SP140 Carbon Fiber Spares

[quickdan]

I recently had an expensive situation - less than a week ago.

My carbon fiber spars got cracked when putting the hoop together. (It turns out)

On a really bad lunch (my fault) the wing went to the right, the lines put weight on the hoop, the spars snapped, the hoop collapsed and smashed the prop. One of the sections of the hoop got really bent and also stripped the sheathing on one of my C lines on my Spider 3.

No damage to me, just my pride.

Spider C lines replaced, hoop section straightened, prop and aluminum 9mm inside dia tubing in the mail.

Hope to fly again shortly.

Has anyone else had trouble with the carbon fiber spars?

This is my first PPG, but 4 years in PG - P3 with SIV.
My current thought is the SP140 with the hour battery is too heavy for a beginner in PPG.
(although, in the air and landing is sweet)
Going to step up my ground handling and try and grow some muscles.
I need to be more skilled.

[Bartlett41]

Can you give more info on your bad take off? Forward launch or reverse…?? So the spars snapped by the wing just coming up at an angle and putting pressure on them? That seems a little weird. I hope they aren’t that fragile.

[quickdan]

Reverse launch - came up straight, turned, in forward as I was running the wing went to the right, and back, I didn’t compensate enough, or kill it and start again. Lines went on to the hoop and it collapsed. They are probably not that fragile for a non-beginner, I was just curious whether it was just me or if anyone else had an issue.

[Bartlett41]

Good to know. I’d love to see pictures of the hoop where the point the lines were pressing on that. Where the damage is and whatnot.

[PilotPaul]

@quickdan
Really informative post - thanks!
I’m a wannabe and find these incidents very helpful to understand the variables and issues that can spoil the day.
Thanks for sharing your experience and lessons learned.

[Voltair]

They are not that fragile but most of the cages gas PPG included, will ovalize due to the tremendous pull and downward force exerted by the lines and the glider. That would be enough once the hoop starts bending to cracks the carbon spars.
The SP has the prop sticking out quite a bit and makes it easier for it to snag a line. Sometime, if a line wraps itself around the hub it will bring the wing to the blades and shred it. This is why inflation practice is so important. Many pilot give too much power before the gilder is fully inflated and stable overhead. Making timely corrections before accelerating is important.
I trained some of my students to not arm the motor before the wing is centered overhead and ready to go. I fly a Batch-1 and the controller switch has the timing a bit on the wonky side - I hope that will be solved in the new upgrades. Regardless, it is still possible to do. Watch one of my students doing that transition to arming the motor when he is good to go with the wing stable overhead in a steady breeze.
Anyone can do it. It is a matter of practicing the move over and over again. The ten thousand hours rule!
Too many pilots look like Dodo-Birds during takeoff.

SP 140 SCHOOL

As for the battery,… yes the one hour is nice if you can launch safely, but it is not the best choice for beginners. The half hour is more suited to learn how to fly with. Once the pilot has his skills under control he could entertain the idea of getting the one hour battery.
My students in the video had the 1 hour battery. One purchased the SP from someone who had to sell it and the one hour came with it. The other student is working out at the gym😆
I am a lightweight pilot and cannot handle the one hour in the sand where we fly. I opted for two half hour. Yes my flights are shorter, but I am having more fun with less weight to deal with. It takes less than a minute to swap a battery.
Phil

[1066]

Phil, excellent post…great information! Most of my launches are reverse launches…especially since I now have my single skin Grasshopper for nil/low wind days (I’m 65 and don’t enjoy running in the sand). In the beginning, I use to just turn and go…that was the past. Now I turn, don’t look at my wing…but stand there for a few seconds and make tiny steps and adjustments until I know the wing is perfect “by feel”…then I lean back and roll the power on. Being able to"feel" what your wing is doing …as you already know…just requires hours of kiting. Kiting is important all through this PPG journey we are on. We should never graduate from kiting. You do a Great job with your students…they are very fortunate!

With the one hour battery it sure helps to have a nice breeze. I have done one “low” wind forward launch with mine, but it was on pavement where running is easier. I have one “half hour” battery and will probably order a second.

