12-23-2016 03:05 PM

Cothron Theiss

Re: pic: Tornades's Custom West Coast Drivetrain

It looks like you're missing something, but I can't think of what it is... maybe the fasteners or something?

In all seriousness though, I assume this is for a chain and/or belt in tube chassis?

12-23-2016 03:17 PM

Chak

Re: pic: Tornades's Custom West Coast Drivetrain

I don't think the bearing blocks have to slide quite that much. Adding 2 chains of even #35 chain only adds .375" to the C-C distance, so the bearing blocks have to move no more than .375", unless you're using chain bigger than #35. Even adding a bit more for safety, that slot looks larger than an inch! I don't think the WCP bearing block cam can even go that far.
All these huge slots might end up compromising the strength of the tube where they meet. The bearing block itself might help reinforce it a bit... probably not. The tube could bend or twist where the slots only leave 4 thin corners. If the huge top slots are only for poking at the chain/belts in the tube, they can be smaller.

12-23-2016 04:51 PM

Chris is me

Re: pic: Tornades's Custom West Coast Drivetrain

Putting these absolutely massive pockets on all sides of your drive tube is making your frame weaker at the exact points where you want it to be strongest, and leaving strength in the rest of the tube where it is less critical. Clearly you're trying to put power transmission in the tube, but if you feel you will need access windows that large to do maintenance, there's no use even bothering to put it in the tube at all.

You've got the open ends on each end of the tube for access. Maybe cut one hole in the middle if you really think you need it, but not these very large holes on all sides of the drivetrain. You have to either compromise accessibility / ease of maintenance or you have to compromise by putting the power transmission outside the drive tube - right now your point of compromise is chassis strength, and for what benefit that is for is unclear.

Ideally if you are putting power transmission in a tube you want it to be a low maintenance system. This is why exact center drivetrains with belts (or chain) are commonly used with this type of setup - with belts you install it once and then you're set.

12-23-2016 10:35 PM

TORNADES 3386

Re: pic: Tornades's Custom West Coast Drivetrain

Its look like not solide you have to conceder le way force are aply to the tube. Actuly we all ready build a prototype and we tested it.
We dead some software static test and we end up with a 5+ safety factor. Hahahaha😂😂😂

12-23-2016 10:41 PM

Cothron Theiss

Re: pic: Tornades's Custom West Coast Drivetrain

And how did you test this prototype? Cause unless your prototype was a full size chassis with tubes cut just like this weighing a full 120 lbs. and driving aggressively, crashing into other robots and objects, I wouldn't put much stock into your prototype and FEA data.

12-23-2016 11:34 PM

mikem1999

Re: pic: Tornades's Custom West Coast Drivetrain

1) Try checking your bearing blocks - they may be upsidedown if you're shooting for a drop centre.

2) Can we get some more info on if you're using gussets or welding? Where do the motors go?

3) You haven't posted much of the design - how can we help you? What areas do you have questions about?

12-23-2016 11:35 PM

Chris is me

Re: pic: Tornades's Custom West Coast Drivetrain

It's extremely easy to run an FEA that gives you a false sense of confidence. If you don't have someone with professional experience with FEAs helping out, the results just aren't that meaningful.

12-23-2016 11:47 PM

frcguy

Re: pic: Tornades's Custom West Coast Drivetrain

FEA is only as good as the numbers you put in it. I would highly recommend you take the advice of the people posting in this thread - they know what they're talking about.

12-24-2016 01:25 PM

TORNADES 3386

Re: pic: Tornades's Custom West Coast Drivetrain

It is welding yes and we tested this preseason.
And also conceder the frame work only with 3 to 5 inch weels diameter.
For the gearbox we decide to go with vex 2 cim balls shifter 3 stage
Otherwise west coast gearbox work aso for it.

12-24-2016 03:09 PM

mikem1999

Re: pic: Tornades's Custom West Coast Drivetrain

I'm not 100% sure what the wheel diameter has to do with the drop centers.

Your bearing blocks appear to be these ones - https://content.vexrobotics.com/vexp...40122-Rev2.PDF

I could be mistaken, but it appears that when they are flipped (so the flat side on top) the central hole is 1/8" higher than when they are not flipped. This would give you a drop center to reduce scrub force when turning.

Yours appear to be the other way around.

What do the gearboxes mount to? Do you have some sort of bellypan? Central stiffening?

I'm generally confused because there isn't a lot in your drawing and I'm not sure where you want help.

12-24-2016 03:46 PM

TORNADES 3386

Re: pic: Tornades's Custom West Coast Drivetrain

Hi Mikem1999 contact me at my gmail i will respond to your question
Thanks their is my gmail redyyh3386@gmail.com

12-24-2016 03:52 PM

pilleya

Re: pic: Tornades's Custom West Coast Drivetrain

When posting an email address, try and break up the address to make it harder for it to be picked up by a bot. Or just send via PM.

12-24-2016 07:11 PM

TORNADES 3386

Re: pic: Tornades's Custom West Coast Drivetrain

Hahaha thanks i am new to chief delphi us a user