Desert Tech TRASOL Official Thread

[Lowlight]

Where should we send bug reports? I just had some consistent crashes when trying to capture Station Pressure in the Density Altitude field.

Send them to @Hundley

Also back to the Pro-Active comment,

When you figure Robert Brantley and Tom Manners really didn't even use software for his DECISIVE K02M win. They fired 12 rounds before, his barrel was set back, it was Tom's old one and he just doubled checked his number with Strelok Lite, the free stuff. When I asked him about his dope, it was really just a "This will work" thought behind it. I even have a picture of a Tom with his hardcopy data.

He used databook dope from minimal practice,

Robert used no software for his wind, so the idea he dialed in SD, CE, CWAJ, is comical at best and he schooled them.

So, sidetrack aside on which is better, clearly, software is not solving the shooter problems

I would like to know what the definition of "CLEAN DATA" is .... seems each week have a new version of that.

 

[WVHick]

Trying to buy it but Apple won’t process my payment. Keeps saying failed. Not sure what’s up.

 

[WVHick]

Trying to buy it but Apple won’t process my payment. Keeps saying failed. Not sure what’s up.

Appears to be a problem with the app. Made another purchase and everything is working fine.

 

[Hundley]

@holdstillplease I’d like to hear more about the crash. Feel free to comment here or email me: [email protected]

 

[darth_ritis]

@Hundley just sent an email, hope it helps.

 

[Nik H]

I just took the plunge and am glad I did

The simplicity of the UI is genius.

 

[BLKWLFK9]

Well.. I went ahead and bought it again on an iPhone this time. I already bought it for Android when IOS wasn't working, but now that IOS is updated, I won't use it on my android. oh well. money well spent I reckon. I love this app

 

[christopher.dow]

@Hundley I really like what you’ve done here. The interface is very clean and the results are great. Here are a couple feature requests:

1.) Please allow for typed input of numbers as well as the scroll wheels. Yeah, I know that’s not easy. The scroll wheels are preferable in the field, but when I’m just running numbers, they’re awkward. Good on you for prioritizing field use.
2.) Please provide means for equipment deletion. I have some duplicates that I believe are from syncing (the three hardest problems in computer science are off-by-one errors and caching). Could be user error, but in any case, I’d like to clean it up.

Do you use Crashlytics?

 

[Crang]

I've never quit using it on my Android. Couple little bugs but nothing I havent been able to deal with. That said cant wait to get an updated version.

 

[Hundley]

@christopher.dow just FYI - you can delete equipment profiles. From the selection screen, just swipe left to delete. See here:

If you’re seeing duplicates, it most likely occurred during migration from the old app. Luckily it’s pretty easy to get rid of the ones you don’t want.

 

[Ruggedtouch]

@christopher.dow just FYI - you can delete equipment profiles. From the selection screen, just swipe left to delete. See here:

View attachment 6937453

If you’re seeing duplicates, it most likely occurred during migration from the old app. Luckily it’s pretty easy to get rid of the ones you don’t want.

Cool factor ^2

 

[Deleted member 113831]

Could you give an explanation of why and how you would use the Drag Coefficient to fine tune, rather than the Ballistic Coefficient?

 

[torrentuser]

Another Android user waiting for the update. I will never touch an Apple.

 

[Lowlight]

The DC is like the adjustment Hornady uses with the AXIAL FORM FACTOR

it's an adjustment that moves the drag curve vs changing the MV or BC to bend it on one side or the other.

Once you have your data fined tuned, and you have updated the BC for your system, if you need any further changes instead of changing the BC you make small changes to the DC

if you look at the Coldbore or FFS manuals it talks about this as the DC of CB/ TRASOL is similar to the DK of FFS

 

[christopher.dow]

@christopher.dow just FYI - you can delete equipment profiles. From the selection screen, just swipe left to delete. See here:

View attachment 6937453

If you’re seeing duplicates, it most likely occurred during migration from the old app. Luckily it’s pretty easy to get rid of the ones you don’t want.

Got it. Thank you. There seems to be a bit of a dead spot at about 50%-25% from the right edge in landscape mode on an iPad Pro. That threw me when I tried it. On the iPhone, it’s solid.

