Wanted good conditon used square hoop to convert my round-hoop - Dave C
Gareth Griffiths NHRC
If you have a round hoop take it to a welder and for about £25 they should be able to turn it into a square hoop.
you can make a carbon one for about £50. £25 for 4 metre 32mm dia carbon tube (ebay),some 200gsm unidirectionl and some 200gsn twill, plus epoxy.
Hoop prior to finishing (sanding and 2pack finish)
Thanks for that. My hoop is ali and anodised so I think a replacement is the best way, quite fancy a carbon one - nice little winter project, I might give it a go.
Dave C.... what is more, the home built carbon built hoop (as shown in the picture) proved unbreakable - even for me!
I was wondering about that! I see the tubes are mitre joints - do you just wrap some carbon tape and then epoxy over or ist it more scientific than that? I imagine that's the critical bit to get right?
Hi Dave, Dougal broke the steel one in 3646 (pulled it out!!!)
The Carbon one should take about 3 days to make. It's actually 28mm dia tubing. Can give you sellers details if you want.
The jig is the important part, the joints are mitred and initially just epoxied (with fillers) together. It is left for 24 hrs for this initial bonding to set.
Once joined together the whole assemble is slid up and over the top of the jig, so that the cross bar as accessible. Clamp the jig vertically in a vice so that you can work on it.
Abrade the mitres prior to laying up uni-direction carbon along axis of tube and over the mitre joints by about 2inches. 3 laminates should do, shrink wrap it and keep it warm. Finally make it look pretty with some twill covering.
If it's Dougal proof it should be ok!
Just been looking at caron tube on e-Bay - it seems to come in 500mm lengths, Where did you det yours from?
Hi Dave, I got it from Chris Garrett chris_tterrag[at]hotmail.com you can call him on 07886240502 Just checked 4metre length £35 it has a key on it,which can be machined (sanded, filed,ground) off. I left it on as it's only about 1mm
Strong stuff, have used it as kingposts in the past.
Thanks Chris, I'll give hin a call.