Jump to content


snakerbot

Member Since 22 Apr 2009
Offline Last Active Yesterday, 08:50 PM

Topics I've Started

Project 12: 100% brushless Vortex blaster

16 August 2020 - 11:59 AM

Attached File  IMG_3867.JPG   176.76KB   2 downloads

 

No, I’m not skipping all the odd numbers. My projects are numbered by when I start working on them, not when I finish. And Project 9 and Project 11 have both hit snags, so here we are.

Project 12 is a 3D printed, brushless flywheel, fully-automatic Vortex blaster. As with Project 8, it draws on the work torukmakto4 did on his T19, but where Project 8 was basically a T19 in a different body, this is much more different. As general highlights, Project 12:

  • Features a brushless outrunner based direct drive bolt. No steppers, DC motors, gearboxes, or solenoids.

  • Has only one powered flywheel, like the Nitron.

  • Has a Turnigy V-Spec 2205 motor for the flywheel drive.

  • Uses an Afro 20FS ESC for the flywheel drive, and an Afro 30FS for the bolt drive.

  • Uses torukmakto4’s Flyshot protocol to set the flywheel speed.

  • Uses torukmakto4’s tach-based single-trigger control that measures flywheel speed in real time and fires when it is up to speed.

  • Can carry a spare magazine in the stock

It is large and very heavy. Somewhat larger than it needs to be, with the muzzle extension and foregrip, but I wanted it to feel like a Nitron. I initially tried it with two powered flywheels instead of an idler because I thought that would give me more control of the disks’ trajectories, and for a little while I thought that maybe I could get more velocity out of it by pushing both sides. Neither of these worked. At the end of all this, the disk trajectory still isn’t as consistent as that of the Nitron. I tried various wheel speeds, flywheel gaps (currently set at 33mm to roughly match the Nitron), and various amounts of control bore, primarily by using printed sleeves to narrow down the bore. I also tried using a non-rotating idler, which fired fine, but didn’t really give any advantage. It currently features a 38mmOD powered flywheel and a 36mm OD idler on 70mm center-center spacing. I’m curious if that softer elastomer rim on the Nitron flywheel is important.

 

It’s having some reliability issues, but only with Pyragon drums. I’m not 100% sure what’s going on here. Might be just because it’s firing so much faster than the Nitron and the drums can’t keep up. 20 round stick mags are fine. I’m waiting for the chance to combat test this to see how it works there before I spend too much more time on it.

 

Printed in Snolabs red, Reicher blue, and black amethyst petg. Weird mixed bag of qualities here. The red is very good, the black amethyst is very stringy, but also has perhaps the best surface finish of any filament I’ve ever used, and the blue is terrible, with a diameter that varies so much I can see the effects in the finished parts.

 

Let’s talk more about the bolt drive, since that’s the big piece of new tech here. It uses a QXMotor QM5006, which despite the name, I think is actually a 4106 sized motor. It is 24N28P, with a KV of 350. It is 48mm in diameter, 20mm tall, and has a mass of 90gm. That really is what I was going for here. I’ve had good history with the stepper on Project 8, but steppers are heavy, at ~400gm. Cutting 310gm would reduce the mass of Project 8 by something like 15% on its own and partially cancel out the added mass on Project 12 of printing much more robustly, making just a bigger blaster overall, and adding a crapton of mass with a Pyragon drum. It’s expensive though, and behaves a little oddly at the moment. More on that later.

 

It uses a custom tuned version of SimonK on the ESC to enable forward/reverse operation and motor braking. I also played around with the throttle pulse widths to better match up with what I was able to get from the ATMega8 on the Arduino. I am using the governor to set the RPM of this motor, not Flyshot, since Flyshot is not currently compatible with the variable throttle needed to get forward/reverse operation, deceleration, etc. that I needed for this to work. I may play around with this and try making new version of it, but it’s not a high priority for me right now.

