Author Topic: Crossfire Extreme XLTC (Read 20902 times)

Bob Hunt · « **on:** March 10, 2013, 12:23:10 PM »

Hi all:

Just thought you might like a sneak preview of my newest Crossfire variant. I call this one the Crossfire Extreme XLTC. The XLTC stands for Extra Long, Tricycle Landing Gear. As the name suggests, this one is longer than the previous variants in both nose and tail moment. The wing and tail are also increased in span. Overall this is a more stretched look and I think it is much sleeker. Yes, those are simulated gear doors and they will hide the arming switch, the timer start button and the timer pin access. I wanted to be able to get quickly to the timer pins just in case I needed to change the program just before I have to fly in competition. Not having to open the hatch to do this makes life easier.

The projected weight is 61 ounces with the battery on board, so it is on track to be about an once and a half lighter than last year's ship. The motor will be a Power 25 from E-Flite and I plan on being able to use a 3300 mAh pack.

I have wanted a another tricycle landing gear ship for years. I have had a few of them in the past. The first of my competition trike gear ships was my Avanti design. Those of you who might think that is a Bob Baron design, well, you are half right. Bob did have an Avanti, but it came years after I had mine!

I also had a semi-scale F-105 Thunderchief that had trike gear. I just love the way they ground handle and I also like the aggressive look of the trike gear. I'll throw in a couple of shots of those planes here as well.

I have to detail fit the hatch, make "real" main gear spats and then I'm ready for finish on the XLTC.

Later - Bob Hunt

Matt Colan · « **Reply #1 on:** March 10, 2013, 12:58:11 PM »

Hi Bob,

Looks great so far!!! Can't wait for the finished product!

How much did you stretch it?

Bob Hunt · « **Reply #2 on:** March 10, 2013, 01:31:39 PM »

Hi Matt:

I extended the nose just about one inch in length and the tail was moved back 1/2 inch. The wing span was extended by 2 inches and the tail span was also increased by about an inch. The flap chord was reduced just a bit from the 2012 rebuild's dimensions. I've also installed somewhat slower controls. I think all these tweaks are in the right direction...

Later - Bob

Jeff Traxler · « **Reply #3 on:** March 10, 2013, 02:15:36 PM »

Hi Bob,
I like the trike gear.That and the subtle changes make it look like it just came in from a 1600 mile crosscountry.Is there enough room in there for a Power 32 so you can use 5s packs?I like the extra voltage.
Trax

john e. holliday · « **Reply #4 on:** March 10, 2013, 02:59:23 PM »

Looking at the pics with out color reminds me of the RPV's our heroes are flying. I love it and imagine it will be even better when finally dressed in colors.

Bob Hunt · « **Reply #5 on:** March 10, 2013, 04:13:00 PM »

Gee Doc, ya' know, it does! The paint will fix that for sure...

Here are a couple more shots. I made the "real" spats (the spats shown in the previous photos were just templates to get the right "look") and installed and sanded them. I'm pretty happy with the looks of this one. It has an aggressive look I think.

Jeff: At the weights we are attaining I just don't think the Power 32 and the 5S are necessary, but, yes, I could install a 700kv motor and a 5S battery if I wanted to.

Later - Bob

George Grossardt · « **Reply #6 on:** March 10, 2013, 05:11:52 PM »

Cool...different...bet it will get some style points...

Have fun with the finishing process.

Dan Bregar · « **Reply #7 on:** March 10, 2013, 06:17:54 PM »

Hi Bob

Interesting ventral finnage fore and aft.

Dennis Adamisin · « **Reply #8 on:** March 10, 2013, 08:01:17 PM »

Looking mighty fine! Also looks like quite log jam at the paint booth - git em done Bobba!

Bob Hunt · « **Reply #9 on:** March 10, 2013, 08:25:17 PM »

Hi Dan:

The thingies in the front on the bottom are not fins, they are simulated nose gear doors...

I've always liked Jim Kostecky's Formula S design and it had similar doors; I just took the illusion a bit farther. Maybe too far? I'm sure they will look more like they were intended to when the paint goes on. I may even de-emphasize them a bit... Naaah!

I wanted an extreme "rake" on this one, and such an aggressive look that -- as Frank Imbriaco just emailed me -- people will fear it will bite them if they get too close. I've drawn probably hundreds of sketches of aggressive looking designs over the years (Well, who hasn't?), and when it came time to build a few of them, I've toned down the extreme looking features. On this one I wanted to just let it all hang out.

