Showing posts with label Technicial. Show all posts
Showing posts with label Technicial. Show all posts

Friday, 3 June 2016

Graphics

This blog cover the graphics.

Overview
In a previous blog the process for creating the labels for the panels was outlined.  

The interior graphics have a major advantage over the exterior one, that is you know the finished size and using the process outlined in the earlier blog work well for this builder.

The exterior graphics proved to be a whole new problem with no ideas about size so the builder had to scale the necessary graphics off a illustration for a decal set for a 1:48 plastic model.


Alley Cat Decal Sheet illustration captured off the web

With the graphic above open in Inkscape the measuring tool was used to find the distance from the spinner to the tail being of a 106 mm

The length for a Tucano is approx 34'  or 10360 mm 
Scaling factor 10360 / 106 =  98

Replica scale = 0.7

To calculate the size for any decal :

Measured dimension x Replica scale x Scaling factor = Decal dimension

All graphics were drawn in DrafSight a 2D Cad package and colour corrected in Paint.net if required and finally sized in Inkscape.

Note: All packages are shareware

After that you can have them printed on vinyl for installation when the aircraft is painted or as required in the cockpit. The satin black has by luck proved to be a near perfect match for the paint used on the panels.


Breaker Panel

Note: Cockpit graphics, these have 1 mm added to allow a final trim when fixed to the plate.

Comment
Two of the graphics had to be customised as on the prototype they both have warnings about things that can go bang or standing back and making things go bang, this could create a reluctance in a world full of OHS to professional help being available quickly.

With the Tucano having so many paint schemes and the replica being so close this technique will allow the development of graphics from any flat illustration. These are all out for printing so if it works as hoped it will be all good.


The text used is the same as on a CT4 RAF trainer seen
at the last Rylstone fly in

This was modified from graphics seen on the UK dealer Tucano
The black background was chosen over clear as it

will become very untidy over time. 

Construction is still proceeding but slow to finish at this time - lots of small issues and generally this builder shooting himself in the foot.

Friday, 20 June 2014

Bolting Guide

For full guidance on recommended practices purchase or download a copy of FAA AC43-13-1B/2A 
The "Rule of Thumb" for determining bolt length is that the bolt must be long enough to pass through the parts or material being fastened together so that:
  • The threaded part of the bolt is never in shear (no threads are allowed inside hole)
  • No more than three and no less than one thread must be showing when the nut is attached and tightened to the correct torque value
  • At least one flat washer must be used under the nut and no more than three are allowed
  • If you need more than three washers use a shorter bolt
Bolting practices:The bolts used in aircraft are about .001 to .003 inch smaller than their nominal diameter. This permits them to be installed in a properly drilled hole. The bolt should lie solidly against the surface of the material. Burrs must be removed before it is inserted and the shank (grip) should extend entirely through the hole, no threads should be in contact with the bearing surfaces, see above. Most applications with bolts require the use of a washer, use the specified type and torque to the specifications of the manufacturer.

Bolt Torquing: The following information is provided for reference when using AN grade hardware. Most of the time torque values are done to feel. But this table does provide a good outline.  
Standard torque table (in inch/lbs): Remember when installing the additional torque to drive the nylock [friction lock] must be determined and added to the recommend torque listed below
Fine thread seriesCoarse thread series
Bolt SizeStandard NutsShear NutsBolt SizeStandard NutsShear Nuts
10-3220 - 2512 - 158-3212 - 157 - 9
1/4-2850 - 7030 - 4010-2420 - 2512 - 15
5/16-24100 - 14060 - 851/4-2040 - 5025 - 30
3/8-24160 - 19095 - 1105/16-1880 - 9048- 55
7/16-20450 - 500270 - 3003/18-16160 - 18595 - 110
1/2-20480 - 690290 - 4107/16-14235 - 255144 - 155
9/16-18800 - 1000480 - 6001/2-13400 - 480240 - 290
5/8-181100 - 1300660 - 7409/16-12500 - 700300 - 420
---5/8-11700 - 900420 - 540
Reference: Standard Aircraft Maintenance Handbook. Certain standards are to be followed when installing bolts in aircraft, some of these recommendations are here:
  • Keep bolt and nuts free from grease and oil when installing and torquing
  • Always use a torque wrench to determine the torque values
  • Torque with smooth even pulls
  • To determine the bolt length, a minimum of one thread must be visible outside the nut and no more than one thread can be inside the bolt hole
  • Whenever possible tighten the nut
  • Typically you would use a bolt and a nut with a washer under the nut as bearing
  • When the bolt is too long you may use no more than three washers, but this increases weight
  • Nyloc self lock nuts should be used with un-drilled bolts, when using a drilled bolt make sure that no burrs exist. Do not use with drilled bolts smaller than AN4 [1/4'']
  • Install bolts pointing aft and to the center of an aircraft where practical
Standard nuts (amongst others) are: MS20365, AN310, AN315. Shear nuts are: MS20364, AN320, AN316, AN23-31  Source Click Here
When bolting is completed and checked mark each bolt using a splash of paint - red or yellow automotive touch up pens are ideal for this task as is nail polish.