Author: JoeO

Powered Paraglider pilot since 2005

Tweaking the Thumper

A assist with rope ratchet

— On Wed, 2/18/09, jo3jo2003 wrote:

Terry Chad,
I’ve been dialing in the “Colorado Bullet Thumper 4stroke”.Epoxy Gel and a new longer split fuel hose anchored the motor end of the throttle cable. It was moving around and preventing a true idle.The engine is max at 3800RPMidle at 1800RPMI can probably Pitch the IVOs more…BUT?Chad…how far can you pitch the IVO blades and how do you know when to stop?Can you “over warp” them and damage the system?Maybe I should learn how to measure the pitch just for the “pure research” as you put it Terry.I was glad to read about “belt Flop” on the slack side of the drive system. I’ve noticed some flop and wanted to ask how to determine correct belt tension. If I understood you right what I’m seeing is about normal.Last…Terry ….what do you think? The local Briggs & Stratton guys say I can install the high altitude carb kit in 15 minutes or less. I’m going to be launching from 8200+ MSL a few times this summer and the rest of the time will be at 5300 MSL. I’m thinking that it might be a good if I used Hi Alt jets here in Denver and the mountains and switched to the stock jets for the coastal stuff. These guys are willing to show me how to install and adjust them for the price of the labor Don’t worry….Before I start changing anything I’ll see how it does at the home field. But I wanted to run it by you.It’s just too damn cold and the best I can do is tweak the machine.
JoeO

Hi Joe, I was thinking of you today.

I think 3800rpm is fine.

Belt ‘flop’ on the slack side is normal, but I find it’s best not to watch it;); BTW, I have never lost a belt or even had the belt jump a groove. Belt tension is not something you need to worry too much about..tension it about like you would your underhood car belt. If the belt ‘flops too much to suit you, tighten it a little more, you won’t hurt anything (however it’s probably just fine right where it’s set now)

I don’t know about hi elevation carb kit, but I am curious about it..I wonder what the kit includes? Smaller jets? Different air filter?
One thing that might help is to remove all the filters from the intake shell. Please let me know what you learn about the kit.

It’s cold here too; I delivered a new unit to Indianapolis on Sunday and I demo’d it for the buyer; a 5 minute flight was plenty for me.

Terry

Flying Circus Wrap Up

The drive home was good. I had a massive cold front following off my left shoulder all the way from Albuquerque. At one point the shadow from the leading edge was playing tag with the truck and we were doing 80 mph! Fortunately it stalled at Raton and I never had to deal with icy roads.
The Arizona Flying Circus was great….frustrating but great. Lots of vendors including ParaToys who would never have been welcome or inclined to attend under Bob’s ownership. Nirvana and Paradrenaline were there and their “factory Pilots” put on a great demonstration of flying in ratty air and high winds.
I spent most of my time dealing with equipment issues. The first morning was the most heart breaking because I walked off the field when the battery died. It was two days later that I realized that all I had to do was use the pull start. Doh !
The new cage arrived on Friday afternoon and I spent the afternoon working with Bob Pelloquin to get it assembled and mounted on the frame. As fate would have it there was a crowd of luminaries standing around when it was time to fire it up. Sure Nuff there was a prop strike and one of the tips was damaged. That evening after dinner with Jim King and a couple of other pilots I sat in the hotel room and replaced the blade with one that Johnny Fetz had repaired while at the Salton Sea.
The IVO Prop is an amazing design that enables you to adjust the pitch of all three blades simultaneously by turning a bolt in the hub. Counterclockwise to increase pitch and clockwise to reduce pitch. I had to take it apart and assemble it twice before I got it right but that seems par for the course for me at this fly-in.
The next morning I attempted a launch but the wind picked up and I didn’t react fast enough when the wing pulled me backwards. The buggy rolled to the left and I was forced to kill the engine and abort. Jeff Goin was filming so he was able to brief me on what the wing did. I’m going to have to increase the tension on the steering bungees so that it rolls straight. While I was out there a pilot asked me to start the machine so that he could hear it. Right away it was obvious that the prop was badly out of balance.
The rest of the day I spent working on the machine. Bob and I did some creative bending to increase the clearance and Kent helped me out with shortening the blades by 2 inches. I was wary of making the cut but Kent dug in and they are looking good and well balanced now.
Saturday afternoon was the Bowling Ball Cannon and later the Banquet. It’s all Good.

