Author Topic: Protroma 2011 (Read 7289 times)

Dennis Adamisin · « **Reply #50 on:** April 08, 2011, 06:47:17 PM »

THe short nose looks great too. Howzit looking for weight?

Crist Rigotti · « **Reply #51 on:** April 08, 2011, 08:40:13 PM »

It'll be 58 to 59 oz. I was shooting for 56 oz.

john e. holliday · « **Reply #52 on:** April 09, 2011, 07:18:41 AM »

Boy Christ a guy can larn a lot or not by coming to this portion of the forum. After talking to Bobby Hunt at VSC I am almost convinced to go to ECL. But, I have so many IC engines. By the way did I say this is a fantastic build you are doing. I like the pictoral presentation. That is what I am slowly doing with my project right now. Maybe see ya down the road if I can get this knee problem whipped.

Crist Rigotti · « **Reply #53 on:** April 09, 2011, 01:17:13 PM »

The fuselage framework is all done. I'm glueing on the sheet balsa sides as I type.

Crist Rigotti · « **Reply #54 on:** April 09, 2011, 02:10:10 PM »

Quote from: john e. holliday on April 09, 2011, 07:18:41 AM

Boy Christ a guy can larn a lot or not by coming to this portion of the forum. After talking to Bobby Hunt at VSC I am almost convinced to go to ECL. But, I have so many IC engines. By the way did I say this is a fantastic build you are doing. I like the pictoral presentation. That is what I am slowly doing with my project right now. Maybe see ya down the road if I can get this knee problem whipped.

Thank you Doc.

Crist Rigotti · « **Reply #55 on:** April 09, 2011, 09:27:12 PM »

Ok, the fuselage is done except for final touch up sanding. 1/2 ounce under budget!

Leester · « **Reply #56 on:** April 09, 2011, 10:05:10 PM »

As we've come to expect it looks great Crist. When do you project the first flights to be

Crist Rigotti · « **Reply #57 on:** April 10, 2011, 08:19:51 PM »

I covered the fuselage today. It still needs trim stripes and some "ink" lines. Here's a sneak peek.

Dennis Adamisin · « **Reply #58 on:** April 10, 2011, 09:46:22 PM »

Looking good Crist! I'd say that color scheme was definitiely "in the groove"..!

Crist Rigotti · « **Reply #59 on:** April 11, 2011, 01:55:37 PM »

Yeah, I can't seem to get past red, white and blue.

Crist Rigotti · « **Reply #60 on:** April 14, 2011, 07:59:48 PM »

A little update. I'm detailing the fuselage front end. Working on both the motor mount and the ESC mount. The motor will have a aft support ball bearing. I should have that done tomorrow.

JohnPrator · « **Reply #61 on:** April 15, 2011, 06:09:40 AM »

Boy that sure is nice, great job so far! You obviously have some wonderful skills, can't wait to see the finished plane.

Leester · « **Reply #62 on:** April 15, 2011, 06:56:53 PM »

Jan does great work Crist

Crist Rigotti · « **Reply #63 on:** April 15, 2011, 07:16:00 PM »

Thanks John. Been building models for a looong time.
Lee,
She is an amazing woman.

Crist Rigotti · « **Reply #64 on:** April 15, 2011, 08:16:32 PM »

Tonight I joined the wing to the fuselage. Tomorrow the stab and fillets.

Dennis Adamisin · « **Reply #65 on:** April 16, 2011, 07:37:14 AM »

Crist:
Inquiring minds want to know: is that an aluminum motor mounting plate? and it is held in..... how?

Crist Rigotti · « **Reply #66 on:** April 16, 2011, 08:32:55 AM »

Yes, it is 2024-T3 .090 thick. It is held in by JB-Weld. I notched the plate on the sides where it fits into the slots in the fuselage for added security.

Crist Rigotti · « **Reply #67 on:** April 16, 2011, 08:00:57 PM »

Today's progress. The stab and the fin are glued in place and all the fillets are done. Getting close.

Dennis Adamisin · « **Reply #68 on:** April 17, 2011, 08:40:45 AM »

Looks like test flights next week!

