CNC Machining Bearing Blocks

[magnets]

We're making an offseason drive base, and we'd like to make our own bearing blocks on our CNC mill, but I can't think of a good way to hold down these parts for machining.

Does anybody have a clever way to make these parts?

[R.C.]

Softjaw? Also Picture of what your trying to machine?

[magnets]

Originally Posted by R.C.

Softjaw? Also Picture of what your trying to machine?

Sorry, I should have been more specific. We're trying to make 6 or so of these:


Ideally, we'd make all of them from one big block of aluminum.

[techhelpbb]

Toe clamp the block and a piece of sacrificial material to the machine deck.
Tab the flange so they do not float till after all the isolation is done.
Then cut them loose.

Use a standard drill to rough out the pockets behind the flange and around the tube.
Then finish it with an end mill.

If the inside is for bearings probably want to use a boring head.
If the outside is a critical dimension you might also be able to use a boring head.

There are other options.
Like using a lathe.

[sanddrag]

We do ours out of 2x2" square bar stock that we hold in softjaws in a 6" vise. We do two at a time out of a piece of 6" long stock. We machine the bearing side first, then pull it out, machine the softjaws to that profile, flip it upside down into the softjaws, and then machine the side with the tube. Simple process. I recommend http://monsterjaws.com/

[Mr. Mike]

Saw stock slightly larger than finish size.
Put flange side down in vise. Hold onto slightly less than flange thickness.
Rough machine hub OD and ID then finish both.
Mount soft jaws in vice and machine a pocket to fit the hub OD.
Clamp part in soft jaw. Caution not to crush hub.
Machine flange shape and holes.

Option if you have a lathe and round stock.
Do all round features then go to the mill to finish flange shape and holes.

[Cory]

Do you have a reason for not buying these?

That's the best bang for the buck you're gonna get. If you want to learn to use your mill to the fullest extent of its capabilities, that makes sense. But this might be a problem to throw money at.

[Michael Hill]

Originally Posted by Cory

Do you have a reason for not buying these?

That's the best bang for the buck you're gonna get. If you want to learn to use your mill to the fullest extent of its capabilities, that makes sense. But this might be a problem to throw money at.

I'd second this. 6 weeks is a short build season. If you can buy it instead of build it, then buy it. This is a lesson I learned last year.

[magnets]

Originally Posted by Cory

Do you have a reason for not buying these?

That's the best bang for the buck you're gonna get. If you want to learn to use your mill to the fullest extent of its capabilities, that makes sense. But this might be a problem to throw money at.

Normally, we would do that, but money for buying robot parts has become an issue for us, and we'd still like to have a practice robot. We could save some money making these and the little cams ourselves.

My plan was to make some of the parts we usually buy on our CNCs on the first few days of build, as the CNC is not usually in use on these first days, and we have students who would do this.

I was originally planning to just do a row of 6 or 10 on one piece of aluminum, but I'm thinking it may be easier to take one, machine the top (the tube end that fits into the other side) all the way down to the base, then put it in a fixture plate with a 1.375" wide square with radiused edges to locate it to machine the outline, the mounting holes, and the bearing flange c-bore.

[kaliken]

Here you go. I remember seeing this a while back..

Blatantly stolen from team 254's 2011 build blog.

http://blog.2011.team254.com/wp-cont...1/DSC_3891.jpg

[Richard Wallace]

Originally Posted by Cory

Do you have a reason for not buying these?

That's the best bang for the buck you're gonna get. If you want to learn to use your mill to the fullest extent of its capabilities, that makes sense. But this might be a problem to throw money at.

Thanks for the link, Cory. I knew these existed but had forgotten where to look. Pretty sure I first saw them on one of your team's robots many seasons ago.

Two questions not immediately addressed at the WCP link (since my iPad doesn't run CAD): (1) what is the material? and (2) do these blocks accept FR8 bearings?

[Gregor]

Originally Posted by Richard Wallace

Thanks for the link, Cory. I knew these existed but had forgotten where to look. Pretty sure I first saw them on one of your team's robots many seasons ago.

Two questions not immediately addressed at the WCP link (since my iPad doesn't run CAD): (1) what is the material? and (2) do these blocks accept FR8 bearings?

Here's the equivalent VEXPro page, which is more detailed.

http://www.vexrobotics.com/vexpro/we...gblocks-g.html

[R.C.]

Originally Posted by Richard Wallace

Thanks for the link, Cory. I knew these existed but had forgotten where to look. Pretty sure I first saw them on one of your team's robots many seasons ago.

Two questions not immediately addressed at the WCP link (since my iPad doesn't run CAD): (1) what is the material? and (2) do these blocks accept FR8 bearings?

Both the bearing blocks and versablocks are 6061-T6 and they both accept fr8 style bearings and hex bearings.

[Richard Wallace]

Originally Posted by R.C.

Both the bearing blocks and versablocks are 6061-T6 and they both accept fr8 style bearings and hex bearings.

Thanks, R.C.

Ordered a set to play with.

[Mk.32]

Originally Posted by magnets

We're making an offseason drive base, and we'd like to make our own bearing blocks on our CNC mill, but I can't think of a good way to hold down these parts for machining.

Does anybody have a clever way to make these parts?

What kind of mill do you have?

The cost of materials, tooling and then machine time (that does "cost" something) versus $20 a piece from vex is sometimes hard to justify.

It's quite a bit of material removal as well.