Chronograph Madness

[Gwhite]

I'm aware of the Nate Chrony, but haven't really looked into them in any detail. For tuning purposes, 1% accuracy of absolute velocity is fine, but I need REPEATABILITY better than that, which is a number nobody else specifies, but the Nate appears to. The Combros were apparently live fire calibrated, and I can even adjust them myself IF I had a decent reference.

I've tested multiple pistols with the Combros that showed repeatability of around +/-1 fps, which is suitable for my needs. I find it hard to believe that multiple air pistols could magically cancel out variations in the Combros, so I believe that they are at least that good. Unfortunately, they don't make 'em anymore, their mounting makes them easy to destroy, and there is some evidence that their absolute velocity numbers are suspect, at least to the level of a few %.

For now, I need to do some more testing to see where the HT-X3006 fits into the picture. If that flunks out, the Nate looks like a good alternative. The specs look like they would definitely do the job, but it means re-doing weeks of designing 3D printed adapters for all of the various air pistols I have to support.

 

[NateChrony]

...... I need REPEATABILITY better than that, which is a number nobody else specifies, but the Nate appears to.

For now, I need to do some more testing to see where the HT-X3006 fits into the picture. If that flunks out, the Nate looks like a good alternative. The specs look like they would definitely do the job, but it means re-doing weeks of designing 3D printed adapters for all of the various air pistols I have to support.

The only other Chronograph i've seen with repeatability accuracy is the Pro-chrono DLX, but they specify it in timing ns... kinda frustrating, you'd have to do the maths on sensor spread & calculate a %.

Adapters - all the work is still valid, you'd just add a 20.1mm round end to slide into a NateChrony, which also uses adapters!

World first - work has started on open sourcing the adapters & helping people make NateChrony compatible adapters:

GitHub - natechrony/Adapters: Adapters for the NateChrony

Adapters for the NateChrony. Contribute to natechrony/Adapters development by creating an account on GitHub.

github.com

 

[Gwhite]

The only other Chronograph i've seen with repeatability accuracy is the Pro-chrono DLX, but they specify it in timing ns... kinda frustrating, you'd have to do the maths on sensor spread & calculate a %.

Adapters - all the work is still valid, you'd just add a 20.1mm round end to slide into a NateChrony, which also uses adapters!

World first - work has started on open sourcing the adapters & helping people make NateChrony compatible adapters:

GitHub - natechrony/Adapters: Adapters for the NateChrony

Adapters for the NateChrony. Contribute to natechrony/Adapters development by creating an account on GitHub.

github.com

All my HT-X3006 adapters are already out there: https://www.thingiverse.com/thing:6977381

I think I can just create a single dovetail adapter that fits the Nate, which would allow reusing the mounts I designed for the HT-X3006.

I want to be able to use the sights on the pistol when firing. What is the distance between the sensor bore-line and the top of the Nate Chrony? If it's more than ~ 1.5 cm, how big is the sensor area? On the HT-X3006, I can offset the pellet path a few mm to get the sights above the housing.

Thanks!

 

[NateChrony]

All my HT-X3006 adapters are already out there: https://www.thingiverse.com/thing:6977381
I think I can just create a single dovetail adapter that fits the Nate, which would allow reusing the mounts I designed for the HT-X3006.
I want to be able to use the sights on the pistol when firing. What is the distance between the sensor bore-line and the top of the Nate Chrony? If it's more than ~ 1.5 cm, how big is the sensor area? On the HT-X3006, I can offset the pellet path a few mm to get the sights above the housing.

The distance from center to top is ~15mm & bottom is roughly the same, however alignment is absolutely critical (new software has alignment detection though - so you can detect if there's an issue)
I would not recommend to use the outer surfaces on the Chrony as a reference point, and only recommend using the center bore as the reference.

Also looking at the designs - they're most likely not rigid enough & you'll see errors in fps with the NateChrony. To get the accuracy, I have to detect on a certain part of the pellet, if there's vibrations/movement the front sensor may detect on a different part of the pellet to the rear - at best it'll be variances of ~5fps, worst it'll be 50-70fps (assuming ~500fps speeds).
The adapters will need some form of bracing/contact top/bottom to secure them enough.