Subject:
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Re: Aviation Tractor MOC
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Newsgroups:
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lugnet.technic
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Date:
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Tue, 18 Jun 2002 08:58:43 GMT
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Viewed:
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1312 times
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Thank you for your comments.
In lugnet.technic, Jennifer Clark writes:
> Nice job Simon! I always like watching these machines at the airport too,
> did the spec sheets you received state what sort of horsepower and max speed
> these things have?
Engine:
Deutz BF 6M1051C - V6
11.906 litres
300kW (400bhp) @2100rpm
1840Nm @1400rpm
Performance:
Max tractive effort 390kN (88000lbf)
Max speed 30kph (18.9mph)
Nowhere near as much bhp as I would have guessed (and I would have expected
more like 20l engine capacity).
> As for the power problem, two 9V gear motors should be able to drive a
> machine of that size and weight quite well. Off the top of my head I'd
> suggest a gear ratio of around 24:1 from motors to drive axles; it will be
> pretty slow, but then the real things are pretty slow anyway. The double
> diff is probably superflous, certainly I've been able to gang two motors
> together without using a diff beforehand, and as long as the RPMs don't
> differ too much I can't see there being any great efficiency losses.
Trying to be too clever I suppose, those diffs are out of there.
> I don't have an 8880 but I remember people mentioning that the CV joints
> have a lot friction in them, so perhaps this is causing some problems?
I'll make the other mods first and see if they work, as my suspension set up
means they are being driven almost level for most of the time I would have
thought this would be minimised already. If it's really a problem I'll have
to go 8465.
> Another thing I've come across, especially with multi motors setups, is the
> requirement for the batteries to be delivering enough current. A 9V PP3 just
> cannot cut it, but 6 normal AAs in parallel are great. Another combination
> I've used recently to surprisingly good effect is 8 AA NiMH rechargables in
> parallel using a battery box from Maplin (about 70p). This gives a total of
> 9.6V and really shifts the motors; motor power goes up as the square of the
> voltage, so if you had previously been using 6 NiMH giving 7.2V, going to
> 9.6V makes a serious difference. Of course the motors are only rated at 9V
> so there may be some risk in this... I'd be interested to hear opinions on
> this.
I'm using the 6AA boxes at the moment so I'll try the Maplin idea after I
redo the drivetrain.
> I'm not sure if the compressor has a cutoff, as running a motor in a heavily
> loaded of stalled state such as when an air tank gets filled up also
> consumes a lot of power from the power source.
The compressor runs off a separate motor with it's own power - to the left
in this pic:
www.brickshelf.com/gallery/Psi/Technic/AviationTractor/compressor_jpg
Thanks again.
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Message is in Reply To:
 | | Re: Aviation Tractor MOC
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| Nice job Simon! I always like watching these machines at the airport too, did the spec sheets you received state what sort of horsepower and max speed these things have? As for the power problem, two 9V gear motors should be able to drive a machine (...) (22 years ago, 17-Jun-02, to lugnet.technic)
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