How do I machine an internal Hex?

[RVJimD]

Hi Guys,

I would like to try and make some new rims for my 1/18 scale RC truck. The first problem I see is how to machine the internal hex. The hex/hole is blind which from my limited experience makes this more difficult.

Here is a short video showing the stock nylon wheel. My plan would be to make a new wheel from aluminum.

Thanks for you input.

 

[DAT510]

Rotary Broach is one way.

Here's a previous H-M thread. http://www.hobby-machinist.com/threads/shop-made-rotary-broach-down-and-dirty.48805/

You can also buy kits or pre-made rotary broaches.

 

[Dave Paine]

Consider making a hole for a 6 sided socket to be epoxied in place then machined as needed.

 

[ddickey]

You'd have to buy or make your own rotary broach.

 

[Wreck™Wreck]

A rotary broach is an option if the quantity of parts is sufficient, if not mill it, this approach works well if you are not constrained by corner dimensions.

I suspect that there are few hobbyists that own a machine that has the power to push a rotary broach to good effect.

 

[cascao]

Make the wheel with a bigger round role and press a allen head bolt into it. (Maybe it need to be done with set screws since it hex is deeper)
Or
Make the wheel with a round role and press a allen wrench segment thought it broaching the hex.( since aluminium isnt that strong)

 

[Superburban]

A dremel, small file, and an exacto knife?

A drill press, or careful with a hand drill, you could drill out the corners, then drill/ file/chisel out the center.

Search out some premade inserts?

Its a matter of inventorying your skills, time, patience, and tools.

 

[ddickey]

Convert the spindle the a square head. That would be much easier to mill.

 

[dave2176]

Consider a 6 point socket from Snap-on. The points are rounded out so the load on the bolt is placed a few degrees from the point. Superburban's photo illustrates this beautifully.

 

[mmcmdl]

Rough an undersized hole with a FB endmill , find the coordinates of the corners and send the smallest end mill do finish depth and then simply mill in an indexer . Your corners will be undercut for the sharp corners on the male hub .