Week 10 - Composites
![](week10/1.jpg)
This week I made a bow using epoxy resin composite material.
![](week10/2.jpg)
First I made a rough outline of a bow. Since the shape was very simple, I used the chain-saw in stead of shop bot.
![](week10/3.jpg)
I was happy with the smooth finish of the chain-saw.
![](week10/4.jpg)
I initially thought that a crease or resting place for the arrow would be useful.
![](week10/5.jpg)
I followed Kenny's vacuum bag technique.
![](week10/10.jpg)
I wanted to have the limbs of the bow to change shape and then return to original position after the arrow is strung. Kenny suggested that I use sisal twines wrapped around four posts to store the energy. However, I followed a simpler approach of wrapping the linen around the foam core.
![](week10/11.jpg)
Equal proportion of 105 Epoxy resin and 205 hardener were mixed in a cup. It took me almost 45 minutes to apply the resin-hardener mix to the tiny strips of linen and then wrap the linen around the bow shape.
![](week10/6.jpg)
Then the bag was sealed and vacuum pump was applied.
![](week10/7.jpg)
After 12 hours, the bow looked adequately cured from outside.
![](week10/8.jpg)
Without much hassle, I extracted the bow from the vacuum bag.
![](week10/9.jpg)
I drilled two holes at the corner of the two limbs for the bow-string (made of rubber-band).
![](week10/12.jpg)
I cut and bent a metal wire for creating the arrow, and then padded it with packaging foam, so that it cannot create much damage.