[melt_fire]

In simply, we have to do a Hexagon sleeve (dimension 8mm) at both side of a 750mm long shaft (dia. 18mm).

Depth of Hex Sleeve: 10mm
Material: AISI 1.0718 / 9SMnPb28 (free cutting steel)
Quantity: only 200

Any advice?
Thanks alot.

[One of Many]

Look into rotary broaching tools. Like these.

http://www.rotarybroaching.com/

DC

[alexccmeister]

Not sure what the purpose of the shaft is for, but I was thinking maybe you could just drill a hole on either end, tap it to receive the right Hex screws and just enlarge the size of the opening a bit and just screw the hex screw all the way in. Put superglue to hold the hex screw in.

Without a broaching machine, I would do that.

[melt_fire]

Right, since the quantity is only 200 (annually), I don't think rotary broaching suits my case.

Tapping is a method we've been thinking, however, we don't know how to fix this 750mm long, dia.18mm shaft for tapping :S

[ALLtra Mach]

Just a thought..I'd use loctite over super glue!?

I am assuming you by sleeve, you want an internal hex.
You can drill and bor your hole to within a fraction of flat width, then sharpen a couple of allen wrenches to use as broaches. Chuck the shaft in a lathe and work the material out.
BTW, what is the mtl?

[alexccmeister]

If you have a lathe like a C3 up, I am sure you can drill a hole for tapping. goodluck.

[One of Many]

Right, since the quantity is only 200 (annually), I don't think rotary broaching suits my case.

Tapping is a method we've been thinking, however, we don't know how to fix this 750mm long, dia.18mm shaft for tapping :S

You have 400 hex socket bores to do on 200 rods?

These rotary broaches mount in a lathe or a mill the same as would be done for drilling and tapping. With a cycle time of around 15 seconds after predrilling, there is no secondary parts or operations. Someone will spend more time and money trying to achieve the same thing with nearly any other method. If you do not have the means or equipment to do it efficiently, send it out to someone who does. 18mm x 750mm should not present that much of a problem in most shops, even around industrialized Hong Kong.

I suppose you could purchase 400 8mm socket wrenches and press or weld them into a bored hole in each end of your rod. Drill and tapping for a 8mm socket head cap/set screw will not gain you a 10mm deep socket. If you have some flexability there and these drive light loads, it may be an option. There is that chance that directional changes could unscrew one end or the other.

As I see it, what ever method there is cost but no value added trying to cover this process with labor intensive but less expensive up front investments. Spending the money on a rotary broach once and having the job done in 1/4 the time is penny wise that will pay off twice the next run.

DC

[alexccmeister]

Hi DC,

Interesting. You have any link to one of these broaching attachment?

Alex

[One of Many]

Hi DC,

Interesting. You have any link to one of these broaching attachment?

Alex

See my previous post in this thread? There is the link. There may also be other manufacturers that produce something similar.

DC

[melt_fire]

Thank you~ I'll try the suggested methods~

[andypugh]

Very late to this thread, but I have been experimenting with another way, using a CNC lathe.
[nomedia="http://www.youtube.com/watch?v=T4q8gCpeY1A"]YouTube - Hexagonal Boring[/nomedia]

[Delw]

no offence but you size of your hex is off by a ton, your allen wrench almost moves 60 degrees before it engages the part to turn the chuck the other way. IE tons of slop, kinda like using a 10mm allen wrench in a 12mm hole.

what type of lathe is that? wouldnt it be easier to just drill it out mill it close then make a hex broach out of tool steel and push it in? your size would be better and you would get alot better finish too.
I am assuming you had miil turn lathe?

[andypugh]

no offence but you size of your hex is off by a ton, your allen wrench almost moves 60 degrees before it engages the part to turn the chuck the other way. IE tons of slop, kinda like using a 10mm allen wrench in a 12mm hole.

It was a proof of concept, and I didn't spend much time on the setup as it was freezing in there. I wasn't even aiming for a specific size, I edited out the fiddling around looking for an allen key that nearly fitted.
Surely you can see that, as it is a CNC lathe, that any size (or shape) is possible? It would be trivial to make a pentagon or heptagon, for example.
or, for that matter, a tapered socket.

what type of lathe is that? wouldnt it be easier to just drill it out mill it close then make a hex broach out of tool steel and push it in?

The lathe is a home-converted Chinese 7x30.
I don't think it would be easier, no. Certainly not for a one-off.

I think you are complaining that the singing pig is out of key.

[ErnieD]

Rotary broaching would be many,many,many times faster.

Ernie