12-09-2014 16:21

Navid Shafa

Re: pic: Fun Bevel Gearbox Idea

Care to share some specs, maybe a transmission close-up?

12-09-2014 16:29

Michael Hill

Re: pic: Fun Bevel Gearbox Idea

I'll admit, the "window" gearbox looks kinda cool.

12-09-2014 16:46

Rjmartin127

Re: pic: Fun Bevel Gearbox Idea

Let's just refer to the quote in my signature.

12-09-2014 16:58

Nate Laverdure

Re: pic: Fun Bevel Gearbox Idea

Reminds me of an idea I once had for a "parallel radial" engine.

12-09-2014 17:35

Tyler2517

Re: pic: Fun Bevel Gearbox Idea

That looks a lot like a duke engine.

12-09-2014 17:54

Nate Laverdure

Re: pic: Fun Bevel Gearbox Idea

Aw, crap. I guess "almost novel" is kind of like "almost pregnant."

12-09-2014 18:11

billbo911

Re: pic: Fun Bevel Gearbox Idea

8 CIM drive?
Can you say "Popped our main breaker"?
Don't worry, you will!

12-09-2014 18:14

AdamHeard

Re: pic: Fun Bevel Gearbox Idea

Actually if teams use the current monitoring properly, a team could maximize the time motors spend in their peak efficiency range (errr, closer to peak at least) and still get large output output torques (less torque per motor, more torque overall).

If done right you'd get a decent performance increase and exactly ride whatever line you set in terms of net current draw.

12-09-2014 18:27

T^2

Re: pic: Fun Bevel Gearbox Idea

That's the biggest "if" I've heard this week.

12-09-2014 18:30

AdamHeard

Re: pic: Fun Bevel Gearbox Idea

Not really.

In many industries torque/current control is THE standard form of control.

It wouldn't be crazy to limit max current to some time varying value.

13-09-2014 01:12

philso

Re: pic: Fun Bevel Gearbox Idea

A large percentage of the three-phase motor controllers I work on in my day job go to customers who use them to limit the peak current during starting, especially if they have high inertia loads such as conveyor belt systems, (down-hole) pumps and rock crushers. All the motor controllers (ours and our competitors) have a "current limit" parameter that the user sets via the keypad.

13-09-2014 01:28

Pauline Tasci

Re: pic: Fun Bevel Gearbox Idea

That actually looks pretty cool and crazy fun!

13-09-2014 02:12

Bryce2471

Re: pic: Fun Bevel Gearbox Idea

I'll try to get a transmission pic up soon. Its two stage and single speed gearbox, with a roughly 7 to 1 gear ratio(1.8 itcr). On a four inch andymark wheel, it should be traction limited. I thought about designing a custom ball shifting version, but I only spent a couple hours on this design, so I never got around to it.
I don't really disagree, but I find it interesting you would say that without hearing what the final gear ratio is.

13-09-2014 02:18

Bryce2471

Re: pic: Fun Bevel Gearbox Idea

Thanks!
Unfortunately, I don't think our team will even be considering this idea because of budget constraints. I think it would be cool to see how this drive would work in real life though. It would certainly save belly pan space!

13-09-2014 10:51

Jacob Bendicksen

Re: pic: Fun Bevel Gearbox Idea

It's the V8!

13-09-2014 11:21

billbo911

Re: pic: Fun Bevel Gearbox Idea

You both are correct. The final gear ratio was not stated, and torque limiting over time could be quite advantageous.

That said, with the size of fields we play on and the wheels that are available to us, 6 CIM drive seems to be about the limit of practicality.

Please don't get me wrong, I really like this design both for it's creativity and it's aesthetic. I would love to see how it actually performs. I know with the right final gear ration, you could drive it continuously at full speed without tripping a breaker. The carpet might not like it, but that's not the point of this design.

13-09-2014 11:47

cjl2625

Re: pic: Fun Bevel Gearbox Idea

Looks more like a 4 CIM + 4 mini-CIM, if I'm not mistaken

13-09-2014 12:17

sanddrag

Re: pic: Fun Bevel Gearbox Idea

Can you comment on what exact gears you would use if you were to make this?

