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 Post subject: Re: Kart Safety - a new forum catagory???
Unread postPosted: Sun Sep 27, 2009 12:18 pm 
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Location: new haven ct
oh boy,
didn't mean it to sound any less important.
any brake system on these karts needs to be better than perfect and inspected before each run no exceptions.
since inspecting at the grid gate before track time isn't practical
it's up to the driver to check his equipment each time.
remember it's your life that can be lost.

And it's true dual brake systems the adjuster is a flawed design.
i've always thought that.
if you wanted to be sure that couldn't happen you'd want two rods and a tether.
the main point everyone is brakes are not a place that you'd even consider cheating on or saving money.
the best parts you can find often isn't good enough.
dave

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 Post subject: Re: Kart Safety - a new forum catagory???
Unread postPosted: Sun Sep 27, 2009 11:26 pm 
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Posts: 187
Alcohol fires are always exciting, I really love hearing the fuzzy little hairs in my ears sizzling and smelling the burnt hairs in my nose in a pit fire, not.


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 Post subject: Re: Kart Safety - a new forum catagory???
Unread postPosted: Sun Sep 27, 2009 11:45 pm 
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David-

I think you're still getting Tom and Russ Smith mixed up. When Tom Smith posts and it shows Tom, it's Tom, when Russ Smith posts and it it shows Russ, then it's Russ. :P

Just keepin' ya straight.

Yer ol' pal Dean


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 Post subject: Re: Kart Safety - a new forum catagory???
Unread postPosted: Mon Sep 28, 2009 12:02 am 
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Posts: 760
I am suggesting tethers more for the enduro karts/higher speed tracks. Just got back running Roebling/Savannah (2 mile track!). The higher speeds there make a back up tether more important (in my view)

I lost brakes at the Barneville 09 Vintage Winternationals, but speeds there are not as hight (.4 mile track). In my case, the whole master cylinder mount weld/braze came undone. BUT plenty of runn off area in addition to the lower speeds.

as an aside, I did not know it was the whole master that came loos, so I steered back onto the track, only to loose a right rear wheel! Did not know it til the crowd was pointing (I was about to wave back!) : The got black flagged since I was running on my sprocket, and did a 180 into the pit exit lane.

For that I earned the coveted "twisted sprocket" award. cb


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 Post subject: Re: Kart Safety - a new forum catagory???
Unread postPosted: Mon Sep 28, 2009 7:33 am 
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Location: West Bloomfield, MI
david a luciani wrote:
Chip and Jeff,
i agree with you that we should make the karts as safe as possible.
but,before we start adding non vintage parts to karts why don't we look over the lost brakes issue from a causative view. ie;: research before reaction......dave


Dave,
You are right on here ... this is what I wanted us to do here in this forum, report observed failures or equipment safety issues, discuss why the failure or situation occurred, and then discuss solutions.... thus leading to a very important and constructive result.

Everyone,
For instance, the most recurring issue I know of, are the plastic brake lines popping out of calipers. What would cause this to happen? .... improper tightening of the brass fitting (too loose, too tight???), wrong size/type plastic brake line, missing parts, etc.... Maybe someone wants to do some testing, to find out how tight the fitting needs to be, or test different types of brake line materials, etc.... We can speculate on how to make things safer, but let's go to the next step and do some real engineering here for our own good.
Maybe in this thread (which will soon be a new forum category), we define best practices for assembling & maintenance of plastic brake lines attached to calipers, or provide sketches of redundant brake linkage setups, or videos of something someone has already devised... (FYI - I have opened up permission to enable uploading many different types of files ... videos, Word, images....)
When I set up the new Safety Forum catagory, it can have seperate threads for each subject, i.e. brakes, steering, fuel...etc..

Jeff


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 Post subject: Re: Kart Safety - initial posting for this new forum catagory
Unread postPosted: Mon Sep 28, 2009 6:33 pm 
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Posts: 215
Location: Way Down in Dixie
Good reasons to keep a fire extinguisher fully charged and near at hand when purging.

http://img32.imageshack.us/img32/6460/fire1n.jpg
http://img15.imageshack.us/img15/4448/fire2th.jpg
http://img33.imageshack.us/img33/8222/fire3q.jpg
http://img62.imageshack.us/img62/2372/fire4u.jpg
http://img41.imageshack.us/img41/6839/fire5d.jpg
http://img32.imageshack.us/img32/9144/fire6.jpg

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 Post subject: Re: Kart Safety - initial posting for this new forum catagory
Unread postPosted: Mon Sep 28, 2009 7:25 pm 
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IF I remember correctly, one of the dangers of an alcohol fire is that the flames are not that visible. True?