Denny: Yeah, the old spray booth is going to receive quite a workout pretty soon. I'm finishing the Second Wind twin design, this one and perhaps even the Rounder that is here on another thread.

Later - Bob

Crist Rigotti · « **Reply #10 on:** March 10, 2013, 08:37:29 PM »

Bob,
How do you do the LG in the wing for a foam wing and trike gear? I'm guessing instead of ribs going forward they go aft!

Bob Hunt · « **Reply #11 on:** March 10, 2013, 08:44:44 PM »

Hi Crist:

You guessed it. And I put a secondary spar in the aft foam support spar. See the attached photos...

Later - Bob

James Mills · « **Reply #12 on:** March 10, 2013, 10:11:16 PM »

Bob,

Very cool, I like the trike gear. The gear doors on the nose and flavor to a point are reminiscent to the Formula S to my eye, one of my favorites. I've played with the idea of dressing up a modern electric with the Formula S aesthetics.

James

Howard Rush · « **Reply #13 on:** March 10, 2013, 10:16:58 PM »

I don't like the color as well as last year's, but it's better than the metallic brown.

Crist Rigotti · « **Reply #14 on:** March 11, 2013, 05:57:53 AM »

Quote from: Bob Hunt on March 10, 2013, 08:44:44 PM

Hi Chris:

You guessed it. And I put a secondary spar in the aft foam support spar. See the attached photos...

Later - Bob

Great idea! Thanks Bob.

bob whitney · « **Reply #15 on:** March 11, 2013, 09:23:42 AM »

Bob, what is the wing area ??

Randy Powell · « **Reply #16 on:** March 11, 2013, 01:22:07 PM »

Very slick. I like the idea of hiding the arming switch and start button and such. I may steal, ah appropriate, that idea for my new plane.

Bob Hunt · « **Reply #17 on:** March 11, 2013, 02:02:50 PM »

Hi Bob:

The wing area is about 660 squares.

Randy: Steal away; I stole the idea from Kostecky...

Later - Bob

Bill Little · « **Reply #18 on:** March 11, 2013, 02:31:50 PM »

Hi Brother Bob,

I think this one is another awesome design from the mind of a great innovator. Thank you for sharing all of your "secrets" with us!

Bill

Bob Hudak · « **Reply #19 on:** March 11, 2013, 07:36:52 PM »

Awesome plane Bob ! Can't wait to see the paint scheme you cook up for this bird.

Mike Ferguson · « **Reply #20 on:** March 12, 2013, 12:01:56 PM »

Looks great, Bob!

If anything, it reminds me a little of the original R/C Crossfire you built ...

Bob Hunt · « **Reply #21 on:** March 12, 2013, 12:07:02 PM »

Hi Mike:

Yeah, there is more than just a little dose of that ship here...

Hey, call me sometime dude! You now live just around the corner. I still have a wing in the shop that belongs to you. It is well aged...

Later - Bob

bob whitney · « **Reply #22 on:** March 12, 2013, 03:04:33 PM »

Bob, what prop do you think you will start with on the E-25,

Bob

bob whitney · « **Reply #23 on:** March 12, 2013, 03:05:51 PM »

Bob, thinking about doing an E-formula-S

Bob Hunt · « **Reply #24 on:** March 12, 2013, 04:18:16 PM »

Hi Bob:

That's an easy one! The 12 x 6 EP APC. That is the prop that made last year's Crossfire "come alive." Albeit after the Nats...

Not sure that would be the right prop for a Formula S sized ship, however. The Crossfire is about 40 square inches bigger than the Formula S.

Bob

Tom Niebuhr · « **Reply #25 on:** March 14, 2013, 07:23:48 AM »

Bob,
Looks great. Can't wait to get back to my e-project!

Mike Ferguson · « **Reply #26 on:** March 14, 2013, 01:45:57 PM »

Quote from: Bob Hunt on March 12, 2013, 12:07:02 PM

Hi Mike:

Yeah, there is more than just a little dose of that ship here...

Hey, call me sometime dude! You now live just around the corner. I still have a wing in the shop that belongs to you. It is well aged...

Later - Bob

Aged a bit longer than I would've liked! Hopefully it's like a fine wine ...

Will touch base with you soon - hopefully I can pick your brain about how to turn the wing into something e-powered ...

Bob Hunt · « **Reply #27 on:** March 14, 2013, 04:01:34 PM »

Quote from: Mike Ferguson on March 14, 2013, 01:45:57 PM

Aged a bit longer than I would've liked! Hopefully it's like a fine wine ...

