Pulled the JMR out of the hanger this morning to test the re-installation of the Tiny Tach per Ron's instructions. Tied the airplane down and ran the engine. Worked great. Thanks.
Problem solved.
Problem solved.
JMR SPecial project. My design.
- Thread starter Pops
- Start date
Help Support HomeBuiltAirplanes.com:
So far with the taxi test I have found 2 small engine oil leaks. One was #1 valve cover pan. I used the thick orange silicon gaskets and you have to watch and not to over tighten the screws and warp the flange of the pan and tighten evenly. Fixed. The other was the oil tank drain plug copper gasket. Found a drop of oil on it. Cut the safety wire and tighten about 10 degrees and re-safety wired. Fixed.
Mounted the camera over my left shoulder today. Put the start and stop button on the mag key ring. Maybe I'll be able to find it there
The brakes takes a little more pressure than I like. The Matco brake instructions says to have a 2 to 1 mechanical advantage with your toe brakes. I have a little less than that. I need to unhook the master cylinders and re-attach in the other hole on the horn. That will give me the 2 to 1.
These are all the little things that you need to take care of for a new airplane. There will be more after the first flight.
Guessing, I think I have a little to much difference between the AOA of the wing and stab. I have 3. 5 difference and I'm sure the stab will need to be adjusted so at cruise the elevator and elevator trim tab will be in neutral with my normal flying CG. I also want the pitch trim tab to be full up trim at my normal CG and at my power off approach speed. Look at Cessna's 172 maintance manual and you will see the pitch trim tab is to set the same.
That is also very close to the take-off trim needed.
Mounted the camera over my left shoulder today. Put the start and stop button on the mag key ring. Maybe I'll be able to find it there
The brakes takes a little more pressure than I like. The Matco brake instructions says to have a 2 to 1 mechanical advantage with your toe brakes. I have a little less than that. I need to unhook the master cylinders and re-attach in the other hole on the horn. That will give me the 2 to 1.
These are all the little things that you need to take care of for a new airplane. There will be more after the first flight.
Guessing, I think I have a little to much difference between the AOA of the wing and stab. I have 3. 5 difference and I'm sure the stab will need to be adjusted so at cruise the elevator and elevator trim tab will be in neutral with my normal flying CG. I also want the pitch trim tab to be full up trim at my normal CG and at my power off approach speed. Look at Cessna's 172 maintance manual and you will see the pitch trim tab is to set the same.
That is also very close to the take-off trim needed.
Last edited:
Did some taxi test today. Found a problem. At full up elevator my lower seat cushion slide forward and was against the stick at full up elevator. The cushion is just something my wife was going to throw away. I have a light gray cow hide and I need to get a new seat cushion sewn and now I know I need to have a cut out for the stick and the cushion firmly attached.
Again I got it up to where it was wanting to lift off and backed off on the power to hold what I had and the mains touching the ground every 80' or so. Used about 300' with no flaps when the load came off the wheels.
Had a camera over my left shoulder and I thought I had it on but it wasn't.
Again I got it up to where it was wanting to lift off and backed off on the power to hold what I had and the mains touching the ground every 80' or so. Used about 300' with no flaps when the load came off the wheels.
Had a camera over my left shoulder and I thought I had it on but it wasn't.
Pictures of the elevator trim servo mounted in the elevator with an aluminum trim tab. Rocker switch for trim beside the flap handle.
I have been using this elevator trim servos since 2007. Works good.
I have been using this elevator trim servos since 2007. Works good.
Attachments
Picture of the JMR before covering. Look at the vertical piece of wood behind the baggage box. Its my com antenna. Its a Jim Weir copper foil antenna epoxied to a 1/8" x 3/4" wood strip and also at the bottom a ground plane going across the bottom of the fuselage, also a ground plane going fore and aft.
The coaxial cable is cut to length for a low SWR. I have been using these copper foil antennas since the early 1980's when Jim's article in Sport Aviation Mag.
Just keep the antenna as far as possible from any metal.
They work very good and cost almost nothing. Low cost, work good, no drag. Win, Win, Win.
The coaxial cable is cut to length for a low SWR. I have been using these copper foil antennas since the early 1980's when Jim's article in Sport Aviation Mag.
Just keep the antenna as far as possible from any metal.
