Robot Scale Recommendation?
 

We are shopping for a new "robot" scale, the one we have is an older postal scale and we always have to put aluminum bars on top and TARE it before we place the robot on it.

Just curious if anyone had some recommendations for a reasonably priced scale that had a larger top on it that we could almost just set your robot on it?

Under $100 would be ideal, but I dunno if we are going to hit that price point or not.

What kinda of a scale does your team use? How do you know it's calibrated?

Re: Robot Scale Recommendation?
 

We used to use a scale that was used to weigh soldiers, to make sure they were within army specifications...so we figured it was accurate, and it always agreed with the FIRST scale within a pound. We did have to put 2x4s across it and zero it before weighing the robot.

Since then we've made seriously underweight robots, and haven't worried about it too much. Just use a bathroom scale to make sure the robot is under 100 lbs when it's near the end of build, and we're fine.

Hopefully someone will have a useful answer for you!

I think we borrowed the wrestling scale once, after we moved our build space from Ft Huachuca, to the high school.

Re: Robot Scale Recommendation?
 

I don't know any that are big enough to just place the robot on them, but I do know of scales with controls / displays that are connected via a wire rather than directly to the unit. If you build your own top for the scale it should meet your needs?

Scales built for FRC robot sized objects generally cost quite a lot.

Re: Robot Scale Recommendation?
 

Our Team has this scale - https://www.grainger.com/product/OHA...Platform-1UXK4

It is quite expensive but it is nice to have setup in the corner of the room so we can keep an eye on weight.

Re: Robot Scale Recommendation?
 

I found a "vet" scale, but I wonder how accurate they are.

https://www.amazon.com/W-C-Redmon-Pr...f_rd_i=desktop

Re: Robot Scale Recommendation?
 

A couple of thoughts.

1. Your local veterinarian most certainly has a platform scale. While you wouldn't want to do it often, once you get close to your local robot configuration, haul it over to your vet to weigh. Be sure to count the vet's office as a sponsor!

2. Any scale needs calibration. FIRST does it at events with a set of four 25 lb. weights. You can do the same by going to Walmart (one with a grocery store) and buying four 25 lb. exercise barbells. While there, take them to the meat department. They will have a scale that has been calibrated by some agency of your state's government. This is done often and the scale the meat department uses is quite accurate. Weigh each barbell and mark it on the barbell. Now you have a very accurate set of calibration weights.

A lot of trouble, but you only need to do it once. Then you can use most any scale configuration you come up with.

3. We always encourage teams to maintain a weight budget. As parts are ready to add to the robot, weigh them and record the weight. This way a small scale can be used to weigh a robot, one part at a time. I know, "That's too much trouble."

Re: Robot Scale Recommendation?
 

We use a bathroom scale during early stages of build season. However, when we get within 10 lbs of the 120 lbs limit, we take our robot to the local UPS store and they are happy to weight it free of charge.

Re: Robot Scale Recommendation?
 

Since you are most likely planning on climbing a rope this year. Why not get one of those luggage scales (for example) and just hook your rope to that scale, zero it, and then have your robot "climb the rope" (or just figure out a way to attach some rope to your bot.

Re: Robot Scale Recommendation?
 

We have access to a digital scale with a remote readout. This is handy because once the robot is balanced on a regular bathroom-type scale, the readout is usually obscured. We lay a couple of pieces of aluminum channel on it, zero the scale, and then balance the robot on top of them.

If we didn't have that scale, I think I'd try 2 bathroom scales and lay a couple of 4-foot 2x2's between them, zero both scales and then put the robot on the 2x2's. Add the two indicated weights together and there you go.

Re: Robot Scale Recommendation?
 

use 2-4 bathroom scales and add up the total weights to get easy results.

Re: Robot Scale Recommendation?
 

This also has the advantage of showing weight distribution. Somewhat useful since weight distribution can noticeably effect performance of some drivetrains.

Re: Robot Scale Recommendation?
 

We have been using this scale with a piece of plywood on top for 5 years. Never had an issue with it.

https://www.amazon.com/gp/aw/d/B001A...40_FMwebp_QL65

Re: Robot Scale Recommendation?
 

Wow...what a great idea! Thank you for this idea.