 

[cro789]

Im having problem. I paid for the full version but when I go to the heads up display it says I need to up grade. It also states Im in free trial version.

 

[_Windrider_]

Im having problem. I paid for the full version but when I go to the heads up display it says I need to up grade. It also states Im in free trial version.

Use the restore purchase option in the settings

 

[EXTREMEPREJUDICE]

Im having problem. I paid for the full version but when I go to the heads up display it says I need to up grade. It also states Im in free trial version.

I had the same problem, it wouldn't allow me to restore the purchase so I deleted the APP, went to the store and downloaded again then restored my profile info.

 

[christopher.dow]

@Hundley Heres another feature request: I’d like to be able to export the data for printed range cards. Emailing a CSV a la AB Mobile or Ballistic AE would suffice.

Thanks,
C

 

[Hundley]

@christopher.dow I'd like to see this feature too. Maybe if you bug @ney1 enough we'll see it happen

 

[cro789]

Got it to work. I set the zero at 100 yards but when I pull up the dope card it show for 100 yards 19.60 U. 150 yards 3.27U thats clicks.

 

[Hundley]

Got it to work. I set the zero at 100 yards but when I pull up the dope card it show for 100 yards 19.60 U. 150 yards 3.27U thats clicks.

@cro789 can you post a screenshot of your equipment screen, as well as the Ballistics screen? Maybe we can help find the problem.

 

[cro789]

Here and thanks

 

[Hundley]

@cro789 could you also give us a screenshot of the main Ballistics screen? At first glance I don't see anything obvious that would cause it.

 

[Lowlight]

Your twist is written wrong just put 11, not 1 in 11

Input error

 

[Blowby]

1 is already in the input field. If he enters 11 the output is 1 in 11.

 

[Blowby]

100 is 19.60 and 150 is 3.27? Your Zero is F’d up.

 

[cro789]

Ok

 

[pell1203]

Are you intending your slope to be 28* and your cant 5* on purpose?

This could be a big part of your problem.

 

[Hundley]

@cro789 It looks like your slope and cant are the culprits. Shooting 29 degrees downhill is pretty steep - it's effectively moving your zero from 100 to 150. Maybe it was accidental, so it's good to check those values before you shoot. Hope this helps!

 

[pell1203]

If not your intent to have slope and cant in solution reset them by selecting the field and deleting the inputs. See top left of screen (delete in red).

 

[cro789]

Ichanged it to 0 on both but look at my adjustment from 100 to 200

 

[cro789]

100 is at 0.0 125 at 2.5 150 at 5.12 175 at 7.77 200 at 5.51 shouldnt the 175 and the 200 be switched

 

[Tree]

Is there a setting to change your results from clicks to moa or mil? 8 clicks would be .8 mils which is close to what I get

 

[Diver160651]

Your twist is written wrong just put 11, not 1 in 11

Input error

The new 2.0 automatically puts the 1 in xx

I don’t see anyway other than that at least

 

[Deleted member 113831]

You need to show us a screen shot of your equipment screen. Your scope settings are suspect, hell, everything is suspect.

 

[pell1203]

@cro789 , what version of TRASOL are you using? Ver. 2.0.1 for iPhone?

What bullet weight and caliber are you using? I ask because I don’t see that in the picture you provided of your equipment screen.

Also, just to try to eliminate as many variables as possible, can you make the atmosphere on the ballistic screen match the atmo on your equipment screen and check your settings screen to make sure it makes sense.

 

[cro789]

Ok

 

[cro789]

I am running the 2.0.1 one a iPhone 5SE. 155 .308 2750 in a Desert Tech 1/11 twist

 

[Tree]

Settings screen shot.

 

[cro789]

Up

 

[pell1203]

Is your Bullet Weight on equipment screen set to 155 grains? Make sure ‘grains’ is selected. I can’t see that value on your screenshot on my iPhone 7 Plus. Could be cause your screen is smaller on your phone and you can only see it when you scroll.

 

[Hundley]

@cro789 your settings are fine, and the app is working as expected.