They work very good and cost almost nothing. Low cost, work good, no drag. Win, Win, Win.
Last edited:
Received a lower nose strut plastic bearing from Zenith for the Zenith 750 to upgrade the lower steel bearing. I'm using the Zenith nose wheel design. I will be installing it, and don't ask about the price for a little plastic bearing. About the same price if it was from Cessna, Piper, Beech, etc, if not more.
Our grass field runway has been getting rougher each year and we haven't been rolling it like we should. Doing the taxi test the nose gear gets a workout and the little wheel and tire on the nose gear doesn't help. The nose gear strut is a copy of the Zenith 601, simple and easy to build. It also has a metal to metal bushing on the lower strut attach point that I don't like. Looking at the beefer nose gear strut on the Zenith 750 HD with the lower plastic bearing I decided to up grade to it.
Yesterday I worked on building the Z-750 HD strut. Maybe I'll get it finished and painted by the end of this week and swap it out . Then to another taxi test to make sure I have the steering rods adjusted correctly.
Remember homebuilts are never finished
Yesterday I worked on building the Z-750 HD strut. Maybe I'll get it finished and painted by the end of this week and swap it out . Then to another taxi test to make sure I have the steering rods adjusted correctly.
Remember homebuilts are never finished
Attachments
Last edited:
Work in progress. That big black thing at the center of the lower firewall is the new nose gear bearing I am installing. Zenith 750 HD nose gear. The new nose gear strut is leaning against the firewall.
Should have it finished in a few days.
Should have it finished in a few days.
Attachments
When my daughter and I restored her 1947 Cessna 140, she had the C-150 seats upholstered by a local man that runs a shop in gray leather. I bought a large gray cow hide and going to get the same man to upholstery the seat of the JMR just like her C-140. Also using the same layers of different foam. These were the most comfortable airplane seats I ever sat in.
Gray leather= old cow
Gray leather= old cow
Attachments
Last edited:
Ready to install the new Zenith -750 HD nose gear strut as soon as I get it epoxied primed. Took a little longer than planed but that is homebuilding.
I'll take questions from the back row today. Yes, you, what is your question ? I wondered if anyone would ask that. The question was " what is the weight difference between the two nose gear struts ? "
After weighing the parts taken off and the parts added, 2.9 ounce increase. Thank you, good question.
Next question.
After weighing the parts taken off and the parts added, 2.9 ounce increase. Thank you, good question.
Next question.
When reinstalling the nose gear bungee I made a simple puller to stretch the bungee for installation. Just hook the bungee on the rear of the strut, then around the cross tube in the "C" channel that is vertical on the firewall and pull up and attach to the other front tube on the NG strut. The puller lays across the top engine mount tubes and the all-thread goes down between the mags and attach the hook on the puller to the bungee and pull up and slid the bungee over on the nose gear tube. Very easy .
Now the hard part. Where to store the puller so I can find it when I ever need it again.
Now the hard part. Where to store the puller so I can find it when I ever need it again.
Attachments
Had the JMR about 8' up going down the runway. After reinstalling the nose gear, I still need a little adjustment on the steering pushrods for neutral nose wheel and rudder. Will be better next time. Everything else felt good.
We got a good 5" of wet snow a couple days ago and now raining all day . The yellow clay runway is so soft that you sink in with your shoes. We have drains everywhere, but the clay is like a brick when dry and muck when wet. Only thing that will be flying will have to have some large tires for a long while. When I first came here, I thought the river valley would be somewhat sandy soil. NOT so. I have over 1500' of french drains in my one acre lot beside the runway. It all drains into 2 small lakes close the the ridge and we have the Little Kanawha river on the end of runway 25.
Maybe I can get some test flying in if I can catch the muck frozen.
Maybe I can get some test flying in if I can catch the muck frozen.
Don't know when I can get the JMR out of the hanger. Putting a VW engine together for the VW Mud Buggy while watching it snow today. Started about 10 AM and suppose to get about 4". Had the wood stove in the hanger going today, hard to stay awake watching the fire. Picture of the Tomato plants I grow in the hanger in front of the patio doors and LED grow lights. Pump comes on every 8 hrs for 20 minutes to water and feed the plants. Usually keeps us in nice salad tomato's all winter. One plant is cucumber , picked 2 today.
