VEX PRO. To use it or not to use it. [Archive]

pmangels17

10-12-2012, 21:27

AdamHeard

10-12-2012, 21:31

There is a huge thread about it already; http://www.chiefdelphi.com/forums/showthread.php?threadid=109868

No teams have product in hand yet. Most people are assuming the quality is high, as the people behind the line are great.

Mk.32

10-12-2012, 21:31

As the build season approaches, I am, along with other team members, building a bit of a CAD library of bases to use this year. However, I recently found the new line of VEX Pro stuff. I want to use their bearings, shafts, wheels, collars, sprockets, and ball shifters. Has anybody had any issues about them such as cracking wheels or deforming plates. Our team has run into cracking issues before, so I just want to make sure they don;t have the same issue. It seems like high quality, lightweight, relatively inexpensive stuff for us to use, I was just wondering if anybody had anything to look out for.

Note: Not trying to bash VEX, they always make high quality stuff.

The problem is that no one, outside of IFI, has ever touched any of the vex pro stuff. They haven't shipped anything yet; we have ordered some products from them with the intent to get a feel of them before full utilizing them in our robot.

But that being said, I do expect everything to be solid the very least.

Taylor

10-12-2012, 21:33

Historically, I have found IFI/VEX products to be mechanically beyond reproach, and the same goes for their customer service. We have had electrical issues before (not from the VEXPro line), mainly traced back to the parts' foreign manufacture.

Since the VEXPro line is relatively new and publicly untested, it is a risk to use their systems. But, they've got some of the best & brightest on their staff, so it's a calcluated risk.

pmangels17

10-12-2012, 21:34

Awesome. Their shifting gearboxes are so lightweight and well put together. Also, in the sprocket description, it says that they are "black anodized for superior performance"....Sounds like my kind of place :D

Dan Richardson

10-12-2012, 22:48

Historically speaking, few companies have launched brand new product lines without a few discoveries along the way.

When Vex (IFI at the time) first launched their wheels in 2006 they had some significant challenges. You can read about them here. (http://www.chiefdelphi.com/forums/showthread.php?t=46167&highlight=ifi+wheels) Over the years, they made improvements and they've resulted in a reliable product.

It doesn't just effect Vex. When Banebots launched a new kit gearbox, teams were picked by whether they used them or not. Their failure rate was just that high. Again, over the years they've rectified a majority of those challenges and have a quality product offering.

Vex has some incredible talent on their team, but even Apple, one of societies pillars for quality, who's products "Just Work," can have issues from time to time on new product launches. (Antenna gate anyone?)

I have faith that Paul, JVN and crew will work tirelessly to rectify any issues that arise but it is too early to tell what issues will arise and where.

sdcantrell56

10-12-2012, 22:52

connor.worley

10-12-2012, 22:59

I'd love to know how a superficial layer of black oxidation increases performance...

Everybody knows computers with red LEDs run faster, but computers with blue LEDs run cooler. It's like that!

JVN

10-12-2012, 23:03

I'd love to know how a superficial layer of black oxidation increases performance...

We do have a sense of humor sometimes.

MrForbes

10-12-2012, 23:07

I'd love to know how a superficial layer of black oxidation increases performance...

The blower drive pulleys (toothed belt type) on the supercharger drive on my old Chevy are black anodized...it increases durability by several times, compared to non-anodized pulleys (30k miles with anodizing vs 10k without).

I'm not sure how this relates to robots...but don't take such things too superficially.

Billfred

10-12-2012, 23:08

I'd love to know how a superficial layer of black oxidation increases performance...

Everybody knows computers with red LEDs run faster, but computers with blue LEDs run cooler. It's like that!

At Peachtree 2011, I told Sean's team that our robot was wrapped in racing tape*, which added ten horsepower. They picked us. (http://chiefdelphi.com/media/photos/36739)

*Yes, Racing tape. That was what it was sold as--we picked it because it was close to garnet and we didn't have a chance to paint before ship.