Will touch base with you soon - hopefully I can pick your brain about how to turn the wing into something e-powered ...

Well, that might be slim pickings, but I'm more than sure we can turn that into an E-wing!

Give me a call - Bob

Allan Perret · « **Reply #28 on:** March 25, 2013, 08:19:37 AM »

Quote from: Bob Hunt on March 10, 2013, 04:13:00 PM

Gee Doc, ya' know, it does! The paint will fix that for sure...

Here are a couple more shots. I made the "real" spats (the spats shown in the previous photos were just templates to get the right "look") and installed and sanded them. I'm pretty happy with the looks of this one. It has an aggressive look I think.

Jeff: At the weights we are attaining I just don't think the Power 32 and the 5S are necessary, but, yes, I could install a 700kv motor and a 5S battery if I wanted to.

Later - Bob

In second picture, looks like the fuse is open at the rear. Is that for cooling ?

Dean Pappas · « **Reply #29 on:** March 27, 2013, 08:14:39 PM »

Yes, Allan it is.

Dean

James Strickland · « **Reply #30 on:** March 27, 2013, 10:08:01 PM »

Quote from: Jeff Traxler on March 10, 2013, 02:15:36 PM

Hi Bob,
I like the trike gear.That and the subtle changes make it look like it just came in from a 1600 mile crosscountry.Is there enough room in there for a Power 32 so you can use 5s packs?I like the extra voltage.
Trax

Hey Jeff, What exactly is it that you like about the "extra" voltage of a 5s over a 4s pack?

Jeff Traxler · « **Reply #31 on:** March 29, 2013, 11:22:13 AM »

Hi James,
I like the extra voltage because it offers a bit more headroom.I can find 5s packs that weigh close to a 4s pack so I don't pay too much of a weight penalty.I feel that my 5s setups run cooler because of the reduced amperage.Some may think it's overkill but having a little too much comes in handy on the windy days.
Trax

Bob Hunt · « **Reply #32 on:** March 29, 2013, 01:23:00 PM »

I'm only using 1800 to 2100 mAh out of a 4000 mAh pack. I have tons of head room!

Bob Hunt

Jeff Traxler · « **Reply #33 on:** March 29, 2013, 05:59:41 PM »

But Bob,It was the extra voltage that got Frankenstien goin'.....Extra amperage would have cooked him

Bob Hudak · « **Reply #34 on:** March 29, 2013, 08:52:52 PM »

But Jeff,
Current in amps is equal to the applied voltage divided by the resistance.

Peter Germann · « **Reply #35 on:** March 30, 2013, 05:29:52 AM »

Quote from: Bob Hunt on March 12, 2013, 04:18:16 PM

The 12 x 6 EP APC. That is the prop that made last year's Crossfire "come alive." Albeit after the Nats...
Bob

Bob, what is your T/O RPM with the 12 x 6 EP APC and which was the prop(s) you've used before?
rgds, Peter

Allan Perret · « **Reply #36 on:** March 30, 2013, 06:16:20 AM »

Hey Bob:
Will you be offering foam wings and/or lost foam jigs for the XLTC version ?

Dennis Adamisin · « **Reply #37 on:** March 30, 2013, 06:58:58 AM »

The Crossfire looks great as a trike. Everything you have done here looks like a bold step forward. Keep plugging away!

Bob Hunt · « **Reply #38 on:** March 30, 2013, 07:38:57 AM »

Quote from: Allan Perret on March 30, 2013, 06:16:20 AM

Hey Bob:
Will you be offering foam wings and/or lost foam jigs for the XLTC version ?

Hi Allan:

Yes, certainly both foam and Lost-Foam components are available for the XLTC. The only real differences in the XLTC compared to the Crossfire Extreme standard are a 7/8 inch longer nose moment, a 1/2 inch longer tail moment, a 2 inch longer wing and a 1/2 inch longer tail. Oh, and the tricycle landing gear...

Denny: It's starting to look more like your Eclipse isn't it?

Later - Bob

Howard Rush · « **Reply #39 on:** March 30, 2013, 11:40:01 PM »

I would be worried that with tricycle gear, a tailwind could flip it over.

Bob Hunt · « **Reply #40 on:** April 01, 2013, 05:07:25 AM »

Quote from: Peter Germann on March 30, 2013, 05:29:52 AM

Bob, what is your T/O RPM with the 12 x 6 EP APC and which was the prop(s) you've used before?
rgds, Peter

Hi Peter:

The TO RPM is in the 8,700 range. I initially used a 13 x 5EP APC prop. The 12 x 6 works much, much better! Thanks go out to Paul Walker for the suggestion to try the 12 x 6.

