Germy Posted March 1, 2020 Share Posted March 1, 2020 Anyone have a moster belt tension bar they want to sell? Thanks germy Quote Link to comment Share on other sites More sharing options...
barkis Posted May 24, 2020 Share Posted May 24, 2020 works well with Hz meter app in your phone if you dont find any bar (430Hz) I have tried both and it will be the same 1 Quote Link to comment Share on other sites More sharing options...
Blackburn Mark Posted May 24, 2020 Share Posted May 24, 2020 2 hours ago, barkis said: Hz meter app in your phone if you dont find any bar (430Hz) What witchcraft is this?! Are people plucking their belts like guitar strings? That is pretty cool... I'm guessing there must be a formula for different belt types / lengths / widths Quote Link to comment Share on other sites More sharing options...
AndyB Posted May 24, 2020 Share Posted May 24, 2020 1 hour ago, Blackburn Mark said: What witchcraft is this?! Are people plucking their belts like guitar strings? That is pretty cool... I'm guessing there must be a formula for different belt types / lengths / widths There is a formula, but it is easier to set one correctly and measure the frequency. AC is 370 Hz. I have done this many times and it is more accurate than torque since you are actually measuring the real belt tension with no friction losses in anything. Quote Link to comment Share on other sites More sharing options...
Blackburn Mark Posted May 24, 2020 Share Posted May 24, 2020 5 hours ago, AndyB said: There is a formula, but it is easier to set one correctly and measure the frequency. AC is 370 Hz. I have done this many times and it is more accurate than torque since you are actually measuring the real belt tension with no friction losses in anything. I have just designed a HTD8 belt-pully drive that is close to 4000mm belt length with a 90 degree twist and 90 degree change of axis.... 1200mm free length which is very likely to need a few idlers to tame resonance. I am reasonably confident in its ability to deliver the power (15 / 20hp) but I am also pretty sure it will destroy the tensioner, itself or even structure if I allow it to resonate at or near 8000rpm I would consider it practical if I can get it to last for 100 hours plus // and perfect at 200 hour plus.... that's peanuts for the type of belt but it will have a relatively tortured life with the angular acrobatics. I have made a quarter size mockup with a 2.5mm toothed belt and I'm sure I can get the pully angles without stressing the belt too much but the resonance might make a fool out of me! Wish I was as confident as you and your AC Andy Quote Link to comment Share on other sites More sharing options...
AndyB Posted May 24, 2020 Share Posted May 24, 2020 Lol. Twanging belt for tension only works well between 2 very fixed objects...otherwise the other bits vibrate as well. Can you do your prop speed reduction before it is fed to the belt? Keep it 2800 rpm? Quote Link to comment Share on other sites More sharing options...
Blackburn Mark Posted May 24, 2020 Share Posted May 24, 2020 43 minutes ago, AndyB said: Can you do your prop speed reduction before it is fed to the belt? Keep it 2800 rpm? I have done drawings for a short Poly-V 2:1 with a long HTD timing belt 2:1 onto the prop but I don't like it. The poly-V belt is likely to slip before any frame damage but Poly-V belts need a LOT of tension which I am not confident in controlling with a tensioner and keeping it light (I need the tensioner because the motor is isolated from all other pullies) // the extra pully hardware will add weight that I want to use elsewhere and the Poly-v tension will put a lot of strain on my rubber motor mounts. Timing belts need much less tension, a single run would be very light and despite being very afraid of the resonance, I don't yet know how bad it will be and that I wont be able to control it with plastic idlers (at least at cruise and full power) I have been looking at harmonic dampers but there is no point until I know what I am up against so I might just have to bite the bullet start building 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.