Small syringes - need hydraulics?

Trying out the small 5ml syringes with a 40cm long tube I found that there was little force transferred in a pneumatic system. I could easily hold the plunger in syringe whilst moving the other through its full range of movement. With no load the syringe only moved 3.5ml when the drive end moved 5ml probably due to the friction inside the syringe countering the pressure change.
After filling the system with water much more force was transferred and much more quickly. I didn't try to stop the syringe moving too much as I didn't want the tube to pop off and spray water all round the room.
I found a 6cm length of masking tape cut in half lengthwise and wrapped around the syringe nozzle made a good seal.

Comments

Post a Comment

Popular posts from this blog

Image
Pulleys and Levers A pulley works like a lever. You can use them to reduce the force needed to move an object but the payoff is that you need to pull more rope through the pulley or move the end of the lever further. Force x Distance = Word Done (which is the same as energy, which can't be created or destroyed) So if you arrange the rope to go around the pulleys such that there are 4 lengths of rope that get shorter when the load moves up (both of these diagrams are the same arrangement) we will need to shorten the rope by 4 times the distance the load moves up. So the force on the rope will be a quarter of the load. The quarter load balances the 4 times distance.
Read more
Image
Putting photos onto blog posts To put photos from my phone onto my blog I had to share them to to Google Photos rather than to my Google Drive. On Blogger, when you click the Insert Photo button you get options From your phone and this lists all photos that you've uploaded to Google Photos. Is there a better way to add photos to your blog? If you know of a different way let me know in the comments. Cheers Adding Video !!! It looks like two options for adding your own video to the blog. Either Upload - send it to your computer so you can upload it to Blogger or My YouTube Videos - upload it to your YouTube channel and then link to it.
Read more
Image
Thinking is HARD (especially period 5 on a Monday) Today I asked my class to investigate how far the end of a lever moved and how it was related to where the pivot was. Their first suggestion as to how we could find this out was to go straight to Google!!!!! After an explanation about cardboard and skewers and several diagrams on the board the idea of being systematic about gathering data seemed alien to them. "How do I measure this," was a frequent question and the answer "That's a good question, how do YOU measure it?" was greeted with quizzical looks. In 40 minutes one group of two had about 5 results, a singleton had several results, a trio had none and a group of seven had 2 results. A couple of groups had opened up Google Sheets to record their results which could lead to good things. Here are my results
Read more