RCV Hubs

[Joshkb]

Hi Guys,

How many of you use RCV hubs, and what has been your experience? I am in favor of a custom design with SKF sponsored bearings, but this is a big undertaking for a first year team. Our focus and time might be better spent elsewhere.

All input appreciated,
Josh

[Joshkb]

To clarify, I am referring to the driven hubs, not front (we run RWD).

Josh

[Ahmad Rezq]

Josh
Use decision matrix to evaluate your different options.

For a first year team it's not a big deal to design your hub and it will give you some degrees of freedom. For hub manufacturing as i faced this year if we didn't had a manufacturer sponsorship we would pay too much in spline manufacturing

Although our team used RCV Hub in 2012 but i cannot help with that as the car didn't run. on the other side this year we had a bad experience with RCV company when we ordered drive train components for two times the package was not sent complete and we had to pay for customs release every time.

[Joshkb]

Thanks Ahmad. We certainly have the manufacturing capabilities, but what worries me is using hardened inserts and knowing if they will be enough to transmit the power, versus an RCV steel hub or a full tripod housing. Who do you use for drive components, Taylor Race?

Josh

[Ahmad Rezq]

Who do you use for drive components, Taylor Race?

We Run RCV Components for two years.

[apalrd]

what worries me is using hardened inserts and knowing if they will be enough to transmit the power,

For the last two years we have used all aluminum tripod housings integrated into the hubs, no inserts at all. You can see them here - https://www.facebook.com/KetteringFSAE/photos/pb.209138079117577.-2207520000.1437315104./960727703958607/?type=3&src=https%3A%2F%2Fscontent-ord1-1.xx.fbcdn.net%2Fhphotos-xat1%2Ft31.0-8%2F1548093_960727703958607_2479839453640219058_o. jpg&smallsrc=https%3A%2F%2Fscontent-ord1-1.xx.fbcdn.net%2Fhphotos-xtf1%2Fv%2Ft1.0-9%2F12908_960727703958607_2479839453640219058_n.jp g%3Foh%3D67208fed73699deeab673160a6469a26%26oe%3D5 61A9109&size=2048%2C1356&fbid=960727703958607

We have not failed any of the hubs.

On the inboard side we use the Taylor Race Quaife diff which comes with tripod housings as an option.

[Joshkb]

apalrd,

Thanks. I am very surprised that these hubs haven't had damage yet, not because they are poorly designed, but because I thought a year or two of use on ANY aluminum hub would cause compliance issues. Can you share your lug BCD, caliper choice and rotor mounting diameter? Did you design these? Please give me a maximum driveshaft angle the housings will accept, as I'm running half shafts with a large rear sprocket. We run dual motors, for a total of 280 lb-ft of torque on each hub for a total of 560, after gear reduction. Please compare this value to your motor/engine's output and let me know.

My current design: GP200 calipers, custom G2 rotors (180mm OD), 100mm lug BCD and integrated tripod housing, 1.03 inch holes on a 1.6 inch pattern, with a 1.425 inch bore in the center. These tripod values were taken from another thread.

Thanks for the info, Andrew

Josh

[apalrd]

I'm not heavily involved in the outboard design, I specialize in the powertrain control models. mcoach would have all of those numbers, probably from memory, hopefully he jumps in here. This is a turbo combustion car, so our peak torques are probably lower than yours.

We have run this hub design for 2 years (2014 and 2015) without issues on the outboard side. The hubs were totally redesigned with our switch to 10s for 2014. No failures on either car, both still run. We made new hubs for 2015 even though the design was identical on the rears (we did make unique fronts which are lighter), so we don't expect more than a season out of a hub.

[Tyler Jones]

apalrd,

Thanks. I am very surprised that these hubs haven't had damage yet, not because they are poorly designed, but because I thought a year or two of use on ANY aluminum hub would cause compliance issues. Can you share your lug BCD, caliper choice and rotor mounting diameter? Did you design these? Please give me a maximum driveshaft angle the housings will accept, as I'm running half shafts with a large rear sprocket. We run dual motors, for a total of 280 lb-ft of torque on each hub for a total of 560, after gear reduction. Please compare this value to your motor/engine's output and let me know.

My current design: GP200 calipers, custom G2 rotors (180mm OD), 100mm lug BCD and integrated tripod housing, 1.03 inch holes on a 1.6 inch pattern, with a 1.425 inch bore in the center. These tripod values were taken from another thread.

Thanks for the info, Andrew

Josh

RCV states in their catalogue that their axles are limited to 12 degrees, so I assume most housings designed around their tripods are similar. Those torque numbers are about what we see when dumping the clutch on our combustion car, so they sound somewhat reasonable for an electric car. We run a very similar hub to Kettering but utilize 8 floating rotor pins in direct contact with the hub to attach our rotors (the rotor pins are custom machined aluminum, but dimensionally the same as RCV's rotor pins), as well as steel liners for the tripod so they aren't in direct contact with aluminum hub. You can get tripod housing dimensions directly from RCV, they provide the STEP file for their rear hubs.

[MCoach]

We tolerance our hubs such that the tripods are not able to 'rock' back and forth in the bores. They are a very close slip fit. If there is any ability of the tripod to wiggle in the housing, the hammer loading under driving torque is painful. That's usually what will wear them out. We actually have an inboard side that mates with the tripod for our dyno that is a Taylor Race copy of their old steel design made from aluminum. This inboard side has been in service since 2009 on the dyno and the only real wear we've noticed is that sometimes they take a set, with a little cupping into the aluminum (local surface yield), and it doesn't matter whether they are anodized or not. The tripod will wear through the anodize coating into the base aluminum, take a set, and stay that way for life. We don't see this with the new ones.

We narrowed the tolerances and decreased the size of the bore that the tripod runs in for 2014 and on and even I was surprised to find that our 2014 hubs still had not worn at all (personally serviced them a week ago). I think the other part of it is generous lubrication of the rolling surface, we've improved our choice there since then too.

The tripods are designed to accept the maximum driveshaft angle that is allowed by the Taylor Race tripod spec (24 degrees total?, 12 degrees each end?)
I'm not sure what the tripod demensions are off the top of my head, but they are easy to find on the website.

BCD = 144mm
caliper = Wilwood PS1, 1" piston
rotor diameter ≈ 7"

Keep in mind that most Taylor and RCV products are not made specifically for FSAE, but just marketed to you. The same tripods in your car are also put behind things like the 200hp+ Level 5 DSR. EDIT: unless in caps it says FSAE ONLY in which case, they really mean it this time.