 

On the Arduino side, I’m using a Pro Mini and the AVR’s Timer2 to get a 488Hz hardware PWM for the throttle signal to the bolt drive ESC. Now that I’m only using one flywheel drive, I could use the other Timer1 channel there to drive the bolt, but I programmed this with the intent to use two powered flywheels, so the bolt motor had to get its throttle signal from a different timer. With that timer and the pulse width ranges set in SimonK, I have 2% resolution on the throttle signal. The codebase is essentially torukmakto4’s S-Core 0.96, with various changes for my use:

  • I changed the pinouts to work with my hand-wired board.

  • I got rid of the variable speed flywheel drive handling code and just set it once at boot time.

  • I got rid of select fire code, although I kind of flipped back and forth between blowing it away completely and just setting it to full auto all the time, so it’s a huge mess. There’s definitely a ton of useless code in there now that I should probably get rid of.

  • Obviously, the changes to use the outrunner bolt drive.

If you just want to see what I did to make the bolt drive work, look at the following functions:

  • fire(), decelerateBoltToSwitch(), and reverseBoltToSwitch(), for obvious reasons.

  • setup(), for enabling the Timer2 hardware PWM signal.

  • die(int major, int minor), because without a stepper to make error code noises with, I had to handle them some other way. I settled on broadcasting them through the serial monitor.

Because the bolt motor is brushless and I retain all the fire control logic from S-core, the bolt is stall- and jam-resistant. It will self-home at boot and reverse if at any time it fails to reach its goal by going forward.

 

There are a couple weird things about how it works though. First is that the typical math for setting the governor (described in https://torukmakto4....loop-speed.html) just doesn’t work with this motor. Right now my TIMING_MAX is 0x0BE4, which should be 938RPM, but I’m actually getting more like 730. No idea why this is.

 

Second is that I had this running like clockwork on a testbed that consisted of just the motor, bolt, and associated electronics, but as soon as I put in in the blaster, everything went kind of wonky. I’m getting a lot of double-fires when I try to single, and a relatively slow tap tap tap of the trigger often gives me a sort of bursty type firing of a bunch of shots. I’m going to continue to play around with the code, try adjusting the position of the limit switch, etc, and see what I can find, but I’m also putting this out there so if anyone with more time and/or programming experience than me wants to take a look at it, they’re welcome to.

 

I mentioned that I tried having both wheels spin at different speeds. That took some code changes to work with flyshot, so I put another version of the code up (in the misc folder) in case anyone wants it. For how I did that, see, primarily:

  • setGovernorBoth (void)

  • updateSpeedFixed (void)

  • ISR(TIMER1_COMPA_vect)

Although there are various other places where it comes into play, like variable definitions, and bits of loop().

 

Anyway, files are all in my google drive if you want to see my code, or try making one of these yourself.

https://drive.google...PID?usp=sharing

 

Attached File  IMG_3868.JPG   133.39KB   2 downloads

Attached File  IMG_3869.JPG   170.07KB   2 downloads

Attached File  IMG_3870.JPG   186.88KB   2 downloads

Attached File  IMG_3872.JPG   158.58KB   2 downloads

Attached File  IMG_3873.JPG   180.58KB   2 downloads


Houston Area Nerfers Unite (HANU) Monthly War #35

20 December 2019 - 08:39 PM

We have these every month, I just forget to post them most of the time. Unless otherwise noted, they are the first Saturday of the month, at 10:00 AM, at this location.

 

Date: Saturday, January 4, 2020

Time: 10:00 AM until 2:00 or so.

Location: Hilton C. Schott Park, 8510 Will Clayton Drive Humble, TX 77396

Take the entrance farthest west, closest to 59, by the big red and yellow playground setup (A) and go all the way to the back. We'll be set up around the gazebo/picnic table (B).

 

Schott park labelled.png

 

Rules:

150fps limit.

Stock or stock-ish ammo only. Workers, Artifacts, and other short darts allowed as long as they have soft, stock-ish tips. No FVJs or voberries. There will be a community ammo bin which is mostly full of accufakes, waffles, and elites.

No blasters with realistic looking paint jobs.

All ages welcome, but if you aren't old enough to drive yourself, someone who is needs to stay with you.

Eye protection of some sort is mandatory.

