View Full Version : Are COTS shop vacs legal? They have motors
RoboMaster
18-03-2010, 18:13
We will probably put this on the FIRST Q&A, but for now we'll ask on Chief Delphi.
We are experimenting with a ball control mechanism that uses small, store-bought shop vacs to suck in and hold a ball.
The thing is, they have motors inside them that run the vacuum. These are of course not from the KoP. Are these vacuums still legal since they're COTS? It doesn't seem so...
Thanks!
Emphasized text is underlined
<R30> Robots entered into the 2010 FRC shall be fabricated and/or assembled from COMPONENTS, MECHANISMS and COTS items that are constructed from:
A. Items provided in the KOP (or their exact REPLACEMENT PART)
B. Additional parts and materials as permitted in these Rules, in quantities consistent with the Budget Constraint rules (found in Section 8.3.3). The use of non-KOP items or materials shall not violate any other robot design or fabrication rule.
<R52> Motors specifically permitted on 2010 FRC ROBOTS include:
A. All motors, actuators, and servos listed in the 2010 KOP,
B. An unlimited number of COTS servos with a maximum output torque of 55 oz-in and maximum rotational speed of 100 rpm at 6 Vdc (e.g. HITEC model HS-322HD or HS-325HB servos, as provided in the KOP),
C. An unlimited number of FIRST Tech Challenge (FTC) servos (HITEC HS-475HB servos),
D. One, two, or three additional 2˝” CIM motors (part #FR801-001 and/or M4-R0062-12) in addition to those provided in the KOP. This means that up to five, and no more, 2˝” CIM motors can be used on the ROBOT.
E. Identical one-to-one SPARE PARTS for motors, actuators, and servos provided in the 2010 KOP that may have failed or become damaged.
<R53> Items specifically PROHIBITED from use on the ROBOT include:
A. Electric motors and/or servos different from, or in addition to, those in the KOP, with the exception of those specifically permitted by Rule <R52>.
B. Electric solenoid actuators (note: electric solenoid actuators are NOT the same as pneumatic solenoid valves – the latter are permitted, the former are not).
EDIT:
One of our team members remembered this rule, which clearly allows off-the-shelf vacuums with provided motors.
<R72> In addition to the items included in the KOP, pneumatic system items specifically permitted on 2010 FRC ROBOTS include the following items. All included items must be “off the shelf” pneumatic devices rated by their manufacturers for pressure of at least 125psi, and used in their original, unaltered condition (except as required for assembly with other components).
H. For the purposes of the FIRST competition, a device that creates a vacuum is not considered to be a pneumatic device and are not subject to the pneumatic rules (although they must still satisfy all other appropriate rules). These include, but are not limited to, venturi-type vacuum generators and off-the-shelf vacuum devices (as long as they are powered by provided or permitted motors).
Dave Flowerday
18-03-2010, 18:19
The thing is, they have motors inside them that run the vacuum. These are of course not from the KoP. Are these vacuums still legal since they're COTS? It doesn't seem so...
No need to ask on the Q&A, this one is definitely illegal. You can, however, disassemble that shop vac and replace the motor with a kit motor to make it legal.
Nuttyman54
18-03-2010, 18:20
No, a COTS shop vac as is is not legal if you are using the motor it comes with. However, it is legal to replace the motor in it with one from the kit of parts (the Fisher Price and Mabuchis are good choices).
Many teams are using the impellers and other mechanical components out of shop vacs, coupled with motors from the kit to power their vacuum mechanisms
RoboMaster
18-03-2010, 18:26
No, a COTS shop vac as is is not legal if you are using the motor it comes with.
Yep, apparently. See my edit.
Dave Flowerday
18-03-2010, 18:31
You didn't finish reading R72:
For the purposes of the FIRST competition, a device that creates a vacuum is not considered to be a pneumatic device and are not subject to the pneumatic rules (although they must still satisfy all other appropriate rules). These include, but are not limited to, venturi-type vacuum generators and off-the-shelf vacuum devices (as long as they are powered by provided or permitted motors).
Therefore, R72 does not apply to your shop-vac.
