Tuesday, October 28, 2008

2008 Trip to Punkin Chunkin!

It is now 6:45PM on Tuesday 10/28/08, do you know where your tractor-trailor carrying your trebuchet is?

Yes, it's in New York state somewhere broken down (broken alternator belt)!
Trying to find a replacement at AutoZone!!!

Do you know how dry your field is at Punkin Chunkin?

Yes, ours is very wet and they do not know if we can go onto the site tomorrow at 10:30AM when the crane arrives (First State Crane Service)!

Today, Tuesday, has been very windy, following a very substantial amount of rain on Monday night and early Tuesday AM. Hopefully the wind will help to dry up the site so we can setup on Wednesday! Pray for no rain, how often do you hear a farmer saying that!

News Alert!!! Tuesday 10/28/08 7:18PM - Our tractor trailer carrying trebuchet is now back on the road and heading for Bridgeville, DE!

Note to our Yankee Farmer Customers, Thank you for our most successful season at the farm stand! Without you we could not attend the annual Punkin Chunkin competition in Bridgeville, DE. Hopefully we will bring back a trophy to Greenfield, NH.

Monday, October 20, 2008

Weekend of October 18, 19 & 20, 2008 --- Strong Throws, Even with a Headwind!

We continued to throw with 11,500 pounds of counterweight. Saturday was breezy and in the mid-50's with a steady 10 to 20 mile per hour headwind for most of the day. As late afternoon approached, the wind died down with a consequence of a significant increase in distance.

We added 500 pounds of counterweight on Sunday morning to bring the total counterweight up to 12,000 pounds. There was a 10 mile per hour headwind but the extra weight seemed to over power the wind. We had fairly consistent throws, with one throw at the 2100 foot mark after changing to a 24 foot sling instead of our standard 25 foot sling.

On Monday we had four schools visit our site. These were high school physics and engineering classes, as well as, some grade school students. Winds were very calm but temps were only in the high 40's. We tried a slightly longer sling (26 feet) to see how the machine would react. The throws were very good, with one shot around 1950 feet but very high.

Results of the 19 throws October 18, 19 & 20, 2008

Note: We added 500 pounds of counterweight (Sunday) for a total of 12,000 pounds.

Saturday October 18, 2008

Throw One - 1650 feet
Throw Two - 1400 feet - low trajectory
Throw Three - 1800 feet - high trajectory
Throw Four - 1400 feet
Throw Five - 1800 feet - good height
Throw Six - 1800 feet - good height
Throw Seven - 1800 feet -good height and calm wind

Sunday October 19, 2008

Throw One - 1900 feet - good height
Throw Two - 2000 feet - good height 15 mile an hour headwind
Throw Three - 1400 feet - low trajectory
Throw Four - 2100 feet - good height 10 to 15 mile an hour headwind and change to 24 foot sling
Throw Five - 1650 feet - slightly low trajectory
Throw Six - 1800 feet - good height
Throw Seven - 1700 feet - high hard left
Throw Eight - 2000 feet - slightly low

Monday October 20, 2008

Note: Changed to 26 foot sling.

Throw One - 1850 feet
Throw Two - 1850 feet - good height
Throw Three - 1950 feet - very, very high
Throw Four - 1450 feet - slight pie

PS This will be the last posting of throws before the competition. We will be practicing next weekend but we won't be posting results because we will be dismantling the machine starting on Sunday night and Monday day and that will consume all our time. The logistics of transporting a 52,000 pound machine and associated support on four separate vehicles can be mind numbing. (I have nightmares about forgetting some critical part).

I wish every team the best of luck in their practice sessions. I hope everything goes well and safe and nothing breaks. This year promises to be quite competitive, now that Pumpkin Hammer and Merlin have had a full year to tweak and tune their new machines. Both these teams have designed very sophisticated and efficient machines. Their efficiency far surpasses Yankee Siege. They are smart machines, finesse machines. Yankee Siege is just brute force. Yankee Siege is probably the least efficient machine in the whole competition (dumb machine). Any one of these three machines could win, or maybe some unknown machine will come along. Win or lose, this year will be exciting!

Steve Seigars, YS

Monday, October 13, 2008

Weekend of October 11, 12 & 13, 2008 --- Yankee Siege Breaks 2200 foot barrier!

The last of sixteen throws of the weekend turned out to be a whopper! With over 16 seconds of flight time, the orange pumpkin flew on a high trajectory and just kept on sailing upward before finally descending to earth after traveling over 2200 feet. We measure our distances from an observation tower located 1200 feet from the treb. The forward observer uses a range finder to measure how far the impact is from the tower and then adds 1200 feet to the total distance.

