hackish

Most people with 30 jumps do not keep a rig for more than a year before downsizing and getting a smaller rig. It's worthwhile to speak to local instructors and get a feel for a longterm canopy sizing goal. Another thing to consider is that newer designs typically have better openings and better flight/landing characteristics. Old designs like the PDR had a lot of R&D go into them which is why they've stood the test of time but in 25+ years the engineers did learn a trick or two. -Michael

I was going to make a wisecrack about water based "personal" silicone lubricant but it's probably exactly the same stuff. Have a cutaway that is minty fresh and makes your canopy tingle! -Michael

Hmmm. $200 machine. $400 in parts, $450 for cams. All that time. Or buy and fix the tacker and sell it. A 42 stitch end start/stop isn't entirely useless. This one is designed for 1" tacks. Any ideas how involved it is to adjust the width/length on a mechanical machine? Every time I think about a mechanical tacker it seems to come back to the same answer. Buy an electronic one. -Michael

Thanks for the info. I just have a line on a busted up 1854 for $200 but it will need a lot of parts so I'm just trying to see if it's worth buying. As with nearly all tackers it's an end start/stop. -Michael

I just have a rag that I use to lube and clean the cables all in 1 shot. I soak a spot on the rag, a lot more than a few drops... I tried last night to get a good accurate measure of the pull force but I need a smaller more sensitive scale. I think too the force required to cutaway is much less than the force required to pop the reserve. -Michael

Quite in line with my point. I'm sure that cutter is more than $100k. I have more than $100k in electronics equipment and software licenses on my desk right now. All things that someone would need to develop and debug an AAD. When you're running a business you get quite desensitized to big numbers. Once a customer saw at my garage that I had $30k in the account. He said "wow you're really doing well here". To which I shrugged, at months end $40k will be spent in bills and I don't know if I'm going to get paid this month. I'm always happy to see people succeed because I know what sort of work it takes to get there. I think open source rigging tools or something like that would benefit the community, not this. -Michael

I haven't ordered them but they require the thicker die. I have that die too. I think they're about $18 ea. I'll probably put up a post/review if I get some and try them. Personally I think the rings themselves will be too heavy duty for our needs. -Michael

I was wondering if anyone has ever heard of a Juki 1850 series of machine with cams to do a center start 42 stitch tack? I have not found a way to get the wife to sign my permission slip to buy a 1900AHS or a B430E so a mechanical tacker seems to be the next best thing. -Michael

Production costs being 10-15% of MSRP is pretty common. I think the issue is not "how much can we soak people for" it's more "how much do we need in order to to pay ourselves and stay in business each year". Back on the canopy thing. Raw materials of $150, 10h of labor and a canopy being sold at $2500. Are all skydivers being taken advantage of or is that really the cost of doing business? -Michael

Good news is that after the SB from vector just about every rigger around has a can of silicone lube. Since I do all the rigs at the DZ every 6 weeks it would be trivial and interesting to do some repeated pull tests for a season on rigs lubed with oil and lubed with silicone. -Michael

Rigging is such a small community. Yes I have the dies and the removal tool and the punch. Well UPS went and lost a few of the parts but I'll have my shipment of rings this week. -Michael

Some years ago these were used on model rocketry type stuff but upon impact they would frequently not maintain contact and data would be lost even if the logger continued to operate. In the case of an AAD I think it's important that data be logged even if it impacts with terra firma. On the topic of open source stuff, one thing I have frequently observed is that commercial enterprises frequently would borrow code and ideas from open source products and projects and use it as a cheap way to develop their own. 99% of intellectual property ownership is obscuring it from theft. The other 1% involves costly litigation. I'm a little conflicted with those who feel that the high AAD price means they're being denied something they rightfully should have. Y'know there is only a few hundred dollars of fabric in a canopy too... -Michael

I always understood the problem with the silicone spray was that it tended to dry out and didn't lube the cables very well. I think John Sherman may have written an article about it at one point. I called UPT a number of years ago and they suggested 3 in 1 oil or sewing machine oil so I've been using that ever since. -Michael

I designed and built one that got integrated into an LCD jump light that showed the altitude and count-down on jump run. Ultimately it was too much trouble to get it approved to install on an airplane so it still sits on one of my tables under a pile of dust. It used that scp1000 sensor I mentioned in the other thread. -Michael

I think the objective was more to get the devices out of circulation because in some countries people would simply purchase old expired units and install/use them where this practice was legal. -Michael

Pluggable micro SDs won't tolerate the vibration. There is also no QC, traceability or anything for a corner store micro sd. If you wanted to charge onboard batteries and/or download data then put a sealable micro USB connector on the head unit. On many rigs that would be convenient. It also doesn't make sense to try and jam a ton of sensors in there that do not help you. If there is a patent that prevents you from using an accelerometer then you're wasting your time adding one. For simple data acquisition to develop the algorithm and filters, check out the ardupilot project as they have prepared boards -Michael

