Broken tent pole inserts

[sambar358]

I was putting up my Mountain Designs Fortress 4 season tent the other day in the backyard just to give it the once-over before winter and while flexing one of the curved over-entry poles two of the pole inserts either side of the central curved pole snapped off level with the pole ends.....bugger ! I've put this tent up heaps of times with no issues and wasn't doing anything different.....so who knows why ? I managed to get the pole inserts out as they were just glued-in & the poles are undamaged so lucky there I guess.

Problem : can't seem to ID these poles as they are not branded at all and emailing MD didn't shed any light on what they are or who made them. So I'm after some advice......poles are .335" OD, 400mm long with a wall thickness of .030". Pole inserts are 75mm long and have an OD of .275" and appear to be high tensile alloy. Can't seem to find anyone who has inserts this size : have tried ANSCO in Melb who stock Easton poles and bits....no good, Mountain Designs who hand-passed me to Remote Equipment Repairs in Pt Cook....boss Ray is away so still waiting there, and no luck with a few other tent outlets in AU and the USA. So looking for some advice on any companies that might worth contacting or if anyone has some MD poles of this description that they no longer use then I'd be keen to purchase them to get the old Fortress going again. Thanks in advance & cheers

s358

[neilmny]

Bit multilingual on the dimensions there mate....Got a picture Sambar, sounds like something any little engineering shop could turn up for you.

[andrewa]

What about this crowd? Stumbled on it the other day when trying to remove tips from old Easton alloy poles...

http://www.questoutfitters.com/tent_pol ... T%20POLES..

A

[stry]

Bit multilingual on the dimensions there mate....Got a picture Sambar, sounds like something any little engineering shop could turn up for you.

+1

Easy job for someone with a lathe and a length of alloy stock.

[Avatar]

Pole diameters are usually given in mm.

0.275"=7mm
0.335"=8.5mm

Might be time to move on.
All the connectors may be fatigued and need replacing, MD don't seem interested, and new poles will probably be > $100 to do.

[Franco]

Sambar
looks to me that your tent does not need any special poles , there is no hub or anything like that that I can see, so maybe replacing the full pole/s is the way to go.
But if you post a photo of the broken part it may give a better idea of what the problem is.

[sambar358]

Yep Franco......no hubs or anything.....just 4 multi-sectioned poles. The problem on is the shorter over-entry hoop....7 sections each 400mm with the central one curved and the others straight. Two inserts broke....one in the curved pole and the other going into the curved pole.....the pole inserts appear to be a HT alloy and both snapped clean-thru where they exit their pole.....sounded like a 22 rifle going off ! The problem is that the poles seem an odd size compared to the Easton poles for my Macpac tent....at .335" OD they are between the two Easton sizes of .333" (8.46MM) and .340" (8.64mm) and of course the Easton pole inserts to suit these sizes are either too small or too big ! Worst-case scenario is that I can make-up a pole from some spare Easton 9mm poles that I have here from my Olympus....but I'd rather not use them as certainly as soon as I cut one down to suit the Fortress I'll bust one of my Olympus poles.

Pics below are of the two snapped pole inserts....darker 1/2 is just glue residue. Cheers

s358

[neilmny]

What is the inside diameter Sambar....perhaps there is a CF rod or some aluminium rod that you could epoxy inside to rejoin them?

[stry]

Not even a step in the middle by the look of it.

Just a straight, one diameter piece of tube ?

Absolute doddle to make some !!!! Tube is readily available in a range of tempers (eg 6 series or 7 series), but anything that is not dead soft would probaby work. No need to butcher or cannibalize anything.

Just buy some tube as close to the OD as you can get, and get some one to turn it down to the right OD. Cut "em to length and glue 'em in.

[sambar358]

Thanks Stry.....yep just a straight piece of tube...no step at all. The tempered tube that you mentioned.....what's it called and where can I get some ? A mate has a lathe so I'm right to get it turned-down to size but I'd prefer to get something of the right tensile strength so I don't need to re-do them. Thanks for the input. Cheers

s358

[stry]

I'm not an expert ion this, so best to confirm, but here goes:

Usually referred to as aluminum tube or aluminium alloy tube

The alloys are usually designated with a four digit number. The first number is the temper The next three are the alloy.

So 5xxx is pretty soft. 6xxx is better. 7xxx better still,which is probably why a lot of poles are 7xxx. The 6s and 7s are often refeerd to as "structural" or "industrial" There may well be 8s and 9s, but perhaps brittleness could become an issue with these. Any body who knows more feel free to correct me.

It is a lot simpler than it sounds as I would simply phone a retail outlet and check out what they have. Sorry, I have dealt with at least one in Bayswater, but cant think of a name, although I know exactly how to get there There would be plenty in places like Bayswater and Dandenong.

Ask the counter jumper what they have in 7 series in your OD or a little bigger. Obviously your final OD must be bigger than whataver the ID is of what is offered.They will tell you and bingo. Probably any 7 series that they stock will work for you.

Your biggest problem will be getting a bit short enough and not being stuck with a 6m length.

If you cant do any good close to home, and find something around Bayswater, I am there every month or so and could pick up and post to you. Might have to cut it for the post, but that's easy if I have a specified length or lengths to cut to.

[stry]

Forgot to include - talk to your friend who will do the turning about dimensions before deciding on what to buy. Sometimes it can be hard to accurately take a very fine cut, and little more meat can sometimes make an accurate outcome easier to achieve.

[sambar358]

Thanks for that Stry.....I appreciate your detailed reply.

I've had a bit of luck just now after ringing ANSCO Pty Ltd in Melb....they stock Easton poles and components and I got one of the sales staff to run their digital calipers over the Easton .333" pole insert. It measured at .276" so only 1 thou over what these broken MD pole inserts are. I bought a few ($1.08 ea) to try and with a bit of luck they'll fit without any lathe work but if .001" needs to come off them then the mate can do that easy-enough. So a win maybe.....but time will tell. Cheers

s358

[stry]

A word of caution (maybe unnecessary) but if the inserts are a little too big, resist the temptation to whack 'em in. It could lead to a split pole. It's a subjective call, because snug/tight would be very desirable.

If it looks like being an issue, perhaps discuss with your mate when the bits are in hand ?

Either way, easier than starting from scratch.

[sambar358]

Understood Stry.....the original poles/sleeves are "snug" rather than "tight' so I'll aim for this with these new inserts and if they seem a bit tight I'll get them machined-down to the dimensions of the original sleeve rather than risk getting one stuck or stressing the pole end. Never had any issues with broken poles before in my backpack tents.....apart from last winter when a big tree fell on my Exped Venus 2 in a violent wind storm.....but that was more a "broken tent" event as the whole thing was cactus ! Cheers

s358

[north-north-west]

... a big tree fell on my Exped Venus 2 in a violent wind storm.....

I think the tent can be forgiven under the circumstances.

[Moondog55]

The old fashioned method of getting that tight fit is to use a shrink fit
Put the sleeves in the deep freezer over night and in the morning put the pole end into boiling water, insert cold sleeve into hot pole and when temperatures stabilise it should be tight and secure
The other thing is to not use epoxy glue but a high strength polyurethane, the epoxy will not hold on aluminium for long but the polyurethane is an expanding glue and holds in two ways, glue action and friction