Jim Howell · « **Reply #69 on:** April 17, 2011, 07:48:02 PM »

Crist, Can you provide some details about the fuse construction? Did it end up the equivalent of 1/2" sq. framework material sheeted with 1/8" balsa sides plus 1/64" ply doublers forward of the wing? I could see that you ran some material - 1/2" square hardwood? - from the very front all the way back to the wing.

Thanks for the build thread. The results look really great!

Jim Howell

Crist Rigotti · « **Reply #70 on:** April 17, 2011, 08:22:54 PM »

Quote from: Jim Howell on April 17, 2011, 07:48:02 PM

Crist, Can you provide some details about the fuse construction? Did it end up the equivalent of 1/2" sq. framework material sheeted with 1/8" balsa sides plus 1/64" ply doublers forward of the wing? I could see that you ran some material - 1/2" square hardwood? - from the very front all the way back to the wing.

Thanks for the build thread. The results look really great!

Jim Howell

The front uses basswood that is 3/8 x 1/2 with 3/32 basswood added. Then with the 1/64 plywood on each side the width comes to 5/8 inch. The portion aft and the canopy is 5/16 balsa laminated to equal 5/8 x 1/2. Then whole thing is sheeted with 1/16 balsa. The balsa on the front uses 1/2 balsa with 3/32 balsa to equal the same thickness as the basswood. The total width of the fuselage is 3/4.

Crist Rigotti · « **Reply #71 on:** April 17, 2011, 09:01:14 PM »

Today's progress. Hooked up the controls, finished the rudder, and made the pushrod fairing. I didn't get to the "ink" lines. The last picture is a close up of the ESC mount. The close up of the flap horn shows the LH "turnbuckle" of both the flap and elevator pushrods. To adjust either pushrod, all I need is a 3/16 open end wrench and turn the pushrod thus adjusting the length of the pushrod. Thank you Tom Morris!

Jack Pitcher · « **Reply #72 on:** April 17, 2011, 09:22:09 PM »

Crist,

Tell us about the fillets. They look good.

Jack Pitcher

Crist Rigotti · « **Reply #73 on:** April 17, 2011, 09:42:24 PM »

30 minute epoxy and microballoons. After trowelling the mixture into the corner I use a 3/16 ball bearing that is glued to a dowel to from the fillet. The ball bearing gives a uniform radius no matter what angle it is held at in relation to the fillet. I dip the ball bearing in rubbing alcohol before going over the fillet. After the ball bearing treatment I take a paper towel folded over several times soaked in alcohol and clean up the excess mixture from both sides of the fillet. After a few minutes of setting I dip my finger in alcohol and gently rub the fillet the entire length to get it super smooth. Then another clean up with paper towels and alcohol. Let dry.

The 30 minute epoxy mixture is 2 grams of each epoxy and hardener, 4 grams total. Then I add about 6 "scoops" of microballoons using a popsicle stick with about 1 inch of microballons on it.

Allan Perret · « **Reply #74 on:** April 18, 2011, 07:13:40 AM »

Your fillet material comes out white, or did you have to paint it to match ?

Crist Rigotti · « **Reply #75 on:** April 18, 2011, 08:11:24 AM »

Painted with Nelson Hobby Paint - color - white Monokote

JohnPrator · « **Reply #76 on:** April 18, 2011, 10:14:00 AM »

Crist,

That plane is just too pretty-pull test your handle!

Crist Rigotti · « **Reply #77 on:** April 18, 2011, 10:43:12 AM »

Quote from: JohnPrator on April 18, 2011, 10:14:00 AM

Crist,

That plane is just too pretty-pull test your handle!

10-4!

Allan Perret · « **Reply #78 on:** April 18, 2011, 05:44:28 PM »

Was looking at the first post in this thread.
Why did you change from the 5S/710KV to the 6S/600KV combo ?

Crist Rigotti · « **Reply #79 on:** April 18, 2011, 08:27:03 PM »

Quote from: Allan Perret on April 18, 2011, 05:44:28 PM

Was looking at the first post in this thread.
Why did you change from the 5S/710KV to the 6S/600KV combo ?

I heard that 6S has lots of torque and wanted to try it. I flew my Pathfinder ARF with a 6S and 580kv motor. Worked very well. However, I just might go to a 5S set up. Stay tuned.

