T19 Build Guide - Part 3 - Breech Assembly

Previous: Part 2 - Cage Assembly

Tools:

• Hand Drill Motor
• 9/64" Drill
• 7/64" Drill
• 6-32 Tap and Tap Handle
• File
• Knife
• Dremel/Mini Grinder/Die Grinder with zip wheel

Parts/Materials:

• T19 Cage/Barrel Assembly - refer to Part 2
• T19 Flywheel Motor Controller Cover x 2
• T19 Breech
• T19 Mag Release
• 6-32 x 2" Socket Head Cap Screw x 1
• 6-32 x 5/8" Socket Head Cap Screw x 2
• 6-32 x 1" Socket Head Cap Screw x 4
• 6-32 x 3/4" Socket Head Cap Screw x 4

Start by cleaning out all 6-32 through holes with a 9/64" drill:

Controller covers: 3 bolt holes each

Breech: 4 cage flange bolt holes

Breech: 4 drive section flange bolt holes

Breech: Right side, mag release bolt hole (Side with counterbore ONLY. DO NOT drill left side for clearance - this will be tap drilled and tapped later)

Mag release: Pivot hole

Then drill the following holes in the breech to 7/64" (or tap drill size to suit material) and tap 6-32 threads:

3 controller cover mounting holes per side (Note: Top two are through entire part)

Left side mag release bolt hole

Mating the cage and breech: Feed motor phase wires through the phase wire holes in the cage flange.

Bolt the cage onto the breech with 4 x 6-32 3/4" length SHCSes. Torque evenly.

Test fit motor controller covers and deflash prints if necessary. Note snap-fit around lower bolt heads - may be tight. Don't pinch wires that are currently here.

Remove covers afterward and put them aside (with their bolts inserted for safekeeping) - they will go on later after mating the breech to the drive section and installing the motor controllers in these compartments.

File the mag release slot in the breech and top layer of the mag release lightly to deburr. Hand fit the mag release further for smooth motion if required.

Mark a 6-32 x 2" SHCS to be cut to length as the mag release pivot bolt. Note: Do not substitute a shorter screw, unless the unthreaded shank length is appropriately long, which is the rationale for cutting a widely available, standard 2" socket head screw. Do not allow the mag release to pivot on threads!

Zip that to length, and deburr.

Install.

Do not overtorque! Apply only enough torque to prevent unwinding. Overtorquing the mag release bolt will cause mag release binding and can distort the magwell enough to make mags not drop free.

Next: Part 4 - Stock Assembly

T19 Build Guide - Part 2 - Cage Assembly

Previous: Part 1 - 3D Printed Parts

This post covers parts prep and assembly of the Hy-Con Gamma Major cage. With the flash hider added, this becomes the externally complete barrel assembly of the T19.101.

Tools:

• Hand Drill Motor
• 5/64" or 2mm drill
• 7/64" drill
• Nearest drill to 3.0mm that you have
• 1/8" drill
• 9/64" drill
• Tap Handle
• 6-32 tap
• 10-24 tap
• Allen wrenches
• Razor blade or sharp pocketknife
• File

Parts/Materials:

• Hy-Con Gamma Major/Main
• Hy-Con Gamma Major/Cover
• Hy-Con Gen3 Flywheel x 2
• T19 Flash Hider
• Turnigy Multistar V-Spec 2205 2350kv x 2
• M2 6mm length socket or button head cap screw x 8
• M3 10mm length socket or button head cap screw x 8
• 6-32 1" length socket head cap screw x 6
• 6-32 1/2" length socket head cap screw x 3

Start with the cage main section:

Use a 3mm drill (7/64" works for me, as my drill measures 2.98mm) to clean out the 8 motor mount holes. These bolts are locational and should be a close (slips in without play) fit on a M3 fastener. Do not oversize to typical "clearance" fit.

Use a 7/64" drill to clean out the 6 cover-to-main bolt holes (near the bore). This is a tap drill for 6-32 threads. I use this size because it works well for PETG. Other materials may call for changing the tap drill size.

Use a 9/64" drill to clean out the six corresponding 6-32 through holes in the cover. Again, these bolts are semi-locational and should be a close fit.

Use a file to clean any burrs or raised extrusions off the sides of the Main part where it fits into the Cover's guards.

File the top surface of the Main (where the bolt holes are) and the matching surface of the Cover, if necessary. Burrs and debris from the top layer extrusion can prevent proper alignment when torqued down.

