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Citizen Flips - Team Demon - NSW
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Glen
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Joined: 16 Jun 2004
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Whelp, had a bit of a test night and found a few things are yay and a few are nay.

- seatbelt tether + wheely bar. Ended up being ripped out where it bolts on, Was only two m5s so i'll need to upgrade it to x4 and hopefully that'll contain the seat belt too, otherwise i might need to look into looping it over something then sewing it.

- ram seems fixed. Didn't get jammed all night, sweet.

- bungee works, arm came back each time and didn't snap even after the seat belt broke.

- drives - to their credit they worked fine the whole night, one is still grindy though so i'll try rectify it before the nats. I also need to give it more ground clearance as that's an issue.

Very happy with it otherwise Smile Should be a great contest at the nat's!
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Post Tue Sep 15, 2015 2:49 pm 
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evil_steve



Joined: 06 Sep 2015
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Location: Adelaide, SA


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Is the 6mm HDPE thick enough for decent armour? I was thinking about using it but thought I'd need to use thicker boards than that.

Post Wed Sep 16, 2015 2:16 pm 
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marto
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For sportsman class it's plenty thick enough.

Steve
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Post Wed Sep 16, 2015 2:30 pm 
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Glen
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Yeah it does the job, saws go through it quick but the stuff is very cheap and easy to cut so i just replace it all regularly Smile
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Post Wed Sep 16, 2015 2:53 pm 
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haz



Joined: 15 Aug 2011
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I like the new look on flips man, awesome.

also you might like this. Girl I work with's brother works for Barr... I mention that I like Iron Bru. Came in to this today lol



Sugar free but oh well
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Post Thu Sep 17, 2015 3:44 am 
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Eventorizon-GB



Joined: 15 Nov 2013
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Location: Ripon, United Kingdom


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If you need any info or help with the seat belts Glen, I may be able to offer some advice. My final year university project was based around seat belts and safety systems.
What you just sad is probably the easiest option, stick it back on itself and run a bar through it that slots into the bulk heads. Or you can clamp it between a pair of zig-zaging Alu plates to make sure you get a really good grip on it, then bolt that to the base plate. You just need to spread the load far enough.

Post Thu Sep 17, 2015 11:02 pm 
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Knightrous
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Or go to pick n pay less and get a center rear seat belt and use the pre made clamps and tabs from the car.
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Post Fri Sep 18, 2015 8:41 am 
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Valen
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Small update

So at the vivid event flips was having problems closing, some mystery crud was getting into the vent hole. Resulting in the loss to an 8 year old, clearly unacceptable.


http://i.imgur.com/a9kkTOY.jpg

Well there's ya problem!
The epoxy used to seal the system was crumbling and getting into the ram.


http://i.imgur.com/Up7unGR.jpg

The application of said epoxy may be described as liberal perhaps?
Unfortunately there's not really a better way of doing the plumbing than epoxy, because of all the fixed angle relationships, you can't do about 3 of the fittings up tight.
So we are going to re-do the plumbing with thicker epoxy and keep it to the back half of the fittings.

Also changed the vent port to this.

http://i.imgur.com/jGlY8Zi.jpg
Basically got the bolt head over a milled out bit so that a single piece of crud can't block the hole.It's like a filter.

In terms of making things better the ram has been "ported" to let it come down faster.

http://i.imgur.com/jP0pNha.jpg
Hard to see here but there are now 6x 2mm holes in the side of the ram that should vent it when it reaches the end of the stroke. The leadin was cut with the dremel and crossed fingers then polished with 400 grit. Hopefully it won't wind up cutting up the O Ring as it goes past the ports.
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Post Fri Aug 05, 2016 12:31 pm 
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Nick
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Are the vents in the side like the ones I proposed for my ram? I think they will be a huge help in retracting the ram but others suggested that the pressure on the up stroke will extrude the O-ring into the holes and then snip a section out of it as it moves past the holes. I will be keen to see how the mods work out.
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Post Fri Aug 05, 2016 1:21 pm 
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Valen
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yeah side ports, The vent holes are fairly small and there is a soft lead in and out so fingers crossed.The o-ring isn't heavily loaded either which should help.

So today was re-assembly day
step 1 through 12 clean everything
scrape all the old epoxy out then acetone wash and wipe every piece. Then dry assemble it and measure the critical dimensions.



Then pack the threads with 1Hr cure epoxy, leaving the first few turns free of goo (hopefully) to minimise the amount that could get into the system.



Then assemble it all 3 times because you did stupid crap like put the valve in backwards, or forgot to thread the whole thing through the mount first.



Still came out nice though, decent bead on the end of all the threads, I'll leak test it on Tuesday see how it goes.
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Post Fri Aug 05, 2016 5:39 pm 
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Nick
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Looking good - maybe Steve should just post you the trophy in advance!
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Post Fri Aug 05, 2016 6:39 pm 
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Glen
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Looking good Smile I think the o ring will be fine but you could also try get your hands on a proper pneumatic piston seal which would be much more durable. Probably run more freely in the cylinder too.
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Post Fri Aug 05, 2016 8:56 pm 
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Valen
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That compressor oil is the stuff!
hydraulic oil and some dry lube stuff had heaps of stick/slip going on, the compressor oil is super slippery and one presumes ok with O rings lol.
I have a few spare O rings as well, its not the end of the world to replace the O ring at the event, I cut the plug off the right side of the cylinder so it all just drops in and out fairly easily now.
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Post Sat Aug 06, 2016 1:10 am 
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Nick
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I had a look at piston seals, and while they probably have lower friction, they don't look like they will work with the fast exhaust holes in the side of the cylinder. Here is a page with good example pictures: http://tinyurl.com/z6fykk3 .

The thin lips on most of those seals are more likely to get damaged by the vent holes than an O ring IMHO.
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Post Sat Aug 06, 2016 9:20 am 
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Valen
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This might be a youtube video


Failing that
https://www.youtube.com/watch?v=2FiFL1En_0o

Flips with the new ported ram, seems to work ok, venting at 90 odd PSI is pretty instant, I'm hoping for a close time of ~2 seconds or so.

No leaks from the plumbing which is nice.
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Post Thu Aug 11, 2016 10:56 pm 
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