That said, there IS always a risk with new products; almost every launch of a new car comes with at least some service bulletins, software launches are usually followed a week or two later with a .1 update, and so on. But if anyone's going to hit at least a double on the first at-bat, it's the IFI crew.

ttldomination

10-12-2012, 23:32

At Peachtree 2011, I told Sean's team that our robot was wrapped in racing tape*, which added ten horsepower. They picked us. (http://chiefdelphi.com/media/photos/36739)

Oh man, I should've told him our robot was powered off unobtanium. Man, can't believe we missed that trophy by that much.

- Sunny G.

sdcantrell56

10-12-2012, 23:40

We do have a sense of humor sometimes.

Sense of humor? What is that?

In all seriousness I love the product line though.

wireties

11-12-2012, 03:01

I heard JVN designed a lot of the mechanical VEXPro stuff - makes me confident about the quality.

pmangels17

11-12-2012, 06:39

Good to know. It looked quality, and when I look at the site, all I see it weight savings, good prices, and black anodized.

Gdeaver

11-12-2012, 07:38

For the First Community, Christmas came early this year. We have lots of new toys to play with. However, Be assured that We are one of the best destructive product testing groups around. Our new toys have had some testing but, have yet to see the abuse of a full season. If there are any weaknesses we will find them. Even if these products are perfectly designed there could be production defects waiting to be discovered. There no doubt will be a problem hear and there. Hopefully no disasters. Please, if a team does have a problem try and collect as much information on the problem and contact the vendor. Work with them. In the past There has been allot of venomous flaming of vendors who have had product problems. Please maintain professionalism.

JesseK

11-12-2012, 10:02

FRC competitions are technical design challenges. With respect to COTS, the process boils down choosing the right product to meet specific design requirements. IFI has simply given the community another source, yet it's an untested source. It's really a tradeoff of cost vs risk of unknown quality, tbh. Some items are less risky (to my team, at least), so those are definitely under consideration. Others, maybe next year.

DMike

11-12-2012, 15:18

I have ordered some of the gears to test what VEX is calling a teflon infused ceramic coating, not to be confused with Anodizing.

Anodizing is utilized to produce a layer of Aluminum oxide within the original base material. Anodizing is a inclusive coating rather than additive , like paint. The controlled formation of the oxide produces a much harder, corrosion resistant surface than the origial base material. The oxide thickness in a Black Anodized part is typically .0005-.0008 inches thick. The oxide structure is comprised of millions of pores per square inch of material. These pores are what allow the dyes to absorb into the coating usually followed by a Nickel sealer. There are also Hard coat Anodizing processes that produce very hard wear resistant surfaces.

Teflon infused ceramic coatings are very hard wear resistant coatings. These additive coatings are typically used and very harsh abusive environments. These coatings are significantly harder than Anodized Aluminum. Generally these coatings are thermally applied thru use of flame or plasma operations. There are wet application processes with 700F cure temperatures that produce an advertised ceramic coating.

I will report my results.

Tristan Lall

11-12-2012, 16:20

I have ordered some of the gears to test what VEX is calling a teflon infused ceramic coating, not to be confused with Anodizing.
It sounds like they're using ordinary Teflon-impregnated anodizing. Aluminum oxide, (a.k.a. alumina, Al2O3, carborundum or sapphire) is a ceramic, although it is somewhat unconventional to describe it as such in these circumstances.

I doubt very much that they're using a flame-sprayed ceramic coating. (What would be the point, and how do you apply Teflon at those temperatures?)

Interestingly, they're apparently applying the coating after machining, given the claims of reduced friction (application after machining also tends to contraindicate a flame-sprayed ceramic in this application). Most high-quality anodized aluminum gears are made from 2024, and anodized before the teeth and bores are finished (i.e. the cut teeth are bare metal).

Bob Steele

11-12-2012, 16:27

It sounds like they're using ordinary Teflon-impregnated anodizing. Aluminum oxide, (a.k.a. alumina, Al2O3, carborundum or sapphire) is a ceramic, although it is somewhat unconventional to describe it as such in these circumstances.

I doubt very much that they're using a flame-sprayed ceramic coating. (What would be the point, and how do you apply Teflon at those temperatures?)

