Step 4 Router and Brass

**Leadhead** · 10-01-2015

I have a rarely used Step 4 540 router on Mach 3 with the standard Proxxon spindle. Used only occasionally on wood and plastic thus far. I have a fancy to use it to machine some brass model plaques and logo`s.
Before I break it trying!! Has anyone tried it on brass. Slow feed/high speed minimal stepover approach presumably?
Also have a larger Kress spindle. But it looks a bit large for the 540. Anybody fitted one please.
Would really like to make more use of this machine. Your experience appreciated.

**Trispectiv** · 18-01-2015

Proxxon will engrave brass, but sooner or later the bearings will give up. It also tends to get rather hot at high RPM if you run a long gcode. However it is a cheap solution for a tiny spindle situation.

Kress will engrave brass without any problems at the extra price and weight.

**Leadhead** · 19-01-2015

Thanks for reply. Have experimented a little without problems, except as you suggest, the spindle gets quite warm. Since the process time is not important. I will interrupt the program every 20 mins or so to cool. Additionally I will air cool it with comp. air and some cardboard ducting to both cool and blow swarf.. So still working round it.
Going to finish mount for the Kress today.Will see what the little servo`s think of it.
Hopefully I can get some more use from the machine in future

**Trispectiv** · 19-01-2015

Could you post a link about the router you are going to mount the Kress on?

**Leadhead** · 19-01-2015

It is a small Step 4 540 Basic. Do you want further info? I have first part of Kress bracket. Need to make an adapter plate to complete.

**Trispectiv** · 19-01-2015

Well, according to the photo I found after searching the name of the router, the manufacturer shows it with a Kress mounted on it already. So I expect it should handle the weight of the Kress just fine.
(en.step-four.at/hp2/index.php?action=1482)

**Leadhead** · 19-01-2015

Aha! I have never noticed that! I even have that sheet pinned on the workshop wall! So need no more reassurance. Thank you!

Mine is an older machine and was fitted with the small Proxxon as standard. I bought this machine a while back and have not given it much attention until now.

**Trispectiv** · 19-01-2015

For the current version on their website, I see no spec about the stepper motors. They are also covered by a case, so I can't roughly estimate their capabilities upon their size either. However, it doesn't take a lot of torque to move the Kress around, I would rather worry about the deflection of the 16mm hanged rods instead. Since you already have Kress mount in production, the only way is forward :)

**Leadhead** · 19-01-2015

Hello again - Here is photo of the units. As you will observe. I doubt if this size Kress was ever standard on this machine.
But I stand to be informed

**Trispectiv** · 19-01-2015

Well, your router looks different from what they show on their website at this moment. If those are 10mm smooth rods, there will be quite a lot of flex. Also, Nema17 in the 0.3Nm range I suppose, will have a hard time pushing it around. But like I said, since you are half-way through already, you will have to mount it even just to check how well/bad your axes coop with the Kress weight.