FX POCKET CHRONOGRAPH

[athlon_oved]

How are people getting readings over 1099 fps on these when fx states on their website:


https://fxairguns.com/accessories/pocket-chronograph/
"Keep in the mind the Pocket Chronograph is not just for high powered airgun use. Any projectile travelling under 1099 FPS can accurately be tracked. The Pocket Chronograph is perfect for archery, CO2 rifle and pistols, airsoft, slingshot, paintball and more."

 

[ram2jeep]

Some may have just tried and got readings but other than that I wouldn’t have any other ideas.

 

[beerthief]

1099 FPS might just be the ceiling of what the design is good for % of accuracy.

 

[BOOMBBQ]

I just received mine and used it for the first time today. It’s so much easier than I thought a chrono would be. My first though. Do you guys use it attached to your barrel or do you just hover your barrel over it when shooting?

 

[BOOMBBQ]

Has anyone tested how far your barrel can be from the unit and still have it picked up?

 

[Peashooter]

I think i have seen speeds over 1100 FPS on the pocket chrono,,,,,, speeds i of course instantly backed off CUZ DAMN my moderator suddenly dident work right.
I generally put mine on the barrel, but i have also used it on a small tripod on the table below the barrel, on my vulcan 3 i need to have the chrono out to a side as there are no room for it below the barrel due to the air tank.

Tweaking in my living room some times i just put the chrono on the table, where my rifle then are propped up in a half hazard way, here i do some times get 0 reading but it is also only 10 feet to the pellet trap.

 

[Peashooter]

O i forgot on the Vulcan 3 i have some times put the chrono on the air tank instead, that work too just a little fiddly to put on

 

[BOOMBBQ]

I think i have seen speeds over 1100 FPS on the pocket chrono,,,,,, speeds i of course instantly backed off CUZ DAMN my moderator suddenly dident work right.
I generally put mine on the barrel, but i have also used it on a small tripod on the table below the barrel, on my vulcan 3 i need to have the chrono out to a side as there are no room for it below the barrel due to the air tank.

Tweaking in my living room some times i just put the chrono on the table, where my rifle then are propped up in a half hazard way, here i do some times get 0 reading but it is also only 10 feet to the pellet trap.

How are you mounting yours on a tripod? Any tips?

 

[Ingwe]

How on earth is this amazing thing reading velocity?

 

[BOOMBBQ]

Apparently it bounces radar off the back of your pellet as it's moving away from your barrel. I've had it successfully measure nerf darts, copper BBs, and lead pellets. It seems so much easier than the chronos with the arches and the labradar. The only issue was that it took me a little while to figure out how to use the iPhone app, which isn't designed all that well. The missing link for me at first was that I needed to select the approximate velocity range I was measuring before it would start reporting back.

 

[heavy-impact]

This is how I use mine. I printed a new flat tripod base for it and converted it to li-ion power but I just sit it on the bench and it never misses a shot.

 

[Chukar60]

I quit putting it on the barrel within about 50 shots. Now I use it just like Heay-Impact and have no issues

 

[starlingassn]

the picatinny mount from midwest elite is a great option,
can put it on a side rail and forget about it.

 

[BOOMBBQ]

For those of you looking, I think starlingassn meant this item:

FX Chronograph Picatinny adapter - Midwest Elite Airgun

No longer do you need rubber bands or long poles holding your chronograph. With the Midwest Elite Picatinny adapter you can slide your chronograph right on to your picatinny rail.

midwesteliteairgun.com

 

[starlingassn]

For those of you looking, I think starlingassn meant this item:

FX Chronograph Picatinny adapter - Midwest Elite Airgun

No longer do you need rubber bands or long poles holding your chronograph. With the Midwest Elite Picatinny adapter you can slide your chronograph right on to your picatinny rail.

midwesteliteairgun.com

yep,thats the one

 

[2L8]

I have data.
It reads it.

Patrick

 

[Ballisticboy]

There are a few basic rules which have to be followed when using any radar based chronograph if you want to obtain accurate velocities. Of course, when you are measuring velocity, you may not need the degree of accuracy we were looking for when I used multiple radar sets in trials. We would always have two muzzle velocity radars operating side by side measuring the muzzle velocity, and they had to agree to within 3ft/sec with each other. These were $20,000 units, so more powerful than FX or LabRadar.