Several thousand onlookers witnessed Yankee Siege throw throughout the weekend. Weather was sunny and in the high sixties. It was almost a perfect weekend. We had one errant throw that came dangerously close to our nearest neighbor, hitting a tree and raining down pumpkin guts. Luckily, we have great neighbors who are very understanding and we promptly repositioned the treb.

We took seven more throws on Monday with some interesting results. We wanted to see what would happen if we put more slack in the sling. We wondered if more slack would give us more consistent distances. We suspect that the elastic recoil of the throwing arm may be producing a harmonic in the sling, leading to inconsistencies in the timing of release. We tried 12 inches of slack in a 25 foot sling. There were no very short throws. All throws were 1600 feet or above. The slack seems to work (we need more testing to verify).

Results of the 23 throws October 11, 12 & 13, 2008

Note: We added 500 pounds of counterweight (Sunday) for a total of 11,500 pounds.
Note: All pumpkins are orange and used a straighter release pin.

Saturday October 11, 2008

Throw One - 1200 feet - low trajectory
Throw Two - 1300 feet - low trajectory
Throw Three - 1400 feet - low trajectory
Throw Four - 1700 feet - change to straighter pin
Throw Five - 1500 feet
Throw Six - 1700 feet
Throw Seven - 1700 feet
Throw Eight - 1650 feet

Sunday October 12, 2008

Throw One - 1800 feet - good height
Throw Two - 1850 feet
Throw Three - pumpkin fell out of sling
Throw Four - 1650 feet - hard left
Throw Five - 1450 feet - low trajectory
Throw Six - 1600 feet
Throw Seven - 2000 feet - good height
Throw Eight - 2200 feet - in the stratosphere!!!

Monday October 13, 2008

Note: Put one foot of slack in the sling.

Throw One - 1650 feet - slightly low trajectory
Throw Two - 1850 feet - good height
Throw Three - 2100 feet - great height, long flight time
Throw Four - 1900 feet - slightly lower
Throw Five - 1700 feet
Throw Six - 1600 feet - tried underweight Lumina pumpkin
Throw Seven - 1850 feet - good height

PS Next weekend (weather permitting) we will try varying sling length and adding more weight to the counterweight.

Steve Seigars, YS

Sunday, October 5, 2008

Sun Returns to Greenfield, NH on the weekend of October 4 & 5, 2008

Sun was back shining on Yankee Siege this weekend. Temperatures were in the mid 60's, winds were calm and we seemed to have overcome some of our engineering problems of the previous weekend.

We tried out some new items this weekend. First, we tried out a new 10 inch steel trough. We fabbed it by cutting a 10 inch diameter steel pipe into equal halves with a metal-cutting "skill saw". This saw looks and cuts exactly like a wood cutting saw. It leaves a very smooth cut with very little cleanup.

Next we tried to cure our problem of the pumpkin falling out of the pouch. Apparently, what is happening, is that the throwing arm is elastically recoiling when the trigger is released. This is followed by a rebound in the opposite direction, causing a momentary slacking of the sling and a subsequent rolling of the pumpkin out of the sling. We have solved the problem by putting about six inches of slack into the sling and allowing the recoil of the throwing arm to occur before the pumpkin moves down the trough. (Our high speed camera shows the sling actually becoming slack as the throwing arm rebounds).

We threw fourteen pumpkins this weekend with the following results:

Saturday 10/4/08 10,300 pounds counterweight.

Throw One - 1550 feet - slightly low trajectory
Throw Two - 1400 feet - low trajectory
Throw Three - rolled out of sling - didn't put any slack in the sling
Throw Four - 1700 feet - broke 3/16 inch cable stay
Throw Five - 1600 feet
Throw Six - 1500 feet
Throw Seven - 1800 feet - good height
Throw Eight - 1700 feet

Sunday 10/5/08 Added 700 pounds of rail road track to counterweight. Counterweight now 11,000 pounds.

Throw One - 1800 feet - good height, broke cable, bend aluminum extension.
Throw Two - 1900 feet - changed to carbon fiber extension and 1/4 inch cable.
Throw Three - 2000 + feet - good height
Throw Four - 1700 feet - slightly low
Throw Five - 1200 feet - pied into two pieces - cable stay strut slightly bent.
Throw Six - 1750 feet - good height.

Next week we will try adding more weight and trying different pin angles and sling length.

PS All throws were done with orange pumpkins no Lumina pumpkins.

Steve Seigars YS