Interestingly, they're apparently applying the coating after machining, given the claims of reduced friction (application after machining also tends to contraindicate a flame-sprayed ceramic in this application). Most high-quality anodized aluminum gears are made from 2024, and anodized before the teeth and bores are finished (i.e. the cut teeth are bare metal).

JVN was joking.....read above...

Tristan Lall

11-12-2012, 16:34

JVN was joking.....read above...
I read that as joking about the idea that a black anodized sprocket exhibits "superior performance" w/r/t a plain-finish sprocket.

DMike was talking about the coating on the gears, which isn't described as anodization, but probably is. Its claim to fame is the inclusion of Teflon in the process, which would only be a sensible thing to include if it actually provides superior performance.

Kevin Sevcik

11-12-2012, 16:50

Most high-quality anodized aluminum gears are made from 2024, and anodized before the teeth and bores are finished (i.e. the cut teeth are bare metal).Are you sure about that? I don't have any specific knowledge, but that doesn't make a lot of sense to me from a mechanical standpoint. I mean, the anodizing process doesn't care about surface geometries, so anodizing before or after wouldn't be too much different. And having a bare aluminum-aluminum wear surface sounds like a rather poor idea to me, what with aluminum's propensity for galling and all that.

DMike

11-12-2012, 17:12

Most Aluminum materials that we deal with here that are required for applications such as gears would be made from 6XXX or 7XXX Aluminum.

MIL-8625 T2-C2 Anodizing is a general use dyed Sulphuric anodize process. Anodizing being inclusive does not change dimensions of a machined part until you strip the coating off.

Anodizing being an electrochemical process is subject to all the same current density pitfalls as any other electroplating process. You will have a thicker coating in the highs and thinner in the lows. In the case of a gear the top of the tooth would be high current the ID bore would be low.

This info is just basic stuff. Finishes are engineered just like material choice, many times they go hand in hand.

Take this info for what you may, it never hurts to learn a little.

Tom Line

11-12-2012, 17:16

I'd love to know how a superficial layer of black oxidation increases performance...

In the sailboat racing world, anything painted orange must be fast. By definition.

Likewise, in the robot world, anything that is either blue or black is better. By definition. ;)

On a more serious note, we had a team meeting to discuss whether or not we should buy vex-pro (limited budget etc). We're buying a couple components to test. We're hoping to have them before kickoff, but seeing how nothing guarantees it, we'll see what happens.

We always know that if we are unhappy with the VexPro quality (which would be VERY unexpected) or can't get parts fast enough, we can always get what we need at AndyMark.

Zuelu562

11-12-2012, 17:43

My team is looking specifically into the omni-wheels. Being a 3rd year team, we figure we might as well start planning for the future, even if we don't use them this year. Which means gears, Versahubs, and maybe a fresh CIM or two, but remember you can('t) have too many cims!

pfreivald

11-12-2012, 18:06

We're ordering the mecanum wheels to test out with our octocanum drive, but have plug-n-play modularity with AM HD mecanum wheels just in case -- the HD mecanum wheels from AM are just plain beastly in terms of durability and reliability. If all goes well, we'll abuse the living heck out of a set of VEXPro wheels within a few weeks of acquiring them and will have something to report to the rest of y'all.

Paul Copioli

11-12-2012, 18:48

The Ceramic Coating as we describe it is based on the MIL spec hard coat anodizing process. There are a few tweaks to the chemistry (including flouropolomers, aka Teflon, and others) with more ceramic like properties. We selected the material because of the years of testing and actual industrial use while I was at FANUC Robotics. It is similar the base hard coat process, but just some extra tweaks.

When we switched to this material for all of our aluminum wear parts, it eliminated a lot of the problems we were having with other processes (hard chrome, electroless nickel, to name a few).

Paul

DMike

11-12-2012, 22:52

Nice, Mil-8625 TIII Hardcoat with PTFE. The coating produced is in the 60-70 Rc range. Mil spec Hard Chrome is 72 Rc hardness, generally ceramics, i think range in the 60-70 Rc These gears should be bullet proof, can't wait to check them out. The price is almost worth the coating alone, in the scheme of Anodizing this is near the top. Very cool stuff and Black too.