I particularly remember this at Indy when going there in the 60's while growing up in SW OH. c


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 Post subject: Re: Kart Safety - initial posting for this new forum catagory
Unread postPosted: Mon Sep 28, 2009 9:34 pm 
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Posts: 187
Brake lines that come out are not assembled right, geez that's a no brainer. One possibility is the is the nut was never tightened and the ferrel was never crimped onto the tube tight enough to hold the tube. This would usually result in a fluid leak instantly in my past experience from being lame and forgetting to tighten the nut on initial assembly. Weatherhead pn 601X3 ferrels are the right ferrel for 3/16" nylon tube. The olive shaped ferrels that come with compression fittings are for copper tube and don't work worth a _hit on nylon tube. Weatherhead compression fittings are used on truck air shifters that use the same nylon tube, NAPA usually has the correct ferrels, they are nice and cheap compared to the hospital. Another possibility is the tube wasn't fully engaged in the fitting when it was assembled.
Dan's pictures are of a gas fire which are easy to see where to aim the extinguisher at. With alcohol fires about all you know is that all of a sudden you're standing inside an oven on high, then start running the hell away as fast as you can run. Water is used to extinguish an alcohol fire. You might be surprised by how many firefighters there are that don't know how to put out a fire they can't see.
Once I caught a Cobra on fire and was getting pretty unhinged about it blowing
itself to pieces along with myself when an old guy calmly walked over with a hugh C02 extinguisher and put the gas tank which was on fire out with it. He told me he was in the Navy in WW2 and his job was battling aircraft fires on carrier decks, said he wasn't worried very much about my little tank of gas on fire and then went back to eating his lunch.


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 Post subject: Re: Kart Safety - initial posting for this new forum catagory
Unread postPosted: Tue Sep 29, 2009 4:23 pm 
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Posts: 170
Location: Gualala, Ca
Guys,

I can remember an incident on the start of C-Open in Texas one year at the Sprint Grands. After I threw the green, and the karts went blazing by me heading into turn one, some driver had his brake pucks spit out in the middle of the pack. Needless to say, he never made the turn and went OVER the chain link fence, kart and all, and went through somebody's canopy. Could have been REAL BAD, but luck was on the driver's side, and the canopy softened his landing. He was unhurt, but the kart was a real mess.

Ernie


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 Post subject: Re: Kart Safety - initial posting for this new forum category
Unread postPosted: Tue Sep 29, 2009 7:56 pm 
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Location: Oregon
A inside madril (correct ID brass brazing rod ) can be used to swage the ferrel to line. This is a done outside the caliper on a spare fiting . This correctly swages the Ferrel equadisent with no lopsided collapse of line . No need to completely engage Ferrel on spare fitting, this only insures good start to swage .then install on caliper and complete full lock down . Smack the pedal a few good times to double insure no leaks.
With a good 10x magnifying glass u can actually see a slight depression in nylon line on a good swage (dont forget to pull out the brass rod!!!... ) no brake fade except my memory :lol: ..thk/u,gus


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 Post subject: Re: Kart Safety - initial posting for this new forum catagory
Unread postPosted: Tue Sep 29, 2009 10:14 pm 
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Joined: Tue Nov 27, 2007 11:27 pm
Posts: 397
Location: new haven ct
opps,
to anyone i mix up it's only cause i like you!!! :lol:
really has more to do with not sleeping much.

i've read with interest about the various ways that the brakes fail on the karts.
some seems preventable but the fact remains that even the best people get surprised sometimes.
Anyway i've been thinking a bit about this and i have a question about failed brakes.
when they go in a race is there no time to react or is it a matter of helplessly hanging on to an out of control kart.
Obviously i'd like to hear from people who've been there so to speak.

i know how it is with cars because in my younger days we used to race?? , if you could call it that, down a steep windy road.
As i was poor and new at building cars i learned how good the e-brake worked several times.
as there were a few high drops (100+ feet) i made it a point to have a functional one.
and from experience even at stupid speed in a curve you have plenty of time to use the e brake.

