Author Topic: Lessons Learned - Safety  (Read 9029 times)

StefanN

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Lessons Learned - Safety
« on: 02 Sep 19, 06:30 pm »
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.

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StefanN

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Re: Lessons Learned - Safety - Bugatti
« Reply #1 on: 02 Sep 19, 07:21 pm »
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.


Slack Alice

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Re: Lessons Learned - Safety
« Reply #2 on: 02 Sep 19, 09:00 pm »
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! 

StefanN

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Re: Lessons Learned - Safety wire
« Reply #3 on: 02 Sep 19, 11:52 pm »
Anton shared this video on Facebook on how to use safety wire so thought I’d share it here too.

RhysN

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Re: Lessons Learned - Safety
« Reply #4 on: 03 Sep 19, 07:25 am »
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.)
We must avoid torturing our brains with false problems, it occupies but it can annoy. In jest!

Slack Alice

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Re: Lessons Learned - Safety
« Reply #5 on: 03 Sep 19, 10:40 am »
I’ve read it Rhys and will consider my setup.

Graham Hill

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Re: Lessons Learned - Safety
« Reply #6 on: 03 Sep 19, 11:29 am »
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.

Marek.Z.N

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Re: Lessons Learned - Safety
« Reply #7 on: 03 Sep 19, 11:37 am »
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.

StefanN

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Re: Lessons Learned - Safety
« Reply #8 on: 03 Sep 19, 12:27 pm »
Anyone got any experience of Nord-lock washers?

TheGiantTribble

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Re: Lessons Learned - Safety
« Reply #9 on: 03 Sep 19, 03:15 pm »
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.


Steve Cole

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Re: Lessons Learned - Safety
« Reply #10 on: 03 Sep 19, 11:37 pm »
I had my rear axle move a bit, this caused the chain wheel to be out of allinment so chain came off ..twice. Investigated more thouraghly to find why axle had moved and found bolts had undone. On the end of my axle I’d drilled and tapped so I could thread on a 6 mm bolt with a big washer to stop wheels coming off. I found on on side this was off so a potential for wheel to come off
Not very proud of this.
Not sure how reliable locktite or spring washers are

Marek.Z.N

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Re: Lessons Learned - Safety
« Reply #11 on: 04 Sep 19, 07:50 am »
about track Marshalls. there are plenty of us standing around when others are driving so we just need to spread out around the track so that we can help. This also would give us some variation when watching so thats a win win ;)

RhysN

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Re: Lessons Learned - Safety
« Reply #12 on: 04 Sep 19, 10:54 am »
Further to Bill's comments about checking previous shortcomings. Putting on my motorsport hat, every car there has a logbook in which things are noted. If something is a bit "not quite as it should be" like an advisory on an MOT then the car can run, this time, but needs to be rectified for the next. More major things must be fixed and rechecked before running.
Now I know this may sound a bit OTT, but when (not if) we get to 20+ CKs running perhaps a logbook should be already in place. Nice record for the car too in the future.
We must avoid torturing our brains with false problems, it occupies but it can annoy. In jest!

RhysN

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Re: Lessons Learned - Safety
« Reply #13 on: 04 Sep 19, 11:26 am »
Anyone got any experience of Nord-lock washers?

Yes, but almost impossible in a situation where you want to reuse. Then again nylocks are only supposed to be ideal for a one time use!
We must avoid torturing our brains with false problems, it occupies but it can annoy. In jest!

TheGiantTribble

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Re: Lessons Learned - Safety
« Reply #14 on: 04 Sep 19, 11:56 am »
I like the sound of a 'Log book', as you say a nice record of the car if nothing else.