Crist Rigotti · « **Reply #80 on:** April 20, 2011, 04:37:56 PM »

OK, I decided to go with using Thunder Power G6 5S 2700mah Pro Lite batteries. Yeah, they are a bit pricey, but they will give me the best performance and last a long time. They are pretty light too. I save 3 ounces over the 6S batteries and I can use a stock motor rather than having one custom wound. This way everything is "off the shelf" so if I need another motor, I can just buy another one rather than waiting to get one rewound. Also I can use the same batteries on next years full fuselage electric stunter.

With the 6S battery, even with the short nose, the plane was going to balance very nose heavy. Now, it'll be pretty close to spot on.

Crist Rigotti · « **Reply #81 on:** April 22, 2011, 07:44:23 PM »

The motor is mounted and front end details completed. All that is left is to add the name and AMA numbers. I'll make up a set or 2 of lines this weekend and set up the control neutral. The battery shown in the pictures is from the plane from 2 years ago. I haven't received the Thunder Power batteries yet. Projected weight is now 55.5 ounces, circle ready.

Allan Perret · « **Reply #82 on:** April 23, 2011, 06:29:37 AM »

Nice motor installation.
Did you get the rear bearing from Boca ?
What is p/n ?

Crist Rigotti · « **Reply #83 on:** April 23, 2011, 08:45:30 AM »

I get my bearings from RC-Bearings. F695ZZ 5x13x4mm flanged bearing.

http://www.rc-bearings.com/catalog/product_info.php?cPath=30_32&products_id=437

Crist Rigotti · « **Reply #84 on:** April 23, 2011, 12:49:00 PM »

Time to go over making the letters and numbers. The letter size for this plane is 275pt. I use MS WORD to layout the letters on a paper size of 17x22 inches. The font is Challenge Extra Bold. There are no square outside corners in this font. After printing, I line the back side with clear packing tape. I suppose you can do the front side, but I haven't so far. I trim the template to a height of 5 inches. I then cut a strip of black Monokote 4 inches high the width of the Monokote. I then remove the plastic backing sheet from the Monokote.

Then I tape down at least 4 layers of newspaper down on my bench. Keep the paper smooth and flat. Then tape down the Monokote, shiney side up, to the newspaper. Then finally the template.

I cut the inside of the letters/numbers out first, then the outside edges. I use a #11 blade and hobby knife. Press just hard enought to go through the template, Monokote, and several layers of newspaper. Cutting out the name shown in the pictures took me about 15 minutes total.

Remove the template carefully and discard the extra Monokote and newspaper.

Measure the width of the numbers/letters on the template. Then measure the room on the wing panel. In this case the letters were 14 inches wide and the wing panel was 27 1/2 wide. I subtracted 14 from 27 1/2 and then divided by 2. 6 3/4 was measured in from the root and the tip. A line was drawn on the Monokote with a fine line Sharpie marker. I then measured up 2 inches from the TE for the bottom of the letters.

I then placed the template between the marks and taped the top edge in 3 places. Then I flip the template up over it self and I crease the tape to form a hinge. I then clean the Sharpie markings off and the clean the wing surface with acetone.

Flip the template back down on the wing and then back up. I use Windex to position the letters. I then spray some Windex on the wing in the area of the first letter and spread it around with my fingers. Flip the template down and position the letter in the cutout of the template. Flip the template back up and smooth the letter down using a soft cloth. Flip the template back down and check for proper position. If not I move the letter slightly into position. The reason the template was lined with clear packing tape is that the Windex won't soak into the template while using it. Repeat the procedure for each letter. Remove the template and let the letters dry overnight. Then I use a Monokote iron set at about 1/2 and go over each letter carefully to bond it to the wing.

Allan Perret · « **Reply #85 on:** April 23, 2011, 04:40:42 PM »

Nice technique for Monokote lettering.

I use Word also to layout the lettering for a spray mask on dope finishes. I like to use a font that has predominately straight lines vs curves because I find them easier to cut out. Curious why you avoid outside square corners.

Also I like to go into the font "Effect" dialog window and change the text to "Outline". Its saves a lot of ink when you print out, and it gives a nice sharp line to follow for cutting.

Crist Rigotti · « **Reply #86 on:** April 23, 2011, 06:50:33 PM »

Quote from: Allan Perret on April 23, 2011, 04:40:42 PM

Nice technique for Monokote lettering.

