09-11-2008 14:47

sdcantrell56

Re: pic: 6wd chassis

This is an excellent job of listening to advice and incorporating the changes to make a superior product. Overall I think this is a great design so far. How thick are the plates? It looks like 1/8".

09-11-2008 17:17

spc295

Re: pic: 6wd chassis

why thank you, but i still need to make a change i realized that by moving a standoff in order to cut the corners of the chassis it will now get in the way of the wheels

09-11-2008 17:39

gorrilla

Re: pic: 6wd chassis

(edit) i looked at the other picture, answered my question

09-11-2008 17:53

ironbears

Re: pic: 6wd chassis

to keep it safe and save money try to use 1/4" plate. looks great

09-11-2008 17:55

sdcantrell56

Re: pic: 6wd chassis

How would 1/4" plate save money over 1/8" plate?

09-11-2008 17:58

gorrilla

Re: pic: 6wd chassis

also it is steel or aluminum?

09-11-2008 19:13

R.C.

Re: pic: 6wd chassis

Aluminum if it is a 1/4" inch or 1/8" plates. No STEEL unless it is that really awesome thin-wall stuff.

09-11-2008 19:39

Cory

Re: pic: 6wd chassis

It wouldn't.

09-11-2008 20:01

Andrew Schreiber

Re: pic: 6wd chassis

Well, it would if you kept breaking it and having to replace it. Obviously you need to make sure that 1/8 is strong enough to do what you want. You do NOT want to be burning money having to replace parts because they werent designed properly.

09-11-2008 20:24

sdcantrell56

Re: pic: 6wd chassis

1/4" thick is always more expensive because it is more material. In the age of bumpers, a properly supported 1/8" plate will more than stand up to the abuses of FIRST. If you want to increase the strength substantially without increasing weight by too much you could bend the plates on the top and bottom to create a flange. This will increase the stiffness of the plate dramatically.

09-11-2008 21:29

JVN

Re: pic: 6wd chassis

Flanges are pretty awesome things. Here on 148, we like them. If you have access to sheet-metal or metal bending capabilities, it will help you make all kinds of very strong, very light pieces.
To paraphrase Ferris Bueller:
"They are SO choice. If you have the means, I highly recommend adding a few."

09-11-2008 22:31

kramarczyk

Re: pic: 6wd chassis

If you have the patience to dig through it, there are a number of examples on how the location of material affects the strength and stiffness of a beam in this thread. http://www.chiefdelphi.com/forums/sh...ad.php?t=67605

09-11-2008 23:50

spc295

Re: pic: 6wd chassis

it is 1/8" alluminum 5052 alloy, so it is harder and stronger then other alloys.

10-11-2008 00:15

R.C.

Re: pic: 6wd chassis

Why not use 2024 or 7075 if your not welding anything to those pieces. 7075 sheets have a brinell of 150 and a yield of 65 ksi.

10-11-2008 00:33

Brandon Holley

Re: pic: 6wd chassis

Nice.



And I agree with JVN here...flanges are an awesome way to strengthen something up and keep it light.

10-11-2008 00:47

R.C.

Re: pic: 6wd chassis

It would help to see some pics of this properly implemented.

10-11-2008 01:25

AdamHeard

Re: pic: 6wd chassis

It's not always a matter of "X material has a higher yield than Y material".

5052 is commonly used in sheet metal applications as it is much easier to bend and flange. Yes, 7075 is harder and has a higher yield strength.... but, good luck shaping it as easily as 5052. In fact, the low radius bends you see on most sheet metal parts in FIRST (148, 228, Kitbot frame) would probably crack 7075 rather than nicely bend it.

10-11-2008 01:27

R.C.

Re: pic: 6wd chassis

I didn't think he was going to bend it, as shown in his CAD drawing. Yes you are right about the 7075 cracking.

10-11-2008 01:42

AdamHeard

Re: pic: 6wd chassis

The next logical iteration in the design (supported by some recommendations by some knowledgeable people) would have been to flange it.

10-11-2008 03:58

Cory

Re: pic: 6wd chassis

Using 7075 or 7068 for the sideplates of a drivetrain is a total waste of money and complete overkill in my (not) so humble opinion. Tons of people have made similar designs with plain old 6061 and it works just fine.

It's always better to figure out why a design actually works and the best ways to implement it than to just assume upgrading to a "better" material will make everything work.

10-11-2008 09:00

sdcantrell56

Re: pic: 6wd chassis

I completely agree with you cory. The only places where I see 7075 as having a noticeable impact on performance is on gears and shafts where strength is very important and there is a constant load working on the shaft. Adding flanges to the sideplates will increases the stiffness much more than just switching to 7075 aluminum. Also 7075 is very expensive stuff.

If anyone wants to see flanges, look at my last drivetrain I posted http://www.chiefdelphi.com/media/photos/32013?