Mid-Boom - Plastic Frame

[blade_crasher]

Hey Jerrymac and PTcflyer, plus others with experience on the mid-boom setup.

I've been flying my 550 for awhile now, but it's feeling sort of "big" for where I fly. I'm pondering buying the mid-boom and belt and transitioning to this size.

It seems like 500mm blades are the size to run, but I think I saw something that sounded like I might also run 520's. Is this true or are 500's the best size.

I'm using a gaui 850 in the 550 and other than getting warm it works great. I've got a Z20 980kv available, but even this seems a bit small, or can I gear it to make it work? What HS should I aim for with 500/520 blades?

I'm just a sport flyer, loops, circuits, etc.

Thanks in advance for your ideas.

[PTcaflyer]

...That set up, IMHO...is the best!
That is what I have running right now ...Plastic Fantastic, Mid Boom, 500CF -blades
Z20-980, CNC Head, X5 tail(entire x5 assy W/ Belt) 600LG
You can run 520's as well and have plenty of blade clearance!
PT

[fiveflat]

I've been tossing around the idea of a mid boom setup as well particularly since the 425 booms are always out of stock and I have a minor ding in mine.

But what are the real advantages of going to 500/520 or even 550 blades?

[Mikej]

Originally Posted by fiveflat

I've been tossing around the idea of a mid boom setup as well particularly since the 425 booms are always out of stock and I have a minor ding in mine.

But what are the real advantages of going to 500/520 or even 550 blades?

greater stability, kinder to batteries, flies bigger. the only down side is that cheap 500 and 520 blades aren't as common

[blade_crasher]

Is the X5 belt better than the 425/550 mid-belt I was expecting to order with the gaui boom.

Are you using an X5 boom also, or does the X5 belt match the boom?

What gearing are you using with your 980 motor?

Originally Posted by PTcaflyer

...That set up, IMHO...is the best!
That is what I have running right now ...Plastic Fantastic, Mid Boom, 500CF -blades
Z20-980, CNC Head, X5 tail(entire x5 assy W/ Belt) 600LG
You can run 520's as well and have plenty of blade clearance!
PT

[PTcaflyer]

The belt is the 500 boom kit belt and I'll check the number when I get home...
Gearing is 15/50/20/61- TC limit at 85%....I'll double check that when I get home too!

[PTcaflyer]

Belt for mid boom is the 522XL...Ya know, The Gaui Wood blades are great!
and at 15.00, not too bad at all!

[blade_crasher]

My Excel sheet estimates that gearing will result in about 2000 HS. Is that enough with only 500 blades?

That is about what I'm flying now with my 550 blades using the 850 motor with 15/42/19.

If 2000 hs is enough that is great. I will order the mid-boom and belt and upgrade the X5 tail grips.

Are you running the tail servo in the frame or mounted on the boom? I've got the boom mounts but they seem somewhat "loose" with only the single point attachment to the plastic collar.

Originally Posted by PTcaflyer

The belt is the 500 boom kit belt and I'll check the number when I get home...
Gearing is 15/50/20/61- TC limit at 85%....I'll double check that when I get home too!

[PTcaflyer]

Yep...Hyperion tail servo inside the frame...You could up the pinion size to 16 or even 18...IF you needed more head speed. I like slower for more flight time !

[Jerrymac]

My mid-boomed Hurri is built on a HeadHunter frame, running a Z30-1100 motor and stock Gaui 500mm CF blades. I run a head speed of around 2200 to 2400. I haven't tried 520mm blades on it so can't comment on them.

Like Mike mentioned, the only downside to 500mm blades is that there aren't really any decent low-cost blades around. The Gaui blades are $60 I think.
The 500 is a nice size, probably my favorite. I like flying my 425's and my 550 but the 500 just has that "perfect feel" to it. More stable than the 425's, but much quicker than the 550. It is also easier on the batteries than the 425's which I run at around 2800 to 3000 head speed on. I use the same 6s 2650mah batteries in both, but, on the 500 I use a small 3s 1000mah RX battery mounted in the front to get the CoG spot on.