 

Gametypes:

A mix of deathmatch and objective based games. A typical day might look something like this:

- 3-15 teams

- Territories

- CTF

- Carpe

- VIP

- 3-15 pistols

 

We're on Meetup and Facebook as well.

https://www.meetup.c...ents/267320334/

https://www.facebook...49451813/?ti=as


Houston Area Nerfers Unite (HANU) Monthly War #34

05 December 2019 - 10:45 PM

We have these every month, I just forget to post them most of the time.

 

Date: Saturday, December 7, 2019

Time: 10:00 AM until 2:00 or so.

Location: Hilton C. Schott Park, 8510 Will Clayton Drive Humble, TX 77396

Take the entrance farthest west, closest to 59, by the big red and yellow playground setup (A) and go all the way to the back. We'll be set up around the gazebo/picnic table (B).

 

Attached File  Schott park labelled.png   1.78MB   28 downloads

 

Rules:

150fps limit.

Stock or stock-ish ammo only. Workers, Artifacts, and other short darts allowed as long as they have soft, stock-ish tips. No FVJs. There will be a community ammo bin which is mostly full of accufakes, waffles, and elites.

No blasters with realistic looking paint jobs.

All ages welcome, but if you aren't old enough to drive yourself, someone who is needs to stay with you.

Eye protection of some sort is mandatory.

 

Gametypes:

A mix of deathmatch and objective based games. A typical day might look something like this:

- 3-15 teams

- Territories

- CTF

- Carpe

- VIP

- 3-15 pistols

 

We're on Meetup and Facebook as well.

https://www.meetup.c...ents/266352850/

https://www.facebook...49451813/?ti=as


Project 10

05 July 2019 - 06:29 PM

Attached File  IMG_3823.JPG   222.28KB   46 downloads

 

Back in December 2012, I made what was then my second homemade, an extension spring powered, bullpup rainbow (later named by Vaan as an ESRB, so that’s what I’ll call it).

 

And while it took a few revisions before it was truly reliable, that blaster has remained in service at the high-velocity games I’ve played at more or less continuously since then. Though it served me very well, a few niggles started to bug me:

 

- The barrel wasn’t quite on straight.

- The wooden handle had spent the last six-and-a-bit years absorbing water from the humid Houston air and was splitting.

- The screws holding the handle on no longer were staying tight.

- The trigger flopped around.

- General jankyness resulting from my lack of skill in 2012.

 

So earlier this year I set out to make essentially a 1:1 replacement for that blaster, intended to address the above issues. I had also hoped that I could improve the efficiency of the blaster by 3D printing a redirect piece with a smoother airflow path, using a lighter plunger rod, etc., but this new one is chrono’ing at basically the same FPS as the ESRB (around 230 with sweet oranges), so I don’t know if any of that stuff worked.

 

As with the ESRB, I don’t intend this to be a fully fledged writeup. Those of you with the experience and tools necessary to make this can probably figure out just from the STEP file what to do.

 

A couple notes though.

 

- This uses the same 1/4” galvanized aluminum plunger rod as Ryan and Kane used on the later version ESLTs, but with a 3D printed piece added on to enable rainbow catch usage.

Attached File  IMG_3827.JPG   99.91KB   41 downloads

- This also uses the same o-ring plunger padding method as the ESLTs.

Attached File  IMG_3835.JPG   84.12KB   43 downloads

- As with the ESRB, this uses a U-Cup to seal the plunger rod in the redirect, but it’s a different part number since the rod is a different diameter. This U-Cup seems to be adding a bit of friction, so I have an o-ring I’ll try eventually.

- The hopper wye has had the top corner shaved down to give the darts a little more room to maneuver the corner, and this uses a brithop. In my experience this is the most reliable method of shooting sweet orange darts.

Attached File  IMG_3841.JPG   70.34KB   43 downloads

- I’m using one of LegoDEI’s rifling attachments on the front. The STEP file just features a dummy piece there.

Attached File  IMG_3830.JPG   150.22KB   44 downloads

- The purple printed wye support is different on the STEP file and the pictures. I added this after I made the rest of the blaster, so a couple screws were in the wrong place. The STEP file represents what I would do if I built this again.

