Re: VEXPro 2014 Product Initial Impressions
 

Our team buys products from all of the better known COTS suppliers such as AM, VEXPro, BaneBots, McMaster, WC Products, Cross the Road Electronics, etc.

The one thing that stands out to me the most:

The presentation of the VEXPro/WC Products GearBoxes and how you choose your options.
Any person who is new to FRC can figure out what they "really" want by looking at the "Specs for Dummies" like me, especially giving FPS specs on the different size wheels.
In the past, we used our own experiments/experiences to judge what we wanted in terms of torque, speed, and drivetrain setup. We would change a variable or two based on past memory to determine how to adjust for a subsequent game.
It takes the guesswork out of us trying to figure out exactly what we want, saving us precious time and energy during an intense 6 week build season.

After doing 15 years of FRC, having more COTS supplier options is a whole lot better than the days of building your entire drivetrain/gearbox from scratch.

Re: VEXPro 2014 Product Initial Impressions
 

Well said.

There is a teachable lesson here for all FIRST team members. Buying from a manufacturer like Vexpro or Andymark is much different than going and buying something from Amazon.

1. Small suppliers can only keep a small supply on hand. They have to pay taxes on inventory, and over building and surplus inventory is a drag on a bottom line. All too often, that bottom line is very very small.

2. Small suppliers order in batches. They don't call a store two counties over and ask to have some stock sent over. They have to guess demand ahead of time and try to stock up.

3. Small suppliers have a small workforce. AM and Vexpro have one 'big' season. During the rest of the year, they're fullfilling orders but on a scale that is probably a couple orders of magnitude smaller. They can't quadruple their workforce then fire all those people.

Those who work in manufacturing or own a small business understand these things pretty well, but for most of our team members it's a new concept. They're use to retail: Amazon, Itunes, and Mcdonalds. Those people who have been with FIRST for some time have a point of reference in comparing good versus bad suppliers. Those who haven't been around don't have a reference point, and don't understand how excellent the service that we're getting really is.

Back to the original subject at hand - I absolutely love versa planetaries. They blow the Banebots products out of the water.

Re: VEXPro 2014 Product Initial Impressions
 

Bad? I'm waiting for parts ordered before build season started that were in stock.

However, this is the only bad thing about vp. Their gears are the cheapest, look the nicest and are generally quite good. I'm not a huge fan of the loose fits of the bearings on the dog gears, but that's pretty minor. Another note, the CAD models don't have the exact/real sizes, they have 1.125" for a press fit hole that's slightly under, and they don't always specify the tolerances and concentricity and the fancy datum stuff, but the vex parts do seem to be a step above other suppliers in terms of accuracy.

Re: VEXPro 2014 Product Initial Impressions
 

Genuinely curious- have you seen another supplier provide 'fancy datum stuff' like concentricity of a gear profile -> bearing hole?

If you are talking specifically about how round bearing openings are in plates, I think you're referring to the measurement known as Roundness.

Either way, I've never seen much GD&T tolerancing appear on vendor specs before, so I'm wondering where the expectation for that information comes from?

-Brando

Re: VEXPro 2014 Product Initial Impressions
 

magnets - Please reply to this thread (or send me a PM) with your order number and who you ordered it from (WCP, Robot Space, or VEXpro) and we can look up the status of your order.

Re: VEXPro 2014 Product Initial Impressions
 

Oops, I meant to add that I wasn't upset because none of the other suppliers really have them. I'm not looking for roundness on the bearing holes as they tend to be quite round, but my problem with the dog gear was the diameter was a touch bigger than I would have made it.

Knowing if stuff is really concentric can really help with design to locate features. For instance, the versa pattern thing on vex parts is very accurately concentric, but for instance, some of the recesses for fastener heads in the gearboxes for mounting aren't quite concentric with the mounting hole. In normal use, it doesn't really matter, but if you're using the plates/gearbox your own application, it's nice to know.

I wouldn't mind seeing stuff like circular runout on hubs and stuff. Whenever our kids draw a part in CAD, I have them do all the GD&T dimensions. We've got a great machinist who won't work with kids and drawings who don't have a good understanding of GD&T. As a result, we end up with a bunch of high school kids who really understand dimensioning parts and tolerances for machining and who understand how poor the field drawing FIRST supplies are.

Re: VEXPro 2014 Product Initial Impressions
 

We agree on this: Good GD & T is essential to make parts that function properly and as required. All of our manufacturing drawings have fully dimensioned drawings with GD & T per ISO standards. Our customer interface drawings will never have them. Why? We believe that is proprietary information. We believe that prescribing total runout (because concentricity in the GD&T world has nothing to do with rotating a surface around an axis) for a hexagonal hole is one of the most complicated things to get right.

