joneill809

I've printed out the available RAM variants, as well as an experimental o-ring replacement for P1. The RAM configurations I'm looking at are:

• RAM2 (current stock version)
• RAM2 - aluminum
• RAM2n
• RAM2r
• RAM2O (o-ring)
• P1C (o-ring)

 caliburn-rams.JPG   64.3KB   85 downloads

My intent is to profile the range of RAM options with a [k26] and a [k25]. I'm posting what I have collected so far. I've looked at RAM2, RAM2O and P1C with a [k26]. I will wrap up the run with the n and r variants after I replace the spreader I broke during testing. I'll then repeat the run with the [k25].

Testing was done with a Caldwell Chronograph and an indoor light kit. I used Worker version 1 stefan darts. To date, these Worker darts have been the most consistent and accurate with my distance and velocity profiling of the Caliburn. I'll continue to use these darts for my testing so I can compare to a larger library of past results. There are some dart types that yield higher velocities (and some lower), but I get better groupings with Worker when I'm pushing back 10's of feet for distance profiling with the chronograph using the Caliburn. Each average represents a population of 100 shots for each RAM / seal combination tested.

Here's the summary data of the average velocities recorded for the 100 shot samples per configuration that I collected. Note there's a 5% to 10% 95th percentile confidence interval around these averages (not pictured here). You can see the full stats below in the complete graphic at the end of this post.

 caliburn RAM and pluger tests summary 2017-09-14.png   90.92KB   81 downloads

The air seal on the full o-ring configuration was a big improvement over my initial print of the original skirt seal configuration and you can see the impact on the velocity readings. You can see the 20 fps gap between the o-o-o configuration and the stock o-s-s configuration. That gap will likely narrow after I run some tests with a sealed bolt, but for now, I'm not sealing the bolts because I don't have enough skirt seals to glue down the bolts on all the RAMs I want to test.

Hopefully these velocity profiles will aide folks in selecting a configuration for the fps limits being targeted for different events. More to come ...

The full data sets:

 caliburn RAM and pluger tests 2017-09-14sm.png   746.52KB   82 downloads

I completed some distance profiling work with the Caliburn. I ran a set of VTN darts for 1, 6, 12 and 18 feet. At 18 feet the VTNs cratered in terms of being able to hit the chronograph consistently, so I truncated the run. I repeated 1, 6, 12, and 18 with the Worker stefans and got much better chronograph reading results so I continued that profiling out to 36 feet.

First up is the summary from the VTN run:

 caliburn-distanceProfile-VTN-summary.png   418.62KB   91 downloads

And the summary from the worker run:

 caliburn-distanceProfile-worker-summary.png   298.75KB   77 downloads

You may notice the date / time stamps for the runs are not in order as presented. I did jump around in terms of how I profiled, so the distances were not collected in sequence. I sorted them in the plots so the presentation of the data made sense flowing from short to long, left to right. I presented three numbers related to the chronograph reading results - the total number of darts fired (100 in these tests), the number of readings registered (these include "errors" on the chronograph where only 1 sensor registered a reading) and recorded values where I got an actual, valid result recorded by the chronograph. For the purposes of the accuracy data, I used the registered reading values, since the dart was recorded by at least one sensor which essentially required the dart to pass through a target with a diameter of less than 6 inches to register a reading. I probably should have kept track visually as to how many darts flew through the chronograph light kit; my feeling was I only recorded values for about half of the darts that actually passed through the light kit bars. Overall I was impressed with the accuracy and consistency of the Caliburn during these tests.

If you compare the VTNs against workers in a summary view, you get a better idea of the drop-off in reading counts with the VTNs (note the velocities recorded were on average slightly lower for worker, but there was not a significant delta):

 caliburn-workerVvtns.png   566.69KB   96 downloads

So I'm continuing to see the same characteristics from the worker darts that I saw with my Retaliator tests from earlier in the year - I get slightly lower velocities with these darts, but they seem to be more accurate. I'll try to get to additional dart types over time with the Caliburn (I have ACC and accustrike knockoffs that I'm cutting down and testing). I'm testing cut down darts at this time, as full length accuracy was horrible with the [k26], and the cutdown darts showed marked improvement.

I'm also contemplating a second methodology for better analyzing spread. The main focus here was on the velocity of the darts as a function of distance with a yes/no "did the chronograph read anything?" result with each round. I will likely drop the velocity aspect of testing for the spread profiling and try a set of concentric catch bins of different diameters, possibly split in half or quarters. I have some design and fabrication work to do there, but that may be an interesting approach to better characterizing spread. I'll post some design ideas here in the future.

