Fant
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| posted on 19/2/17 at 06:42 PM |
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Dyno rolls
Hello,
I was thinking about building my own chassis dyno. I could get an used eddy current brake, the electronics and software is also no problem.
The only thing left is a good idea for the rolls. Big rolls are expensive and heavy, small rollers have the disadvantage of bad tire deformation and
wheel slip.
So the big question is: why not use regular car wheels/tires as rolls? This would give big diameter and low weight, is easy to balance and is
cheap.
What happens when running tire-on-tire on high speed and load? What other disadvantage might there be?
I would appreciate any thoughts about it.
Regards, Fant
[Edited on 19/2/17 by Fant]
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Ugg10
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| posted on 19/2/17 at 06:59 PM |
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Have you had a look at the hub dyno's. May be easier to engineer then a true rolling road.
http://www.dynomitedynamometer.com/axle-hub_dyno/axle-hub-dyno.htm
---------------------------------------------------------------
1968 Ford Anglia 105e, 1.7 Zetec SE, Mk2 Escort Workd Cup front end, 5 link rear
Build Blog - http://Anglia1968.weebly.com
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Fant
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| posted on 19/2/17 at 07:03 PM |
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quote:
Originally posted by Ugg10
Have you had a look at the hub dyno's. May be easier to engineer then a true rolling road.
http://www.dynomitedynamometer.com/axle-hub_dyno/axle-hub-dyno.htm
Hub dyno would be easier to engineer but would require a second eddy current brake or some sort of left-to-right hub linkage.
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SPYDER
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| posted on 19/2/17 at 08:13 PM |
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There are various sets of brake testing type roller sets on the bay. Start prices at £200, £600...
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Fant
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| posted on 19/2/17 at 08:41 PM |
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quote:
Originally posted by SPYDER
There are various sets of brake testing type roller sets on the bay. Start prices at £200, £600...
I doubt that these are suitable for high speeds...
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coyoteboy
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| posted on 19/2/17 at 11:42 PM |
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I may be miles off but I can't see rubber on rubber traction being even remotely as good as rubber on adhered ceramic grit on a roller. Plus the
risks of a blowout are double.
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Fant
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| posted on 20/2/17 at 05:55 AM |
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quote:
Originally posted by coyoteboy
I may be miles off but I can't see rubber on rubber traction being even remotely as good as rubber on adhered ceramic grit on a roller. Plus the
risks of a blowout are double.
Might be true, but since the roll (=tire) also deforms at the contact patch the contact area grows much bigger than with a steel roll.
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peter030371
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| posted on 20/2/17 at 04:21 PM |
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Its very common practice for at least one major Tyre manufacture to test tyres by running one against another in a 'tyre on tyre' test.
Providing you monitor the tyre pressure and heat build up it could work. However the 'tyre on tyre' tests are carried out in what look
like, and I suspect in reality are, concrete bunkers as explosions can happen when things get too hot but then that maybe only on prototype tyres (I
never asked about that and I suspect they wouldn't have told me even if I did ask).
If it was my money (and safety) then I would try and find a metal, balanced roller that is designed for the job 
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Adamirish
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| posted on 20/2/17 at 06:21 PM |
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I have nothing to add except I would love a rolling road in my garage! I doubt my neighbours would like it so much though!
Keep us up to date if you go ahead with the project, I'd love to see how you get on.
MK Indy 1700 Xflow
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Fant
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| posted on 20/2/17 at 06:30 PM |
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quote:
Originally posted by peter030371
If it was my money (and safety) then I would try and find a metal, balanced roller that is designed for the job
That would be the best technical solution for sure.
But I would like to have the possibility to disassemble the whole thing and move the parts around - without a big fork lift 
I'm not going to send 1000hp+ through the dyno, so I'm searching for a "Add lightness" solution.
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gingerprince
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| posted on 21/2/17 at 07:12 AM |
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quote:
Originally posted by Fant
That would be the best technical solution for sure.
But I would like to have the possibility to disassemble the whole thing and move the parts around - without a big fork lift
I'm not going to send 1000hp+ through the dyno, so I'm searching for a "Add lightness" solution.
If you want relative comparisons of mods rather than absolute power values you could do worse than what I did
http://locostbuilders.co.uk/viewthread.php?fid=9&tid=170736
Much cheaper and less likely to annoy the neighbours
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nick205
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| posted on 21/2/17 at 10:01 AM |
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Only done one once, but it's not that expensive to take your car on a rolling road with trained operators. Odd hearing your car "go for
it" when it's static, but the equipment's all there and with you stood out the way the safety element has to be higher too.
Don't get me wrong I'd love to have my own RR, but there are a few other things I'd be looking to have first!
Primarily a garage that wasn't being converted into a bedroom 
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nick205
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| posted on 21/2/17 at 10:03 AM |
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Question to OP...where are you?
Can't see a location in your profile, but if we know where you are another member may be able to recommend a rolling road local to you.
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Fant
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| posted on 21/2/17 at 11:58 AM |
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quote:
Originally posted by nick205
Question to OP...where are you?
Can't see a location in your profile, but if we know where you are another member may be able to recommend a rolling road local to you.
I'm located in southern bavaria.
It is of course utter nonsense to build your own rolling road.
But what is it to build your own car with hundreds of hours work?
A friend of mine has a saying: Why does the dog lick his balls? Because he can! 
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Angel Acevedo
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| posted on 6/3/17 at 02:31 PM |
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There was a member that went to the adventure of making a dyno..
I´m sure that if you search you´ll find the thread, else, someone with better memory will post user and thread...
Beware of what you wish.. for it may come true....
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