Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by ThirdString

  1. ThirdString

    New Laptop for Designing

    I'm running a Lenovo W530 that I upgraded to SSD and 16GB memory and Solidworks doesn't have any problems. I haven't done much simulation on it though. The SSD is a MUST, no matter what laptop you choose. Get the basic P50s with Quadro M500M for US$825. (MAYBE upgrade to the i7 for US$40, I...
  2. ThirdString

    Do you google for ideas with designing custom equipment like assembly jig?

    I've only really done work in one industry, and so my experience is quite limited. I know how to design one kind of product, but that's it. As I try jumping out into other products, a google search is absolutely necessary for me. I like to think I'm creative, but reality says the combined...
  3. ThirdString

    Force at Crankshaft Pedal

    Haha, it may have been a D, I've been out awhile. I actually started the MIT online course in dynamics to help understand this problem better. But I think the key step is breaking the mental association of momentum and force is key. Thanks for the feedback, helping me stop the snipe hunt. I'll...
  4. ThirdString

    Printer recommendations

    Sanika, I've got a DaVinci 2.0A, and I don't recommend it. ABS is okay, but you have no control over curl because you can't control temperatures. You also have to buy their filament which is almost 2x the cost of other quality brands. Don't get a DaVinci if you want to do PLA. The Ultimaker is...
  5. ThirdString

    Force at Crankshaft Pedal

    So in real-life, there must be an angular acceleration, which is the force that is felt on the foot. If your pedal hits an immovable object while spinning, you have a huge force since the acceleration is huge. If it's spinning free, there is momentum, but no force. On a bike, there would be...
  6. ThirdString

    Force at Crankshaft Pedal

    I want to preface this with the fact I got a C- in dynamics! I'm trying to analyze a flywheel with a crank attached. A simplification of the design would be a bicycle pedal, crank arm, and a flywheel. All I need to do is calculate the force at the pedal, but just can't do it. I know the...
  7. ThirdString

    11L17 for Crimping application?

    Cory, Thank you again, that is exactly what I was looking for!
  8. ThirdString

    11L17 for Crimping application?

    Cory, Thanks for the response. Strength is not our biggest concern with component, so we might be able to go down to the 1008. I will have to check into that option. Any chance you can explain how to determine what alloy is better for crush/crimp applications? I'm guessing experience, but I...
  9. ThirdString

    11L17 for Crimping application?

    We are trying to design a hydraulic unit that gets sealed by a threaded cylinder forming a crush fit with a base. 12L14 is the material we are starting from for the base, as it is good for crimping from what I have been able to find. However, 12L14 is not standard in a flat bar, only rounds. We...
  10. ThirdString

    Hydraulic Fluid Replacement frequency

    Thanks for the responses, both give some insight. The system doesn't get too hot, as it's usually running at a lower pressure than I mentioned (2000 psi max, 800 psi norm). And we have right around 50 gallons, so it's probably just one of those borderline decisions. Actually, with 2 machines...
  11. ThirdString

    Hydraulic Fluid Replacement frequency

    How do you determine how often to change hydraulic fluid? We have a custom-made hydraulic test machine that is fairly low pressure (2000 psi max), and it's been 10 years since the fluid was changed. We use it almost daily, but probably 1-2 hours of operating time a day. Will the fluid break...
  12. ThirdString

    Bolt & Cap Nut lock themselves together - need to modify design

    A washer would work with the design, but not the application. Having to put on a washer would make it less user-friendly. However, if that is our only option, that is what we will have to do.
  13. ThirdString

    Bolt & Cap Nut lock themselves together - need to modify design

    Thanks for the feedback, and sorry for the confusion. The nut body is contacting the bolt head. I was using "bottoming" incorrectly! The shaft is undercut on the bolt between the threads & head, so the nut is only contacting thread-to-thread until the nut body touches the bolt head. I would...
  14. ThirdString

    Bolt & Cap Nut lock themselves together - need to modify design

    I've taken over a project where basically two parts are mated using a 1 5/8 - 5 1/2 thread. One is essentially a bolt, the other essentially a cap nut. When the parts are screwed together, the nut bottoms out on the bolt head. When it bottoms out, the two parts actually lock together...
  15. ThirdString

    Chinese steel tube

    We use Q235A plates, and the info I have for it is 240 MPa yield strength. Tensile is 380 MPa.

Part and Inventory Search