Arcflash Labs SGP-34 User manual

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SGP-34
Single Stage SCR Coilgun
User Manual
Arcflash Labs, LLC
8620 Belford Ave, Unit 603
Los Angeles CA 90045 - [phone]
Hwww.arcflashlabs.com [e-mail]

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Limited Warranty
Warranty: Arcflash Labs, LLC. (hereinafter referred to as “Arcflash Labs”) warrants to the original purchaser these products to be free from defects in
material and workmanship under normal conditions of use and service for a period of 30 days from date of shipment. Arcflash Labs will, as its option,
repair, replace or refund the purchase price of any products that prove defective within the warranty period, if such products are returned to Arcflash Labs
in accordance with the warranty claim procedures set forth below. REPAIR OR REPLACEMENT OF THESE PRODUCTS, OR REFUND OF THE PURCHASE PRICE
AS PROVIDED UNDER THIS WARRANTY, IS THE BUYER’S EXCLUSIVE REMEDY. This exclusive remedy will not be deemed to have failed of its essential
purpose so long as Arcflash Labs is willing and able to repair or replace any defective product, or refund the purchase price, in the prescribed manner. In
the event Arcflash Labs fails to provide the Buyer with free repair or replacement, or refund the purchase price as aforesaid, Arcflash Labs’ entire liability
shall not exceed the amount paid by the Buyer to Arcflash Labs for its purchase of the defective product. THIS WARRANTY IS EXCLUSIVE AND IN LIEU OF
ALL OTHER WARRANTIES NOT EXPRESSLY SET FORTH HEREIN, WHETHER EXPRESS OR IMPLED BY OPERATION OF LAW OR OTHERWISE, INCLUDING BUT
NOT LIMITED TO ANY IMPLED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Limitations: Products which are purchased from other equipment manufacturers and sold by Arcflash Labs as part of a system or on a resale basis will bear
only the original manufacturer’s warranty. The above warranty shall not apply to fuses, lamps or other items which are expendable by nature, unless
otherwise provided.
IN NO EVENT SHALL ARCFLASH LABS BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, TORT, PERSONAL INJURY, PROPERTY, CONSEQUENTIAL OR
OTHER DAMAGES, INCLUDING BUT NOT LIMITED TO DAMAGE TO OR LOSS OF PROPERTY OR EQUIPMENT, PHYSICAL INJURY, DEATH OR HARM TO
GOODWILL OR BUSINESS REPUTATION DIRECTLY OR INDIRECTLY ARISING FROM THE SALE, HANDLING, OR USE OF THE PRODUCT, OR FROM ANY OTHER
CAUSE RELATING THERETO. Arcflash labs shall not be liable to the Buyer for any claims, demands, injuries, damages, actions or causes of action
whatsoever based on negligence or strict liability. Arcflash Labs shall have no liability of any kind under this Limited Warranty unless the Buyer
commences an action against Arcflash Labs within 1 month of the date the cause of action accrues.
Unless otherwise agreed in writing by an authorized representative of Arcflash Labs at Arcflash Labs’ headquarters in San Diego, California, the products
sold hereunder are not intended for use in connection with any nuclear facility or activity. If so used, in the event any damage, injury or contamination
occurs, Arcflash Labs disclaims any responsibility of every kind, and the user of the products shall indemnify Arcflash Labs and hold Arcflash Labs harmless
from any and all liability for any such damage or contamination whatsoever arising out of any such use, including liability in tort or strict liability.
WARRANTY CLAIM PROCEDURE: In the event the products purchased hereunder prove defective, the Buyer shall notify Arcflash Labs’ Service Department
in writing at its offices in San Diego, California of the claimed defect, and such notice shall include the model and serial number of each such product, as
well as the number and date of invoice therefore. Upon receipt of this information, Arcflash Labs will send notification to the Buyer as to the service
arrangements and will provide written authorization and shipping instruction, and the Buyer shall return the products to Arcflash Labs, transportation
prepaid, in accordance with such shipping instructions. If, after inspection, Arcflash Labs determines the defect is a result of misuse, mishandling,
installation, abnormal condition of operation, unauthorized repair or modification, or due to Buyer’s failure to install, maintain or operate the products in
compliance with the written instruction, all necessary materials, labor and other expenses shall be for the account of the Buyer at Arcflash Labs’ standard
repair rates. Any products returned to Arcflash Labs for replacement shall become the property of Arcflash Labs.
The Buyer shall be responsible for all costs of shipping, customs clearance and other related charges in connection with Arcflash Labs’ repair or
replacement of products located outside the continental United Sates pursuant to this Limited Warranty.
The validity, performance and interpretation of this Limited Warranty shall be governed by the internal laws (and not the laws of conflicts) of the State of
California. All disputes arising in connection with this limited Warranty shall be resolved, if not sooner settled, by a court of competent jurisdiction located
in California, U.S.A.
9/19
Copyright © 2019 by Arcflash Labs, LLC. All rights reserved. Under copyright laws, neither the documentation nor the software may be copied,
photocopied, reproduced, translated, or reduced to any electronic medium or machine readable form, in whole or in part, without the prior written
consent Arcflash Labs, LLC except in the manner described in the documentation

