Post by luke213 on Mar 8, 2015 14:03:36 GMT -5
Well guys I've been planning on picking up a chrono again since I started fixing my own guns. I borrowed one but I wasn't convinced in the accuracy of the results since it went against what I expected to see by around 30 FPS. More less guns all seemed to register around 30 FPS lower than expected across the board. So since that is a known issue with allot of airsoft chrono's I started looking at better units that would hopefully be more accurate. Well the price starts to go up and honestly I'm not convinced they are going to be any more accurate than the cheaper ones.
So I started looking at real steel chrono's like I used to use. I was pretty happy with mine overall but I'd rather not spend $100 on one. I could but I'd rather not. So I started looking at DIY stuff and ran through a bunch of different options and finally decided to just buck up and build one myself.
So I ordered up the parts yesterday they are coming from China so it will take a little time to get here but I'm curious if anyone else has done this before here? I've read about it on other forums etc, and it seems fairly easy to do hooking to a laptop MIC input and recording the shot times and then converting to FPS or run a soft chrono app to do that for me(more likely option). One of the major reasons I'm thinking about building it rather than buying is I've got an idea to make it adjustable. IE adjust the length between the sensors to be able to actually tune the chrono to a known accurate chrono. So instead of the stock solutions where if it's off 30fps your just stuck dealing with it. On this setup I should be able to change that length by very small amounts to get it as accurate as I can manage. I'm thinking this type of setup will be fairly inexpensive to build likely around $20 in materials and should out perform the cheaper chrono options and maybe even better ones in our application since as I said it could be tuned to get pretty close to exactly what it should read.
Allot of this is theory till I go ahead and build it, but I'm planning on documenting the process with some pictures and maybe video. Make it sort of an open source project for guys who are fed up with cheap inaccurate chrono's(like myself).
So any input for guys that have done this before would be appreciated. Otherwise I'll go after it with what I've learned and build it out. Current plans is something fairly small probably using a foot or so between the sensors to keep it accurate(I think longer distances will be more accurate to a point until velocity drops off). Some of the off the rack solutions are only 6in. or less between the sensors which seems like it would be way to close to get a good accurate reading. I'm planning on building the tube from PVC, lighting it with IR Led's since I've got a bag of them around here somewhere. And Building the wiring and electronics into either a larger tube around the inner tube, or something. basically a robust housing that will be mostly water tight and durable so it can get beat around without failing. Something that can handle being used on a field or hauled around to games. Planning to run on voltage provided by the MIC jack on the laptop though might swap over to battery power depending on how much power is necessary for the whole system. I'm also considering putting in a little micro controller or something to read and output FPS with an LCD but likely the first version will require a laptop, or maybe a smartphone app if I can find one that handles MIC input for chrono not sure if that exists or how hard it would be to build as I'm not a programmer at all.
So that's the plan I'll keep you guys posted how it turns out, and I might even see if I can't mail it out to some people with existing chrono's to get comparison readings since I'd really like to get this thing as close to spot on as possible.
Luke
So I started looking at real steel chrono's like I used to use. I was pretty happy with mine overall but I'd rather not spend $100 on one. I could but I'd rather not. So I started looking at DIY stuff and ran through a bunch of different options and finally decided to just buck up and build one myself.
So I ordered up the parts yesterday they are coming from China so it will take a little time to get here but I'm curious if anyone else has done this before here? I've read about it on other forums etc, and it seems fairly easy to do hooking to a laptop MIC input and recording the shot times and then converting to FPS or run a soft chrono app to do that for me(more likely option). One of the major reasons I'm thinking about building it rather than buying is I've got an idea to make it adjustable. IE adjust the length between the sensors to be able to actually tune the chrono to a known accurate chrono. So instead of the stock solutions where if it's off 30fps your just stuck dealing with it. On this setup I should be able to change that length by very small amounts to get it as accurate as I can manage. I'm thinking this type of setup will be fairly inexpensive to build likely around $20 in materials and should out perform the cheaper chrono options and maybe even better ones in our application since as I said it could be tuned to get pretty close to exactly what it should read.
Allot of this is theory till I go ahead and build it, but I'm planning on documenting the process with some pictures and maybe video. Make it sort of an open source project for guys who are fed up with cheap inaccurate chrono's(like myself).
So any input for guys that have done this before would be appreciated. Otherwise I'll go after it with what I've learned and build it out. Current plans is something fairly small probably using a foot or so between the sensors to keep it accurate(I think longer distances will be more accurate to a point until velocity drops off). Some of the off the rack solutions are only 6in. or less between the sensors which seems like it would be way to close to get a good accurate reading. I'm planning on building the tube from PVC, lighting it with IR Led's since I've got a bag of them around here somewhere. And Building the wiring and electronics into either a larger tube around the inner tube, or something. basically a robust housing that will be mostly water tight and durable so it can get beat around without failing. Something that can handle being used on a field or hauled around to games. Planning to run on voltage provided by the MIC jack on the laptop though might swap over to battery power depending on how much power is necessary for the whole system. I'm also considering putting in a little micro controller or something to read and output FPS with an LCD but likely the first version will require a laptop, or maybe a smartphone app if I can find one that handles MIC input for chrono not sure if that exists or how hard it would be to build as I'm not a programmer at all.
So that's the plan I'll keep you guys posted how it turns out, and I might even see if I can't mail it out to some people with existing chrono's to get comparison readings since I'd really like to get this thing as close to spot on as possible.
Luke