8.Computer controlled machining Group Assingment¶
8.1 Machine¶
our machein is ShopBot PRSalpha
some of the machine features:
Step resolution of .0004”.
Positional accuracy of +/- .002”.
Impressive cutting speeds of up to 600 inches per minute (depending on cutting bit and material) and rapid transit speeds of 1,800 inches per minute.
Dust Skirt ready to connect to your dust collector.
specs
| Metric Units | ImperialUnits | |
|---|---|---|
| XY Move Speed (with full cutting force) | Variable, max. 15.24m/min. | Variable, max. 600”/min. |
| Z Move Speed (with full cutting force) | Variable, max. 9.14m/min. | Variable, max. 360”/min. |
| XY Positioning Speed | Variable, max. 45.7m/min. | Variable, max. 1800”/min. |
| Z Positioning Speed | Variable, max. 22.86m/min. | Variable, max. 900”/min. |
| Step Resolution | 0.0127mm | 0.0005” |
| Positional Accuracy (no load) | +/- 0.076mm | +/- 0.003in |
| Linear Cutting Force | Approximately 68 Kg | Approximately 150 lbs. |
| X and Y Axis Drive System | Rack and Pinion | |
| Z Axis Drive System | Rack and Pinion |
Input Voltage : 110 volt (30 amp); or 220 volt (15 amp) [Single phase, 50-60Hz] VOLTAGE must be specified at time of purchase. The PRSalpha requires a fused disconnect installed by a licensed electrician. Spindle may require 3 phase.
8.2 Design¶
Ues Vcarve Software .
8.3 Runout:¶
the Runout test is to start the machine in the counterpoint and make sure that everything is going well no wired sound or vibration in the machine, every time we use the machine we need to do this.
8.4 Alignment:¶
in the as it shows in the design the border is a rectangle shape and when it cut it off the border are a straight line and we check that every cornare is 90 degree angle, after this small tist if the machine has good almint or not
8.5 Speeds and Feeds:¶
speed : it meant the Revolutions per minute(RPM) of the dirll bit.
feed : it ment how fast the drill bit move from point A to point B.
and these two controll how cleen the cut will be and how long it take the workpice to be ready. And each matireal has different max spped and feed.
to test this two-parameter of the machine I made two sets of three-line the first set was the constant speed but different feed and the other set was the opposite.
| No. | speed | feed |
|---|---|---|
| changing the speeds | ||
| 1 | 12000rpm | 150 |
| 2 | 10000rpm | 150 |
| 3 | 8000rpm | 150 |
| changing the feeds | ||
| 4 | 12000rpm | 160 |
| 5 | 12000rpm | 120 |
| 6 | 1200rpm | 80 |
When you want to have fine cut you can do one of two things Increase the RPM or Slower the feed When you increase the RPM the cut will be cleaner because the cutting bit will remove smaller material duo that it low feed and high RPM and the same thing will happen if you slower the feed with normal RPM , but you need to lower the feed when the drill bet have more contact with the material so the bit don’t get heat . Other things you need to know about it material remove rate .(MRR) is the measurement for how much material is removed from a part in a given period of time. MRR= vfd . v speed of cut, f feed and d depth of cut
8.6 toolpaths:¶
the toolpath meant what the machine will do to the workpice
This workpice used three toolpaths :
8.6.1 cut out¶
it ment that the drill gose through all workpice .
8.6.2 ingread¶
it ment that the drill gose to some depth in workpice . we made two difrent ingread
8.6.3 drilling¶
it mean that making hole with the bit size . we made four holes, in each cornere one l=hole
8.7 Workpice¶
