I was wondering if you all could help me with a part I am trying to model? I have a ladder that needs a small cage and that has the cage bars extended down to the nearest guardrail per OSHA/MSHA requirements. This ladder is not our design, we are matching an existing design, or I would simplify a lot of things about this. The part I need modeled is shown in this picture:
I have created a part that should show you what is needed. The lines in the sketches show the profiles of the part at the various locations.
1.) This needs to be plasma cut from a flat steel plate, then bent to the angles needed.
2.) No twisting of the steel is allowed, only bending.
3.) The profile doesn't neet to have a uniform width (2") in between the upper and lower portions but something close would be preferable.
4.) I originally tried creating surfaces and thickening to get a shape but some of the bends need to be thickened inside and some of them outside and I couldn't get the results I needed.
Anyone care to take a crack at helping me with this?
I'll give it a go, but is there some reason why sketch 7 isn't aligned with sketch 2? It would be quite a bit easier a job - both modelling and manufacturing - if it was.
If there's no field welding, then how are they planning to install the new cage parts?
Honestly, for something like this, I'd probably just grab three pieces of flat bar and field run everything. Wouldn't be any less functional. Weld it all to the outside of the existing cage, then there's no issues with cleaning up catchy spots.
OSHA doesn't care if it's pretty, they care if it meets their requirements.
Here's the critical part. You can attach the upper and lower straight segments to your shop's preferences. This is done as a solids bend, so there may be slight variance from actual results, but it should be close enough for a field fit.
Take the line as you now have, add another sketch at the top or bottom may be best in this case, and sweep the profile similar to the attached. We do this all the time for our caged ladders. When you are done convert to a sheet metal part, set the sheet metal thickness and it will create your flat pattern for the shop.
Since your line is touchiing the frame, simply attach the rectangular shape to that line so it sweeps away from the frame, not into it. this can be done by projecting the end point of the line into the new skrtch for the metal shape. When setting your top sketch start your workplanes, click on the endpoint of the line, then the line itself, setting the WP perpindicular to the line. Start sketch on that WP.
And I seriously doubt the original has no twist, being that it is not aligned at all points towrds the center, but was probably added in the field to make it fit both ladder and handrail. At the most you will get a gap on one side and a small intrusion into the cage rail, unavoidable without twisting the part after it leaves the cagerails.