Not sure what the efficiency rating is on the Z20-980, but, at 90% you would get a head speed of around 1950 to 2150 running 16/50/19/61 gearing. If you already have a 50T first gear installed you can try it with a 16T pinion and see how it flys. If it needs more head speed you can run a 42 front with a 15T pinion and get somewhere around 2200 to 2400. Keep in mind that these are just "guesstimations" on the head speeds as the nominal voltage on a 6s is 22.2 and the charged voltage is 25.2, so it should be somewhere in that range depending on the motor efficiency.

[Mikej]

2000HS is fine for sports flying and circuits - Jerry is just mad for HS

The best 500mm blades that I found for quality against VFM are the Z-weaves from HK

[blade_crasher]

At the risk of being laughed at or warned away, what do you think about the idea of "cutting down" a spare set of Align 550 CF blades I have. They had a tip strike once and the tips are "worn" some. I'm flying undamaged 550 CF backup Align blades in the 550 build.

Thought I might just take a hacksaw and carefully trim them to 500 (or maybe 520 first), bevel the edges of the cut and apply a light epoxy coating to bind the loose fiber ends or whatever is in there.

Would wear my respirator during the sanding - don't want to breath that stuff.

[PTcaflyer]

...Depends on what you call a "Strike" IF it was just a tip over and ground the tips on pavement or ground during spool down, then I would just sand smooth and re paint and balance...Let's see a photo of the damage...

[SQRT(-2)]

Originally Posted by blade_crasher

At the risk of being laughed at or warned away, what do you think about the idea of "cutting down" a spare set of Align 550 CF blades I have. They had a tip strike once and the tips are "worn" some. I'm flying undamaged 550 CF backup Align blades in the 550 build.

Thought I might just take a hacksaw and carefully trim them to 500 (or maybe 520 first), bevel the edges of the cut and apply a light epoxy coating to bind the loose fiber ends or whatever is in there.

Would wear my respirator during the sanding - don't want to breath that stuff.

I would not do it. Something that spins at a couple thousand RPM and is that long I would not risk. Besides CF and FG blades are a shell built up around wood or foam, I don't know what it would do to the strength of the blade to be 'open' on the end.

[Mikej]

Originally Posted by blade_crasher

At the risk of being laughed at or warned away, what do you think about the idea of "cutting down" a spare set of Align 550 CF blades I have. They had a tip strike once and the tips are "worn" some. I'm flying undamaged 550 CF backup Align blades in the 550 build.

Thought I might just take a hacksaw and carefully trim them to 500 (or maybe 520 first), bevel the edges of the cut and apply a light epoxy coating to bind the loose fiber ends or whatever is in there.

Would wear my respirator during the sanding - don't want to breath that stuff.

It depends on the blades - most blades have a foam core (or wood on some) and a lead weight in the front tip of the blade - you risk weakening the blades if you cut back far enough to get back to the core, and the idea of lead weights flying about at 200mph doesn't bear thinking about - personally I wouldn't do it, but if you do then make sure you video it for our enjoyment, plus you could watch it in hospital

[blade_crasher]

Watching my stupidity in the hospital does not sound fun. Guess I will look for 500mm blades. Thanks to all.

[PTcaflyer]

...Get a set of the Gaui Wood 500mm blades and try 'em...no biggie at $15 bucks
I HAD a set of Z weaves and they were nice...for a while anyway untill I tried to cut up asphalt with them...I have bought some like new but used 500CF blades here on the Freak...still flying on one set and a set in the gubbins drawer...

[Jerrymac]

Originally Posted by Mikej

2000HS is fine for sports flying and circuits - Jerry is just mad for HS

I like 'load testing' my batteries.

I wouldn't recommend cutting down any blades. I once dropped my 550 while loading my helis in the truck. I looked it over but didn't see any damage. I spooled it up in the driveway to make sure it was OK, and the little weight flew out of one of the blades and shattered one of the windows out of my garage.