Attached File  IMG_3829.JPG   135.83KB   42 downloads

- The STEP file does not show most of the fasteners. The shoulder screw goes on the catch. The 3/8” screws hold the barrel support on, and hold the wye to the redirect. The 3/4” screws go through the rear barrel spacer and the handle clamp. The 3/8” Flat head screw goes in the front of the handle clamp and into the grip. The 1” flat head screws hold the back of the grip to the handle clamp. The 1 1/4” screw is what the trigger pivots on, and is cut down to length.

- The physical blaster has two holes one inch aprt for the front sprint post, for different amounts of pretension. The STEP file only has the one I’m currently using. The set screw I’m using for the spring post has been cut down so it doesn’t poke out of the body.

Attached File  IMG_3833.JPG   94.52KB   41 downloads

- The purple parts are printed in Color Me 3D Purple Haze PETG. The white parts are eSun/Inland solid white PETG.

 

I used this blaster in the Foam Pro Tour at this year's Endwar, where it was the only hopper-fed blaster there, and one of only two (that I saw) old-school PVC contraptions. The other was an AABow with an RSCB. Unfortunately my team went 0-2, but the blaster performed well enough, and I blame our poor showing more on our almost zero practice than anything else.

 

Anyway, files are here.

https://drive.google...7VF?usp=sharing


Project 8

06 January 2019 - 09:48 PM

Attached File  IMG_3782.JPG   105.99KB   56 downloads

This is what I’ve come to call “Project 8” or just P8. It is a fully 3D-printed, magazine fed, fully-automatic blaster heavily inspired by/based on Torukmakto4’s T19. It uses the same Hy-con geometry wheels, but with the 11mm gap instead of the base 9.5mm. The important parts of the flywheel cage geometry such as spacing and bore diameter are the same, although both parts of the flywheel cage have been modified somewhat.

 

It also uses the same stepper motor bolt drive, although again, some slight geometry changes have been made to fit them into this blaster.

Flywheel motor controllers run the same build of SimonK that the T19 does, but with the motor speed governed at 21,291rpm instead of 25,510. The slower speed at the larger gap flywheels are meant for 150fps games, and although there wasn’t a chronograph at the last game, a test cage with the same geometry was getting ~145fps with community bin accufakes and ~150fps with community waffles. The new wheels were printed with different settings that better matched the intended profile, so I dropped the speed by about 5% (to the current speed) just in case it was shooting too hot.

 

The core arduino code is near-stock T19 “Core 26.1”. The only change I made was to reduce the base feed delay from 185ms in non-turbo mode and 180ms in turbo mode to 145ms and 140ms, respectively since the flywheels don’t need to reach quite the same speeds.

 

Essentially this is a T19 in a differently shaped body. I did not really intend this to be so, but once I started doing the CAD, the design took on a life of its own and this is where it ended up. In general it features smoother contours than the T19, especially on the user contact areas, where the grip, the stock pad, and the front of the magwell are all very heavily radiused. It also has large windows on the left and right sides of the magwell so I can see how much ammo I have left in the magazine. The breech is also not a fully enclosed breech like the T19, although the jam door, when closed, serves the same purpose a closed breech does, aligning the dart with the bore. This jam door was really intended to be a top loading door more than a jam door, but I’m not sure I’ll ever actually use it for that. I used to top load my rapidstrike, but it lost that ability about seven months ago and I can’t say I’ve missed it.

 

Issues as they exist right now:

- It’s pretty large and heavy. Not unreasonably so, but a hypothetical Project 9 may make an effort to be lighter.

- The weight balance is a little off. The center of gravity is about an inch behind the handle with the battery in place. Not a huge deal, but noticeable in some circumstances.

- The magwell required huge amounts of sanding, filing, and scraping to make the mags drop free. I’ll edit the CAD eventually, but I haven’t yet.

- One of the screws in the handle digs into my knuckle if I hold it in certain ways.

 

And so you can see it in action, here’s a video of the CTF rounds we played at the last HANU game where I used this blaster.

https://www.youtube....h?v=wdj4fMtDgTg

 

More info on the T19 can be found at Torukmakto4’s blog:

http://torukmakto4.blogspot.com

 

The cad files and code for P8 are available here:

https://drive.google...ccV-W0eCXEGhUSc