13-09-2014 18:37

Oblarg

Re: pic: Fun Bevel Gearbox Idea

Dumb question: How would one remove a motor for maintenance, if needed? There doesn't seem to be much access.

13-09-2014 18:49

Chadfrom308

Re: pic: Fun Bevel Gearbox Idea

We had 4 CIMs/4 Mini-CIMs on our drivetrain and didn't ever pop the breaker. That being said, we got a little lucky

13-09-2014 19:06

Deke

Re: pic: Fun Bevel Gearbox Idea

I love the outside the box thinking, looks like it was fun to work on!

14-09-2014 02:25

scca229

Re: pic: Fun Bevel Gearbox Idea

I thought the same right when I saw the render but now I'm envisioning some sort of twist-lock being used to hold the motors in place.

I know I'd love to see this in reality.

14-09-2014 02:48

Tyler2517

Re: pic: Fun Bevel Gearbox Idea

Just a few questions i guess. It looks like you are using 4 bevel gears.

If you are using 4 would you not be loosing a large amounts of mechanical efficiency?
I love the idea i just think that using that many bevels would be a mistake even though it is a pretty sleek design.

14-09-2014 05:21

asid61

Re: pic: Fun Bevel Gearbox Idea

If you have access to a mill, lathe, indexing head, and pedestal grinder of any size, you can actually make your own bevel gears and regular gears to save a little on costs. Look up "how to make a gear hob". If you have a community college in your area, they might have a machine shop you could use.

Nice design for the gearbox. Looks like it can save on valuable horizontal real estate.

14-09-2014 14:24

Ian Curtis

Re: pic: Fun Bevel Gearbox Idea

I'd love to see a 2 CIM version so you could have a "V-Twin" or even a 1 CIM that looks like a 1900ish motorcycle engine or model airplane engine.

15-09-2014 01:30

Bryce2471

Re: pic: Fun Bevel Gearbox Idea

I actually designed this gearbox with four mounting points for motors, partially so that I could mess around with different motor configurations.

15-09-2014 01:53

Bryce2471

Re: pic: Fun Bevel Gearbox Idea

It sound like an awesome process to learn about. Unfortunately, my team has never had access to a pedestal grinder.

Of course there's no time like the present! we just got done building a CNC router on a super tight budget, so I feel like we might be able to make something work.

15-09-2014 02:01

Bryce2471

Re: pic: Fun Bevel Gearbox Idea

Just like on any other transmission, each motor has a pinion gear on it, but there is only one large bevel gear on each side of the drive. Because these transmissions only have two stages of reduction, they shouldn't be any less efficient than you average gearbox.

15-09-2014 02:09

Bryce2471

Re: pic: Fun Bevel Gearbox Idea

Questions aren't dumb!
I didn't put a ton of thought into it, but my first instinct was a ball-end hex wrench.

15-09-2014 02:13

Bryce2471

Re: pic: Fun Bevel Gearbox Idea

I cant say for sure, I already had the CAD for these bevel gears sitting around in my computer. Although, I think the model originally cam from a QTC online catalog, so you could probably buy them there.

16-09-2014 10:18

JustPlyZ

Re: pic: Fun Bevel Gearbox Idea

We've had 6 CIMs/ and 2 mini CIMs,
4 of the CIMs were powering our drive and 2 CIMs + 2 minis were powering out shooter, we have yet to pop a breaker.

16-09-2014 15:46

R.C.

Re: pic: Fun Bevel Gearbox Idea

That's not the same as all motors in drive...

17-09-2014 08:01

Chadfrom308

Re: pic: Fun Bevel Gearbox Idea

We also had 2 CIMs on our thrower

17-09-2014 13:39

Bryce2471

Re: pic: Fun Bevel Gearbox Idea

Wow! that's a lot of CIMs.

I just realized that over 25 lbs of you robot was made up of CIM motors.
At least 21% of you robots mass was CIM motors.