The Aerosente Glider Workshop

The Lawrence Tech LT-IV

  

Video of the lawrence Tech IV flight 27th june 2012

flight   Here is the so long expected  video:

building the Lawrence Tech IV note 47

Hi  my friends,

 

The  Lady has made her maiden flight. She perfectly flies ! Only the balance point a little forward, best for the  first flight... She is impressive up in the air. No need  to  modify the trim positions on the transmitter  except for the elevator. I can't say  more about  my first feeling, I thought to you Tom ! you can be  proud,  the project is proved. Unfortunately the video recorder failed!!!So you' ll have to  wait for next flights. Sorry..It was  a great moment in  my modeler career.

best regards Marc

building the Lawrence tech IV note 46 and last one ?

to Tom, Mike, Annett, and all the modellers  who have followed this  topic,

I am happy to  show you the pictures of the completed Laister lawrence Tech IV. A tribute to  Tom's talent as  a designer  and  Mike's craftmanship.  The painting  time was long and interesting. All letters ,markings and scalloped patterns are painted.Only a few  details are remaining such as glueing the front part of the canopy since the balance with lead  is made and so on... The sailplane weights about 10kg so the wing loading is about 63 g/dm2. That's not too much indeed. Next step will be the maiden flight in two weeks. It was  a  nice challenge for me and  a very interesting building thread to  offer to  you. I hope following builders  will have found it useful. best regards to all from France. Wish me good luck for the first flights !

Marc

 

building the 1:3 Lawrence Tech IV note 45

Hi,

I can't resist to the  pleasure to  present  to you  another step of the completion of the LT. I have just taken the protecting papers off. The light defaults  are not yet corrected but today, the LT is really an american sailplane, don't you think so? She's got  her name  but  I won't throw  a  bottle of  champagne on  her flank  to  christen her or only in mind...I hope  you'll like her..

Marc

Answer to Annett

Thanks a lot Annett  for your comment. This project is  mainly due to Tom Martin and Mike Smock's prolific activity... Here in France, I  am happy to  complete this lovely sailplane of a famous Lawrence Tech  Institute's alumnus !.

I also  remember that the Laister Lawrence Tech IV has  flown in France in a meeting  near Paris in 1935..So, it was  a kind idea to entrust this project to  a french modeller. I will continue to post  on Aerosente  so you'll be able to  follow the completion of "Yankee Doodle"

Best regards 

Marc Hecquet  France

building the 1:3 Lawrence Tech IV note 44

Some others pictures:

 

To follow  for the next step : red and black paintings 

building the 1:3 Lawrence Tech IV note 43

Hello ,

 The Laister Lawrence Tech  IV  is  almost  completed. Finishing step is well advanced. I have  chosen this  blue  and  decided  to paint  the  wing root fairing   wholy in blue.The  red  colour ( on wings, rudder, elevators  and fuselage)  remains  to  be  placed as   welll as  the  black one ( letterings  and  numbers; The canopy in two parts is completed. the front part is not fixed for I haven't put the lead for balance in place  under the  panel instrument. Anyway, I hope you'll be pleased  to  see  her  at  ths  step

best regards   Marc 

 

building the 1:3 Lawrence Tech IV note 42

Finishing step  has begun. The LT has received her white satin cloth, (car  quality paint) . Thanks to my friend Richard. next step will be long and delicate, much masking tape has to be placed for scalloped patterns, stripes, markings and so on in blue, red and black:

building the 1:3 Lawrence Tech IV note 41

Covering step completed:

building the 1:3 Lawrence Tech IV note 40

hello Tom, Mike and  all aeromodellers,

Here are the last pictures  after  an interryuption due to a cold workshop and other troubles..

The covering finishing step  is almost completed. I had  to  cover the top again because unsatisfied  but this will give you an idea. You will notice the fine shape of the rudder whose design I like very much and  the  presence of the fuse with apparent stringers  and the long  wings. I dress up the lady outside when covering is finished  .

best regards  Marc

 

building the 1:3 Lawrence Tech IV note 40

hello Tom, Mike and  all aeromodellers,

Here are the last pictures  after  an interryuption due to a cold workshop and other troubles..

The covering finishing step  is almost completed. I had  to  cover the top again because unsatisfied  but this will give you an idea. You will notice the fine shape of the rudder whose design I like very much and  the  presence of the fuse with apparent stringers  and the long  wings. I dress up the lady outside when covering is finished  .

best regards  Marc

 

building the 1:3 Lawrence Tech IV note 39

Some finishing steps work pictures: Airbrakes  are set up. I made a new nose , the previous one didn't have the correct shape. It is  plain balsa now, like expected by Tom. It is covered  with fiber glass cloth. The tow release system is included in it, as  well as 300g g extra lead  for  balance. I built  an  hinged  canopy. R/C elements are settled, ( 15kg torque servos for release and rudder) everything is hidden when seat  and panel instruments are  installed.

Merry Christmas and a Happy New Year to everyone. Good flights in 2012l

Marc

 

building the 1:3 Lawrence Tech IV note 38

Hi friends, here are  the last pictures of the building. The wooden Lady is completed. Next step : covering and painting. I send you a hello from France, the last picture is showing the vintage and the modern, only 60 years between these two gliders, the Laister Lawrence tech IV and the Ventus 2CX. ( I like  new sailplanes too !!)