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1. Introduction
The Arcflash Labs SGP-34 (Solenoid Gauss Pistol –Model 34) is a single stage, SCR switched, high
voltage capacitor driven, slide-action coilgun.
It is a single stage design with TTL operation and no microcontroller components. The charging of
the capacitor is activated by powering on the unit and discharging is initiated through the SCR and coil
upon a trigger pull, or through a high wattage bleeder resistor when the power is shut down. The
capacitor will remain energized for approximately 10 seconds after the power is removed.
The SGP-34 is configured to ONLY fire 0.25x0.75” steel projectiles (dowel pins). Arcflash Labs
recommends the use of 2575 Magnetic Armatures (sold separately) but any 0.25x0.75” steel dowel pin
should work.
The SGP-34 is shipped standard with a CFS (constant force spring) magazine which can hold up to
18 rounds single stacked. The gun is also shipped standard with a 850mAh 4S Lithium Polymer battery
(charger sold separately) which can provide power for over 50 shots before needing to recharge. We
recommend the use of the B6 V2 6S LiPo Balance Charger (sold at
https://arcflashlabs.com/_accelerators/components/ ), but the “YoungRC A400 3-4S Lipo battery
charger” is also an effective third party charger for the SGP-34 battery.
As one of our crowdfunding supporters, you are privileged to join an exclusive community of
electromagnetic gun developers and enthusiasts around the globe. Until now, only a handful of
individuals have ever seen an electromagnetic gun, let alone fired one. Congratulations on your
purchase of a piece of history.

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1.1 Terminology and Safety
The list below and throughout this manual is a summary of the major hazards associated with
the device, but is NOT ALL INCLUSIVE. There are many other hazards associated with the device which
are not laid out in this manual. We recommend wearing high voltage, flame retardant gloves at all
times when using the device as well as goggles and thick clothing. Never use the device indoors or
around flammable materials and always have a fire extinguisher on standby.
The SGP-34 is NOT WATER RESISTANT AND NOT IMPACT SAFE. Exposure to water or dropping
from distances greater than 1 foot may cause irreversible damage to the gun, fire, explosion, electrical
shock or venting of toxic gas from the battery or capacitors. If the SGP-34 is dropped or exposed to
water: discontinue use immediately and return the gun to its manufacturer for repairs.
The following terminology is used throughout this manual for the purpose of denoting
important and safety critical information:
An operation, procedure, or practice which if not correctly followed could result in
personal injury or loss of life.
An operation, procedure, or practice which if not strictly observed, could result in
damage to the device and/or voiding of the device’s warranty.
A recommended procedure, suggested practice, or point of additional information which
may facilitate the ease of use for the operator, or point out a feature of particular
importance which is useful to know, but not safety-critical.

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2. Overview of components
LiPo Battery
Compartment
Charge/Power
indicator LEDs
Drive coil
Slide injector
Battery release
screw
Magazine slot
Trigger
Capacitor
Muzzle
Heat Sink
Power switch