File the guard edges on the Cover where they contact the Main surfaces if necessary to relieve any interference and allow assembly.

Use a 7/64 drill to clean out:

• The three flash hider bolt holes (above)
• The four outer mounting holes on the breech flange (below)

N.b.: The inner set of breech flange holes on the Gamma Major are not used in the modern T19. That is an obsolete pattern for compatibility.

Don't drill the holes any deeper than the existing printed pilot bore.

Tap all these 6-32 threads:

• The 6 main-to-cover holes in the Main.
• The 2 flash hider holes and 2 outer mounting holes in the Main.
• The 1 flash hider hole and 2 outer mounting holes in the Cover.

Use a sharp tap and go slow!

Seat the cover and main together and start at least 2 cover bolts for the next step.

Use a blade to clean up the barrel crown and slightly break the edge as a chamfer. The printer can leave a motion system acceleration defect (corner swell) on the crown. This can protrude slightly into the bore and potentially impact accuracy.

Alternatively, one may torque the main and cover parts securely together, then use a countersink cutter to cut the barrel crown.

Next comes flywheels.

Use a 5/64" drill to clean out the 4 flywheel bolt holes.

Use a 1/8" drill to clean out the "3mm" motor shaft clearance hole. (N.b.: This is NOT a pilot bore. I'm telling you to make sure it is oversize for a reason. The Gen3 flywheel is piloted on the rotor outside diameter. This shaft hole SHOULD NOT be a tight fit on the shaft with the Gen3 wheel because it is an overconstraint. If this hole and the rotor bore do not agree perfectly, it can cause the flywheel to be forced to warp when torqued down and thus have runout which is bad.)

Use a blade to scrape down any Z scar/layer change blips and other protruding detritus inside the rotor bore. Careful not to egg it out. Follow the existing surface. Sand slightly, if necessary.

Now comes the time to mate the wheel to the motor. It should be a snug fit with some interference, but should push on easily by hand. Some hand fitting of the bore may be required - take your time, be careful, get the fit right.

Caution: Do not thrust load the motor bearings while fitting the wheel. Support the rear end of the shaft on a surface while pressing on the wheel. DO NOT push on the stator base while fitting the wheel! DO NOT hold the motor in your hand and mash it into the wheel. Place the SHAFT END against a hard surface and push the wheel down onto the rotor. Thrust loading the bearings can brinell them.

Start by visually clocking the rotor and wheel bolt holes to match before putting the wheel onto the rotor. Use an allen key or other tool through one hole to help align the bolt holes while pressing.

Be sure the wheel is fully seated on the rotor (<1mm of the rotor backiron should be visible above the wheel bore edge).

Install 4 M2, 6mm length bolts and torque evenly in a cross pattern.

Repeat for the other rotating assembly.

Mate these to the cage main.

Hint: Insert the phase wires into the phase wire channels first, then jockey the rims past the groove fillers and the rear shaft end/snap ring into the shaft end clearance pocket.

Install 4 M3, 10mm length bolts per motor and torque evenly in a cross pattern.

Now is the time to roll the wheels over by hand and check for excessive runout, contact or other problems. Many wheels do wobble slightly, as is unavoidable in FDM parts, but this should be minimal. In some cases, the flywheel bolts may need to be loosened and retorqued, or the motor and wheel pulled and remated. Major runout or contact of the wheel rim with the cage most likely indicates a significant tolerance issue with one or more of the parts or trapped debris in a fit somewhere.

Once satisfied with the wheel install, check the torque on the bolts.

If you have a motor test setup on hand, connect a suitable drive to each motor at this time, power it up, and give each rotating assembly a test spin. The motors should start and run normally. No wheel rim contact with anything should occur at speed. This is a good time to detect typical lemon motors with shorted turns, which generally exhibit a drag torque. If one wheel stops much faster than the other when undriven, that motor is defective.

Mate the Main and Cover. Start six 6-32, 1" length socket head cap screws.

Torque evenly, starting in the center and alternating sides.

Use a 9/64" drill to clean out the 6-32 through holes in the flash hider and bolt it on with three 6-32, 1/2" length socket head cap screws.

I prefer to do this step after assembly for stability: tapping the front top rail mounting hole in the Main part.

