V2 & V3 Drafting project.

[SuperHog]

Companies that do aerospace tolerance use continuous tolerance compensation by automatically adjusting the offset table so tolerance is held regardless of expansion.

Some of the older Fadal used chilled fluid to maintain ballscrew and spindle temperatures. Seen them on mills doing mold making.

[ThunderCactus]

I know the HAAS has options for thermal comp, not sure if they're any good
Forgot which machine it was, but I know someone actually continuously measures their ballscrew length to compensate for thermal comp

[zzzzsleepy8]

Originally Posted by ThunderCactus

If it's got a roller bearing on one end, then they're not stretching the ballscrew, but they're probably allowing it room to stretch. Unless you're accounting for that in your software, it'll result in small positioning errors. Our HAAS lathe would change about .003" over lunch as it cooled down.
The angular thrust bearings on the servo side are probably to help dampen vibration and possibly correct any servo misalignment.
I know some machines just use roller bearings on both ends of the ballscrew, but you don't want to buy those machines for serious work lol

I work on anything that has a fanuc controller

But even the 'smaller' mills need box ways if they're doing moderate work, like the DNM500
I ran a HAAS VF3 and new style VF4 for a few years, I can tell you how important it is to have rigidity in the machine. And it makes a big difference even when you're doing moderate machining of steel. I could flex the head of that HAAS just running a 1" indexable end mill at 2100rpm and 50ipm at .125" depth and 70% cutter immersion.

linear rails are for things like;
-making sure large overhead panels slide straight when there's only one actuator that's off-center
-for mounting controllers to so they can slide back and forth on a long bed lathe
-for doing really fast positioning but low load actions like positioning laser cutter heads, or drilling and tapping small parts

They're great for fast and accurate positioning, but they're just not meant to handle loads.
But they're great on those tiny little chinese machines, wouldn't trust anyone scraping those so the linear guides are an advantage. And you're not likely to be doing anything very heavy on them anyway

Yeah you're right about the axis losing accuracy under load or thermal expansion in fixed-free bearing setup, but only so while operating in open loop. Actually, you just need to close the loop with a DRO glass scale on your axis as feedback into the motion/CNC controller and you can achieve great accuracy again. The fixed-free setup enables less stresses to be developed on the ballscrew itself and the corresponding bearings used, unlike in the case of a fixed-fixed setup.

The angular thrust bearing was just to create a rigid anchor point that can absorb axial loads to the ball screw. The misalignment between the ballscrew shaft and the shaft of the servo was solved with a flex linkage as a shaft coupler.

Thats not all true. A few commercially available very high precision vertical milling CNC machines use standard linear bearing rails. Lots of Mori Seiki machines use linear rails. You use box way designs because they can handle bigger loads. But precision, speed and accuracy can be handled in a variety of ways, such as doing closed loop position feedback control on the axis. All good machines should have DRO glass scales or some laser interferometer distance transducer on each axis.

Actually, most cheapo home CNC machine probably use dove tails. I know hobbists change up the come-with lead/acme screw with ball screws, but havent' seen a project where someone managed to add linear rails on them. Unless they custom build something themselves, like a DIY gantry type CNC machine.

Originally Posted by SuperHog

Companies that do aerospace tolerance use continuous tolerance compensation by automatically adjusting the offset table so tolerance is held regardless of expansion.

Some of the older Fadal used chilled fluid to maintain ballscrew and spindle temperatures. Seen them on mills doing mold making.

Yeah, I think ballscrews used on Mori Seiki machines are internally cooled and like all high-end precision machines they have DROs setup for closed loop feedback to their controller.

[ThunderCactus]

Ultimately the glass scale DRO is the most surefire way to maintain accuracy, but if you know how much the ballscrew expands, you just have to measure the temperature of the machine and you'll good results with offsetting for temperature.
Depends how much precision you want, the Doosans are good to .0002" even on the big horizontal machines, but you'd want microns on something like a 5 axis grinder.
As far as I know, Doosan only uses a rotary glass scale in horizontal machine rotary tables, that's really the only place they need that kind of resolution.
Doosan's target is the middle price range, wouldn't expect to see high end features on them. Great machines for the price though.