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2.1 Barrel
The SGP-34 is a single shot handheld gauss pistol –its core component is a high voltage
switch called a silicon controlled rectifier (SCR) which quickly discharges all the stored energy in
the capacitor into the drive coil, creating a large magnetic field. The field is designed to expand
as the projectile moves towards the center of the drive coil and contract a precise amount of
time after. The expansion and contraction of this magnetic field is precisely timed to accelerate
the 2575 armature. Projectiles longer or shorter than the standard may not fire at all or may
fire less effectively. The nominal exit velocity is between 22-32 m/s for the 2575 armature.
While its muzzle energy is comparable to most bb-guns (around 1.6 joules or 1.2 ft/lbs),
it should be treated the same way as a firearm: with the utmost respect. While the muzzle
energy is roughly the same as a bb-gun, the projectile mass is far higher. Hazards from
accidental discharge include broken bones and severe injuries –in short, never point the device
at anything you don’t want to destroy. Treat it as loaded at all times.
Some versions of the SGP-34 ship standard with an aluminum barrel and some ship
standard with a brown Garolite (polymer composite) barrel. Do not be alarmed if your barrel
appears different from the picture. All coilguns are tested and verified before shipment to
ensure they meet specs.
The drive coil of the SGP-34 may appear larger or smaller than the picture. Despite its
small size, it is mathematically optimized to deliver the most energy from the capacitor into the
projectile. Do not be concerned if the coil you receive appears smaller than the pictured
version, as the physical size of the coil is in no way correlated with the muzzle energy.
The device is powered by a low voltage (16V) battery, but this low voltage is internally
stepped up to 450V and stored in the capacitor. The SCR is capable of delivering this energy to
the coil at over 1000A. Never touch any metal parts of the gun while it is powered or shortly
after it is shut down as it takes approximately 10 seconds for the gun to fully power down, even
after the green power light has extinguished.
- Lethal shock hazard: The SGP-34 operates at 450 Volts and 1000 Amps. Never touch any
components inside the ventilation holes. Never disassemble the unit. Never touch metal
components while the unit is powered on, or within 10s of being switched off.
- Muzzle energy is sufficient to break bones, cause serious injury or even death. It goes
without saying: never point the gun at anyone or anything you do not intend to destroy.
- Never fire projectiles longer than 0.75” – firing projectiles other than Arcflash 2575
Mangetic Armatures or 0.25x0.75” steel dowel pins could result in fire or explosion.

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2.2 Injector
Projectiles are pushed out of the magazine by a hand-operated slide injector. This
mechanism is similar to that of a conventional firearm in appearance and function, but more
delicate since it relies on a small magnet for retention and proper positioning rather than a
flange. This injector dispenses single rounds from the magazine into the chamber, where the
action of the trigger activates the SCR, creating an expanding magnetic field in the drive coil and
sucking the projectile out of the injector mechanism and into the barrel where it is then
accelerated out of the gun.
To operate the injector, insert a magazine, and pull the injector slowly back to the rear
position until you hear a light click and the slide encounters resistance, then slowly move the
slide forward again until it is fully reset to the original forward position. This will chamber an
armature. After each shot, you must manually rack the slide to chamber the next round, similar
to a bolt-action.
It may be useful to inspect the chamber after removing the magazine to verify whether
then gun is loaded. To do this, rack the slide back all the way with the magazine removed, hold
the top of the gun up to a bright light or light-colored surface (like a wall or ceiling) and look
down the magazine well. If you can see light, there is potentially no armature in the chamber.
If you do not see light, or see only a small light, there is likely an armature chambered.
- Do not slam the slide or let go of the slide at full extension like a conventional firearm. This
will damage the retention mechanism and it will also NOT properly seat the round.
- To properly seat a round, rack the injector slowly, keeping your hand on the injector slide
mechanism at all times.
The injector held in the rear position.

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While this method demonstrates one potential way to check whether the gun is safe,
just because there is no armature in the chamber does NOT mean that the gun is safe or
unloaded. There still may be a round jammed in the barrel. The only way to fully verify that
the gun is unloaded is to insert a wire or rod down the barrel and observe the end of the rod
through the magazine well.
2.3 Heat sink
The SGP-34 relies on an ultra-compact high voltage boost converter to step up the
battery voltage and charge its capacitor rapidly. Due to the small size of the SGP-34, it relies on
a less advanced technology than Arcflash Labs’ patented CQR chargers. The boost converter
generates a great deal of heat and its core components are mounted to the bottom of the
aluminum plate that runs the length of the top of the gun. This aluminum plate serves to cool
the charger –it is not recommended to tape over it or cover it as doing so may result in
overheating of the charger, fire or explosion of the electrical components.
Armature in chamber
Potentially safe
- Lethal shock hazard: The SGP-34 operates at 450 Volts and 1000 Amps. Never touch
metal components (including the heat sink) while the unit is powered on, or within 10s of
being switched off. Never touch any components inside the ventilation holes.
- While the heat sink is electrically shielded from sources of high voltage, there still exists
the possibility, however slight, that a component may become dislodged and the heat sink
may become electrically charged during operation, therefore we advise against touching it
while the unit is powered on.
- Serious burn hazard: The heat sink gets hot enough to burn after extended operation
(>150oF). Don’t touch it. Wear gloves.