So finally my point, if there is time to react in a race it would be a nothing to add a mechanical or second hydrolic e-brake to the rotor of many karts out there.
while it wouldn't be really effective it might be enough to cut speed before impact.
the wt would be negotiable in my mind.
to my thinking it adds a secondary system when the primary system fails.

dave 8)

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 Post subject: Re: Kart Safety - initial posting for this new forum catagory
Unread postPosted: Tue Sep 29, 2009 11:19 pm 
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David, Jr. Neal can probably answer your questions about having time to react etc. from one instance I remember seeing. In that case Jr. reacted quickly enough to mow down some corn in the field next to the kart track. Maybe you should try driving a C-open twin up to a corner about 70 MPH and then try and make the corner without touching the brake pedal. That should give you a real accurate idea about how much time there is to react while you're going thru a hay bay or stack of old car tires.
I've intentionally gone off the track when I was wide open to miss 3 karts in front of me all spinning out and blocking the turn, Terry Trader was inches of my bumper and plowed right off into the grass as well. We didn't hit anybody or each other by taking an evasive line but I can tell you for a fact that the brakes were useless at that speed on grass when we kept right on racing off into the back 40 before either one of us could get slowed down. At first I thought he was still trying to pass me in the grass no less until I realized he was having even more trouble trying to slow down a heavier dual B-Bomb kart on grass than I was. Point is that without brakes sometimes you're just ballast along for an exciting ride somewhere.


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 Post subject: Re: Kart Safety - initial posting for this new forum catagory
Unread postPosted: Wed Sep 30, 2009 1:25 pm 
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..in my case, I was going down the back straight at Barnesville at the 089 Vintage Winternationals, approaching the sharp turn at the end of the straight as you go into the "S" turns: I knew how deep I could go into the turn and my braking point, from 1.5 days on the track. When I went to apply brakes: NOTHING!

After the initial shock of it, I started to make my turn into the corner, immed knew I was not goin to make it, and steered off into the runnoff area.

We do not go very fast at Barnesville, I had scrubbed off some speed maing my turn in, and most importantly, we have a lot of run off area there. So stopping was achieved with no damage to man nor machine.

ps: The whole master cylinder bracket was found to have come unwelded/un brsaed from the frame, BUT I may have lost brakes first due to lost brake fluid and the loss of the master was due to te off course excursion. c


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 Post subject: Re: Kart Safety - initial posting for this new forum catagory
Unread postPosted: Wed Sep 30, 2009 2:52 pm 
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Dave,
With the faster class karts, I don't see how there could be time to react and use an e-brake. Going to real numbers, consider on many tracks, the braking zone will be about 100 feet at the end of the straight, heading into the turn apex. If you go too deep, and miss your braking point by 20 feet, you might get around the turn or spin out ... if you miss by 50 feet, you will be exiting the track at considerable speed (i.e. an accident that could hurt). Do the math with the fast classes, the difference between 50 and 20 feet is less than 1/4 sec. An effective secondary brake would have to be available in less than 1/4sec IMO. The driver may panic momentarily, then move to do something unusual to actuate that secondary brake, but... it is just too late, that 1/4sec passed long ago. The redundancy or secondary brake needs to be built into the primary brake system, it can not be dependent upon exactingly fast driver reaction time in order to be effective.

Years ago, there were hand brakes mounted on the steering wheel, intended for use for the front brakes. I could see using that system as offering some safe redundancy. The driver would be using that hand brake for all high speed braking, it would not be unusual to use the hand brake, and there would be no reaction time delay. If the rear brakes failed, at least some reduction of speed could occur before 'exiting the track'.

I still favor muliple master cylinders each operating seperate calipers. Along with that, linkage that will still operate the good MC(s) if one MC drops to zero pressure, and also have redundant tethers to 2 or more MCs. Now the only weak link is the pedal and pedal pivot ... let's see... the pedal could bend, the pivot pin could fall out, the frame pivot weld could break, ....

Jeff

Jeff


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