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snakerbot

Member Since 22 Apr 2009
Offline Last Active Sep 15 2019 02:27 PM

Topics I've Started

Project 10

05 July 2019 - 06:29 PM

Attached File  IMG_3823.JPG   222.28KB   9 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   9 downloads

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

Attached File  IMG_3835.JPG   84.12KB   9 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   9 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   9 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   9 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   9 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   24 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


Houston Area Nerfers Unite (HANU) War #24

27 December 2018 - 01:54 PM

Date: Saturday, January 5, 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   25 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...xMTA5NjgyNDBlYw

https://www.facebook...12567972183035/


Uploading attachments to PMs

12 March 2017 - 03:10 AM

I was having a private message conversation with another user and needed to include an image, but couldn't upload the image as an attachment, at least not that I can see. We can include attachments in messages, but only if they've been uploaded in a topic post. I found that I could begin to post a reply to a topic and upload the attachment from there, then cancel the post before actually posting anything, and then attach that image to the private message, but a way to upload directly through the messaging window would be helpful.

 

Actually, I don't even see the uploader down below this editor. I know I've attached images both to replys and to new topics. Under what circumstances does it show up?


Extension Spring Rainbowpup post-construction writeup

20 July 2016 - 11:15 PM

Attached File  IMG_1715.JPG   136.58KB   78 downloads

I had planned to do a full writeup with step-by-step instructions and pictures and all that, but as months of non-work turned to years of non-work, I decided I should get this out to the community in whatever form it took. By now nothing in this blaster is in any way new or revolutionary, (with the possible exception of the Dura brand PVC bushing trick) but I want to have this information out there.

 

I’d like to give credit to the rainbow clan for the rainbow catch, Ryan and Kane for the BullPAC and the original Rainbowpup, Carbon for the Snap/Revolution, Ryan for the original catch and handle templates, and Diamondback for the slightly modified ones.

 

In lieu of an actual writeup, I’m uploading the .dwg and template file that I have now. They are included as attachments at the bottom of this post. If you don’t have autocad, you can download draftsight for free at http://www.3ds.com/p.../free-download/ and it’ll do all of the same things. Alternatively you can find various free viewers (not editors) at http://www.autodesk....cts/dwg/viewers. I’m also including various pictures of the only one of these I still have, so you can get an idea of what the actual parts look like, especially where I wasn’t super detailed in my .dwg. The pictures I include are of a somewhat earlier revisions than what the .dwg shows, so be aware of that.

 

Parts needed.

Spoiler

 

Here’s the part I think is least clear in the .dwg: what I call the seal block. This is what seals the plunger rod. It’s made from a 3/4" to 1/2” PVC bushing nested inside a 1” to 3/4” bushing with a 9691K53 U-cup seal sandwiched in the middle. I cut down the outer lip of the U-cup to about half height. The PVC here stops the plunger when it hits home. I use SCH80 PVC since the thicker walls provide a little more surface area for the plunger head, but I don’t think it’s that important.

Attached File  IMG_3381.JPG   113.18KB   83 downloads

Attached File  IMG_3386.JPG   113.9KB   79 downloads

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The rainbow catch is directly in front of the seal block.

Attached File  IMG_3393.JPG   222.16KB   83 downloads

 

Here’s my plunger head. It’s a little longer than the one in the .dwg, but concept is similar enough. You can use whatever you like here to interface from the nylon plunger rod to the skirt. The .dwg and parts list use a U-cup since it’s cheaper, but I used a skirt for this one because this was the first one of these I made. Use whatever you like, but keep in mind the skirt is 1/8” taller. Those grommets there provide a little cushion when the plunger head hits home.

Attached File  IMG_3402.JPG   92.74KB   74 downloads

 

This is the front of the plunger rod. I use a really long eye bolt to mount both the spring and priming disk to, as well as providing room for the catch, which works against the front surface of the nylon rod.

Attached File  IMG_3405.JPG   95.86KB   71 downloads

 

You can use a long set screw or cut the head off a regular screw to support the spring at the front. I use these things called weld nuts to hold the spring centered on the screw.

Attached File  IMG_3411.JPG   121.1KB   81 downloads

 

The priming grip is simple enough, but I want to point out the screws that poke in through the slots and push on the priming disk. That is how this blaster is primed. Also, the slots on the top and bottom need to be the right size to be out of the way. The .dwg shows the priming slide being stopped when the bottom slot hits the front of the handle/trigger block, but this one here stops when the plunger bottoms out against the catch. An important thing here is that you can’t really use thinwall 1-1/2” PVC for the pump grip. The walls are too thin and flex inward with those slots cut.

Attached File  IMG_3413.JPG   101.02KB   73 downloads

 

Finally, the redirect. For the actual elbow part I use a 1/2” CPVC street elbow, with the spigot end hammered into a short piece of 1/2" PVC to interface with the wye. The socket end has a short piece of CPVC in it. I just drill a hole in the coupler and plunger tube and insert the CPVC into that, but you can do various things here. I use a 5/8” forstner bit and my drillpress to make this hole, and it seals perfectly without glue, but you may or may not be able to do this, depending on your tools.

Attached File  IMG_3417.JPG   80.83KB   88 downloads

Attached File  IMG_3418.JPG   102.38KB   82 downloads

Attached File  IMG_3422.JPG   59.71KB   77 downloads

 

The template file is attached to this post. I can't attach .dwg files so I put it on google drive: https://drive.google...Ym9VaGtfSkZSLW8