HMA 500 versus HMA 300

[morris 0]

I´m sorry for everyone I´m boring with linedrag once more! (in case - just stop reading)

Sometimes like ten weeks ago Mel wrote, that the line PD calls HMA 500 is a 450 line and what they call HMA 300 is a 350 line.

If you calculate the diameter of those linetypes, the difference ("circle-surface-calculation") is just about 11% - if there wouldn´t be the brakelines that are way thicker on both linesets and causing therefore a bigdeal of the overall linedrag.
1st conclusion: The difference in overall linedrag is for sure way less than 10% (being optimistic for the thinner lines). That´s not even including "reynoldsnumber", if you include it, it´s eating up even more of this advantage...

Now I´ve been thinking about the fact that the wing is causing for sure way more drag than the parasite drag created by pilot, lines, etc. (otherwise a ghostrider would be a suicide mission).

Optimistic again for the advantage of thinner lines you could say that the wing has just a bit more drag than the "parasites" (might be even a lot more, I don´t know) and doing so calculate the wingdrag with 60% of the overall drag of the system and the parasite drag with 40%.
Doing this, the difference would be down to an advantage of less than 4% overall drag.
This would still make sense...
But:
The parasitedrag created by the pilot is at any given speed about ten times as high as the drag created by the lines :-(
Now we´r down to less than 0.4% and most likely even way less...
Couldn´t it be that - if there´s a difference in performance - it is most of all a psychological one?
I remember Jonathan saying "give me 500 - I don´t care"...
I´m not saying that thinner lines in general doesn´t make sense.
Theory is just saying, that from a certain point on, it doesn´t really make sense anymore...
For me the difference between Vectran 500 and HMA 500 is quite big, but the difference between those linetypes is way bigger and in addition it takes place in an "diameter-area" where it still makes sense to "downsize line diameter".

So the question goes especially to pilots with experience on Velos with HMA 500 and HMA 300:
Do you see a REAL difference in performance or does it just make you feel better?

Thanks for any opinions,
Morris

[ianmdrennan 2]

Compared to 500 Vectran, yes (although I have the PD 300 HMA). I remember jumping Isaiah's 96 a while back with 500 HMA and I liked it more than the 500 Vectran.

The plan is to get a 2nd velo this summer and get 500 HMA on that one so I can compare properly. If the difference is negligible I'll probably settle for the 500 HMA since I dont like

1) Worrying about blowing a line off on a terminal jump.
2) Having to replace my lines approx 200 jumps.

Honestly, I'd guess a large part of the difference is 'making us feel better'.

Nice read though.

Blues,
Ian

Performance Designs Factory Team

[superstu 0]

personally i think the real advantage to the smaller line doesn't come with the overall top speed of the canopy, but in the mantenance of that speed the pilot has generated. i've flown both the 300 and 500 and i feel that with the 500 i lose the speed that i have generated quicker then that of the 300. also noticed a definite increase in distance when switching the lines in favor of the 300. however, yes, if you give tagle or jaymo or any other quality pilot either type of line they'll most likely whoop some ass.

does this make sense?

Slip Stream Air Sports
Do not go softly, do not go quietly, never back down

[proswooper 2]

i have been replacing my hma300 at around 450+ jumps but i guess i have more lines than you?!

[morris 0]

You´r saying you "feel"! that you would keep the speed longer...
Do you have any numbers at hand about differences in distance?

And, can´t it be that thinner lines recover a bit faster??
If thats correct you´d need to initiate a bit higher on thicker lines. Otherwise you´d need a bit more rearinput and this could be what´s killing a bit of the speed...
Thoughts on this?

[superstu 0]

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Do you have any numbers at hand about differences in distance?

compared to a velo w/ 500 i'm going about 6-12% further on a regular swoop, and i've gone 25% further on my longest swoop.

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And, can´t it be that thinner lines recover a bit faster??

i don't have any factual data on this, but can tell you what i "feel" the canopy is doing AND also hear what the canopy is doing from video on the ground. i do infact feel that the canopy is able to recover quicker with the thinner lines. i say this for a couple of reasons:
1. with more speed you have more lift, with more lift it's harder to keep your canopy in a dive so when you stop rotation the canopy wants to come out of the dive as soon as possible. and with the higher the air speed the quicker the recovery.
2. with thinner lines the suspened weight (the pilot) is able to get through the recovery arc quicker because the air resistance (drag) caused by the lines is actually less. this is kind of like doing your turn with your legs fully extended you'll actually stay in a dive longer then if you had them tucked in.
3. also, with more speed your inputs become more sensitive. so the amount of rear riser or toggle input needed is less, but applying these inputs also shortens the recovery arc.

however, even though with the added speed and efficiency of the lines helping you get through the recovery arc faster (if done correctly) you still go through the altitude quicker because you are going at a faster speed. so really you shouldn't be starting lower with the smaller lines you should be starting at roughly the same altitude or higher.

but then again swooping is largely based on theory, and with the very next post we could find out something new and my whole post could go up in smoke. that's the beauty nobody really knows

Slip Stream Air Sports
Do not go softly, do not go quietly, never back down

[masterrigger1 2]

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i have been replacing my hma300 at around 450+ jumps but i guess i have more lines than you?!

Paul, Just a foot note...the lines that you and everyone else is callind 300 is actually 340LB!

You guys are going to have me calling it 300 and it's my line FCOL.

Cheers,
MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

[proswooper 2]

i know mate! i keep calling it 300 for some stupid reason.

if your talking about your blue coated line i dont have it on my current canopies but will have it on my next two that are arriving soon.

[Canuck 0]

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if your talking about your blue coated line i dont have it on my current canopies but will have it on my next two that are arriving soon.

You're going to use an aftermarket line on your JVXs? Do you prefer Mel's blue lines to the 300 HMA that comes from the Daedalus factory?

Canuck

[proswooper 2]

no i am talking about getting a lineset from the factory that has the blue coating

[morris 0]

So far, superstu has been the only one to come up with some numbers.
Anyone else please?

Mel wrote me that in his opinion the difference between 340 and 450 could only be notified by "the most attuned pilots"...

[masterrigger1 2]

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no i am talking about getting a lineset from the factory that has the blue coating

It is the same. In fact they (NZA) got My order and I am still sitting waiting on a new batch FCOL.

Cheers,
MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

[RMURRAY 1]

my buddy just got the blue 340HMA on his Velocity90 - he has well over 1000 jumps on the canopy with the stock Vectran. I will let you know what he says after the first jump on MELs lines. Won't be numbers, just an impression.

rm

[morris 0]

Thanks, please let me know, I expect the difference to be quite reasonable.
What I´m still more interested in is the differences inbetween the different types of HMA, 300 (340) and 500 (450).

[RMURRAY 1]

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my buddy just got the blue 340HMA on his Velocity90 - he has well over 1000 jumps on the canopy with the stock Vectran. I will let you know what he says after the first jump on MELs lines. Won't be numbers, just an impression.

rm

"definitely faster" was the comment....

what is the size of the HMA that PD sells, is it about the same size as the standard vectran?

rm

[kamalasound 0]

I have both lines on my velos and honestly think there is a difference between the 2.

[morris 0]

So, what is the difference in your opinion?

[kamalasound 0]

Faster overall, but I feel the difference during the recovery arch; it does seem to lose less speed than the 500