4. Guide Bushing Support – part example – muzzle break with 150 holes in it. Star SR20 has ¾ of an inch of bearing surface on the guide bushing so once you machine ¾ of an inch you can never machine more than that and then go back. We try never to do any secondary or off line deburring. So once you’ve machined it, it’s going to drop out of the support of the guide bushing. You’d have to break this part up into thirds which gives you blend lines – it’s impossible to get a perfect blend between those two rough and finish passes. We want to make our parts look like a diamond – perfect. We don’t want the blend lines but they are unavoidable on Swiss. Not an issue on the Eurotech Rapido.
5. Bar Stock Quality. With a Swiss a lot of companies like to run ground stock but it’s not optimal. (Grind lines on ground stock are perpendicular to your axis of force so grind lines are going around a bar, while you’re trying to push against the grind lines). Swiss do not require ground stock; however, without it, we have to hold an OD tolerance of +/-0.0003” within material lot. Having to retension a guide-bushing between different lots of the same material is a huge waste of time. Long unattended runs over a weekend are not possible on Swiss machines unless sufficient material from one lot is available. With Eurotech lot control is not required, as in a brass part, we can load up the Rapido with mixed lots of material and run for 48 hours unattended as the size variations from the different material lots is compensated for by the collet where the guide-bushing of a Swiss machine would prevent this.
6. Chucking and Manual Operations. We try to service customers as best as we can and sometimes that requires small runs of manual parts or modifying existing parts. We don’t have manual equipment. Locating the part in the sub-spindle of a Swiss because it is not long enough for the guide-bushing support causes many issues in maintaining length and positional tolerances. While we really hate to stop the efficiency of working off a bar to hand load a Rapido, occasionally, it is necessary, easy, and meets a customer’s critical need.