BROKEN bolt? Are your goose-neck bars strong enough? Paramotor geometry part 24

[@markweston7198]

I greatly appreciate this series of videos. I have enormous faith in my choice of paramotors. Patiently waiting for my new Scout to arrive! :)

[@RwP223]

Many motor frames have dealbreaker swingarm attachments, from hanging off a bolt and/or loose wobbly connections.

[@WoodysGamertag]

I'm still loving this series. FYI, that second pilot's machine had a grade 5 bolt in it. I'm pretty sure that they've either upgraded the bolts they use or it was always meant to be a better bolt and they grabbed from the wrong bin. That doesn't invalidate anything you've said, but it's good to know. :)

[@SCOUTaviation]

+WoodysGamertag and it has thread unnecessary long making it weaker...

[@SCOUTaviation]

+WoodysGamertag yet, the safety margin should be way more than just a difference of bolt grade...

[@CalebJohnsonlivingca]

As an engineer, this gives me a hard one.... fantastic engineering ;D

[@skipnoel]

You mentioned that there is a constant lateral load due to the riser angle. Is there any value to mounting the bars at an angle to match that of the risers? The bars would then pivot down and slightly in rather than straight down.

[@rickardjonsson4526]

I know this comment is years old but this videos will be relevant for a long time. That load can be fixed by tensioning the cheststrap so the bars cant be bent outwards from the neutral position. Miniplane has this in their manual

[@lobbyrobby]

Excellent video. I've been wanting to get into paramotoring for years and doing lots of research on which paramotor to buy after training. Scouts are amazing machines but I wonder if they are good for beginners. I'd probably be crashing a lot.

[@SCOUTaviation]

If you have a good instructor there is no reason for crashing in the first 6 months after training. Later the intermediate syndrome kicks in and you will start making shortcuts ("i see my glider is not stretched perfectly into the wind but I am too lazy to unstrap and readjust"). Then you will pay for your first prop and if you learned your lesson you will keep that for a long time:-) It is sad that many pilots take crashing for normal. It is not. Landing is normal. yet even the scout can take some beating: kzbin.info/www/bejne/onecnoSpg6t_eLM

[@rickardjonsson4526]

What grade bolt would you belive is best suited in this application?

[@vulturepowerppg4115]

What about using no bars or suspension system? Harness with connected to motor with stronger straps?

[@Pestifer138]

Do I have to lubricate the Swingarms, what kind of oil is appropriate?

[@michroz]

Hmm... I would like to dispute a little here. On my paramotor this joint is flexible (a rubber bushing is introduced into the joint). This fact a) prevents the bolt from tensile stress and b) gives a great deal of flexibility and comfort. Because the bars are flexible in sideways direction. Additionally, probably, this allows more weight shifting as compared to the non-flexible version. I find this solution comfortable and safe. Never saw any problem with this, never a sign of wear. The danger of the "scissors" effect, I believe, is slightly exaggerated, since there is only a limited load on this bolt. Have you calculated how much load there actually is in this direction? The stress from the wing to the bars is applied at the carabiners attachment points, while the great deal of pilot weight is applied at the bar front end, where the sit is attached (notice your video example of the collapsed bar!). The bar bolts are loaded mainly with the paramotor(+frame+fuel) weight only. If we look at the bar from the side, we can clearly see the levers ratio of the front end and the bolt end of the bar relative to the carabiners(~1:2). Well, the propeller thrust is also applied to the bolts. This gives us additional up to ~80Kg of peak load on this joint. In horizontal flight it is much less though. I cannot say how much of this thrust is applied actually to the pilot's back thru the harness (and, hence, to the front of the bar thru the sit-to-front bar attachment). Anyway, the scissor effect for the forces of this proportion is nothing for the 2, say, M10 steel bolts. On contrary - I see some noticeable wear on your demonstrated (very well engineered indeed) wide plate joint. This convinces me that the joint probably _must_ be somewhat flexible. And probably it is better to be steel, not Aluminium. Alu is eventually worn out with the constant relative rotation friction and the inevitable sideways motion of the bars.

[@roberte.3541]

Why not put a backup cable so if the bar does break you'll have some redundantcey

[@577buttfan]

You can use a strap also.

[@stanRmeyer]

in considering the bolt breaking the vibration in the motor can have a detrimental effect on the life of the bolt!

[@YankeeinSC1]

Obviously cost is a consideration in any manufacturing process. Amortizing tooling costs over short production runs, adds further to the cost per part. There just isn't an enormous market for goose neck arms, but why don't manufacturers forge these critical components?!!!!! Bolt grade technology is a proven science with nothing left to chance when aviation grade components are selected. Paraglider manufacturers shouldn't have to reinvent that wheel.

[@RealDonLarson]

Try a 3/4 inch Grade 8 bolt and it won’t break any more.

[@dekutree64]

Why not carbon fiber for the bars?

[@SCOUTaviation]

+dekutree64 could be but not hand made as inconsistent quality of the bars would be deadly... Machine made carbon bars would do a good job...

[@Henrik.Yngvesson]

Carbonfiber use to be sensitive to cracking straight through if scratched.

[@progDes]

With these videos you are forcing me to become the first Scout owner in my country. Stop it :)