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2.5 Battery
The SGP-34 contains a Lithium Polymer battery. As with any device containing a large
lithium battery, it presents a number of hazards including shock, fire, explosion or venting of
toxic gas. Always store the gun and battery in a cool, dry environment indoors, away from any
flammable materials.
To insert or remove the battery, simply turn the thumbscrew at the bottom of the
battery compartment to release the latch, then connect the battery with the main switch off.
Position it appropriately as shown below, and tuck the charging cables neatly into the
remaining space before closing the compartment. Ensure that no wires are pinching when
closing the compartment as this could result in a short or battery fire.
- The SGP-34 contains a large 4S Lithium Polymer battery. Never leave a charged battery
unattended and always store in a cool , dry environment.
- Take care not to pinch the wires when closing the battery compartment.
Proper positioning of the battery after connection

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2.6 Trigger
The trigger of the SGP-34 is connected to a small microswitch internally and is actuated
by a small spring. The trigger only has roughly 0.06” of travel length and the spring return is
very fragile. If excessive pressure is exerted on the trigger, the spring return could detach. If
this occurs, discontinue use of the gun and immediately return to the manufacturer for repairs.
If further pressure is exerted on the trigger, damage to the microswitch and/or main control
board could result.
2.7 Magazine
The SGP-34 uses a proprietary 18 round magazine design based loosely off of the MG20.
Similar to the MG20, it uses a constant force spring and accepts Arcflash Labs 2575 magnetic
armatures. The SGP-34 is NOT compatible with the MG series of magazines. To order a
replacement or extra magazine, please contact Arcflash Labs directly at
[email protected] .
2.8 Capacitors
The SGP-34 contains one large electrolytic capacitor (1,500 uF total capacitance). It is
capable of delivering over 1000A burst current at 450V and storing over 150J of energy.
The capacitors remain charged for approximately TEN SECONDS after disconnecting all
power from the gun. During this time, the gun may still fire. To power down the gun we
recommend the following procedure: 1) set the main switch to the off position, ensuring the
green power light is not active, 2) remove the magazine from the gun, verify that there is no
round still remaining in the barrel, and 3) wait approximately 10 seconds before removing the
battery.
The red LED near the barrel indicates the state of charge on the capacitor. If the red LED
is illuminated, the capacitor is fully charged.
- Do not exert excessive pressure on the trigger. It is a fragile component.
- The SGP-34 contains one large 1500uF capacitor capable of storing over 150J of energy.

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3. Operation
3.1 Startup
1. Ensure battery is charged to its nominal voltage of 16.8V.
2. Open battery compartment and connect the battery as shown in section 2.5.
3. Stuff connector and wires into the battery compartment gently, ensure wires clear pinch
points and close the compartment.
4. Insert a magazine into the bottom of the handle, apply force to the bottom of the magazine
to ensure it is fully seated. It may be necessary and it is encouraged to slap the magazine to
ensure it is fully seated against the injector rod.
5. Activate the main switch.
6. Observe the barrel of the gun, ensure the green LED immediately illuminates; the red LED
should also illuminate 1-2 seconds after activating the main switch. If the red LED does not
- It is unsafe to power up the gun with a magazine inserted.
- Always check that there is nothing inside the barrel before powering up. Any rounds or
debris inside the barrel during startup could result in a misfire.
Insert magazine
Seat magazine fully

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come on, this indicates a charging system fault. If this happens, please contact Arcflash
Labs for support.
7. The red LED indicates that the capacitor is charged and the gun is ready to fire.
8. Rack the slide slowly back until you hear a light click, and gently guide the slide forward to
chamber the first round. DO NOT let go of the slide from the rear position.
9. The gun is now charged and loaded. Press the trigger to fire.
3.2 Shutdown
1. Remove the magazine.
2. Discharge any round still left in the chamber.
3. Shut off the main switch, ensure both the red and green LEDs extinguish.
4. Wait 10 seconds, and perform a chamber inspection as described in section 2.2, being
careful to point the gun in a safe direction.
5. Remove the battery.
6. Wait for the heat sink to cool before storing. Use the back of your hand to feel the air
above the heat sink without touching it. The heat sink may still be hot enough to burn,
even after the gun has been shut down.
Ensure the green LED activates
Ensure the red LED activates
- The heat sink is hot enough to burn you after extended operation. Even without firing a
round, the heat sink may still be hot.

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4. Software
The SGP-34 is operated by hard-wired TTL and has no software.
5. Hardware Specifications
Accelerator Specifications
Primary power source
1x 4S LiPo –16.8V, 850mAh
Power supply
100W (IGBT boost driver)
Capacitors
1x 1500uF/450V electrolytic
Switches
1x 1.1kA pulse-rated SCR
Projectile
0.25x0.75” carbon steel, 71gr
Capacity
18 rounds
Rate of fire
<1.0 rounds/sec
Muzzle velocity
72-105 fps (89 fps nominal)
Muzzle energy
~1.2 ft-lbs
Efficiency
1.1%
Physical Dimensions
Active barrel length
1.1”
Bore
0.25”
Physical Dimensions
10.5” x 7” x 1.8”
Overall Weight
(unloaded, no battery)
1.67 lbs