{edit} I think you're misinterpreting the word "provided". Provided means "in the KOP", not "provided in the COTS vacuum".
What part of <R53> is hard for you to understand? If it isn't permitted, it's prohibited. <R52> lists the only permitted motors.
If you have a motor that is not listed in <R52>, then you have to replace it with one that is listed in <R52>.
By using the stock motor with the vacuum, you violate <R53> and, by extension, <R30-B>.
Your team member needs to re-read <R52> and <R53>.
Did you read the last line in parentheses of R72, the rule you quoted??
(as long as they are powered by provided or permitted motors).
The only provided or permitted motors are the ones that FIRST gave you in the Kit Of Parts (or their exact replacement). The motor that comes on the shop vac is NOT permitted. As was stated earlier, you have to take the shop vac apart and replace the motor.
We replaced the motor from a cheap Wal mart 1 HP, 1 gallon shop vac with one of the KOP Fisher Price motors. Cut the shaft off the existing motor then ream it on a lathe to a press fit on the Fisher Price shaft - .125 inches. If you try to drill it with an 1/8 inch bit it will most likely be too big. It works perfectly, you can't knock the ball off it.
Bayou Regional Champions with 1461 and 3362 - See you in Atlanta!
What part of <R53> is hard for you to understand? If it isn't permitted, it's prohibited. <R52> lists the only permitted motors.
If you have a motor that is not listed in <R52>, then you have to replace it with one that is listed in <R52>.
By using the stock motor with the vacuum, you violate <R53> and, by extension, <R30-B>.
Your team member needs to re-read <R52> and <R53>.
Settle down.
robself705
18-03-2010, 20:48
Our team actually took two shop vac impellers and mounted them on a custom turned steel shaft from the lathe. We then used the built in housing from the vacs to enclose the impellers. We then built a wooden frame to mount the impeller housing and bearings for the shaft. In the middle of the wooden frame, we put belt sprockets on the shaft and mounted two fisher price motors with belt sprockets as well. This gives us a VERRRRRYYYY powerful vacuum. Two fisher prices are more powerful by one cim by a factor of around 1.3. Check out this link at around 1:22 to see exactly what I mean: http://www.youtube.com/watch?v=X_dnzebFqDk
Good luck! Let me know if you have any questions!
RoboMaster
19-03-2010, 18:27
...pneumatic system items specifically permitted on 2010 FRC ROBOTS include the following items... ...off-the-shelf vacuum devices (as long as they are powered by provided or permitted motors).
We understood that there were certain permitted motors allowed, but thought that vacuums were exempt because the above rule allowed them. We also took the word "provided" to mean provided in the COTS vacuum, but a lot of people are saying this means provided in the Kit of Parts.
I have heard a bunch of times how teams needed to/have replaced vacuum motors with KoP motors. So this matches up with the "illegal" opinion.
I also look at the original third rule I posted, <R53>, which bans all electric motors except permitted ones. It includes the phrase "except those permitted in <R52> [basic permitted motors list]" and if the vacuum motors were to be allowed it would probably also reference that related rule too. More evidence for the vacuum motors being "illegal."
The FRC manual also says to not twist or legalize the rules and always take them in the spirit of Gracious Professionalism. When I rethink these rules in terms of GP, I actually think that this would mean the vacuum motors are "illegal". One could argue that the vacuum motor is part of the COTS component and also doesn't offer a large energetic/mechanical/power advantage, but theoretically it could. Motors are a source of power and there is a reason FIRST restricts them and all other such devices (compressor, pistons, etc): to give teams a fair advantage. While it is not technical, I think this is a big support for the "illegal" viewpoint.
I will check with my team and see what they think about what has been said. Personally, I could still take the word "provided" multiple ways, so I don't know. We might just post this on Q&A to completely be sure. Thanks for what has been commented so far!
