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--- projects:welcome [2017/11/14 17:10]
jerzydziewierz Added the Krautkramer machine info - basic.
+++ projects:welcome [2017/11/14 18:36]
jerzydziewierz
@@ Line 27: / Line 27: @@
------------ Risk : Environmental - office conditions versus dust, noise, vibration e.t.c. -------
+----------- Risk: Environmental - office conditions versus dust, noise, vibration e.t.c. -------
 [2017-11-14]
-At this point there would be no noise, no dust, no vibration e.t.c.
+At this point, there would be no noise, no dust, no vibration e.t.c.
-Detailed explanation to follow soon
+This is because:
+ * the machine is not actually operable. The servo amplifiers are missing and there is no end effector on it.
+ * When powered, the movement of the primary axes is completely noiseless. This is because these are linear servo motors optimised for ultrasonic research and hence optimised for not generating acoustic noise (which would interfere with measurements). These kind of motors are very unlike stepper motors (which would buzz).
+ * When we are ready to install the end effector, this will be the point to consider the amplitude of noise and dust generation:
+ * for a 3D printer head, we can all agree that regular ventilation & noise would make it acceptable
+ * for a precision 3D scanner head (actually, one of the original uses of this machine) there would be no noise whatsoever
+ * for a general purpose CNC machine: I am afraid that this table is not really suitable for a general-purpose CNC operation. This is because the linear motors will have a very limited force that they can exert. Hence, I believe that with current motors, metal and wood processing would not be feasible. One could think about installing stronger motors, but really, that would cost a lot. In any case, if we decide to do this, the dust would have to be extracted up to a cleanroom standard (possible, but not cheap) and the noise would be a serious consideration. High-quality spindles (with controlled runout) actually do not create that much noise, but they cost cost cost.
+ * for a PCB router: This is much more possible to do. It is possible to build a low power dust extractor from base materials ( i actually have all the parts that I can contribute). The noise would be manageable.
+ * a spark erosion processor: In such case, there is no dust, no noise, and the end product could be of extremely high quality (injection moulds are often finished with this technique). This method is limited by the available electric power, and in general, very slow. EM interference can be managed by enclosing the working area in a Faraday cage.
 ----------- Risk: Health and Safety from the moving parts ------------
@@ Line 36: / Line 52: @@
 [Bob]: H&S?
-[Jurek]: I to have to give You that this machine could potentially be a H&S issue. It has heavy moving parts. There is no sharps, but there is a potential for finger capture if one puts his finger into just the right place at just the right time.
+[Jurek]: I to have to give You that this machine could potentially be an H&S issue. It has heavy moving parts. There is no sharps, but there is a potential for finger capture if one puts his finger into just the right place at just the right time.
 The risks are mostly similar to the ones coming from a regular 3D printer (that is already there) or the motorized table saw, which is also already there.
-To mitigate this risk, we could build it into a lockable cabinet to make it even more obvious that it is not to be messed with.
+To mitigate this risk, we could:
+(proposal 1): Build it into a lockable cabinet to make it even more obvious that it is not to be messed with.
+(proposal 2): Instead of a cabinet, we could install a nightlatch on each of the two heavy axes: https://www.ironmongerydirect.co.uk/product/yale-77-traditional-nightlatch-nickel-bronze-603896  ; there is enough space there to install it, and it would prevent people from moving the axes by hand (and trapping their fingers in the process).
---------- Risk : How to remove it from the club after the interest wanes out  ------------
+--------- Risk: How to remove it from the club after the interest wanes out  ------------
  [2017-11-14]
@@ Line 48: / Line 66: @@
 [Jurek]: I must agree with this.
-In order to mitigate this risk, may I suggest that we start a fund, to be held by the CCA, in which there will be a deposit to cover for the machine’s eventual disposal. I guess we might need to find somewhere in range of 300gbp . Another method might be to get an official quote from one of the scrap metal collectors:
+In order to mitigate this risk,
+(proposal 1): I suggest that we start a fund, to be held by the CCA, in which there will be a deposit to cover the machine’s eventual disposal. I guess we might need to find somewhere in range of 300gbp .
+(proposal 2): Another method might be to get an official quote from one of the scrap metal collectors:
 https://www.yell.com/s/metal+collection-glasgow.html
 since there is easily 300kg of metal in this thing, I would guess they might be interested in picking this thing up for free from us.

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