I use Word also to layout the lettering for a spray mask on dope finishes. I like to use a font that has predominately straight lines vs curves because I find them easier to cut out. Curious why you avoid outside square corners.

Also I like to go into the font "Effect" dialog window and change the text to "Outline". Its saves a lot of ink when you print out, and it gives a nice sharp line to follow for cutting.

Square corners can lift.
I'll have to try the outline method next time. Good idea.

Crist Rigotti · « **Reply #87 on:** April 24, 2011, 09:25:35 PM »

Ok, the build is finished. I used my Monokote iron on the numbers/letters. I bench set up the controls and made up a new set of lines. Set neutral on the handle. Gave her a coat of wax too. Just waiting for the batteries. After break in, it'll be ready to go later this week.

Crist Rigotti · « **Reply #88 on:** April 25, 2011, 09:49:33 PM »

I got a battery (others are on the way) tonight and did the final weigh-in and balance check. The battery is advertised as 292g, mine was 298g. I check the balance point and it was a little too far forward so I added 1/4 ounce to the tail. Total weight now is 55 ounces and the balance point is 23%.

Crist Rigotti · « **Reply #89 on:** April 30, 2011, 10:04:56 PM »

Flew it for the first time this evening. 9 1 minute flights getting lap times, wings level, and equal turns adjusted. Still needs more tweaking.

BTW, I got one of Will Hubin's programming box and several FM-9 timers. Well worth the money! Electric stunt is even easier now. I'm running in high governor mode right now because it is easier to adjust RPM to get lap times where I want them. BTW, 1 change of 75 more rpm put me right where I want for lap times....5.2 - 5.3 seconds.

If your flying electric stunt and you're not using Will's stuff, you are making hard on yourself.

Also making the LG 1/2" longer because what I have now will only accommodate a 12 inch prop. After doing some test flying today it looks like I can go to a larger prop and not go over 80% battery capacity.

I have a new flying site that is only 35 minutes away. A coworker lets me fly at his church out in the country. 3 sides are pretty clear with the east side having 4 large trees. 115vac for my charger and picnic tables to pit on. Pretty nice. Fairly secluded too.

Allan Perret · « **Reply #90 on:** May 01, 2011, 08:14:25 AM »

Beautiful flying site. What is your portable runway made from ?

Crist Rigotti · « **Reply #91 on:** May 01, 2011, 08:27:16 AM »

10mm coroplast.

http://www.coroplast.com/

Tom Taylor · « **Reply #92 on:** May 01, 2011, 12:27:30 PM »

Crist, What motor are you using?

Crist Rigotti · « **Reply #93 on:** May 01, 2011, 04:03:09 PM »

My set up is listed in post #1. A Scorpion SII-3026-710.

Crist Rigotti · « **Reply #94 on:** May 06, 2011, 08:33:23 PM »

OK. I have about 20 flights on the plane. I'm going to post my set up and would like some comments on it.

Scorpion SII-3026-710
CC ICE Lite 50
Thunder Power G6 Pro Lite 25C 5S 2700mah battery
APCE 13x4.5P cut down to 12.5 and pitched up to 5.5 from station 12 on the Prather pitch gauge
56 ounce plane weight
62 foot eye to eye .015 lines
5.25 lap times
10,050 RPM
Phoenix high governor
30 second delay
5 minute 25 second flight time
Governor mode: high
Governor gain: 35
Spool up rate: 6
Head speed change: 6
Battery volts: 18.5
Motor kv: 710
Poles: 14
Gearing: 1:1
Brake strength: 100
Brake delay: 1 second
Brake ramp: very slow
Cutoff volts: Auto lipo
Current limiting: very sensitive
Cutoff type: soft cutoff
Auto-lipo volts/cell: 3.5
Motor start power: medium
Motor timing: normal
Motor direction: forward
PWM: 12khz
Power on beep: enabled
BEC volts: 5.0
Current firmware: v3.26

I used about 2100mah on tonight's flights. The wind was calm. Battery usage was about 78%.
I'm a little concerned that I'm using a bit more battery than I thought that I would. I see others using the same prop and basically the same combo but drawing a lot less from the battery. The other day when it was windy (13+ mph) I was using about 2000mah running 10,500 rpm but with the stock pitch of 4.5. I thought that was a little too high of RPM that I really wanted to run at. With the prop repitched to 5.5 at station 12, 10300 rpm gives me 5 second laps and good wind flying.

