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#Post#: 1328--------------------------------------------------
Lessons Learned - Safety
By: StefanN Date: September 2, 2019, 12:30 pm
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One of the most proactive and focussed things we can do to
improve safety is to review our cycleKarts after driving them,
checking for damage or things becoming loose and of course
reviewing breakages/component failures. The activity becomes
massively more useful is we share the process with each other so
that we can learn both what might go wrong and the solutions.
So, this please review your cyclekart(s) and share what you've
found - did anything shake loose, break, bend or otherwise fail?
At this stage, this is only for builders to comment on their
own cyclekarts.
#Post#: 1330--------------------------------------------------
Re: Lessons Learned - Safety - Bugatti
By: StefanN Date: September 2, 2019, 1:21 pm
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I checked over the Bugatti and pleasingly almost everything was
in place and still tight. Here's what I found:
One of the nyloc nuts holding the front wheels on the spindles
had loosened a little. It had undone about 1mm and I've got
lots of spare thread because I've been wanting to make this more
secure, so not catastrophic. The nyloc is pretty new and still
tight. Both threads are normal right hand threads and
interestingly its the right wheel which, if anything, should be
tightened by wheel rotation. So I will either switch to a
castellated nut, wire it or add a locking nut.
The nut on the front eye of one of the leaf springs had
loosened, again a small amount and again its a nyloc. This
already has a second nut on the thread, so just needed tweaking
up.
The nut on the end of my steering column loosened. The end of
the column goes through a hole and is kept in place with a nyloc
nut (see photo with nut and washer removed) I made the thread a
bit short so I may remake this section and/or I'll drill and tap
the end of the column and add a big washer and bolt on a spring
washer.
#Post#: 1332--------------------------------------------------
Re: Lessons Learned - Safety
By: Slack Alice Date: September 2, 2019, 3:00 pm
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My rack and pinion was about to fall apart...both bolts were
really loose.
I am discussing a new assembly with Little French.
I am checking all fasteners between sessions but I missed these
on the rack.
I must create a checklist to cover everything.
On another matter, I must do something about making the kart
stay upright!!...two meetings, two overturning!
#Post#: 1335--------------------------------------------------
Re: Lessons Learned - Safety wire
By: StefanN Date: September 2, 2019, 5:52 pm
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Anton shared this video on Facebook on how to use safety wire so
thought I’d share it here too.
HTML https://youtu.be/FJ7wHpER9R4
#Post#: 1337--------------------------------------------------
Re: Lessons Learned - Safety
By: RhysN Date: September 3, 2019, 1:25 am
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While I didn't have a car there I hope a few observations are in
order. My thoughts are focussed on safety, I'll leave
performance issues out.
Brakes, a disc operates by being able to get rid of the heat
when the kinetic energy is converted to heat, which happens by
pressing the brake pads against the disc. If the disc is'nt
able to get rid of the heat, you will get brake fade. I am
convinced that created Dave's lack of brakes, and thereby the
falling over. In my opinion in his case the disc is too small in
width to be a working brake, OK for a parking brake. If the pads
are not making full contact with the disc, ie only a part being
used, there efficiency is not what it could be, and furthermore
when the pads wear down there will come a time when the unworn
parts butt up against each other and no pressure will apply to
the disc, guess what, no brakes. The operating system, be it
hydraulic or rod or cable is simply that, an operating system.
Hydraulic will not mean better brakes, and if there is a
mismatch between master and caliper, it may be worse. More
calipers on the same disc will not help, in fact might be worse
as the second caliper masks even more of the disc, and it's
ability to get rid of heat.
I know that Stretton appears hard on brakes, but I know that at
another event I discovered my left foot had been resting on the
brake pedal for a distance, thus still generating drag, heat
etc. Are you positive you don't do the same as there are really
only 3 corners at Stretton which need much brake, 2 together
just before Start/Finish, and the other at the far end?
Caliper mounting, the bolts here, from experience gained this
last weekend i believe MUST be mechanically locked, either
safety wired, or a tab system just like every car. Locking
chemically is just not good enough, nor are spring washers and
similar. (My opinion and I will be using that mechanical
method.)
