stunthanger.com
General control line discussion => Open Forum => Topic started by: Mark Mc on August 14, 2018, 12:00:52 AM
-
I decided that I need an incidence meter so that I can ensure I get the engine, wing, and tail of my planes at 0-0-0 when I build. So I went online to buy one. I checked Tower which showed the Robart incidence meter (https://www.towerhobbies.com/cgi-bin/wti0001p?&I=LXET66). $36.99 plus shipping, when it gets off of back order. Then checking Horizon showed the E-Flight incidence meter (https://www.horizonhobby.com/anglepro-ii-5-in-1-digital-throw-incidence-meter-efla280). $59.99 plus shipping, but it was in stock. Ridiculous.
So, I drew out my own and built it. I jotted down some numbers and then took a $2.00 stick of 3/8” x 36” spruce, a couple of bubble levels from the Dollar Store, and some scrap ply from the junk box to make my own.
(https://s5.postimg.cc/8bjvgt9qv/Incidence_meter1.jpg) (https://postimages.org/)
(https://s5.postimg.cc/jnwgylq5j/Incidence_Meter2.jpg) (https://postimages.org/)
And then the last part I need to make this a set. I took a length of 2” aluminum angle and cut off a 1” section. I dressed up the edges and the corners, and then I took a uni-bit and drilled a hole in one leg sized for the engine shaft. I ensured there was room for my line level to butt up against the corner. I used a triangle to make sure the angle is square, as I’ve gotten aluminum angle that wasn’t completely at 90 degrees.
(https://s5.postimg.cc/68n3fe27r/Prop_Level1.jpg) (https://postimages.org/)
I sandwich the angle piece between the prop hub and the prop, and put the line level on the bottom of the angle. I put the wing incidence meter on the wing at the root and raise the tail until the wing incidence is level, and then checked the engine to see that it is level with respect to the wing giving me a 0-0-0 alignment of the stab-wing-engine thrust line.
(https://s5.postimg.cc/vrffsethj/Prop_Level2.jpg) (https://postimages.org/) (https://s5.postimg.cc/6lehlkzx3/Prop_Level3.jpg) (https://postimages.org/)
Total cost was about $5.00 for the project using on hand materials and Dollar Store components, and about four hours of time.
Mark
-
Looks like a fun project. Is the spruce stick really straight? Thanks for sharing. #^
-
That's a terrific idea. You could use 3/8 x 1/2 aluminum channel for the bar instead of wood.
-
Sure beats the "OK, that looks good" method I have been using! Make a smaller one for the stab? You are going to take all of the drama out of that first flight.
Ken
-
What Ty said!!!
-
do you have a way to calibrate the dollar store levels? I found that they are not always seated "flat" into the base - so you get a false reading if you level the bubble one way. if you take the tube out of the case and just use that it is more accurate
-
I have 5 of the Robart incidence meters and haven't paid more than 5 bucks for one at local swap meets. Don't know if eBay would turn up any cheap ones. They are handy. I jig up the fuselage nice and level, hang one on the engine, one on the wing and you can take the needle/gauge assembly off the bar and just set it on a flat stabilizer, and it's easy to read if you are going for a 1 degree or so positive stab alignment set up. Keep your eyes open at those R/C swap meets!
Type at you later,
Dan McEntee
-
By golly that's pretty slick, I think I might build one. y1
-
This looks like a nice rig but I absolutely must commend you for typing 'ensure' in that first sentence.
Kudos.
-
Thanks for the comments, All.
John, yes the stick is very straight. I went through all the sticks at the hobby shop to get a straight one, and I verified it on a straight edge when I built this.
Perry, I didn’t have any aluminum on hand. I was initially thinking the aluminum channel frame material for window screens. But the stick was quick and easy, and mostly importantly, available.
Ken, I still just make flat stabs, so I use the same line level for the prop hub and the stab. Also, with my life, I take my excitement where I can get it.
Ty, maybe I’ll write something up and see if anyone’s interested.
Wynn, I’m kind of a bad person. I buy the level at the dollar store for the bubbles, and then when I get out to the parking lot I pry open the mounts and pull the bubbles for my own use. Then I throw the plastic housing in the trash can in front of the dollar store. When I get home I compare them to a reference level, sanding the plastic to make sure they’re all matching.
Dan McEntee, I only get to one show a year. And I wanted something now, not later. But swap meets are a great sources of jigs and tools.
Dan Berry, accurate building is important to me on days that I fly, accurate English is important to me every day.
Mark
-
Hey Mark Mc, they are always looking for articles for Stunt News. I already have incidence meters obtained at swap meets. H^^
-
didn't someone have a build plan for incident meters? Like in flying models?
Derek Moran? maybe did the work?
-
Pretty sure that Derek Moran's incidence meter was published in Model Aviation, of all places! Also, Larry Renger showed his adaption of an angle finder to do the thrust line duty, here on Stunt Hangar. Both are highly recommended and vastly more accurate. H^^ Steve
-
Can somebody post the Derek Moran incidence meter drawings or perhaps a photo? I like Mark Mc's concept, but Steve H suggests the Derek Moran is more accurate.
I like the concept because one really needs several and this concept is low cost.
-
didn't someone have a build plan for incident meters? Like in flying models?
Derek Moran? maybe did the work?
Reviving an old post. I just saw that on Outerzone, he posted the January '78 issue of Flying Models which has the article on building Jerry Smith's wing incidence meter:
https://rclibrary.co.uk/title_details.asp?ID=2377
(https://rclibrary.co.uk/images/thumbs/covers/2377.jpg)
Mark
-
the other one is in model aviation
http://library.modelaviation.com/ma/2006/11/killer-incidence-meter-200611 (http://library.modelaviation.com/ma/2006/11/killer-incidence-meter-200611)
with some 3 d print parts this project should be re done. Derek di an awesome job.
-
Hi Mark,
I made a similar incidence meter some years ago with exactly that same spirit level for use on a string. I seem to remember that it was a Stanley product. One of my first smart phones was a Nokia Lumia 520 and I downloaded the Clinometer app for it. It uses the built-in accelerometer and the needle resolution is 0.1 of a degree. I just put the phone on the stick instead of the spirit level and it works great! I have a newer phone now so I keep the old one which is not too big for this function.
Keith R
-
Keith, I'll see if I can download an app for my phone and try that. But I don't really have much faith in the Samsung Galaxy electronics accuracy. The accelerometer in my Galaxy S4 would constantly drift, so I haven't even tried the accelerometer in my S7.
Dave, thanks for that article link. I can make the long leg with the plumb bob and scale and screw it to the frame of the level I made quite easily. And the aluminum angle prop hub jig I have is better than what the article has, I think.
Mark