I'm enclosing a graph for what ever it would be worth.
The graph doesn't show the numbers on the bottom. They are:
Voltage: min 17.4, max 20.9, ave 18.7
Current: max 32.1, ave 18.7
Amp hours: ave 1.0, max 2.1
Watts: ave 345, max 641
RPM: ave 8339, max 10163
Power out: ave 65, max 85.5

Next time out I'll try varing the PWM down to 8khz to see what effect that would have.

BTW, the temp were:
Motor: 105 degrees f
Battery: 115 degrees f
Outside air temp: 65 degrees

Comments?

Ward Van Duzer · « **Reply #95 on:** May 08, 2011, 08:38:24 AM »

Crist,

Way too much of a newbe to make comments on your "set-up", but...

I did notice that you changed your PWM from "outrunner" to "12 khz". Oddly enaugh, while discussing my future setup with Bubba he made the same suggestion.

Now my question...What's PWM? Why make this change?

Ward

Crist Rigotti · « **Reply #96 on:** May 08, 2011, 05:47:11 PM »

Ward,
PWM is the speed in which the speed controller communicates with the motor, I think. Stands for Pulse Width Modulation.

Reading the Castle Creations Forums, the "Outrunner" setting shouldn't be used for our needs. I forget what that particular setting is really for, but for us 8khz or 12khz should do.

Here is quote from RCGroups Castle Creations, for what its worth :

Quote:
This may have been asked before but what exactly does "outrunner" mode do?

As I recall it’s a variable PWM mode that is needed for very high pole count motors at high RPM to keep the commutation frequency from exceeding the PWM frequency. From my experience it decreases efficiency and smoothness for low pole count motors where it’s not needed. Personally I don’t think it should be the default and CC should change it.

Crist Rigotti · « **Reply #97 on:** May 08, 2011, 05:56:28 PM »

I was talking to Floyd Layton today and we were discussing how the Protroma seems to hunt. We were talking about thrustlines, incidences, etc. Floyd talked about some guys use a little bit of slop. That reminded me of what I did for the Resolve, my previous electric profile. So I did the same thing for the Protroma.

I used a Great Planes 4-40 ball link. It is the same length as the Rocket City #87? links commonly used. I then pushed out the ball using a pair of round nose pliers. Then I screwed the ball link on the threaded end of the pushrod.
I cut a piece of 5/32 O.D. brass tubing to a length of 3/16. The brass tubing od is smaller than the hole in the ball link. This difference provides a small amount of slop. Seeing the link is riding on a 5/32 diameter shaft, there is very little chance of wearing it out. Here are 2 pictures that show the installation. Very easy.

Ward Van Duzer · « **Reply #98 on:** May 09, 2011, 07:44:24 AM »

Crist,

Thx. I am so buried in info right now I never saw that one!

W.

Crist Rigotti · « **Reply #99 on:** July 16, 2011, 09:08:13 PM »

OK. I have about 126 flights on the plane. I'm going to post my set up.

Scorpion SII-3026-710
CC ICE Lite 50
Thunder Power G6 Pro Lite 25C 5S 2700mah battery
APC 13x4.5EP /thin hub version
56 ounce plane weight
62 foot eye to eye .015 lines
5.25 lap times
9,553 RPM
Phoenix high governor
30 second delay
5 minute 20 second flight time
Governor mode: high
Governor gain: 50
Spool up rate: 20
Head speed change: 20
Battery volts: 18.5
Motor kv: 710
Poles: 14
Gearing: 1:1
Brake strength: 100
Brake delay: 1 second
Brake ramp: very slow
Cutoff volts: Auto lipo
Current limiting: very sensitive
Cutoff type: soft cutoff
Auto-lipo volts/cell: 3.2
Motor start power: medium
Motor timing: normal
Motor direction: forward
PWM: 12khz
Power on beep: enabled
BEC volts: 5.0
Current firmware: v3.28

I flew it tonight with the proper thin hubbed 13x4.5EP prop. Working very well. Notice that I have the governor gain as high as it will go along with the head speed change and initial spool up rate set to their max (20). When I'm flying, you can hear the motor "singing" or "ringing". You cannot hear any change in the rpm throughout the flight. Very strong running set up.