This hole prints at a tappable dimension with high thread engagement, due to the characteristics of the larger 10-24 thread and its taps which will cut cleanly in PETG in such a case, and does not need drilling.

Use a tool to measure the depth of the hole.

Transfer this dimension to the tip of your 10-24 tap with tape.

This will help avoid overpenetrating with the sharp tap tip and DENTING THE BORE. Be mindful!

Go slow and back out every few turns to remove chips. Stop at indicated depth.

Now you have set up what may be your first Hy-Con and the most critical and tedious part of the T19 assembly process is behind you! The rest is more fun now that the high-speed spinny bits and internal ballistic headaches are squared away, don't worry.

Next: Part 3 - Breech Assembly

T19 Build Guide - Part 1 - MASTER POST and 3D Printed Parts

This will be a many-part series of posts covering the build process of the T19 blaster in standard "Model 101" trim:

• Part 1 - 3D Printed Parts (this post)
• Part 2 - Cage Assembly
• Part 3 - Breech Assembly
• Part 4 - Stock Assembly
• Part 5 - Grip Assembly
• Part 6 - Drive Section Mechanical
• Part 7 - Blaster Controller
• Part 8 - Logic Power Supply Module
• Part 9 - DC Bus Harness
• Part 10 - Flywheel Motor Controllers
• Part 11 - Core Controller Firmware
• Part 12 - Final Assembly and Commissioning
• Part 13 - Tuning and Customization (coming later)

Anyways, a good place to start is with all the non-COTS parts that are supplied as models for you to manufacture. I assume that you are going to FDM print these as they are designed for.

Tools:

• FDM 3D printer
• Computer with slicer

Parts/Materials:

• Filament

The models are available here from the DZ Industries Google Drive: https://drive.google.com/open?id=17zi6XGi_Rp5biofmGVj_0ZyBb71Q0HPR

Some general notes: NO supports. Assumptions are 0.2mm layer height unless noted otherwise, and 0.4mm nozzle/~0.45mm extrusion width (you figure out the conversions if you run atypical nozzle sizes). You should be able to run all of these parts with a 170x170x170 (ish) build volume. It is strongly recommended to use PETG, or ABS, or other materials with reasonable mechanical properties, passable toughness, and serviceability at ambient temperatures that may be encountered in combat conditions. I do not test and cannot support PLA. If you use PLA and it warps or cracks, that's your problem. Machine accuracy, extrusion settings, etc. are also your responsibility. I am not responsible for incorrectly printed parts and I am not your printer technician.

Grip Frame

Mesh Filename: T19_GripFrame.stl

Print Parameters: 5 perimeters, 8 top/bottom solid layers, 40% hexagonal infill, aligned start point

Orientation: Right side of grip on bed

Grip Frame Insert Plate

Mesh Filename: T19_GripFramePivotPlate.stl

Print Parameters: 5 perims, 8 tops/bottoms, 40% hex, aligned

Orientation: Right (flat) side on bed

Trigger

Mesh Filename: T19_Trigger.stl

Print Parameters: 3 perimeters, 6 tops/bottoms, 30% hex, aligned

Orientation: Side on bed

Grip Panels

Mesh Filename: T19_GripPanelLeftFinal_fixed.obj, T19_GripPanelRight_fixed.obj

Print Parameters: 3 perimeters, 6 tops/bottoms, 30% hex, aligned

Orientation: Back sides (flat) on bed

Grip Baseplate

Mesh Filename: T19_GripBaseExt_Rev2.stl

Print Parameters: 5 perims, 8 tops/bottoms, 40% hex, aligned

Orientation: Flat side on bed

Mag Release

Mesh Filename: T19_MagRelease.stl

Print Parameters: 3+ perims, 6+ tops/bottoms, 100% infill, aligned

Orientation: Side on bed

Crank

Mesh Filename: T19_Crank.stl

Print Parameters: 3 perims, 6 tops/bottoms, 30% hex, aligned

Orientation: Bottom (side with chamfer, NOT fillet) on bed

Crank Pin Bushing

Mesh Filename: T19_CrankPinBushing.stl

Print Parameters: 2+ perimeters (part is all perimeter extrusions)

Orientation: End on bed

Bolt

Mesh Filename: T19_Bolt.stl

Print Parameters:
* Standard - 3 perimeters, 6 tops/bottoms, 30% hex, aligned
* Lightened (Recommended) - 2 perims, 4 tops/bottoms, 20% hex, aligned

Orientation: Top/bottom side on bed

Notes: Upcoming "Class 4" bolt kit will be destroked and further lightened for better high ROF operation.

