Відео

Better to watch the other videos for that. In this instance the mustard coloured part in front of the blue part moves sideways and the design relies on pins that go up to the rail carriage.

No. I don't sell them. I made them to experiment with the concepts and I made all the designs available on the web site. The time cost for me to prepare one for you would exceed the cost of a seb rest which seb can churn out on a cnc machine for nearly nothing.

I cannot recall precisely but it was more likely 70%

Video comments have a link to the site containing the source files.

I don't know why youtube held this comment for 2 weeks :-( This design is theoretical. Even I never printed it. Your Shadetree top will be significantly more rigid. As for freecad... every component is separated within it. You open it in freecad, click on each body and choose export in the menu to export the stl. Then if you don't want freecad you can just uninstall it.

Theoretically yes. Thankfully in the forming process everything is done with the base as a reference including the shape of the boattail. The boattail dimensions have the highest chance of being the most consistent dimensions of the projectile.

Nothing will happen. Lead does not interact with electromagnetic fields. The sensor won't see it at all. But for cast lead projectiles it's a bit pointless because lead is so soft and easily dented.

I guess I just wanted proof of concept.@@MrBCRC

You're right to raise that concern. It depends on the sensor and oscillation circuit design. I had to do a lot of investigation (reading research and white papers) in the early days of development and that was one of the things that came up. If you want to investigate further look for papers what cover penetration vs frequency. Aircraft sub skin crack detection is a good one to search for especially where you need to penetrate through more than a layer of paint. Basically the lower the frequency the deeper the penetration. In a self oscillating (self resonating) circuit the oscillation frequency will tend to be very high and you will only measure the outer surface. To penetrate into the jacket better you need to control the frequency which is why my oscillation circuit is driven at a specific frequency intended to do just that. I actually talk about it in some videos and even have some projectiles measured on video where they mic to 0.1 thou all the way around but show a significant variation indicating a detection of an internal flaw. I think it was some berger 6mm's I tested for a friend.

As I said in another comment reply... The bearings and linear rail are listed in the description. The rest is just whatever m3, m4 and m6 bolts you can find at your local hardware store. This is a proof of concept though and a full "down to the last detail" parts list would be misleading and I would end up with people complaining that they built it using my parts list and it didn't work.

Yes. Plenty of blind tests and positive results but with long range shooting any single point in time can be washed out by environmental or other conditions. Like shooting your best ones in twitchy conditions or bad mirage then when you get to the bad ones the conditions settle. It's hard to compare the two because you know they're not comparable. So it's not a reliable test :( The main noticeable difference is the reduction in unexpected fliers that don't go where they should for a bad wind read or a typical user error. The ones where you adjust on it thinking it was a good shot and the next shot is out the other side by the exact same amount. The fun of long range shooting :)

You've probably noticed from the other videos on the channel that it's basically complete. They work, they're stable after a quick warm-up and there isn't really much I can do to make them better without making them unnecessarily overpriced.

@@MrBCRC Outstanding work and thanks for responding! I still pull out my Juenke when I buy a new bunch of bullets. I've found that bullets have improved vastly over the past 20 years. What used to have duds that ran 20+ Dev units just isn't there anymore. The majority run under 10 and only a few (All Hornady) get up 14 or 15 Dev units. My Lapuas never get over 9 - 10 Dev units and a lot are under 5...

The bearings and linear rail are listed in the description. The rest is just whatever m3, m4 and m6 bolts you can find at your local hardware store. This is a proof of concept though and a full "down to the last detail" parts list would be misleading and I would end up with people complaining that they built it using my parts list and it didn't work.

They're on my website. www.mrbcrc.com

I use an ender 5 pro which is my second printer and it's good because it doesn't have artefacts in the print from the inertia (and other forces) associated with the bed moving.

Respectfully it's impossible to use a dial gauge without some preload. It's a comparative measurement and you have to preload it to establish your zero. There are flaws in the process but that's not one of them. For instance the flat of the indicator isn't perfectly parallel with the base. If your projectile is perfectly centered each time then you will get more consistent comparative measurements. But if you're off center you can introduce 1/2 thou of error. Is that a problem though??? One truth for all measurement mechanisms is that there are tolerances and you have to define your tolerances with acceptable limits for the process you're achieving. With this mechanism you can reliably establish base to ogive variations within 1/2 thou. When I'm batching with a batch range that's sometimes up to 4 thou, small variations just don't matter much. I just ran a 1000 JLK's 22's through and got a full range variation of 4 thou with zero discards.

See link in video description.

@@MrBCRC cant open file sir 🙏🏻

It's probably covered in a few of the other videos but the short answer is yes. It is definitely covered on the website. See: mrbcrc.com/what_is_it.html Two materials make up a projectile. Copper which is relatively lightweight and lead which is obviously very heavy. Copper has an effect on electromagnetic fields and lead doesn't. So the EBC measures the presence of the copper. The variations shown indicate higher and lower amounts of copper. Ignoring the improbable situation of air gaps, we can conclude that more copper equals less lead and visa-versa. The less uniform the distribution of the lead is, the less chance that the projectiles center of gravity is central to the projectiles axis of rotation in flight. While it's nearly impossible to spin a projectile at the right speed to measure the effective Dynamic Balance directly, this represents the next best option.

I agree that many care about the weight which is why a lot of serious rests have cast iron bases. But there's a big market out there for shiny and lightweight or things like the Seb Mini-X wouldn't exist.

If you mean can you just swap in the newer board? The answer is no :-( The main reason is that the sensor won't be in the same position (depth wise) and that will ruin the tuning. That rules out a board swap even for the same board layout you have in yours. It's a tradeoff between precision and maintainability. With respect to the 32 bit board there is the additional reason in that the board layout is different so the cutout clearances for the through hole components are in different locations. If your curious, I honestly I don't think that the shifting to a 32 bit chip alone is all that much of an improvement. In the prototype design I made a lot of other changes to the circuit that really increased it's precision and I really believe that I should incorporate those changes into the original design with the original chip to make it more precise.

I was just using PLA mainly because it prints very cleanly for me. I've been using PETG lately for a lot of things but it's quite stringy for me and will need extra work but it's strength is impressive so it's sometimes worth the tradeoff

Just adjust the drawings to whatever you can get your hands on. The full files are there. You can check the dimensions in the cad files and/or choose to change them as required. A lot of people have chosen to modify my designs to better meet their own requirements before printing. 3d printing isn't precise and there may need to be some adjustment to get parts to fit and slide smoothly. 10 thou here or there can add up.

@@MrBCRC Ok thanks for the quick response. I just figured that while I was ordering the bearings, I would order the shafts.

Links to the bearings and linear rail are in the description. The rest are just standard m4 bolts of varying length to assemble and M6 bolts and nuts for the handle/shaft. This version is just a concept that requires modification.

I've been trying to work on it and also on the EBC bullet sorters but in reality my day job and my family have been taking up most of my time so I havent put in the time I would have liked. I do have a lot of printing that I need to do for my latest version but it's moving way beyond the simple prototype I initially designed and into being very complex. At least filament is cheap :)

@@MrBCRC i totally understand. Family and work need to take priority over hobbies. At leat that's what my wife tells me :)

I'm presuming you've seen the videos of the second version. I'm still pondering how best to do the third version. Unfortunately doing the design work is going to be time consuming so I have been delaying that task. Additionally I've been working on the prototype for a newer version of the EBC bullet sorter.

Absolutely brilliant! I'm just getting back into benchrest and f class and the cost of the coaxial rests are so off putting. This really is game changing. Thank you!

visit www.mrbcrc.com