background image

 

X

4

MR

250 

 

MexAir RC 

 

 

Other “stuff” typically installed on a racing multirotor frame includes: 

Flight Controller Board 
Motors 
Propellers 
Speed Controls (ESCs) 
FPV Gear and cameras 
Batteries and Battery Connectors 
 
In some frame designs, including the

 X

4

MR

, there are varying options for positioning and mounting 

components.  We listed options for those that have shown to be useful and tested successfully with the 

X

4

MR

s we build in-house.   

 
Recommended Options: 

 

Voltage Regulator(s) 

o

 

Note:  If you do not have 5V and/or 12V supplies that may be necessary for your camera 
systems, these can be handy add-ons wired direct to the supplied PDB. 

 

Satellite receiver vs. standard receiver?   

o

 

Testing with a Spektrum satellite receiver showed no adverse effects on range or signal 
reception.  It is a good lightweight alternative to traditional receivers due to small size 
and less wiring as might otherwise be necessary.  It can be mounted almost anywhere 
on the

 X

4

MR

 airframe. 

 

General Guidance to make assembly faster, easier and safer: 

1.

 

Read through the assembly instructions completely PRIOR to beginning construction. 

2.

 

Inventory all kit supplied parts, your electronics and tools, organizing them according to your 
intended build.  Do not forget about any general supplies such as solder, heat shrink, small tools, 
etc. 

3.

 

Use small amounts of blue loctite thread locker on all metal-to-metal screw contact surfaces, 
especially motor mounting screws. 

4.

 

“Dry-fit” and test all electronics and FPV gear, to the extent possible during the build, so 
disassembly will not be required after you have completed the frame assembly. 

5.

 

Pre-plan purchase of motors that have sufficient motor wire length and diameter to allow for 
embedding the wires into the motor arms.  The minimum length of the leads should be 4 inches.  
The wire diameter, including insulation, should be a maximum of 1/16” (~20 gauge) to fit into 
the arm holes.  If larger, the holes can be widened as described in this manual.  Alternately, any 
wire length or diameter can be used by surface mounting them. 

6.

 

Take care in soldering components to prevent shorting between solder pads or overheating any 
sensitive electronic components. 

7.

 

Although the skills, techniques, and “hazards” associated with this build are typical for many 
hobby related activities, we always strive for safe and efficient construction techniques.  We 
therefore  repeat here what you have likely learned from your previous experiences: 

a.

 

The 

X

4

MR

 airframe kit does not require any drilling for the typical build.  If drilling 

holes in the carbon fiber (CF) for self tapping screws or larger component attachments 
use a sharp drill bit and work with light pressure and a relatively high speed drill.  CF can 
not be “punch marked” for drilling.  A small electric rotary tool or drill press is 
recommended to prevent the bit from “wandering” as you start the hole.  Wear 
appropriate safety gear, including air mask/filter, if creating carbon dust. 

Summary of Contents for X4MR 250

Page 1: ...Class Racing Quad airframe We specialize in the design and construction of the airframe Since the various electronic components and peripherals are widely available through many sources our focus is...

Page 2: ...me comes configured to mount the supplied Power Distribution Board with the included PDB standoffs and predrilled main frame mounting holes This PDB mount allows for piggy back mounting of a 30 5mm co...

Page 3: ...o metal screw contact surfaces especially motor mounting screws 4 Dry fit and test all electronics and FPV gear to the extent possible during the build so disassembly will not be required after you ha...

Page 4: ...ary to start tightening it back it out slightly repeating this process until the fastener is threaded to the proper depth This creates a threaded hole that should hold firmly without any other aid For...

Page 5: ...both the positive and negative wire ends at the main body hole the large elongated hole You can always trace the polarity later during the build if you forget to do it now If supplied with colored wir...

Page 6: ...ile holding the standoff in place Take care not to over tighten the standoff and shear off the screw For added assurance to prevent the screw from ever backing off a small dab of RTV Silicone Seal can...

Page 7: ...s Verify that there will be sufficient wire to reach your intended ESC solder pad locations or connector A minimum wire length of about 4 inches is necessary If not use the Surface Wire Option describ...

Page 8: ...o the arm using small tie wraps ii If using this option you may also consider surface mounting your motor ESCs directly on the arm surface Again this will additionally increase drag and turbulence and...

Page 9: ...r This will allow for soldering the motor wires later and THEN moving the heat shrink over the ESCs prior to final shrinking d TEMPORARILY place the ESCs onto the bottom plate so that the motor pads f...

Page 10: ...ole is clear of any obstruction When finally tightened this creates a very rigid frame Temporary and partial frame assembly may be desired as you progress through assembly CF Tube Standoff Configurati...

Page 11: ...piece If there is any noted slipping or twist verify that all standoff fasteners are properly tensioned f Landing Gear Installation Note Nylon landing gear can be cut to desired length i Embedded Mot...

Page 12: ...pivot with moderate force Tighten loosen the arms as necessary so that they are firmly seated but can pivot with moderate force Do not over tighten to cause excessive dimpling of the laminate or poss...

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