You can also show them Rev C of the Inspection Checklist. The following can be found on the second page: ____ Only KoP Motors – 5 CIM, 2 Denso Left, 2 Denso Right, 2 Fisher Price, and 2 Mabuchi. <R52.A,D,E>
Come to think of it, it might help you to go over that checklist quickly in the pits before going to inspection. The less stuff the inspectors find that doesn't pass, the faster you get done.
jamie_1930
19-03-2010, 18:34
Just go to the Q&A, the opinion of anyone on chief is just opinion we have no official ruling.
RoboMaster
19-03-2010, 18:40
Just go to the Q&A, the opinion of anyone on chief is just opinion we have no official ruling.
Yes, but posting on Q&A is a hassle since you can only use one account. We just wanted to quick see what CD said.
Yes, but posting on Q&A is a hassle since you can only use one account. We just wanted to quick see what CD said.
One account, and I think they're only really answered once a week at this point in time. If you're going to develop this and you have a Week 4 event, you'd no sooner get a ruling than you'd have to pack up the vacuum.
Also remember: some of the folks on CD are inspectors of various stripes. Those are the folks who'd ultimately have to pass the robot or not pass it at the event. They can contact the GDC if they need to, but they'll usually use the checklist or the Manual first.
jamie_1930
19-03-2010, 19:37
One account, and I think they're only really answered once a week at this point in time. If you're going to develop this and you have a Week 4 event, you'd no sooner get a ruling than you'd have to pack up the vacuum.
Also remember: some of the folks on CD are inspectors of various stripes. Those are the folks who'd ultimately have to pass the robot or not pass it at the event. They can contact the GDC if they need to, but they'll usually use the checklist or the Manual first.
In that case, this is the man to talk to
Al Skierkiewicz (http://www.chiefdelphi.com/forums/member.php?u=172)
In that case, this is the man to talk to
Al Skierkiewicz (http://www.chiefdelphi.com/forums/member.php?u=172)
I happen to be an inspector, though not a lead inspector. Yes, I did pass the certification test.
Al is one of the people I was thinking of when I wrote that post. Dave Brinza (LRI at Los Angeles) was another.
Mark McLeod
19-03-2010, 20:18
Here's a related Q&A:
http://forums.usfirst.org/showthread.php?t=13981
It addresses COTS clutches, but the GDC makes it clear that while the COTS part is legal, if it uses any non-Kit motors, those are not-legal.
There are a couple of others, as well.
http://forums.usfirst.org/showthread.php?t=14498
http://forums.usfirst.org/showthread.php?t=13928 (Note on this one: I think that if you made it work using only KOP motor(s), it would be legal, but because that wasn't specified in the question, it was declared not legal.)
Jeff Pahl
21-03-2010, 00:00
I'm not the LRI at your regional, I'll be at the one across the street that weekend...
However, in spite of the fact that "Nothing on CD is official", I can assure you that a shop vac with the original factory motor, will not pass inspection. It has to have the motor replaced with a motor that came in the kit of parts.
If you would like more confirmation, send me a PM and I will get in touch with you.
Ramiro_T
21-03-2010, 00:38
COTS are considered illegal since there was never any in the kit. It's like trying to use last year's globe motor this year. I suggest you replace those with a fisher price moto.For our robot, we took these little mounts from an ROV rotor and retro fitted everything to work. Always read the manual.
RoboMaster
21-03-2010, 17:25
Ok, so I notified my team and we realized that it wasn't legal. Apparently the people I talked to looked at this thread that I sent them or had realized beforehand it wouldn't work. We are going to see if we can get it to work a different way. Thanks for all the suggestions and discussing this with us.
Al Skierkiewicz
21-03-2010, 19:44
Thanks for the confidence but Eric is pretty much on for his postings of the rules and Jeff is a right hand man and division LRI. I also will be at your regional helping out. WildStang is currently using two vacuum blowers coupled to FP motors in the exact duty you describe.
My team gutted a handheld vacuum and replaced the motor inside with a fisher price. It's basically just an enclosed impeller assembly on the inside. The most difficult part was replacing the motor. The impeller was pressed onto the shaft of the old vacuum motor, so we had to cut the shaft of the old motor and press the impeller onto the shaft of our fisher price.
We showed the inspector pictures (that prominently displayed the fisher price's serial numbers) of the process and we were good to go.
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