Thread: Stirlsilver's Disco Ute Project

Originally Posted by slug_burner

By the shape of the winch comment I take it you cannot increase the size of the gusset to that in the violet or even the red below?

That's right, on one side the motor is sticking out and the other the gearbox so I am limited in those directions.

Originally Posted by slug_burner

Increase the material yield strength, use a bisalloy with a higher hardness?

Always an option, but I imagine the material is more expensive and I would probably need a special weld filler? I would prefer to stick with carbon steel to keep things simple.

Originally Posted by slug_burner

Use a doubler plate as per the yellow?

I agree along the lines you are going, basically increasing the thickness. I initially didin't want to go that way as having up to 20mm of steel in areas seemed excessive!! Anyway I beefed up the material in certain areas and I think it's now about as good as it will get. Thanks for your advice.

Originally Posted by Paulie

as someone who is slowly trying to learn my way around solid works...

are your images above showing deformation and the areas of red are areas of max deormation??
if so, would it be better to look at the FOS images to see what the minimum FOS is for the design.
l

The diagrams I am showing are stress levels in the material which basically gives the same information as FOS. When looking at the stress distribution I was just looking for areas that were greater than the yield stress of carbon steel (250MPa).

With Factor of Safety all you are looking at is Yield Stress/Stress so you would be looking for values lower than 1 (stress being higher than yield stress) so it's basically the same. Good luck with learning SolidWorks!! Quite a useful tool.

By simply increasing the top plate size at the end of the chassis runners from 5mm to 10mm I managed to cut out the areas of excessive stress that were there before:


I then simply made the material 20mm in the area where the stress was occurring and basically addressed the problem:




While I do have some very small areas where the stress exceeds the yield stress of the steel, I don't think I will bother worrying about it. The reason for this is that I checked how the part handled with 60,000N being applied tangentially (so being pulled from the side). And I found that the failure occured in the 3mm chassis rails, so no point trying to beef it up anymore if one of the failure modes is the chassis:

The part drawings of the Rear Winch Mount are done I'm getting better at it.

Good stuff Stirl. Next they'll have you managing projects in power plants and things

Do a sim on what it looks like without the small gussets. It might save you a bit of welding.

Well the winch mount is starting to come to life. One problem was encountered. It seems that the way I modelled the winch wasn't correct. The gearbox and motor foul with the gussets far more than I had expected. But that is easy to fix, I'll just sit the winch off the plate by about 40mm and it will all be fine.

Below are the photos of what got done today:










I actually got most of the welding of the parts shown above done, however part way through I ran out of filler in the mig and by the time that was all sorted it was late. So I'll save it for another day. I'm happy with the work I got done today though!

You are going to plate the winch bar to the chassis and not just butt weld?

Originally Posted by slug_burner

You are going to plate the winch bar to the chassis and not just butt weld?

Right now the assembly is just tacked on to the chassis, i'll then pull it off to get to welds I couldn't reach insitu. When I put it back on I'll fillet weld around the perimeter of the chassis/winch mount joint. Then I'll put 3 5mm strapping plates on each rail across the joint.

Sounds like a plan