it's removable couldn't I shorten it?

Re: Magnetic Solenoid
 

Typically, the rules are strict about these components and the lean towards no modifications unless specifically listed.

Re: Magnetic Solenoid
 

Well maybe they will be more lenient next year we have about 50 of these:

Magnetic Solenoid

Re: Magnetic Solenoid
 

If they are illegal for competition, you could always make an awesome demo bot with them! :)

Re: Magnetic Solenoid
 

Yes quit an awesome robot. They are extremely powerful. We set up a portable power supply to 12V 3A;as per data sheet; to test it, it pulled in a screw that was an inch away from it.

Re: Magnetic Solenoid
 

I don't see why you couldn't limit the stroke to one inch (per 2016 rules), as long as it was accomplished without modifying the solenoid itself.

It's pretty common to put "sleeves" on the rod of pneumatic cylinders to limit the amount that they can retract.

Re: Magnetic Solenoid
 

That's a good way to think outside of the box. I wouldn't have thought of that. Would we still need a custom circuit board to limit the current to the device such that it only draws 10W of power instead of 30W of power?

Re: Magnetic Solenoid
 

To be legal for official competition the COTS device alone would need to be properly rated as per the rules.
In general, no custom circuits are allowed to modify actuator pathways.

Re: Magnetic Solenoid
 

For those of you wondering...
R30 The integral mechanical and electrical system of any motor must not be modified. Motors, servos, and electric solenoids used on the ROBOT shall not be modified in any way, except as follows:
A. The mounting brackets and/or output shaft/interface may be modified to facilitate the physical connection of the motor to the ROBOT and actuated part.

The solenoid specification in R29 is the standalone specification, not those that are modified by external circuitry or mechanical stops. Sorry. However, you may always ask of the Q&A in the season.

Re: Magnetic Solenoid
 

That picture doesn't provide enough information for an inspector to tell if the solenoid is legal per 2016 rules. If it were rotated to reveal the part number, that might make it possible to retrieve a data sheet, which in turn might provide enough information.

What is the part number?

Re: Magnetic Solenoid
 

I just realized that I did that. Thanks for noticing. The information on it says:

MSA
9333/0150
12 VDC-ID

I only know the current because I hooked it up to a bench top power supplies and measured the max current.

Re: Magnetic Solenoid
 

Looks like a Magnet Schultz label. The top line (MSA) indicates that.

The second line is a model and date code. I could not find a standard model 9333, but that may just indicate this model was made for a particular customer; i.e., the company that donated these parts to you.

The third line indicates that the part is rated for 12V DC, intermittent duty.

What are the dimensions? Body diameter, rod diameter, and overall length should be sufficient to compare this part against an equivalent standard part. An ohmmeter measurement at the electrical leads will be sufficient to compare against an equivalent continuous duty rated one.

Re: Magnetic Solenoid
 

Rod Length: 70.64mm / 2.781in
Rod Diameter: 11.10mm / 0.437in
Body Length with Thread: 60.55mm / 2.384in
Body Diameter: 25.48mm / 1.00in

Resistance is 4.0 Ohms

12Vdc 2.5amps tested with a bench top power supply