You have to remember when choosing the position of your radar that it doesn't know where your gun muzzle is and quite frankly it doesn't care. All the radar is measuring is the speed, and maybe the distance, of the pellet/slug as it travels away from the radar. It does not measure the speed at the barrel, nor does it measure the speed of the pellet/slug away from the barrel. As a result, the further away from the barrel the radar is positioned, the less accurate the readings will be due to the angles between the radar beam and the flight trajectory and the bigger the error between the calculated speed at the radar and the true muzzle velocity.

If your radar is positioned too far away from the barrel muzzle, it will be further down range before the radar picks up the pellet/slug. It will also have less data to use before it looses the trajectory, particularly with smaller calibres. As the radar does not measure the velocity at the start of the trajectory, it has to take the data it does have and try to work back to calculate the velocity of the trajectory at the start. The more data it has and the sooner it starts, the more accurate the calculated velocity at the radar will be, but it is still an estimate which will depend on the method used to work back from the measured data.

So the further the radar is away from the muzzle, the less data it will collect and the longer distance it will have to try to work back to calculate the speed at the radar at the start of the trajectory. This is in addition to the angular errors in the measurements, which will be greater for the initial data points and thus have more effect on estimated muzzle velocity. This is true for all radars, not just the FX.

On all the trials I used to carry out on small arms, apart from the weather, it was always the muzzle velocity radars which gave the most problems and caused the most delays.

 

[HogKiller]

This is how I use mine. I printed a new flat tripod base for it and converted it to li-ion power but I just sit it on the bench and it never misses a shot.

View attachment 305027

You could have a nice little side business going with that base, just a thought. FX has something but I've yet to see it available.

 

[HogKiller]

For those of you looking, I think starlingassn meant this item:

FX Chronograph Picatinny adapter - Midwest Elite Airgun

No longer do you need rubber bands or long poles holding your chronograph. With the Midwest Elite Picatinny adapter you can slide your chronograph right on to your picatinny rail.

midwesteliteairgun.com

This is going to be perfect, gets the weight off of the barrel and zero chance of trying to put a pellet though the unit (don't ask). I've ordered one and it's going on my Mavericks lower rail

 

[HogKiller]

There are a few basic rules which have to be followed when using any radar based chronograph if you want to obtain accurate velocities. Of course, when you are measuring velocity, you may not need the degree of accuracy we were looking for when I used multiple radar sets in trials. We would always have two muzzle velocity radars operating side by side measuring the muzzle velocity, and they had to agree to within 3ft/sec with each other. These were $20,000 units, so more powerful than FX or LabRadar.

You have to remember when choosing the position of your radar that it doesn't know where your gun muzzle is and quite frankly it doesn't care. All the radar is measuring is the speed, and maybe the distance, of the pellet/slug as it travels away from the radar. It does not measure the speed at the barrel, nor does it measure the speed of the pellet/slug away from the barrel. As a result, the further away from the barrel the radar is positioned, the less accurate the readings will be due to the angles between the radar beam and the flight trajectory and the bigger the error between the calculated speed at the radar and the true muzzle velocity.

If your radar is positioned too far away from the barrel muzzle, it will be further down range before the radar picks up the pellet/slug. It will also have less data to use before it looses the trajectory, particularly with smaller calibres. As the radar does not measure the velocity at the start of the trajectory, it has to take the data it does have and try to work back to calculate the velocity of the trajectory at the start. The more data it has and the sooner it starts, the more accurate the calculated velocity at the radar will be, but it is still an estimate which will depend on the method used to work back from the measured data.

So the further the radar is away from the muzzle, the less data it will collect and the longer distance it will have to try to work back to calculate the speed at the radar at the start of the trajectory. This is in addition to the angular errors in the measurements, which will be greater for the initial data points and thus have more effect on estimated muzzle velocity. This is true for all radars, not just the FX.

On all the trials I used to carry out on small arms, apart from the weather, it was always the muzzle velocity radars which gave the most problems and caused the most delays.

So, how far is too far? I've noticed that it likes to be back a bit, 4" - 6" to enter the cone. Also being more on the same plane, or close to it, as the barrel seems to help.