There is a MEMS pressure sensor. SCP1000. I've used it before and it has reasonable sample rate, digital processing and temperature compensation inside already. Using an accelerometer, you'd have to make sure it doesn't infringe on existing AAD patents. The micro doesn't need to be complicated. A small bit of flash, RAM and eeprom inside. You need good current drivers to fire the cutter and usually a storage cap. AAD had a good solution they designed and patented for this. You probably need/want an external EEPROM/flash to store flight data. Then a small LCD unit with a button and maybe IR transciever and small micro to communicate with the AAD processor. -Michael

I don't think you'll find a legal requirement but it's the technical norm for devices of this nature. There are specific types of failure analysis, testing and even parts tracking that go into designs. For example there was a recall once from Airtec that affected certain Cypres units. They knew that a specific batch of pressure sensors could have been affected by a defect. AAD also published some details about the issue. That alone demonstrates that our AAD manufacturers do have QA and traceability systems in place on the hardware side. What if a software bug pops the AAD in the door and leaves a smouldering hole in the local schoolyard? It wouldn't be the first time an accident/incident is traced to a software bug. Ariane 5? Toyota's unintended acceleration? How difficult is it for a lawyer to show negligence if the designers didn't even follow industry standard norms for quality assurance? I think that the costs of a commercially produced AAD are justified. The per unit cost of the components and casting is quite low but the IP and management costs are huge. A couple of hobbyists hacking together a unit, bypassing all the expensive safety and design checks and distributing it as an AAD platform would be doing the entire industry a big disservice. -Michael

I think your post speaks of someone who has 0 experience working on a project like this. I've combed through hundreds of applicants just to find a single person who can turn an idea into some well written code. Writing clear maintainable code to standard is not trivial nor is it easy. Producing a PCB from a gerber file is cheap but someone needs to draw, test and validate the schematic. Generate a netlist, and route it. What are you going to use for that? Eagle is not going to cut it and orcad licenses cost thousands. The cost is in the design not the end product. You're not going to hand solder 1000's of units are you? You did remember how you'd verify the assembled units right? Let's not forget this is a safety critical device. Solder bridges and mis-placed components are not acceptable! Inspection, test fixtures, test points/probes cost time and money. How about toolchain and debugger? Is GNU going to do what you need? MISRA rule checkers start at about $10k. The debuggers we use will set you back $20k. Are you going to use an RTOS? Back to coding standards. Remember too that you need full documentation and traceability on everything. Micrium licenses will be an easy $5k. I think fully CnC'd cases for free is wishful thinking. Billet 6061 is far from free. CnC time is not free. Tooling will run into the hundreds of dollars just for the mills you need. Even the time to design the case and produce toolpaths is going to cost. Does that include solidworks licenses? You might be able to skip out on a few of these steps but what risk will you or the developers endure if one fires at the wrong time and takes off the tail? In general you can't waiver away negligence but building your own AAD without industry standard engineering and testing can be exactly that. I've been working in these areas for many years and I know from experience that it's not trivial as you suggest. -Michael

I think the problem is that few people can code well enough to even follow MISRA or do178 type requirements nevermind the documentation and test cases that go along with it. Reverse engineering and duplicating even an old airtec design is certainly not legal or ethical. No doubt the components are long out of production anyway. Producing a circuit, layout, test jigs and all that isn't for the casual bystander either. A cast durable and waterproof enclosure is also a consideration. A proper solution requires investment in the hundreds of thousands of dollars. After all that, you produce a few thousand of these discounted open source AADs and it only takes a couple of failures and people will still be shitting on it a dozen revisions and a decade later. Definitely not my idea of fun. -Michael

I was asked to build a d-bag for a crew guy. I don't know anything about crew. From researching it some people recommend using cotton. Rather than going down that path I question why not just use a d-bag attached file the slider like swoopers use? Can anyone enlighten me?

This is a very interesting discussion. While some might want to run away from the company involved, after this their risers are probably going to be the most carefully inspected and safest in the industry. Before reading this probably 90+% of riggers would have missed this problem. If next week the same set of risers passed through our lofts what % would miss the problem? How about next year? Hopefully it's caused some net improvement. -Michael

Ok, so a few things to consider. This aircraft pressurization scenario happened at WFFC was it a decade ago? I think 4 vigils popped and 30 cypreses shut down and stopped working. This is also 2 generations earlier than the units they are presently selling. The manual says 150 feet of altitude, not a single spurious reading showing 150 feet or more. If you take a look at their patent application you will see that it has to be in the activation range for upwards of 5 seconds. Since I reverse engineer devices for a living I can say for sure that few items work as simply as an outsider would assume. Basing your purchasing decisions on these assumptions is not a good idea. A better strategy would be to ask the manufacturer themselves how the device will react in a set of circumstances. If slamming a door was statistically likely to set off the vigil then you'd see regular reports of it. Not single data points that happened years ago. -Michael

I have a pilot chute built by canadian aerosports. I believe there is a phone number on it and it was purchased a few years ago. I can check it for you next time I "unpack" it. I also recently packed a reserve made by a company in Quebec. Took a lot of work to find a manual. I don't recall the company name off the top of my head. -Michael

Thousands of AADs are slammed in trunks each weekend. If this were really a design issue or big problem it would be reported regularly not a couple of data points years ago. I'm not for or against any of the AADs out there. In my mind they're all good and suffer a very very low rate of failure. It's just that saying it's a problem is not supported by either facts or statistics. -Michael