Stock Buttplate

Mesh Filename: T19_StockButtplate.stl

Print Parameters: 3 perims, 6 tops/bottoms, 30% hex, aligned

Orientation: Flat side on bed

Drive Spacer

Mesh Filename: T19_DriveSpacer.stl

Print Parameters: 3 perims, 6 tops/bottoms, 30% hex, aligned

Orientation: Bottom (flat) side on bed

Drive Cover (Top Cover)

Mesh Filename: T19_DriveCover.stl

Print Parameters: 3 perims, 6 tops/bottoms, 30% hex, aligned

Orientation: Top (flat) side on bed

Lower Drive Housing

Mesh Filename: T19_DriveHousing.stl

Print Parameters: 3 perims, 6 tops/bottoms, 30% hex, aligned

Orientation: Top (flat) side on bed

Breech Housing

Mesh Filename: T19_Breech_Rev2_fixed.obj

Print Parameters: 3+ perims, 6+ tops/bottoms, 30%+ hex, aligned

Orientation: Top on bed

Hy-Con Gamma Major/Main

Mesh Filename: Hy-Con-GammaMajor_Main_Rev2.1.stl

Print Parameters: 4+ perims, 8+ tops/bottoms, 100% infill (for the love of the friction-ballistic gods, please heed this and leave the "100% infill not any stronger" armchair design BS at the door), aligned.

Orientation: Top (flat surface) on bed

Notes: Skookum part or die

Hy-Con Gamma Major/Cover

Mesh Filename: Hy-Con-GammaMajor_Cover.stl

Print Parameters: 3 perims, 6 tops/bottoms, 30% hex, aligned.

Orientation: Bottom (flat surface) on bed

Hy-Con Gen3 Flywheels

Mesh Filename: ./Hy-Con-Gen3-Wheels/Hy-Con-Gen3-[dimension]mm.stl

Print Parameters:
* Standard - 3 perimeters, 4 bottoms, 3 tops, 20% hex, random start point.
* Optional - 0.1mm layer height with 8 bottoms, 6 tops.


Orientation: Flat end on bed.

Notes: A range of flywheel models of different gap settings are supplied to suit tuning preferences/desired velocity/dart damage. 9.5mm is the default for higher velocity. 10mm is a good starting point for FDL-like performance, perhaps. Two copies required. These are high-speed rotating parts, so pay particular attention to machine accuracy before running this job, and use random seam position. Print parameters as specified are important to produce OEM-equivalent moment of inertia and thus compatibility with default assumptions of drive dynamics in the Core firmware. Make sure your machine's part cooling system works properly to get an accurate and smooth surface on the overhanging groove flank as this is a somewhat demanding overhang print.

Motor Controller Covers

Mesh Filename: T19_ControllerCover.stl

Print Parameters: 3 perims, 6 tops/bottoms, 30% hex, aligned

Orientation: Outside surface on bed

Notes: Two required, a right and a left. Only one model supplied. Reflect one copy about an axis when slicing.

Stock Body

Mesh Filename: T19_Stock2.stl, T19_Stock_Charge2.stl

Print Parameters: 4 perims, 6 tops/bottoms, 30% hex, aligned

Orientation: Back end on bed

Notes: There are two versions of this part. One has the provision for a DE-9 connector for internal charging of the battery. One does not. If you use lipos, internal charging is not advised, so I recommend the portless version. Also, this part contains bridging extrusions and prints with a 0.2mm membrane over the stock tube hole to aid this.

Stock Base

Mesh Filename: T19_StockBase2.stl

Print Parameters: 5 perims, 8 tops/bottoms, 40% hex, aligned

Orientation: Back (flat) surface on bed

Flash Hider

Mesh Filename: T19_FlashHider2.stl

Print Parameters: 5 perimeters, 8+ tops/bottoms, 100% infill, aligned

Orientation: Back (flat) surface on bed

Notes: Perhaps you can tree why this "seemingly inconsequential" part's updated version is beefy, and why slicing it robustly is recommended - it's on the very front of your blaster, and is the first part to get into the carnage.

Here's what your full set of prints should look like:

Next steps will be prepping and cleaning up these prints, introducing the "vitamins", and building subassemblies.

Next: Part 2 - Cage Assembly