What you're seeing is an artifact of the underlying ballistics engine, where the trajectory periodically needs to be "adjusted" to account for the changing velocity throughout the bullet's flight. The theory is pretty heavy, but basically: your Ballistic Coefficient is dependent on velocity (most published values assume a specific set of conditions), and as the bullet slows the drag needs to be re-computed to account for the new velocity. In a perfect world this would happen at each time step (i.e. each yard), but this would be pretty compute-intensive, so instead the adjustments happen at predetermined intervals.

To help visualize this better, here's a graph of your specific bullet's trajectory, zoomed in to the interesting portion:

Here you can see 3 instances where the adjustment occurs, and the first "spike" explains the result you're seeing. This might seem undesirable, but keep this in mind: these spikes are relatively small (I adjusted to graph to exaggerate the detail), and the effects actually become less pronounced at longer ranges. At the distances most shooters are using TRASOL, the effects are completely negligible. The benefits to these adjustments, however, are significant.

Hope this helps.

 

[cro789]

Thanks

 

[pell1203]

Nice to have the developer participate on this forum. Excellent!

Thanks @Hundley!

 

[Hundley]

@Skookum @Lowlight

Although the mechanisms are different (and the math is fairly complicated), the ultimate effect of adjusting Ballistic Coefficient vs Drag Coefficient is very similar. Take these two examples for a .338 projectile:

In the first graph, the Ballistic Coefficient is kept at 0.300, and the Drag Coefficient is adjusted from 0.1 to 0.9. The full trajectory from 0 to 2000 yds is recomputed for each DC value:

In the second graph we do the opposite: we keep a constant Drag Coefficient and adjust the Ballistic Coefficient from 0.280 to 0.320:

Keep in mind that this isn't a perfect comparison, because the spread of the BC/DC values are different. If I had computed the drag coefficient on intervals of 0.15 (instead of 0.2), the graphs would probably look nearly identical.

I've run quite a few simulations, and have seen no evidence that BC vs DC adjustments produce significantly different curve shapes. Instead, I see Drag Coefficient as more of a "finer" Ballistic Coefficient; i.e. a change of 0.150 DC is roughly equivalent to a change of 0.010 BC (depending on other variables).

I'm happy to run more simulations if there's a specific set of parameters you want to test.

 

[LastShot300]

I tried out the same data plus many others from my saved tracks on CB Desktop and Drop in inches or clicks showed no bumps or spikes whatsoever. I don't know how the engine works in either Trasol or CB, just pointing out my findings FWIW

 

[Hundley]

@LastShot300 I’ll do some comparisons with CB too. Maybe we can apply some smoothing for TRASOL.

 

[LastShot300]

@LastShot300 I’ll do some comparisons with CB too. Maybe we can apply some smoothing for TRASOL.

Maybe it's just that smoothing. Indeed what you detailed about the engine's inner workings is truly awesome and makes perfect sense. Thanks for sharing your knowledge about it.

 

[Deleted member 113831]

@Skookum @Lowlight

Although the mechanisms are different (and the math is fairly complicated), the ultimate effect of adjusting Ballistic Coefficient vs Drag Coefficient is very similar. Take these two examples for a .338 projectile:

In the first graph, the Ballistic Coefficient is kept at 0.300, and the Drag Coefficient is adjusted from 0.1 to 0.9. The full trajectory from 0 to 2000 yds is recomputed for each DC value:

View attachment 6938136

In the second graph we do the opposite: we keep a constant Drag Coefficient and adjust the Ballistic Coefficient from 0.280 to 0.320:

View attachment 6938137

Keep in mind that this isn't a perfect comparison, because the spread of the BC/DC values are different. If I had computed the drag coefficient on intervals of 0.15 (instead of 0.2), the graphs would probably look nearly identical.

I've run quite a few simulations, and have seen no evidence that BC vs DC adjustments produce significantly different curve shapes. Instead, I see Drag Coefficient as more of a "finer" Ballistic Coefficient; i.e. a change of 0.150 DC is roughly equivalent to a change of 0.010 BC (depending on other variables).

I'm happy to run more simulations if there's a specific set of parameters you want to test.

Thank you for that explanation, it was exactly what I was looking for.