Later - Bob

Ward Van Duzer · « **Reply #41 on:** April 01, 2013, 08:59:52 AM »

Bobba,

Slick as sn-t. but which way is forward?

Ward-O

Tom Niebuhr · « **Reply #42 on:** April 01, 2013, 10:33:08 AM »

Ward-o,
That was BAD!

I can't wait to see the new Crossfire and the Twin completed. And they will not have Brown or bronze on them.

But I will have some metallic brown on my new airplane!

PJ Rowland · « **Reply #43 on:** April 01, 2013, 06:08:43 PM »

Bob : Finish one project at a time....

You're making us look bad.......

Crist Rigotti · « **Reply #44 on:** April 01, 2013, 08:56:26 PM »

Quote from: Bob Hunt on April 01, 2013, 05:07:25 AM

Hi Peter:

The TO RPM is in the 8,700 range. I initially used a 13 x 5EP APC prop. The 12 x 6 works much, much better! Thanks go out to Paul Walker for the suggestion to try the 12 x 6.

Later - Bob

Bob,
When you say try the 12x6 prop, which prop do you mean specifically? Thanks.

Bob Hunt · « **Reply #45 on:** April 02, 2013, 05:29:17 AM »

Quote from: PJ Rowland on April 01, 2013, 06:08:43 PM

Bob : Finish one project at a time....

You're making us look bad.......

Hi PJ:

Each one of my many personalities is working on only one project each...

Bob Hunt

Bob Hunt · « **Reply #46 on:** June 02, 2013, 01:39:43 PM »

Here's a progress report on my new Crossfire Extreme XLTC:

The main trim color is on here. Red is next!

Later - Bob Hunt

Tim Wescott · « **Reply #47 on:** June 02, 2013, 02:04:29 PM »

Bronze highlights would look good on that.

I'm partially colorblind so I can't tell if that's a gray-blue, a dark green-blue, poiple, or what. What is it?

(and yes -- my wife helps me out on color schemes if I venture beyond red, white and blue)

Bob Hunt · « **Reply #48 on:** June 02, 2013, 02:08:23 PM »

Hi Tim:

It's a dark blue. All my planes will be Red, White, and Blue from now on to show my patriotism...

Here are a couple more shots of it as it sets now.

Bob

FLOYD CARTER · « **Reply #49 on:** June 02, 2013, 02:41:30 PM »

That canopy (?) style seems to be popular. I suppose it doesn't matter on a model, but on a real plane it would be uncomfortable if the pilot had to lie down (feet get in the way of a clear view of oncoming traffic?)
Floyd

Bob Hunt · « **Reply #50 on:** June 02, 2013, 02:54:31 PM »

I've lost a lot of weight, Floyd...

Bob

RC Storick · « **Reply #51 on:** June 02, 2013, 05:35:36 PM »

Where do I get a needle nose spinnner like that one?

Bob Hunt · « **Reply #52 on:** June 03, 2013, 06:41:18 AM »

Good morning, Sparky!

That spinner is a Randy Smith/Aero Products unit that was modified by Jersey Jim Martin (The designer of the famous "Banshee" RC Pattern ship) for me. He clamped the spinner base side down onto a rotary dividing table and then used a straight end mill to make the "gun port" slots. I'm not sure that the slots actually make the motor run any cooler, but they make the plane look cooler...

He also used the rotary dividing table to drill evenly spaced holes in the backplate. I think it is required to have angled slots in the backplate to induct air into the plenum chamber in front of the motor. Of course all this works only if you also have a motor mount that has passage holes for the air. For instance, the Hardnose mount that I offer has those holes and they line up perfectly with the cooling slots in the motor.

I spoke with Jim about doing the slots in the spinners and the holes in the backplate for others, but he is not interested in getting into that business. Sorry. I'm sure that Jim Lee could do this operation, and I suggest getting in touch with him about it.

Later - Bob

Bob Hunt · « **Reply #53 on:** June 03, 2013, 06:46:50 AM »

Quote from: FLOYD CARTER on June 02, 2013, 02:41:30 PM

That canopy (?) style seems to be popular. I suppose it doesn't matter on a model, but on a real plane it would be uncomfortable if the pilot had to lie down (feet get in the way of a clear view of oncoming traffic?)
Floyd

Had a thought on this, Floyd; Profile models with painted on canopies would be even more uncomfortable for the pilot, and just as hard to see from...

