Blog update

Today we went ahead with making the A frame. After pushing and gluing the vertical side into the horizontal piece of wood that utter brilliantly.
we measured up the wooden frames for the long diagonal frame. Though we measured it out to what we thought should be perfect - it didn't end up that way. So when we glued one of the sides on we had to add a thinner peice of wood to it so it would e more secure.

Blog Update

I'm going to try my blog in a different layout, see if it works:

Lessons Learned

• That for major holds in the A frame, to nail the fittings in with the PVA glue so that the holds will hold the parts together
• Accross the base and other major joins in the A-frame, have another peice of timber glued accross in order to fully secure the frame. 
• Have thicker blocks to hold the two A-frames together at the same distance appart. 
• Use pre-made wheels (equipment available)
• Watch the length of the leaver so that the A-Frame is long enough to compact with the length of it. -Mr Ward is having to change his
• Mr Ward is good at cutting big pieces of wood to a good measurement

What we did this lesson

Today we started building the T shape for the A frame. We are going to use the box fit and we cut of the box needed for this. We have it ready to fit even through it could have been more accurate. Next lesson we will be able to glue it.

I am still not overly confident with the machines but i guess that will come with experience.

Blog Update

Yesterday Mr Ward showed us how to make a house fit in which it is one point in which is suppressed and then with the added glue, it will make a very tight and secure fit.
Ruby and I went on to creating the dimentions to our frame. We are planning to go into the workshop in the next possible lesson

Tips From http://www.butlercc.edu/engineering/en115/en115_basic_treb_design.cfm

Object	Design guidelines	Material
Counterweight	75 to 100 times heavier than projectile	should be adjustable
Arm	angle should be about 45 degrees when cocked; upper part of arm should be 3 to 5 times longer than the lower end	pvc pipe
Base and framework	must be heavy enough to support arm and counterweight and for precision, yet light enough to have a high material efficiency	pvc pipe
Sling or rope	should be slightly shorter than upper part of the throwing arm (for starters, that is); too short will release the projectile too early, higher trajectory; too long will drag the ground, lower trajectory	any material
Sling release pin	a more hooked prong will hold the sling loop longer than a straighter one. ie a prong less hooked or in line with beam gives an earlier release, higher trajectory;a prong more hooked or forward-pointing gives a later release, flatter trajectory	metal or other material
Projectile	a heavier projectile tends to pull the loop off the prong earlier than a lighter projectile does. heavy projectile gives earlier release, higher trajectory; light projectile gives later release, flatter trajectory	tennis ball-provided
Trigger	you need some way to release the projectile in a repeatable way	any material
Trough	the projectile needs to slide down some type of guide; friction will be important here	any material
*Base wheels-optional	wheels added to the base may increase distance; repeatability(? )	any material

Blog Update

Today we went over the new assessment. Mr Ward went over his planning for his trechubet and and how it is to work. There seem to be alot of ways in which to approach this unit, some trechubets are sturdied not on wheels but on an axel. However I think having wheels will make the trechubet more stable than if it were held by just a few wheels.

Ruby and I got to work on our planning and with images of trechubets open, I worked out a design for the framing of our catapult. I rember learning somewhere that triangles are the sturdiest shape to build a from so I took that Idea and made the framing of the trechubet many trianges. We worked on the height to length ratio also.

Blog Update

This week was a good fun one. In our first lesson we had our last adjustments to our kart and i just adjusted the glue to make sure the wire at the front stuck. We also discussed what to do for our next assesment. Zara wanted to build some sort of wood work and we all wanted to make rockets, though I had allready done that in year 5 so I wasn't as keen. But then I had the idea to make a catapult (partly because I was thinking of Lord of the Rings and other because my brother had just found a nerf gun). But anyway, the idea was accepted and everyone seemed keen.

The race day, well I got kicked out on the first round -very close through - and I lost to Amber who won so, well, luck of the draw. I was on timer and it kept me busy so I was happy.

Last lesson we discussed more on our new unit which is building a trechuet (catapult). It looks really exciting and I am actually really keen to do the history about it because medieval history is pretty much my favourite era to look at.

I will be working with ruby and we started researching designs for our machine and we have found some variables in the design

• wheels or no wheels (we already know from a video that Mr Ward showed us that it works better with wheels because it increases the thrust of the object fired
• The holder can be either a spoon shape, a "sling-shot" type shape, of a netted basket
• How much scaffolding is on the model
• what is used as the weigh (usually it is a box that the weight could be changed)
• length of the rope

Blog Update

Today if the day before the kart racing and my kart is just getting slower and slower. It started off at an origional speed being 2.645 and now the times aren't even clearing 3 seconds. I changed the batteries but it doesn't make much of a difference. I find it is because the kart is beginning to go off course because from what i remember the wires were tighter at teh start, now my kart is travelling to other sides of the course.

But then again it could be any other feature aspect of the kart that could be deterioating.