#Post#: 1343--------------------------------------------------
Re: Lessons Learned - Safety
By: Slack Alice Date: September 3, 2019, 4:40 am
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I’ve read it Rhys and will consider my setup.
#Post#: 1347--------------------------------------------------
Re: Lessons Learned - Safety
By: Graham Hill Date: September 3, 2019, 5:29 am
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Well I nearly ended up with my brake caliper in my lap on Sunday
as the two locating bolts disappeared somewhere (sorry Nick at
Stretton). I have to admit I had not checked the torque of these
two for some time. I checked every other damn nut and bolt, but
these two are out of obvious view on my kart and I overlooked
them. In my defence however I changed to new pads on the Friday
and despite a lot of tugging and levering to get the old pads
out there was no sign of looseness.
We did take the kart out for a rattling shakedown around the
oval on Saturday and at the same time was braking hard to wear
the pads in.
The story does not end there. On Sunday I did hear a clunk and
pulled into the pits, the kart was rubbing somewhere and I
needed help pushing it. However a first inspection showed that
one of the covers on the TAV was loose and wedging the belt. The
bolt had come loose, even though I had checked it previously,
Bill kindly helped me fix it, I assumed everything was sorted,
no rubbing, all seemed fine.
However with hindsight, the clunk would have been the brake
caliper coming loose, and I did not look any further than the
issue with the TAV.
This thread is generating a lot of discussion about the security
of fastenings and rightly so. I still consider myself a newbie
and as I progress understand that CycleKarts are not toys. When
driven hard they experience a lot of stresses and vibrations.
In my opinion we should be reviewing three areas:
The quality of components; some cheap internet options may not
be up to the job.
Quality of the build, suitability of materials, welds and
fasteners etc.
Maintenance and self-scrutineering. Having an allocated
scrutineer buddy up on the day may help.
I'm glad we are reviewing this now, I don't always appear to
take things seriously, but this is important.
#Post#: 1348--------------------------------------------------
Re: Lessons Learned - Safety
By: M.Z.Nahajski Date: September 3, 2019, 5:37 am
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well said. just before you realised what was wrong with your
cyclekart I was driving it and the brakes were working
tremendously (even if they weren't actually attached by anything
;) ).
I agree with the track buddy. This means your kart gets looked
over for a second time but with a new set of eyes which could
spot mistakes better.
A simple diagram of a cyclekart which has a coloured dot or
cross wherever a bolt is would be a good idea so that none get
missed out.
#Post#: 1349--------------------------------------------------
Re: Lessons Learned - Safety
By: StefanN Date: September 3, 2019, 6:27 am
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Anyone got any experience of Nord-lock washers?
#Post#: 1350--------------------------------------------------
Re: Lessons Learned - Safety
By: TheGiantTribble Date: September 3, 2019, 9:15 am
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Ok I've put on my serious hat, albeit doesn't fit very well!
I personally think we should have three people (can be different
each event) that does an inspection of each CK before an event.
Three sets of eyes has to be better than one.
Paying special attention to Ck's that have previously had
problems.
To use myself as an example, as we all know I had steering
problems, at the next event it would be visually inspected to
see that I had made alterations, and they were deemed an
improvement. Also physically inspected by variously tugging,
pulling, and jumping up and down on it!
As proof of what Graham mentioned earlier about the size of the
forces being generated, the steering couldn't be pulled apart by
hand, so it passed a physical test but actual driving, well we
all know how that went!
Also, and yes hindsight is wonderful, maybe we all need to
consider access to nuts and bolts when we are building, it's
easy to construct a part fit it and then realise once fitted we
can't actually access all the fixings on it. The harder it is to
get to a fixing the more likely it is to be ignored or forgotten
about.
Finally I do think we need a couple of volunteer track marshals,
potentially with flags, not just to warn drivers of a problem,
but also to potentially assist with pushing a CK out of trouble
and or back to the pits. It feels a long way when pushing. I
feel we would only need a couple at Stretton based one at each
180 Deg. bend.
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