DrFun

My Feedback: (4)

Hello all,

I would like to buy a incidence meter and there are 2 different ones in the Tower,

GP Laser for $19.99
Robart for $26.99

I made a search in RCU and find out that they also mentioned digital levels but they cost more than these.

Which one of these incidence meters do you recommend? If you have an alternative from a hardware strore like a digital level.

Also the cost should be reasonable <$35.

The Robart and GP one can be used to measure the thrust angle how accurate are these measurements 2,3 degrees seems to be very small and can it be measured accurately?

Thanks,

BobbyRichardson

I have the Great Planes laser and it works great in my opinion. Very accurate in measuring thrust or incidence.

smitymax

I have both, bought the laser first and used it awhile, was a little bit cubersome to set up...lot of adjusting to zero it out each time you used it. Got the Robart and have not used the laser since. In my opinion, quicker to set up, can read to within 1/2 degree consistently, not sure the consistency of the laser, to many variables depends on how well the laser capsule swings.. I just like the ease of use of the Robart more.

dickj

My Feedback: (1)

I have used the Laser, but have two Robart Incidence meters and love them for a correct setup. Easy to use and very accurate. Have had 3 TOC guys fly my planes and they were satisfied with the flight characteristics. Only wish I could repeat their type of flying!

Al Stein

I've used the Robart for years and am very happy with it.

I've also used dowels rubber-banded to the underside of wings, etc. and was able to get within half a degree that was as well... so it's not a matter of having to pay more to get good results. For me, it's a matter of building a lot of planes when I'm in building mode and that makes the Robart guage a real convenience -- especially when I use two of them.

DBCherry

My Feedback: (4)

Never used the laser one, but my Robart works very well. I think, if the plane is properly leveled, and you're careful, you can be accurate to less than 1/2 degree.
Dennis-

DrFun

My Feedback: (4)

Sounds like Robart is the one.

Thanks for your help.

patternwannabee

My Feedback: (1)

I'm surprised not more people have chimed in for the laser incidence meter, so here's my $.02

I have both the Robart and the GP laser. Both are very cumbersome to attach to the surface you're trying to measure. I'm not sure there's any real good solution here.

To use the laser you have the additional difficulty of zeroing (calibrating) the meter to read zero. For the Robart, there is no difficulty here, cause you can't calibrate it. You have to level your plane or wing. This is not necessarily an advantage.

The Robart meter is jewelled, and the GP laser gimbals are on ball bearings. I think both systems are accurate enough since they seem to read the same surface consistently.

The biggest advantage the GP laser has is that it's way easier to read than the Robart. For the laser, you have a scale which reads degrees about the size of inches. For the scale on the robart, degrees are about 1/8", and you can only read it straight on. If you're trying to take readings on an assembled model in a cramped apartment I can say from experience that this ease of reading is a big factor.

Both units allow you to attach the meter to your engine to measure your thrust, but in both cases, the attachment is pretty flimsy plastic, and I would not trust either to measure this.

Since the GP laser is cheaper, I'd definitely go with that one.

Al Stein, can you elaborate on your rubber banded dowels method? I'm always looking for better ways to do this.

Edwin

My Feedback: (2)

I use a homemade incedence meter. Cost me about $5 to make. I have a robart that I got from a swapmeet. It just confirms what I setup. Its basically telescoping brass tubes with a protractor glued to the outside tube. These are held up with wood on the ends with V notches cut down at equal distances from the centers of the tubes on both ends. The pointer is just a quick link with 1/16" wire in it. I use a rubber band around it to hold the telescoping tubes together. Been building planes for 8 years with it and its never let me down. A fancy version would be to use a dialed level finder instead of a $1 protractor, just doubles the cost.
Edwin

tommy157

My Feedback: (1)

Edwin could you post a picture or a simple sketch of your homemade incidence meter?

Edwin

My Feedback: (2)

I have a picture. Lets see if this works. It was drawn with turbocad2d and converted to jpg
Edwin

GOFLYIN

I have what may seem to be a really stupid question. When using the GP Laser meter is the plane intended to be level or on it's gear?
Mark

Edwin

My Feedback: (2)

I usually have my stab at 0 deg. I place a bubble level on it and prop up the plane, longitudinally and laterally. Then use the incedence meter to see where you wing falls. I will also use a dial level finder on the crank shaft to check for down thrust. Side thrust is a little harder. Maybe lay the fuse on its side with the bubble level on the fin, or measure. I usually just guess and it works ok.
Edwin

DMyer

My Feedback: (2)

Edwin,

If I didn't already have two Robarts, I would build one like yours in a minute! Great design. The only thing I would add is a bubble... I use it instead of the degree meter when incidences are 0/0 as I believe a bubble is more accurate.

Dan

Edwin

My Feedback: (2)

Levels of all sorts are in my collection of tools. I use 3 6" pencil levels, 3 bubble levels, 2 string levels (about 3" long), 2 incedence meters, and a dial angle finder that fastens to brass tubes I put on the crank shaft for engine incedence. Build it straight and light and it will fly.
Edwin

JimTrainor

GOFLYIN, it doesn't matter how the plane is sitting.

Just put the Great Planes meter on the horizontal stabilizer (or wing, or engine, or whatever your reference is) then adjust it to read what ever the plan says the stabilizer should be. Now move it to what ever location you'd like to measure, and it will give you a measurement that is correct relative to the stabilizer. That's the whole point of the gimble that the laser is mounted on and the little wheel that hangs beneath it.

DrFun

My Feedback: (4)

Edwin,

Great design I will give it a try before I buy one, I am building a biplane, so I need min 2, I can do it with one but having 2 seems like better.

Heck I will try building 6 of them, cost seems nothing, 4 for wings 2 for the stab. Hence The incdence of Stab to each wing, will be correct.

Great idea, Thanks.

tiggerinmk

Question on the GP laser meter:

I've just dug mine out to measure the incedences on a Kyosho Tiger moth. The scale (and engine attachment) fits very snugly to the end of the rail so no problem there; but at the other end, the laser assembly slides very easily along the rail.
As GP says it's important to have the laser set at 20" away from the scale, surely a more rigid attachment would be desirable for the laser holder.
Does anyone else have problems with the laser sliding on the rail when moving the meter from one location to another?

JimTrainor

Mine's snug.