here is a picture of modifications to the origninal chassis I posted, as you can see I stiffend the structure across the middle there are now two 21s and one 11. also I cut the bottom for ramp climbing capabilities, It can climb a 47 degree ramp before bottoming out
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".
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
(edit) i looked at the other picture, answered my question
to keep it safe and save money try to use 1/4" plate. looks great
How would 1/4" plate save money over 1/8" plate?
also it is steel or aluminum?
Aluminum if it is a 1/4" inch or 1/8" plates. No STEEL unless it is that really awesome thin-wall stuff.
It wouldn’t.
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.
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.
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.”
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/showthread.php?t=67605
it is 1/8" alluminum 5052 alloy, so it is harder and stronger then other alloys.
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.
Nice.
And I agree with JVN here…flanges are an awesome way to strengthen something up and keep it light.
It would help to see some pics of this properly implemented.
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.
I didn’t think he was going to bend it, as shown in his CAD drawing. Yes you are right about the 7075 cracking.
The next logical iteration in the design (supported by some recommendations by some knowledgeable people) would have been to flange it.