Thanks again!

Bill

[Wadecker]

Hey dude, take a lesson from trikes. Anytime your gets too far to one side or another you and the prop is spinning you have a chance that a line(s) will get snatched by the prop. Even if you know definitely that there are cracks in the spars, it’s much more likely that a line was caught a bit and that is what pulled the hoop into the prop.
That’s exactly why trikes usually add the hoop extension to cover the prop zone, but it is not strictly limited to being a trike phenom.

[quickdan]

Sounds right. Thanks

[jsneeb]

I too have noted the carbon fiber spars are sort of fragile. I cracked the tip of one my first time assembling the cage by pushing it down to deep over the tapered edge of the post.
I since sanded the crack and super glued it with a layer of glass cloth tape over the outside saturated in super-ca glue.

Personally, i would like to try some aluminum or titanium rods.
Though what I really would like is to replace the “studs” on the frame and cage with ones that have a 8.5mm OD and so I could use something like a standard tent pole kit available online or from a camping store in a pinch as a replacement part.

https://www.amazon.com/Brightfour-Replacement-Poles-Aluminum-Female/dp/B07GBWT8YL/ref=sr_1_20?crid=2VK64AZABJYAE&keywords=heavy+duty+tent+pole&qid=1650280989&sprefix=heavy+duty+tent+pol%2Caps%2C109&sr=8-20

[quickdan]

That would be cheaper. I thought it was 9mm inside dia but it’s slightly bigger. I’m using: Order 12mm OD x 1.5mm Wall x 9mm ID Aluminum Round Tube 6060 Metric 60" Length Online, Outer Diameter: 12mm, Wall: 1.5mm, Inner Diameter: 9mm and have a 23/64 drill bit coming to ream it out a touch. I’ll let you know when I get it right.

[MikeD]

Phil, I don’t think you could adjust your hang points far enough back to fly with the one hour battery. I’m 210# and my hang points are already back on the J-bars bends in order to get the proper angle. Although, you could add a water ballast blatter like they do for the PG EN certification.

[Voltair]

You are correct about the 4kw/h weight and reason why I recommend my lightweight students not to get it. I am one of them feather pilots just under a buck fifty. My connections are as far back as they can be.

[jsneeb]

Yall need to try relocating your battery.

I am 155 in my clothes and gear, and I have the hang point within the middle section of the bend on the bars. Only mod I had to do to get comfortable hang point and riser location.

The red mark is where the sides of the ring clamp used to be before the battery move, about 1 3/4 inches down the straight part of the bars.

[1066]

Here’s an .stl file of a 60mm reinforcing sleeve for the carbon fiber spar ends of the SP140. This was designed by my friend and forum member, Jack Burton. ( jackwburton on this forum) I think it is a good idea for a retrofit. Air conception does something similar with their spars…they use a short metal sleeve with a longer section of heat shrink.

I hope this helps someone!
Bill

16od 13pt5 id 60l.stl (73.5 KB)

[satoney]

this sounds like a great solution but how and where did you move the battery to. I would like to move my hang point up is possible. thanks. are you talking about the 30 min battery or the hour battery or either?

[jsneeb]

You can see a few posts above the image where I moved the battery. It is moved to the typical gas tank area, behind and underneath the seat rather than behind your back.

I have since relocated the battery back to behind my back and am experimenting with using foam behind the seat to correct the hang point.

[satoney]

yes now I see, the battery was a little camouflaged. thanks for the clarification

[grigsby]

@Voltair

I trained some of my students to not arm the motor before the wing is centered overhead and ready to go.

That’s an interesting idea. I might try that. I keep finding that I’m triggering the throttle and spinning the prop just while getting ready to pull the wing up. I have small hands, so having the throttle controller, brake toggle, and riser in my hand is a bit of a juggling issue for me. I keep accidentally squeezing the trigger. Maybe I should try waiting until I have the wing up before arming the controller. I’ll have to practice that and see how it feels. It seems like it’d be harder to do in nil wind/forward launch though.