Seriously, these models are in no way meant to be scale models, rather pieces of flying artwork that reflects the personal styling preferences of the builder/finisher. Let's not examine them too closely for scale effect. "Real" planes are not tethered and flown in circles around the pilot either...

Bob Hunt

Randy Powell · « **Reply #54 on:** June 03, 2013, 09:55:20 AM »

Boy, Bob has that right. My current model (in finishing process) would be a killer for the pilot. Probably literally. Could see much but the dashboard.

Steve Helmick · « **Reply #55 on:** June 03, 2013, 11:56:02 AM »

Sparky and Bubba both have cooling air going through the fuselage and out the back. Did you "waterproof" the inside, and are there no bulkheads or framework to stiffen the sides, etc.? I'd love to see construction pictures of that. I'm concerned that flying in even misty conditions, the fuselage could absorb water, shift the CG and ruin the finish from the inside. Show us! (PLEASE!)

Steve

Bob Hunt · « **Reply #56 on:** June 03, 2013, 09:21:25 PM »

Okay, got a bit of the red on today; more to go...

Steve: Yes, the fuselage is open all the way through for cooling on very hot days. I can seal off the opening into the fusselage for rainy days and just use the air outlet in the bottom of the cowling. That outlet is between the simulated gear doors and has a wicker bill in front of it to make it scavenge quickly and completely.

Later - Bob Hunt

Randy Powell · « **Reply #57 on:** June 03, 2013, 09:40:12 PM »

Looks very cool, Bob. Where's the bronze?

Mark Scarborough · « **Reply #58 on:** June 03, 2013, 10:10:37 PM »

Geez Bob,, whats taking so long,, that stuff is ready to mask in like 45 minutes,, ya coulda painted the whole thing in one day

Bob Hunt · « **Reply #59 on:** June 04, 2013, 04:53:20 AM »

Quote from: Mark Scarborough on June 03, 2013, 10:10:37 PM

Geez Bob,, whats taking so long,, that stuff is ready to mask in like 45 minutes,, ya coulda painted the whole thing in one day

Mark: You're right; I'm so ashamed...

Randy: The "bronze age" is over...

Bob

Randy Powell · « **Reply #60 on:** June 04, 2013, 09:20:17 AM »

>>Randy: The "bronze age" is over...<<

Finally went through that 55 gallon drum, huh?

It looks really good, Bob. And don't listen to Mark. A good finish takes time.

Mark Scarborough · « **Reply #61 on:** June 04, 2013, 11:45:32 AM »

............................................

Matt Colan · « **Reply #62 on:** June 04, 2013, 09:14:43 PM »

It's looking real good Bob!

john e. holliday · « **Reply #63 on:** June 05, 2013, 09:06:19 AM »

Quote from: Randy Powell on June 04, 2013, 09:20:17 AM

>>Randy: The "bronze age" is over...<<

Finally went through that 55 gallon drum, huh?

It looks really good, Bob. And don't listen to Mark. A good finish takes time.

As does building planes.

Bob Hunt · « **Reply #64 on:** June 05, 2013, 07:19:28 PM »

Getting close! The red's all on and the canopy has been shot. Tomorrow all the letters and numbers go on. Friday is a bit of cleanup (very, very little this time!) and it's off to the spray booth for clear. Should be flying by next week.

Later - Bob

Airacobra · « **Reply #65 on:** June 05, 2013, 08:54:07 PM »

Wow, I like this version a great deal. I will be anxious to hear the flight report.

Derek Barry · « **Reply #66 on:** June 06, 2013, 05:55:56 AM »

Looks Good Bob!

Derek

Allan Perret · « **Reply #67 on:** June 06, 2013, 06:42:09 AM »

Hey Bob, looking good.
Question, when you make the molded top block, does it include the part for the removable canopy hatch, or do you make that as a separate part ?

Bob Hunt · « **Reply #68 on:** June 06, 2013, 07:03:18 AM »

Thanks, Keith, Derek and Allan...

Allan: The forward portion of the canopy is the hatch. This can be molded, but it is difficult to get a molded part to be removable and have perfect seams I choose to use a solid balsa block in that area, carve it to shape and then hollow it out to a thin wall. The rear part of the canopy is molded in one piece along with the remainder of the top shell.

Later - Bob

MarcusCordeiro · « **Reply #69 on:** June 06, 2013, 07:35:17 AM »

COOOOOL!

Marcus

Bob Hunt · « **Reply #70 on:** June 06, 2013, 10:39:41 AM »

Thanks, Marcus!