260 261 262 Thumper’s maiden Voyage

I was a little nervous laying out the wing but the motor started like a champ and the Thumper took off just fine. The brake pressure required was alot more than I was used to. and I didn’t like the way the buggy was pitching. Chad didn’t think there was anything to worry about but I’m not liking it. After landing Jerry Frost made it a point to tell me that I needed to raise the hang points because I was wheelbarrowing during launch.
The second flight was very short. The machine was so quiet that I forgot to put in plugs and put on the helmet. Right after lift off The hat went through the prop and when I heard the “wack” I was thinking broken prop or worse. I got off the throttle quick and came out of the dive with just barely enough time to flare. I bounced floated and landed. I write that one off to unfamiliar equipment and move on.
The third flight was pretty good. I stayed up maybe 30 minutes and experimented a bit with the wing. It’s really hard to pull. There is plenty of power at sea level . I’ll know more when I get a chance to fly in Colorado.
//www.youtube.com/get_player

#259 and Carnage at the Sea

hLast flight of the Simo
It was a normal launch in every way…Until… I looked up to check the lines and sure enough there was a great big twig twisted into the A lines. It was deforming the leading edge near the center of the wing and I decided right then to get down so I flew over the field and the scrub that borders the north edge and set down in the first sandy patch available. Up to this point it was a non event, I had plenty of clear space ahead and the surface was soft but not too soft… so I set up for another launch. The wing inflated and the taxi was going fine until the sand got allot softer and the buggy sunk in to the mixture of sand and shells. Instead of killing the engine and aborting I added power and a split second later heard a loud crack.
Some lines were cut, the prop was broken, both of the top pieces of the cage were bent and the frame broke at the top motor mount. It’s hard to believe that a line in the hub could do so much damage.
I was hugely bummed to say the least. Grounded and there was still 6 days of flying ahead!

251 252 253 254 255 256 Salton Sea

Big Day lots of firsts…

Most Flights in one day. It should probably be 256.5 because I did a touch and go that was so long I taxied the full lenght of the field.

First time to fly a performance wing Spice 24 (or there abouts)
First time to fly a 4 stroke. I took up Bens machine with the eden 28.

The thumper flight was marred when I rigged the brake line thru the hangpoint rings and had a friction lock. Landed dead stick at the rocky end of the field. I had to take a wrap on the Brake line above the ring.

Tonight there was a prop burning and outdoor movies.

I had dinner with Ben at the Mexican Resturant…Huge Special plate.

#246 #247 #248 #249 #250

Lots of airtimeSalton Sea! I started at 9am. 5 good launches and 5 good landings. Lots of the low and slow. Flying with the birds. Great day of flying!

Hooked up with Robert K, Ben M, Johnny F. and Terry L at the new resturant on the Hwy. Talking 4 stroke…props….wings.

Bad day for the Thumpers …both Ben and Terry took damage from getting lines in the prop.

El Mirage The Flying J Ranch

#238

After visiting with Saundra Painter in Santa Barbara I drove out to El Mirage and waited for the wind to die. I’m camping at a small private airstrip that caters to ultra light Delta Trikes. They have a Quonset hut hanger with 6 trikes and several shipping containers where guys like Chad are storing their equipment. To the south east there is another facility where they are assembling and test flying the Predator unmanned vehicles for the military. All afternoon while I set up my camp there was a predator circling over the field. Its a very strange looking plane with the bulbous nose and lots of junk hanging down. The landing gear are on long sticks and the twin rudders are mounted below the fuselage. At the right angle when you cannot see the wings it looks like an insect…more like a grasshopper that a plane flying at 800 feet.

About 40 minutes before sundown the wind dropped and I went up for a test flight. Beautiful smooth air ! While I had the chance I practiced spot landings and several times I was able to touch down within a few feet of my wing bag.

I climbed to 100o feet and chased the sun. The dry lake is partly full but even so there was only a couple of inches of water. It’s less than a mile from the airstrip and a wonderful place to practice the low and slow, there are miles in all directions without a post or obstruction of any kind. 8/10 of a mile to the south west is a small uprising (probably 1000 elevation climb)called Grey Mountain. I climbed until I was even with the top and watched the sun set. When the shadows disappeared I cut power and descended to the LZ.

It got cold quickly and rather than try to heat up a can of soup I drove to the edge of the closest town and had a burger. Back at the tent I listened to the IPod and spent a very cold night in the desert.

I