[LeadingEdge]

Article Written by: Tony "WoodISGood" Russo

I received a new product from Pauly’s R/C Products to try out. It is a on board temperature and tachometer for rc planes. The temp-tach reads cylinder head temperature and rpm's in real time. The unit can be mounted anywhere but is best to put it under the canopy so it can be viewed by looking down through the top of the canopy. The lcd screen even has a small screw located on the front to adjust the contrast of the screen for better viewing. The coolest feature is that you can record temp and rpm readings at any point in your flight. The unit is programmed to any 3 position switch on you transmitter. While in the center position you can watch your RPM’s and engine temp. Once airborne you can flip the switch down and take a reading at that point in the flight. The temp-tach stores this reading until you clear it out by flipping the switch to the up position. You can also reverse the switch directions by just reversing the channel in your TX.

I installed the temp-tach in my 35% 260. Installation takes about 30 minutes. The entire unit weighs in at 3.2 oz with all wiring. I mounted the sensor for the RPM's on the end of the sensor for the Desert Aircraft DA 100. This leaves about a 3/16" gap between the sensor and the magnet. I verified my rpm reading with a hand held unit and found that they both had the same readings. The temp sensor was mounted on the rear most cylinder( right cylinder on the DA ) on the back side. The rear most cylinder usually runs a few degrees hotter than the left. On the JR 10x transmitter I used the Aux2 channel as it is already on a 3 position switch. I made a small floor the temp-tach to sit on and secured it with double sided tape. The temp-tach comes standard with 3 ft leads. Some airframes may need longer leads depending on where you want to mount the unit. Longer leads are available, just ask.

At the field I started the engine and watched the temp and RPM’s climb. I was turning 6200 rpms on the ground. I took off and flew around about 5 minutes to make sure the engine was at normal operating temperature. The first maneuver I did was a outside loop. I took the rpm and temp reading at the first 90 degree mark of the loop. After I landed I looked at the readings. I was very surprised. The rpm's were 7380 and the temperature was 262 degrees. I had no idea the prop unloaded this much in the air. The next flight I did 2 positive snaps on an up line and took the reading right after the snaps. RPM's were 7080 and the temp was 252. The last test I did was to harrier around for about 1minute and then pull into a hover. The temp climbed to 283 degrees.

I found the temp-tach to be a very informative product. It is very nice to have when trying out different props or tuning your engine for best performance. It will not make you a better pilot but it does provide you with vital information on how your engine is performing.

The temp-tach sells for $139.95 and comes in red, blue, and green and is available from:

Pauly's R/C Products
2663 E.4269 N.
Twin Falls, Idaho 83301
(208) 736-1848

Tell them you saw it on the Flying Giants.