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Mechanical Engineering

PabLo Dal Buoni

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Everything posted by PabLo Dal Buoni

  1. Hi Bruce ! thank you anyway. Do you think these values are an average? ok now, if my original round material is 100mm diameter and the diameter of the final piece in the risky zone is 70 mm, I will use YTS for 100 mm of the chart. I think it is ok for me with some of your responses, now I wonder if this is an average of Jominy results. Best regards Bruce, and thanks again.
  2. Hi Michael, yes !! that is the best answer I think. Thanks a lot. Do you think these values in the chart are averages?
  3. Hi Andika, thank you for your response. NO, I do not want to know the connection between hardness and wear design calc. I did not say that. I do not need the equations either. My question is, what YIELD TENSILE STRENGHT I have to use for calculation, since the bar has different YTS along the diameter. Just that. Regards. Hi Abdulrahman, thank you for your response. Yes, I think I have to choose the minimum YTS, corrected to the final diameter size, like you said. Hi Balaji, thank you for your response.
  4. Steel with heat treatment (for example AISI 4140 Q+T) has different tensile strength with different diameters of the material, and also different tensile strength in a same diameter according to distance to the center of the material, like Jominy test demonstrates (hardenability). since the bar has different YTS along the diameter, which yield tensile strength should I use for the calculation of a shaft? Moreover, why this image attached shows differents curves with different specimen diameters ? Thanks.
  5. Thank you Sergio. I think the same thing, even though I saw this in some books and bearing manuals.
  6. Interesting. I have never seen this. I know tilting is important in middle-high speed curves. Wich is impossible with a regular 3 wheels scooter. I also think this is not a very difficult design. I see the front suspension just like any other motorbike. Fatigue is not a special problem.
  7. Hi !! I think you are pretty right this kind of benchs are not like machines with thousands of revs, so a bushing is not necessary. I think the shaft is directly in contact with the base frame. the rest of items.... I agree - A bearing end cap - YES, OR SIMPLY A WIDE WASHER WITH A BOLT FASTENER - A pillow block bearing - YES - Bearing lock collar - I CAN NOT SEE IT - Brass coloured bushing or sleeve? - Through hole plate welded to base frame. - MAY BE NOT NECESSARY - Box section end and pipe within? Box section attaches to seat pad. - YES - Through hole welded to base frame. - YES - Brass coloured bushing or sleeve. - MAY BE - Bearing lock collar. - MAY BE - Pillow block bearing. - YES - Bearing end cap. - YES , (OR WASHER+FASTENER) YOU CAN USE SEEGER CIRCLIPS TOO - Obviously, there is some sort of shaft running through the whole set up. - YES, IN THIS KIND OF MACHINES, YOU CAN USE VERY LARGE CLEARENCES IN ORDER TO MAKE THE ASSEMBLY A LOT EASIER. I hope I helped you Regards.
  8. I would make the frame a little taller in the 4 sides for containing the plate and let gravity to do its job you do not need to clamp the plate, unless it is a rotating grill
  9. Hi ! I am designing a C-hook for handling coils (10 tons) I am going to oxycut it. Anybody knows a book about it? I need to confirm: material (i´d think in low-medium carbon non alloy steel), norms, gage of material, should I relief tensions?, etc Thank you in advance.
  10. do you need something like this? (attached)
  11. It really seems excessive. If the formula is ok, I would re check the constant R (toughness) and the angle (sometimes the formula refers to half angle)
  12. Hello ! if I want to use sealed bearings (for making maintenance much easier) and it is not enough with 1 ball bearing, is it correct to use 2 radial ball bearings in tandem? (not angular bearings, just regular radial ball bearings like a 6208 2RS) This is for a shaft with no axial forces. Of course, it would be 4 bearings in total, 2 + 2. Thanks !
  13. Yes ! I agree. There are some formulas I could find (even considering plastic deformation) but they are very inconsistent. Finally, I took this like a rectangular beam and I considered Tensile Strenght for my calculus. After that, I could find a formula for Power needed. And with the velocity, that I know, I got the Torque. Unfortunately, I can not test nothing. The machine does not exist yet. Based on this and some expierence in the field, It was the best I could do. Thank you very much DrD !! you are the best !
  14. Hi Steve. Thanks. Yes, I know that. I read this in an article in the web. I need some formulas to calculate torque and power needed. Thanks.
  15. First, make sure you are using good quality 12.9 steel allen screws. If they come loose, you may use grower washers.
  16. hello, a drawing would help. I am sorry I can not help you.
  17. hello, you can easily find info in internet and videos in youtube. CVT is a device for power transmission with teorical infinite ratios and no tooth gears. Some cars are using it lately. Honda for example.
  18. anyone knows how to calculate the necessary torque and power for a sheet metal straightener machine or a 3-roller bending machine? I know material streght, thickness, width, rollers diameters and distance between rollers are factors to consider. Thanks.
  19. DrD, JAG, thank you for the responses. I have got it from: "Sheet Metal Forming Processes and Die Design" By Vukota Boljanovic I really think there is a mistake, Knowing E: 210.000 MPa, E square (ExE) would make always ZERO that division, considering YS, D and T very smaller numbers, don't you think? It has no sense. Furthermore, units do not work and there is no constant to fix it, like DrD said
  20. may be with a CNC spring coiling machine I recommend you to make your post short and specific. Sometimes you do not get answers just because there is much to read... good luck
  21. Hello, I am trying to know the force for a 3 roll bending of a 3 mm steel sheet. it seems like this formula is wrong. Units do not match. That E square is not ok, what do you think? thanks !
  22. Hi !! i am designing parts of a strightener. ¿which would be the formula to know the force in the rolls? I considered it like a three-roll bending. I think the formula attached has a mistake because of the units. Someone knows another formula? Thanks a lot !
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