The best to all of you:

 

 

building the 1:3 Lawrence Tech IV note 37

I am busy with the long and not very spectacular step : planking wings, ribs caps and gussets,airbrakes..but here is what a LT IV should look like, I guess, much work is remaining before maiden flight..:

building the 1:3 Lawrence Tech IV note 36

I started  to plank wings with 0,6mm plywood.As the wings are covered and painted, I have chosen to  build a false balsa leading edge and to place  plywood panels instead  of  wrapping the whole front part of wings as I usually do on plywood varnished models. This method will be faster. A hard  wood leading edge   will be installed after planking. Where panels join, I placed   extra ribs to  increase glueing surface . The panels are not simply placed side by side  , their edges are sanded to allow them to be slightly superposed on about 3mm, see pictures.It 's important  for wings strength and reaction in the air. There will be 20 panels for a wing. ,top and bottom. At the curvature, the panels are  narrow  to  keep the smooth curvature and the right shape of the wing.

building the 1:3 Lawrence Tech IV note 35

The ailerons have been completed. I have assembled  the gull winged LT IV  on my favourite airfield.

She looks  great indeed. Next  step, planking of the wings...

 

 

building the 1:3 Lawrence Tech IV note 34

The ailerons are being built. The basic structure  is  built along the trailing edge  of the outer panels of  wing.So all ribs come face to face and the  whashout naturally comes  with a 3mm wedge under rib 42. A 3mm vertical grain  balsa infill  is glued  against 3mm spars.  Then the structure receives  the  balsa trailing edge which is sanded  to  shape ( 3mm balsa infill between 2  0,6mm plywood strips) Tip blocks  are  added  and  sanded too and planked  with 0,6 plywood. I have added  diagonal ribs that ere  not featured on Tom's drawings  but  he will add them later  for we have a document showing it. Anyway this  will give stiffness  to  the ailerons

 

Next step, glueing the balsa leading edge of the ailerons, plywood parts on TE and LE, gussets ,caps and  hinges

Getting Busy - It's That Time of Year

Shipped six kits today. It's that time of year - build season - our busy season.

building the 1:3 Lawrence Tech IV note 33

The work on the outer panels is well advanced. No need to use the plan. I first glued the rear ribs on the spar using a square and the I glued the tail of the ribs on the TE using a template that gives equal distance. The trailing edge of these panels is made with 2 3x3mm spars glued on strips of plywood (0,6mmx11mm) that protudes about 3mm to provide a gap for the aileron leading edge. A 3mm balsa strip joins the spars between ribs and there will be also a 3mm balsa infill with vertical grain between the spars; The ailerons will be built in the same way in the prolongation of the outer panel with a 1,6 ° washout along their trailing edge.

building the 1:3 Lawrence Tech IV note 32

The work on the wings is going on ,Tom, and your dream to  see the wings on the fuse is progressively coming true !

I have built the inner panel flat and  square to  the jig without any difficulty ( ribs 1 to 14), everything fits well. Some adjustment  on the drag  spar is necessary to fit  correctly with all ribs ( 2 to 8) Don't forget ( as Idid first !) to drill a hole on its  end to allow a passage for radio wires. I have made some minor modifications of my own such as  the  rib 18 which has  been doubled  with  1mm plywood. The root junction aileron  is often a weak area. The trailing edge is made  with  two strips of 0,6mm plywood, 12mm wide, and  a  balsa infill to  provide the good shape. You will notice the nice curved shape  that  the trailing edge naturally takes   (ribs 14 to 18) I will add  triangular piecs to reinforce the glueing of  all rear ribs to the spar.

building the 1:3 Lawrence Tech IV note 31

 
The work has  begun with the last step of the  building : the wings. The spars  had  already been built as  you have seen. I first verified  the right  junction of the 2 first root ribs with the fuse  and  placed the incidence indexing parts. Then I glued  all the front ribs ( w1 to w44) with the spar  flat on the jig. No problem except I forgot to shape the  top and bottom spar caps to  the right depth at the extremity  but this  can be done later. I verified  the good  alignment of the ribs  by tracing  a  data line on the spar and with a stick as a false leading edge when glue  is drying and then glued  the definitive leading edge. The result is nice to look at. i like  the smooth  curve of the  gull wing.

building the 1:3 Lawrence Tech IV note 30

First coming out fot the LT, the work on the wings is about  to  begin. The canopy is not the definitive one Some  pictures  to  admire this  beauty and her generous shapes:

building the 1:3 Lawrence Tech IV note 29

 
I have  completed  the karman, this was  rather long to shape correctly , drawing  templates  was  necessary (one for the intermediate rib  and one for the fuse junction )  here is the result :

 

building the 1:3 Lawrence Tech IV note 28

I have begun to plank the wing /fuse junction with 0,6mm plywood. The remaining gap will be filled  with carved  balsa due to the rounded  shape. A rib  template  has been made to verify the junction to the fuse, it will be cut in 0,6mm plywood to support balsa and  allow neat shaping:

This is the most delicate work on the fuse to obtain a nice shape..next steps are  the positionning of the canopy, radio wires , lead in the nose and  glueing the fibre nose .Then the fuse will be ready to be covered. End of the job on the fuse  which is, according to me, the  biggest part on the LT construction