And high precision machines use linear guide because they're high precision. But you wouldn't be doing 30in³ removal rates on a high precision machine lol
The Trumpf lasers are often seen as being the best, they're all linear guides. Those were pretty awesome to work on too, except for the RF cabinet, damn things still scares me lol

[Bandit50]

On a side note some of the external pieces of my rifle have proven, plastic So ill be doing some small smithing tomorrow on saturday, with some sheet metal, mig welder, grinder and a File or two. Ill be sure to take some pictures for anyone else with a broken Masada and start another thread. -.- and before you ask. No, I can't make the pieces for you for a price. Sorry I am not a store or a shop kids, I am just a person who likes to display craft for other enthusiasts and professionals to enjoy.. I might however, produce some technical drawings on paper that others could take them to a shop and have them reproduce the parts. No, these will not be in a CAD file either.

Pencil, ruler and my bad hand writing.

Edit: For those interested in what I did this Saturday, and have some reading time http://www.airsoftcanada.com/showthr...164331 http://

[Bandit50]

I'm back, and I thought I would post something to show some simple progress.



Just some of the Tools I use when I draft things out in a CAD world. I know most of the things look a little gray, but color and material will be visible and added in the final assembly. I find that the gray does however show dimensions and definition better for those that really want to see the detail in each image.

The next thing I will work on is the tapper plate, which slides the feed nozzle back and forward to feed bbs into the hop up chamber. As well as control the single cycle for the semi fiction of the gear box. It also shows off some more of my CAD skill as it has some various features. Something, I want to focus on is the spring rest/catch. I have never liked the initial design, as I find it's to flimsy, and doesn't provide a fast enough return, even on high speed applications, I aim to change that using the Sector gear and some old skool tech. :P



And just for the record, to say "I thought of it before any major airsoft company". Where the Steam Cylinder is, I plan to mount a spring much like how a shock works in your motor vehicle. To provide almost instant return. (11:57pm 13/06/2014) This last part is to time stamp the idea as it hit the web so it holds up in court.

[Dynamo]

word of advice, if you design something unique and possibly revolutionary for airsoft... keep it to your self until you get the design patented.
no worse feeling than coming online and seeing practically the same design release by some over seas company. especially if you have spent a decade working on the design, stupidly posted pictures of it on some obscure forum the year prior.

[Bandit50]

Originally Posted by Dynamo

word of advice, if you design something unique and possibly revolutionary for airsoft... keep it to your self until you get the design patented.
no worse feeling than coming online and seeing practically the same design release by some over seas company. especially if you have spent a decade working on the design, stupidly posted pictures of it on some obscure forum the year prior.

I don't think it's revolutionary as seen above, I just think it's a change that should be done. Kind of like making a AEG Magazine more like pistol magazines to get perfect 100% feeds.

[ThunderCactus]

I wonder what other manufacturer has that design lol

[Bandit50]

So the "Tapper Plate" is done. I rather it be referred to a Feed Plate, because that's really what it does. Without this lone piece in your gear box, it will not do the most important job. Load a BB's into the chamber. Meaning all of that compressed air is for nothing. You might even notice that I am drafting this in the steps to fire the BB.

Again most of the things I am releasing in this thread is the Stock version, the concept stuff will be done and released later. I have decided to leave some areas of this part unfinished for now. As they're only a few things that can be decided and changed later. To make it really fit the gear box, and mesh with other components, once it's assembled. For now though it's near 85% complete. The final version will be uploaded once these changes are made.

If you want to see the finished part, it's on page one.

Also, I am thinking gears and the cylinder head next, that and maybe the spring guide and bearings for the head for the main spring.

[ThunderCactus]

PTW's don't have tappet plates and they work just fine lol

[Bandit50]

As of sometime next year I will be updating my software from an perpetual educational version. To a full fled copy. At that point I will be open to creating custom parts that you could print from sites like shape ways, and who knows maybe actually have some bigger ambitions then that.

I will continue on this project in the mean time, as its brushing up on some old skills and giving me new ways to create/design objects. This project it will remain free and submitted once fully completed by the end of this year.

More updates still to come.

[Bandit50]

The files, are available on the Grabcad Community.

https://grabcad.com/library/partial-...t-v2-gearbox-1

The project was completed by another member of the Global Airsoft community, using Solidwork

Jens Halsoe.

I am working on producing my own models and components from here forward. Thanks for begin patient everyone. I will create an exploded view, and assembly as promised for local techs and give credit to Jens.

Happy Airsofting.

[Bandit50]

Here is what's contained in the file and there is enough there to reverse engineer the other side.

[Amos]

Wow... OP delivered lol