Okay, the numbers and letters are on and there is extremely little clean up to do before the clear goes on.

This will be the last report until this thing is cleared, sanded, buffed and made ready to fly.

Hey, these things take a lot of work!

Later - Bob

Doug Moon · « **Reply #71 on:** June 06, 2013, 10:56:03 AM »

Looks good! I like those colors, they are very familiar...hahahahaha!!

Bob Hunt · « **Reply #72 on:** June 06, 2013, 11:12:14 AM »

Yes they are... Do they remind you of this... ?

Bob

Doug Moon · « **Reply #73 on:** June 06, 2013, 12:31:56 PM »

Quote from: Bob Hunt on June 06, 2013, 11:12:14 AM

Yes they are... Do they remind you of this... ?

Bob

Nah, not as much as this....

< ========== << look, just to the left, a little bit.

Bob Hunt · « **Reply #74 on:** June 06, 2013, 12:41:10 PM »

Oh yeah... That's a nice one too...

Looking forward to another battle in Muncie - Bob

Mark Scarborough · « **Reply #75 on:** June 06, 2013, 02:43:50 PM »

It looks really clean Bob,,
now about that clear,, I think it looks outstanding in satin,, maybe just somme satin gloss

Randy Powell · « **Reply #76 on:** June 06, 2013, 07:18:05 PM »

Very slick and professional looking, Bob. Should be a great plane.

Bob Hunt · « **Reply #77 on:** June 06, 2013, 08:08:58 PM »

Thanks, Randy - and everyone else - for the encouraging comments. I really like this ship and only hope that it flies as well as my last Crossfire. It is a couple of ounces lighter at this point than the last one was, so I'm hopeful that it will be in the high 50 ounce range with the battery on board.

Randy: I'm really looking forward to seeing your new/first electric ship in color. It is a fantastic design; very futuristic. Reminds me of a pod racer for sure!

Later - Bob Hunt

Randy Powell · « **Reply #78 on:** June 06, 2013, 10:50:21 PM »

Thanks, Bob. The covering is on. Just building up to paint.

Tom Niebuhr · « **Reply #79 on:** June 19, 2013, 07:24:31 AM »

I got word from "an unnamed source" that Bob's Extreme XLTC has had the clearcoat applied and he is wearing his fingers to the bone rubbing it out since they recommend compounding in the first 24 hrs +.

We should see pictures and initial flight reports soon.

Airacobra · « **Reply #80 on:** June 26, 2013, 01:29:50 PM »

It's just short of a full week since the last post. The way Bob works, this thing has been buffed and has 25 plus flights on it by now, what say you Bob???

Bob Hunt · « **Reply #81 on:** June 27, 2013, 08:18:05 AM »

Hi Guys:

It's all rubbed out an flown, and it is nearly trimmed. Just a few little things to address. No big deal. It turns absolutely equally in both directions, takes off and lands perfectly pretty much all by itself. I'm a happy camper. Still not sure that this is the bird I'll be flying at the Nats, however, as last year's ship is flying amazingly well with the trim changes that Paul Walker suggested. I incorporated those trim changes into the new ship and it seems to like them as well. Will be nice to have two great models to choose from. I'll make my decision on which I'll fly at the Nats by the weekend.

Here are a few finished shots of the ship...

Later - Bob

Matt Colan · « **Reply #82 on:** June 27, 2013, 09:21:48 AM »

It looks really good Bob! Really like the tricycle landing gear look!

MarcusCordeiro · « **Reply #83 on:** June 27, 2013, 09:35:01 AM »

Oh boy!!!

Marcus

Tom Niebuhr · « **Reply #84 on:** June 27, 2013, 09:58:32 AM »

Bob,
Looks great. Have you raised the gear yet? I that could give a few more "impression points" in flight.

Dave Denison · « **Reply #85 on:** June 27, 2013, 10:44:29 AM »

Quote from: Bob Hunt on June 27, 2013, 08:18:05 AM

Hi Guys:

However, as last year's ship is flying amazingly well with the trim changes that Paul Walker suggested. I incorporated those trim changes into the new ship and it seems to like them as well. Will be nice to have two great models to choose from. I'll make my decision on which I'll fly at the Nats by the weekend.

Here are a few finished shots of the ship...

Later - Bob

Bob.

The new bird looks outstanding, great color contrast. The trim changes that you and Paul applied to the ship, can you give us more specifics? I see your leadouts are fairly far forward, has the CG found it's way forward also?....most interested.
Thanks for your time

Dave

Bob Hunt · « **Reply #86 on:** June 27, 2013, 11:10:19 AM »

Quote from: Tom Niebuhr on June 27, 2013, 09:58:32 AM

Bob,
Looks great. Have you raised the gear yet? I that could give a few more "impression points" in flight.