Tristan Lall

12-12-2012, 01:31

Are you sure about that? I don't have any specific knowledge, but that doesn't make a lot of sense to me from a mechanical standpoint. I mean, the anodizing process doesn't care about surface geometries, so anodizing before or after wouldn't be too much different. And having a bare aluminum-aluminum wear surface sounds like a rather poor idea to me, what with aluminum's propensity for galling and all that.
I'm basing that mainly on the high-quality fine-pitch aluminum gears available from SDP/SI and PIC Design, and those gears I've observed in random precision machinery. (So "most" isn't strictly the right descriptor—more like "most of the ones I've encountered".) Those ones are quite noticeably machined after anodizing (plus it says so in the catalogue).

As for galling, in a normal atmosphere that will oxidize the bare surface, at least there's some protection. I don't know if the tooth-to-tooth contact stresses are high enough to break through the natural layer of oxide and promote galling.

Cory

12-12-2012, 02:45

I'm basing that mainly on the high-quality fine-pitch aluminum gears available from SDP/SI and PIC Design, and those gears I've observed in random precision machinery. (So "most" isn't strictly the right descriptor—more like "most of the ones I've encountered".) Those ones are quite noticeably machined after anodizing (plus it says so in the catalogue).

As for galling, in a normal atmosphere that will oxidize the bare surface, at least there's some protection. I don't know if the tooth-to-tooth contact stresses are high enough to break through the natural layer of oxide and promote galling.

So...it's a cosmetic surface finish?

I don't understand why you'd anodize the gear if you're going to machine it away at the only point where it matters.

Tristan Lall

12-12-2012, 04:44

So...it's a cosmetic surface finish?

I don't understand why you'd anodize the gear if you're going to machine it away at the only point where it matters.
To be perfectly honest, I don't know their rationale either.

Here's proof from PIC. (http://pic-designcatalog.com/Images/pdfcat/section_12.pdf) (Most of the aluminum gears in that catalogue are notated "Anodized Before Cutting".) And similarly for SDP/SI. (https://sdp-si.com/ss/PDF/79001101.PDF) (Typical of their 2024 aluminum gears, but not the 5052 aluminum ones.)

Kevin Sevcik

12-12-2012, 10:33

To be perfectly honest, I don't know their rationale either.

Here's proof from PIC. (http://pic-designcatalog.com/Images/pdfcat/section_12.pdf) (Most of the aluminum gears in that catalogue are notated "Anodized Before Cutting".) And similarly for SDP/SI. (https://sdp-si.com/ss/PDF/79001101.PDF) (Typical of their 2024 aluminum gears, but not the 5052 aluminum ones.)
I could understand it on fine pitch gears. As DMike pointed out, it'd be difficult to get good coating thickness down in the teeth, and you'd probably yield the teeth before you built up enough pressure that galling and wear became a problem.

MichaelBick

12-12-2012, 12:34

I know the coating/ano affects the tooth shape. For that reason I know WCP modifies their gear profile to account for the coating and ano. Does vex do this too?

JVN

12-12-2012, 12:53

I know the coating/ano affects the tooth shape. For that reason I know WCP modifies their gear profile to account for the coating and ano. Does vex do this too?

Yes we do. :)

-John

Nikhil Bajaj

12-12-2012, 13:02

I could understand it on fine pitch gears. As DMike pointed out, it'd be difficult to get good coating thickness down in the teeth, and you'd probably yield the teeth before you built up enough pressure that galling and wear became a problem.

Whether wear or yield/fatigue failure comes first depends on a lot of design parameters, which are mostly accounted for if you look at say, the AGMA gear design methodology and equations. Most undergraduate-level machine design textbooks will have this in detailed form.

I'd be careful about generalizing the statement, but for FRC purposes I'd guess you're usually right if gearboxes are designed and sized appropriately for the application, since our designs are generally very intermittent (what's the actual use life of an FRC robot? A couple hundred hours tops?) so wear is usually not as much a factor as the fatigue caused by the shock loads.