For those that are interested in the eye charts I'm including the full graphics below.

 caliburn-distanceProfile-VTN-detailed-sm.png   1.27MB   87 downloads

 caliburn-distanceProfile-worker-detailed-sm.png   396.47KB   84 downloads

It may be interesting to use the same dart type for full length and cut down, but I don't think the long darts make it to 18 ft. Ten test full length rounds at 18 ft were scattered all around the chronograph catch bin, with none coming close to registering a reading (in fact only 1 hit the bin, and I am fearing for my walls, blinds and house decorations as this full lengths are veering off in all kinds of directions). Compare that to 15 worker short darts from the same distance - all hit my catch bin. I will need significantly more than 100 full length shots to get to my floor of 30 readings at greater distances. I can start with the full lengths and increase the range until I start seeing a significant drop-off in readings with 100 shot samples, but from what I can see so far, I think that will stop at 12 ft. 

The other option may be to back off to the [k25]. Dial back the velocity in the hopes of improving full length accuracy. But I am setup with the [k26] right now so I'll likely start with short darts. Is my thinking accurate here - if you want to run full lengths, back off to the [k25]? I defer to you guys on that question - I have limited experience here so it's possible I'm doing something else wrong when optimizing for long darts.

In terms of other darts, the ACC-like darts ("Phat Welt Wackers") look like VTN / FVN / Lily Arms. I do have some black ACC's on the way. Both of these seem to be close to the ACC Gen 2's I've been using from Monkee Mods which have held up well under higher fps rates and have been pretty accurate relative to other darts. My plan was to cut these darts down and give them a go. From what I read they hit too hard and are often banned, so I can bring in some USC's to give them a try as well. What is a USCS? A "short" USC like this? (I'm new and catching up!)

Plus I really want to give this a go since I sunk some time into designing and printing:

 dartcutter.png   282.1KB   86 downloads

 caliburn-fps-2017-07-31-full-5ksm.png   392.98KB   77 downloads

Here's a look at the original formatting before my tinkering this weekend for the older Apollo runs:

 apollo-fps-2017-07-29-full-4ksm.png   580.94KB   90 downloads

I can switch back to the darker fonts if that is easier to read, but I was trying to be more selective in the use of dark colors to call your attention to the more important bits. I can go a shade darker on the new gray if it's too hard to read on some of your monitors. Right now, I prefer the new layout of information in the summary. That may change in a day or two.

Meaker VI, on 29 Jul 2017 - 4:31 PM, said:

I really like the data you're putting together here, don't worry about posting as often as is necessary to update.

Thanks! It's been an interesting project. I'm still trying to figure out the best way to present the data sets and some of the stats that I *think* are important. The plots are evolving a bit - I worked over the layout this weekend to condense some of the summary data and I'm sure it will continue to change. 

Yeah, I'm spending a lot of time with the Caliburn because I think it will be a solid reference blaster once I get used to operating it consistently. I think a lot of the variability that I am seeing is just my learning curve (like lithium grease vs. silicone grease).

I ran two more sets of experiments this weekend. I did one wrap of e-tape around the Ram to see if the decline in fps I was seen was tied to the o-ring seal. Turns out it wasn't, and now I'm seeing slight drops in my reference blasters. I'm wondering if it's something I'm doing. Either way, it's about 1% on both the Apollo and Caliburn, so I'm not sure what to make of it yet. Here's the o-ring data bracketed by the Apollo reference blaster. In this case, I recorded 194 +/- 10, compared to 197 +/- 14, so no change. The decline in fps was -1.8% with the e-tape versus -3.2% without. Not sure of the significance of that yet, so I'll keep watching. Here's the data:

 caliburn-oring-2017-07-29.png   890.07KB   105 downloads

Next up, full length darts. I picked up some ACC-like darts ("Phat Welt Wackers") off Amazon. I also picked up some Koosh darts. I ran the Apollo, then runs of 100 PWW's, 100 Kooshes, 100 PWW's, then the Apollo. I collected the PWW's twice because of how lousy the Koosh performed and I wanted to rule out any platform issues. Here's the data set:

 caliburn-fullLengthACCkoosh-2017-07-30.png   591.47KB   76 downloads

The error range on the second run of PWW's was impacted by a bad dart - if I drop the 123 round (tip was blown off the dart) then the fps reading was 200 +/- 12, nearly identical to the first run. So the koosh darts performed poorly, and my elbow needs a break after 500 rounds today

If you're interested in the plot designs, I tweaked the data layout a bit and tried to highlight the confidence interval more clearly. The + and - design is something I lifted from Tufte. I'm still trying to figure out if I like it better than a straight "201 +/- 12" but it kind of looks cool. The population statistics are presented below the average, and I moved the box plot like graphic up next to the stats that it represents. It's a bit redundant, but I like having the numbers to review, but I think the plots make for an informative rapid assessment across data sets. 

I'm trying two plots on top of each other. The solid gray band is a bar plot representing the shot velocities for each experiment. The vertical axis is consistent across all plots. The scatter plot is a representation of the same data in the bar plot, but with an exaggerated vertical axis tied to the min/max of the specific experiment. There are two curve fits to the scatter plot, a linear fit and a 10 point moving average. They are not terribly intuitive at this point, but once you know what to look for, they are a good tool for evaluating the data set quickly. I'll keep iterating on the design, so feedback is welcome!