Hi Tom:

Raising the gear might be neat, but it would be difficult to do as there are no retracts in this plane; that's the twin that has the go-away gear...

In the future...

Later - Bob

Bob Hunt · « **Reply #87 on:** June 27, 2013, 11:13:50 AM »

Quote from: Dave Denison on June 27, 2013, 10:44:29 AM

Bob.

The new bird looks outstanding, great color contrast. The trim changes that you and Paul applied to the ship, can you give us more specifics? I see your leadouts are fairly far forward, has the CG found it's way forward also?....most interested.
Thanks for your time

Dave

Hi Dave:

because this model has minimal leading edge sweep, the leadouts are further back than they may appear; and they may go back farther... That's one of the trim tips I received from Paul. The other one was to go to a 12 x 6 EP instead of the 13 x 4.5 prop. I got much more turn from the smaller prop and better tension everywhere as well!

Later - Bob

Tom Niebuhr · « **Reply #88 on:** June 27, 2013, 11:16:32 AM »

Bob,
Whoops,

I guess I am still rooting for the twin.

This airplanes is still very impressive.

Tom Niebuhr · « **Reply #89 on:** June 27, 2013, 12:11:23 PM »

Bob,
I just noticed that your new Crossfire has one motor missing!

Dennis Toth · « **Reply #90 on:** July 28, 2013, 07:12:21 AM »

Bob,
Great job at the NATs, since you elected to fly the "new" Crossfire let's hear the backstory. Why did you elect to go with it over the other ship? Did the design changes you made work as you intended? Is there more tweaking you can do to get it better or is it really close to peak?

Curious minds want to know.

Best, DennisT

Bob Hunt · « **Reply #91 on:** July 28, 2013, 09:14:22 AM »

Hi Dennis:

Both of my Crossfire Extremes (the tail-dragger and the trike version) fly very well and there is little between them to make one preferable to the other when it comes to the flight maneuvers. The decision to use the trike version was because of the ground handling virtues of that ship. Takeoffs and landings are very easy with that ship, even in high wind conditions. I received a lot of big numbers from all of the Nats judges on those maneuvers with the new ship and I think that is significant. I don't understand why more fliers don't opt for trike gear. I do know that the placement of the main gear relative to the CG is very important, as is the angle at which the ship set on the ground. The main gear must not be positioned too far aft of the CG (with battery on board) or the tendency will be for the ship to abruptly hop into the air. You must be able to raise the nose gear and let the ship run on the main gear and then lift off at a low angle to get max points. The ship must also not set at a nose down attitude. I wish I could tell you that I adjusted and trimmed the new ship's landing gear geometry to get it perfect, but the truth is that I hit it perfect right off the board. Dumb luck on my part to be sure...

The new ship has a longer nose to allow me to use a lighter battery placed more forward to achieve the proper balance point. That worked out perfectly. The older ship uses a 4,000 mAh 4S battery that weighs in the 14 ounce range and the new ship uses a 3,300 mAh 4S battery that weighs around 12 ounces. With the addition of the nose wheel strut the ship balanced just about perfectly without the need for additional nose weight. The new ship came out 1/2 ounce lighter on the Nats scales compared to last year's ship. The new one weighs 62 ounces and last year's ship is 62.5 ounces. Note that the new ship is stretched all over and hence is bigger. The new ship has one inch per panel more wing span, 1/2 inch per panel more tail span, a one inch longer nose and 1/2 in longer tail moment. So, compared to last year's ship, this one has a lower wing loading. Can't say that I really notice the difference in flight performance however...

I do know this: Everyone (Judges, co-competitors and spectators) told me that this new version presents very well in the air. I've always believed that having a signature look to my models was important. I like my models to be unique and have a look that is different than everyone else's models. It is one of the many intangibles of our event; setting yourself apart from the crowd is often likely to gain attention. Sometimes that's good and sometimes that's bad. I think in this case - this time - it was a positive.

Am I going to continue trimming and adjusting on the new ship? Certainly. In fact, I never stop trying to find more performance in all my models. Just recently I made great gains in flight trim on my Genesis Extreme. That ship was built in 2,000!

