Browse Source

add tracer test results to openchrono

Thomas Buck 2 years ago
parent
commit
532f45c85b
1 changed files with 30 additions and 11 deletions
  1. 30
    11
      input/projects/openchrono.md

+ 30
- 11
input/projects/openchrono.md View File

@@ -4,7 +4,7 @@ parent: projects
4 4
 git: https://git.xythobuz.de/thomas/OpenChrono
5 5
 github: https://github.com/xythobuz/OpenChrono
6 6
 date: 2022-06-26
7
-update: 2022-07-01
7
+update: 2022-07-07
8 8
 comments: true
9 9
 ---
10 10
 
@@ -146,6 +146,8 @@ lightgallery([
146 146
 
147 147
 Attaching the whole unit to a airsoft gun barrel turned out to be a bit tricky.
148 148
 
149
+### M1911 Red-Gas Blowback (Part 1)
150
+
149 151
 The first gun I wanted to test with is a full-metal TM 1911 clone with a gas blowback system.
150 152
 The repetition imparts a big impulse on any barrel attachment, big enough to break my self-made silencer adapters in the past after a single-digit number of shots.
151 153
 Of course OpenChrono is much heavier than a plastic silencer imitation, so predictably it broke after only three test shots, even though I supported the weight with my hand.
@@ -158,6 +160,8 @@ lightgallery([
158 160
 ])
159 161
 %-->
160 162
 
163
+### M11 Co2 Non-Blowback
164
+
161 165
 For the second test run I tried to use a non-blowback ASG Ingram M11 Co2 gun.
162 166
 Besides some unrelated problems with the magazines it worked relatively well.
163 167
 Even without blowback the impulse on firing is still big enough to cut out the AA battery power.
@@ -191,6 +195,8 @@ With the first shots with a fresh capsule the speed is about 105m/s, which is 1.
191 195
 The speed then reduces with each shot and goes back up again when waiting long enough between shots, as the capsule slowly heats up again.
192 196
 With the last couple of shots I took only 0.23J were left.
193 197
 
198
+### M1911 Red-Gas Blowback (Part 2)
199
+
194 200
 After getting a metal threaded adapter from 14x1mm-CCW to 12x1mm-CW I was also able to continue testing with my 1911 blowback pistol.
195 201
 It worked fine!
196 202
 The printed female thread can withstand the forces much better.
@@ -202,19 +208,33 @@ lightgallery([
202 208
 ])
203 209
 %-->
204 210
 
205
-The measured speed / energy seeme a bit low, that's because I was using a propane magazine with a Co2 hammer spring.
211
+The measured speed / energy seeme a bit low.
212
+I suspect that's because I was using a propane magazine with a Co2 slide spring.
206 213
 Another topic is the weight of the OpenChrono device.
207 214
 When attaching large weights to the front of a 1911-style mechanism, the force required to actuate the slide is much larger.
208 215
 Therefore the valve is open for a longer time, increasing the gas usage.
209 216
 So the magazine gas chamber empties quickly and, I suspect, the BB force is reduced as well.
210 217
 That's a drawback of this style of chronograph mounting for some guns.
211 218
 
219
+### Tracer Unit
220
+
221
+Unfortunately the tests with the UV LED tracer did not work out that well.
222
+When dropping a BB through the device it actually visibly lights up as expected.
223
+But the velocity is far lower in this case compared to a real shot.
224
+When trying the same with either of my two guns the BB is not visible at all, even in complete darkness.
225
+The power output of the two LEDs is simply not enough (`2 × 3V × 20mA = 120mW`).
226
+[Experiments done by airsofttech.dk](http://airsofttech.dk/Guides.cshtml?Page=TracerUnit) suggest we need at least 20 times as much power, with ~3W going into the LEDs.
227
+
228
+So for now I do **not** recommend to build OpenChrono with the tracer option as it currently can be found in the repository.
229
+
212 230
 ## Build Guide
213 231
 <a class="anchor" name="build_guide"></a>
214 232
 
215 233
 Also take a look at [the "Hardware" section of the README.md](https://git.xythobuz.de/thomas/OpenChrono/src/branch/master/README.md#hardware).
216 234
 You can find detailed parts lists, schematic and wiring plan there as well.
217 235
 
236
+### Parts
237
+
218 238
 Before starting the build you need to acquire the following parts.
219 239
 
220 240
 <!--%
@@ -239,13 +259,13 @@ tableHelper([ "align-right", "align-right", "align-right monospaced", "align-lef
239 259
 )
240 260
 %-->
241 261
 
242
-For the UV tracer option you also need the following parts.
262
+<s>For the UV tracer option you also need the following parts.</s>
243 263
 
244 264
 <!--%
245 265
 tableHelper([ "align-right", "align-right", "align-right monospaced", "align-left" ],
246 266
     [ "Description", "Type", "Count", "Link" ], [
247
-        [ "UV LED 3mm", "", "2x", "<a href=\"https://www.ebay.de/itm/373071970513\">eBay.de</a>" ],
248
-        [ "Resistor", "30Ω", "1x", "<a href=\"https://www.ebay.de/itm/372813822157?var=642490601725\">eBay.de</a>" ],
267
+        [ "<s>UV LED 3mm</s>", "", "<s>2x</s>", "<s><a href=\"https://www.ebay.de/itm/373071970513\">eBay.de</a></s>" ],
268
+        [ "<s>Resistor</s>", "<s>30Ω</s>", "<s>1x</s>", "<s><a href=\"https://www.ebay.de/itm/372813822157?var=642490601725\">eBay.de</a></s>" ],
249 269
     ]
250 270
 )
251 271
 %-->
@@ -338,11 +358,11 @@ lightgallery([
338 358
 ])
339 359
 %-->
340 360
 
341
-### Tracer Option
361
+### <s>Tracer Option</s>
342 362
 
343
-If you want to build the left half with the UV LED tracer option included I recommend using the existing ground connections of the IR LEDs and phototransistors.
363
+<s>If you want to build the left half with the UV LED tracer option included I recommend using the existing ground connections of the IR LEDs and phototransistors.
344 364
 That way you only need to run two additional wires.
345
-I placed the 30Ω resistor on the underside of the Arduino, shielding it with some heat-shrink tubing.
365
+I placed the 30Ω resistor on the underside of the Arduino, shielding it with some heat-shrink tubing.</s>
346 366
 
347 367
 <!--%
348 368
 lightgallery([
@@ -603,12 +623,11 @@ That explains some strange design decisions, like using cylindrical screws for t
603 623
 I'm sure it is also possible to make better use of the space inside the device and make wiring much easier that way.
604 624
 
605 625
 Also the tracer feature has been kind of an afterthought.
606
-I have no real use for it and have not really tested it.
607
-So I'm not sure how well it will work in practice under different conditions.
626
+I have no real use for it and it does not work the way it currently is dimensioned.
608 627
 I also don't think it's realistic to take this bulky device onto a field, but who knows, I'm not really into that.
609 628
 
610 629
 To be quite honest, I'm happy with the device as it is now.
611
-But I'm always open to feedback and pull requests of course 😉
630
+But I'm always open to feedback and pull requests of course, especially ones improving the tracer option 😉
612 631
 
613 632
 ## Potential Other Uses
614 633
 <a class="anchor" name="potential_other_uses"></a>

Loading…
Cancel
Save