So, in general, for VEXpro items, things that are supposed to be locating features (versakey system, bearing bores) will be true and things that are fastening (screw counterbores) will be at the maximum allowable tolerance for the fastener to fit.

Re: VEXPro 2014 Product Initial Impressions
 

I don't think they make great machinists that will work with people who don't have a good understanding of GD&T. Watching people realize how hard it is to really know where something is is one of my favorite parts of the manufacturing phase of FRC.

Re: VEXPro 2014 Product Initial Impressions
 

Yes, I agree, VEX went out on a limb during their super busy VEX season to launch new VEXPro products. :rolleyes: In VEX and VexIQ we don't do that big math stuff, just trying to remember how big a difference in "a couple of orders of magnitude" is. "...middle and high school robotics program globally with more than 7,300 teams from 25 countries playing in over 400 tournaments worldwide." Lets see that's almost twice the number of FRC teams, so does that make it two orders of magnitude?

I'm impressed, my shipments of VEX and VexIQ parts are chugging along, sorry that your VexPRO stuff has had some snags. Kudos to the people in shipping that are making this happen.

Re: VEXPro 2014 Product Initial Impressions
 

Seconded. Call me lazy, but I visited the product page, didn't see a ratio, moved on to something else, and never looked back. It should have the ratio on the product page.

Re: VEXPro 2014 Product Initial Impressions
 

Thanks, but we've already been in contact. We don't desperately need the parts, and the customer service has been really great. Sorry for coming off as harsh.


This I get, and I must say, that all of the vex pro parts are just awesome in terms of tolerances.

You're right about the concentricity. I was going to write about something else, but totally forgot to add it. The GD&T concentricity (average or median location of points on circle, I forget which one) is useful for shafts, as at high speeds vibration happens. We've only seen this being a problem when reusing custom gearbox shafts in high speed applications.

Tonight, out of curiosity, I measured a few parts to check the tolerances. I was unable to measure any runout on a hex hub we got today with some cheapo digital indicator. This is the first time I've ever seen this on an FRC supplier part like this.

Re: VEXPro 2014 Product Initial Impressions
 

I unfortunately don't have PR people of my own, so I can only try to be as honest as possible about my VEXPro experience. Yes, I did consider that some teams may already have the specific cylinders required for the gearboxes. However, I did not and do not know how great that number is. Frankly, I assumed it would be a small minority of teams who choose to purchase a shifter from VEXPro. I'm curious to know if I'm wrong about this.

To me, and to several other posters in this thread, it was fairly clear that we had to additionally purchase a cylinder. I don't think it was clear enough for everyone, though; oftentimes, what instructions are obvious to some can be missed by others. Example 1: the FRC game rules, and the numerous CD threads that follow Kickoff asking for clarification. Example 2: When my team purchased a Classmate laptop last year, the website came with an option to buy an AC adapter for the computer, in such a way as to imply that we needed to buy it separately. Eventually we found that this was not the case. Upon exploring the new VEXPro product pages, I got a similar feeling.

This, I believe, could be easily rectified with a few changes to the website's formatting. First, let the defaults for the parts that need purchase be what most teams actually buy. I'll use the 3-CIM shifter page as an example, because it has the most options. I notice that the default for "Base Options" isn't "none", but rather "3 CIM Ball Shifter Base Kit". Similarly, the default for cylinders should be for 1 cylinder and 1 fitting kit. Second, options should not be completely hidden. Currently, when I change the radio button from "Base Kit" to "Base Kit with WCD 3rd Stage", "3rd Stage Gear Kits" and "WCD Sprocket Options" appear. (I can't select "Base Kit with 3rd Stage" at the moment, but I assume that only "3rd Stage Gear Kits" will appear.) This is a bit confusing for customers who want a third stage. Having the "3rd Stage Gear Kits" and "WCD Sprocket Options" sections be grayed out, rather than invisible, when purchasing the base kit or "None" would be preferable. These are both small changes, but they would make my buying experience better.

I was talking about this year's items, not last year's. I simply meant that no new parts have been in competition yet, hence the "initial impressions" thread.

Re: VEXPro 2014 Product Initial Impressions
 

I think it was as clear as it could reasonably be that the cylinder wasn't included.

Re: VEXPro 2014 Product Initial Impressions
 

QFT

Re: VEXPro 2014 Product Initial Impressions
 

Concentricity is the median position of all the points on a cylinder, with respect to an axis. It's extremely hard to properly establish. Total runout is almost always a better callout.