I used a Cobra 28/26-10 this year. It has a huge bearing in it (not that I was having any bearing problems with the E-Flite Power 25 that I had used in the past), and it is extremely quiet, even compared to the previously acknowledged quiet electric setups. I like the lack of noise most of all in electric. I think it makes the performance seem even smoother.

I'm going to try a lower Kv motor soon and that will allow me to try the 5S batteries that many are touting. Leave no stone unturned... I'll also be trying a variety of three-blade props (both pusher and tractor). I'll try lines that are a foot and a half shorter as well. I like the solids that I've been using for many years, but will give cables a try too.

I do believe that there is more performance to be had from this ship, but I am well pleased with how it flew at the Nats with only a handful of patterns on it. I left for the Nats with only six full patterns on the ship! It now has somewhere around 35 flights on it. Third was not bad for such a new ship, but I really should have put well over 100 flights on it before the Nats. It was not to be...

I now have two really great flying Crossfire Extremes in my stable and can start to experiment with other configurations. Certainly my Second Wind twin is at the top of that list and I'm getting back to work on that one now so that it will be ready to fly in the spring of 2014. Hopefully I can get those 100 or so practice flights on that one before competing with it.

I have several new and very radical ideas that I want to try. Electric power certainly allows for experimentation with multiple motors and unique motor placements. There are a number of other things that electric power allows, and Dean Pappas and I are examining some stuff that promises to bear a lot of fruit in the future.

I had given a lot of thought o retiring from competition this year, but I've changed my mind and have decided to rededicate myself to development and competition flying for as long as the Good Lord allows.

It just keeps getting better... Bob Hunt

Randy Powell · « **Reply #92 on:** July 28, 2013, 11:12:38 AM »

I'm glad to hear this, Bob. Wouldn't be the same without you.

Dennis Toth · « **Reply #93 on:** July 28, 2013, 12:55:50 PM »

Bob,
Great summary, interesting to see how a design evolves. Have you tried the low pitch high rpm with the 12" diameter? It would be interesting to see if the lower pitch would pull out of the corners stronger. It seems that with electric higher rpm seems to draw more current and could require a higher capacity pack even with the lower pitch and same diameter. If it works it would be interesting even if we need more capacity.

Checking the battery pack options it seems that the 5S 1P 2700 TP (10.2 oz) is a lighter option than the 4S 3300 (11.4 oz). The big big break for electric will be when we can recharge in 10 mins or less and use 95% of the pack without reducing battery life or have power drop off.

Best, DennisT

William DeMauro · « **Reply #94 on:** July 28, 2013, 03:14:30 PM »

Quote from: Dennis Toth on July 28, 2013, 12:55:50 PM

The big big break for electric will be when we can recharge in 10 mins or less and use 95% of the pack without reducing battery life or have power drop off.

Best, DennisT

Dennis,
We already have the 10 minute charging. We can have the 95% of the pack, IF you want to ABUSE your packs and don't care about lifespan. There are a few that do this. I don't and I don't recommend it but, yes it can be done. Bob, myself and others have the ability to charge a pack in 9-11 minutes but we rarely go at full speed and usually take 12-15 minutes, It's still a great rate of charge. I regularly bring 12 batteries (6 4s 3700mah and 6 4s 2700 mah) up from storage mode in around 20 minutes. At this point, we may be more limited by the chargers available to us than anything. We are pretty much maxing out what we can get out of 24V power supplies and 110 standard US house current. I've already popped a breaker. What I think we will eventually see are some 48 V power supplies and 2500 watt chargers. 10C charging rates are here, though not the norm yet. At that point we will have 5 minute charge times.
William

Dennis Toth · « **Reply #95 on:** July 28, 2013, 05:04:48 PM »

William,
I understand there are some cells that are able to take a very high C rate charge but those are not Stunt packs, they are usually 30% heavier then the ProLite cells. I don't know what packs you like but I have tried several an go back to the Thunder Power's. The new G8's are getting there but you still need to leave 20% head room. The only cells that you can charge at 10C and take down to 95% without hurting them are the A123's. Problem is they are very heavy and not available in convenient sizes. Electric has come a long, long way and is only going to get better.

Best, DennisT

john e. holliday · « **Reply #96 on:** July 29, 2013, 08:49:48 AM »

If you are flying alone I can see the 10 minute charge rate, but is that after the battery has cooled down. When I was flying with the guys and granddaughter, which made four of us. I/we would get to fly every fourth flight. If a person has say at least 3 packs for flying, is that enough time to let a pack cool while using the next pack. Myself I usually start losing concentration on about the fifth pattern when flying, that is when the play plane comes out or I sit and relax for a couple of hours.