So I have been looking at where to source my precision rods and bearings. I have done some other projects with linear motion so I have a little experience. I am trying to design around relatively inexpensive parts. Mcmaster is not the best source for inexpensive parts, but if you can find it on McMaster then you can find it somewhere else cheap as well.
For the rods I am thinking about these:
Hardened Precision Steel Shaft
- Hardened and precision ground is a must for this application
- 12" long, 3/4" diameter, and tapped on both ends
- $44.84 each and I will start with using two diagonally. But the parts will be machined to accept 4.
For the bearings I am thinking about these:
Dust Resistant Linear Sleeve Bearings
- $7.31 Each
- PTFE
- Static load capacity of 1400 lbs
- Dynamic load capacity of 100 lbs at 100 fpm (should not see much dynamic loading because it will move slowly.)
I also did a little research and have been looking at standard mold design. There is a huge amount of information on injection molding and it has taken me a while to really wrap my brain around some of the aspects of the mold design. This molding machine will be too small to use a standard mold design, but some elements can be copied. I am planning on doing something similar to this design. However, I will not have a spacer blocks, and the bottom clamp plate will be combined with the support plate.
Discussions
Become a Hackaday.io Member
Create an account to leave a comment. Already have an account? Log In.
Did you see the clearance the bearings have? We sometimes use them and are often amazed how much space there is between them and the rod (sometimes even out of spec). The site says between 0,04 and 0,09mm. One tenth of a millimeter sounds way too much for me (in this application)?!
Are you sure? yes | no
Hi again, jupdyke. You could source some hardened rods from Ebay or Aliexpress. I bought some 1/2 in ones a few years ago and they were fine. They're really cheap and could allow you to make some prototypes without spending though the roof.
http://www.aliexpress.com/store/group/Linear-shaft/834897_252708834.html
Are you sure? yes | no
This is just wrong, so we're going to a link for hardened shaft - then every image on that page has a note in red text: "can be cu_t any length". Hilarious. Those are great prices though!
Are you sure? yes | no
LOL nice catch, fantastic wordplay by the chinese!
Are you sure? yes | no
It definitely made me double take, I was like oh nice - they'll cut it to... wait a second!
Are you sure? yes | no
They definitely know how to sell their stuff ;)
Are you sure? yes | no