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gas strut newton force for side opening pop top
Posted: 25 Feb 2006, 15:24
by spareuser
Hi, I'm in the process of replacing my autohomes Kamper roof for a side opening pop top bought of of ebay with the promise that all the parts were ok! yeah right busted hinges, missing toggles you get the idea!!!!
I need to replace the 2 gas struts and do not know the newton rating needed to lift the roof, can anyone help?
Now the techy bit- the existing struts are 625mm when extended with a stroke lenght of 250mm and the tube length is 315mm.
I am guessing that the roof is a 3/4 lenght dormobile but i have not seen this version before.
Posted: 25 Feb 2006, 16:29
by HarryMann
Empiricism dear Badger!
~ a suitable billet and a set of bathroom scales, juxtapose appropriately, keep head and neck out the way, record, pop back inside and convert (Kg ~ Newtons)
Newtons are Kgs x 9.81, job done, cup of tea
PS. Try a couple of angles but just about opening will be about it I expect, so maybe disepnse with wood and just squah scales, also, think about allowing at least 10~20% for conservatism (in case they get in next time)
Ohh! Allow for angle of dangle if strut not normal (rht angles) as it's 'just opening' (send load and angle and I'll compute for you)
Posted: 26 Feb 2006, 13:54
by spareuser
Hi and thanks for the tip, was never any good at physics! will have to scout about for some scales but will have a go tomorrow. still waiting for my new hinges to turn up though!
Just one further question, once I have caluculated force required to lift the roof will I have to devide by 2 as I am fitting 2 struts?
P.S. I am not a fan of the liar B, but I was around in the 80's and do hope they don't get in again - I will allow for the 20% though!
Regards
Posted: 26 Feb 2006, 16:30
by redstar
Harry, i thought 9.81 was gravity pull.... should it not be newton x metre?? i.e. Nm?
Posted: 26 Feb 2006, 20:23
by DiscoDave
gravity pull is measured in newtons and is indeed 9.81N, however a newton is a unit of force in any direction(scalar), gravity is a force with direction(vector) a newton is a unit of force, newton metres are a unit of torque!!
Posted: 27 Feb 2006, 22:15
by scoobydrew
Jesus, to technical for me I am off.

Posted: 27 Feb 2006, 23:09
by HarryMann
Yes, divide by 2 of course if there's 2 struts..
should it not be newton x metre?? i.e. Nm?
Dave is right,
NO
... if it gets any simpler than measuring a straight force, we'd be in nappies back at Kindergarten, or eating apples in Eden - what's happening to this world

Posted: 28 Feb 2006, 00:57
by HarryMann
Answer: Ah, I know it must have been when first decimalisation and then metrication came in, yes that must be it... like simplifying everything to work in multiples of tens, then silly introducing things like Newtons, bars, and KPascals and all that, damn silly idea

Posted: 28 Feb 2006, 07:20
by DiscoDave
gas strut newton force
Posted: 28 Feb 2006, 07:49
by spareuser
Thanks for that. Have weighed roof at 15kgs slightly open. can not get angle of the dangle until i've fitted hinges. They still have not turned up, Ahhhh... :
camper shop does insist they were sent???
Regards
Posted: 07 Apr 2006, 08:29
by Opium
Probably too late to comment, but am going through the same process myself, but thought the conversion had 4 struts!

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Posted: 08 Apr 2006, 08:18
by spareuser
quick update on the roof, Its all fitted and working!!
]
After a chat with mike from gas strut engineering, have fitted 2 gas struts with 400 newton each and works fine, maybe a bit of a tug to lower but as all struts leak gas over time I figured they would last longer!
Piccies?
Posted: 08 Apr 2006, 08:28
by Opium
Any chance of a photo to see how it works with new struts?

Posted: 09 Apr 2006, 08:56
by thewibbit
Hi... if you still have the old struts you could try this:
http://www.sgs-engineering.com/gas-struts/
Click on the re-gassing link. Aparrently though if you push them in and they judder really badly when they pop out again it's not worth it. Be nice to keep the originals though!