Pieter Visser

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Re: Pieter Visser

Postby Pieter001 » Thu Jan 11, 2018 9:01 am

I did the strengthening of the rudder attach points today, as well as cutting carbon for the elevator pulley bracket and the aileron bell crank brackets.

For the rudder attachment points I decided to use 5 layers 300gr bi-ax carbon for the upper and lower area and finished the job with peel ply. To ensure that the parts cure at the correct angle, I put packaging tape over the peel ply and then fit the LH fin skin. I've already done the trail fit a couple of days ago when I glued on the RH fin skin.

The carbon is a great product to work with, I love it! I opt to wet out the piece of cut cloth on a piece of paper (much like wax paper) on both sides and then to place it in position, using a brush to "stab" it into all the corners and areas. I also use a little composite roller tool every couple of layers to roll out any air bubbles there may be, as well as excess resin. The excess resin can only be rolled out by rolling in one direction to the outer edge of the carbon cloth and by applying a good bit of pressure. I do the same once I've applied and smoothed the peel ply. The result I get using this method is fantastic in my opinion, but I'm not an expert by any means.

One learns a lot of things building your Whisper, not only about composites, resins and tools, but also about one self ;)

20180111_190334.jpg
bottom rudder attach point - 5 layers carbon 300gr bi-axial complete with peel ply
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20180111_190344.jpg
top rudder attach point - 5 layers carbon 300gr bi-axial complete with peel ply
20180111_190344.jpg (297.5 KiB) Viewed 75 times

20180111_190435.jpg
made a template for elevator pulley hole and drilled the corners
20180111_190435.jpg (206.94 KiB) Viewed 75 times
Last edited by Pieter001 on Thu Jan 11, 2018 10:24 am, edited 3 times in total.
Pieter001
 
Posts: 181
Joined: Wed Jul 03, 2013 7:03 pm
Location: Heidelberg GP

Re: Pieter Visser

Postby Pieter001 » Thu Jan 11, 2018 9:03 am

20180111_190854.jpg
Packaging tape over wet resin to fit RH fin skin
20180111_190854.jpg (212.5 KiB) Viewed 74 times

20180111_192902.jpg
RH fin skin fitted for the cure using screws
20180111_192902.jpg (214.56 KiB) Viewed 74 times
Pieter001
 
Posts: 181
Joined: Wed Jul 03, 2013 7:03 pm
Location: Heidelberg GP

Re: Pieter Visser

Postby Pieter001 » Sat Jan 13, 2018 4:00 am

Glued the bronze wing pin bushes onto the rear spar plank, so not a big work day, but at least something was done ;)

The flange areas of the bushings are put against each other for this clamp and cure to put pressure on the busing when the planks are clamped. The front plank and bushings was already glued earlier, so the areas and wing bolts were waxed up proper to ensure that nothing gets stuck together that should not be.

PS: The best course of action here is to glue the bushes with the entire assembly set. Doing it the way I did here resulted in my bush being off by around 0.8mm, which is not too much, but a pain to get the wing bolt through all the bushes now :cry:

20180112_172338.jpg
Leveled the planks and clamped them to cure
20180112_172338.jpg (190.81 KiB) Viewed 67 times

20180112_172400.jpg
The wing bolts have to be level too
20180112_172400.jpg (167.8 KiB) Viewed 67 times
Last edited by Pieter001 on Fri Jan 19, 2018 7:36 am, edited 1 time in total.
Pieter001
 
Posts: 181
Joined: Wed Jul 03, 2013 7:03 pm
Location: Heidelberg GP

Re: Pieter Visser

Postby Pieter001 » Sat Jan 13, 2018 10:19 am

Made hard board templates for the aileron bell crank and the rudder pulley. Then cut a section of polystyrene for the pulley bracket and made a carbon layup: 11 layers 300gr bi-ax carbon.

Before the 12th layer, the resin started gelling, so I stopped on 11, but this is one SERIOUS layup! Rolled out the excess resin, using a roller occasionally and after I applied the last layer of peel ply (started with a layer of peel too).

I believe 11 will be sufficient, I have no doubt! Carbon is generally 2x the strength of E glass, so this bracket is going to be a beast!
20180113_195937.jpg
Polystyrene pulley bracket template cut and lines indicate where the layup is to go
20180113_195937.jpg (156.18 KiB) Viewed 64 times

20180113_210906.jpg
11 layers carbon 300gr bi-ax finished with peel ply and air- and excess resin rolled out
20180113_210906.jpg (268.07 KiB) Viewed 54 times
Last edited by Pieter001 on Mon Jan 15, 2018 1:11 am, edited 3 times in total.
Pieter001
 
Posts: 181
Joined: Wed Jul 03, 2013 7:03 pm
Location: Heidelberg GP

Re: Pieter Visser

Postby Pieter001 » Mon Jan 15, 2018 12:51 am

This morning I handed in the bronze wing bolt bushings to be shortened, both to a length of 101mm. I should be able to pick them up sometime this week, which means I will start cutting glass to do the layups of the carry through spar :)

Not done much else... did extend the cut lines of the elevator pulley bracket, which I still need to cut and then start shaping and cutting the final 2 brackets.

PS: Bronze bushing was cut to 103, after I read rather too than too short, but turns out they are indeed 2mm too long now :cry: Lesson is to trust your measurements, so I live and learn. I am considering trimming then down, but that will take another week and R230 per bush :shock: NZ is really expensive compared to SA. I may just grin and bear, or buy a lathe!
Attachments
20180115_114947.jpg
Silver coloured marker used to extend the cut lines on to the peelply
20180115_114947.jpg (156.53 KiB) Viewed 55 times
Last edited by Pieter001 on Fri Jan 19, 2018 7:37 am, edited 2 times in total.
Pieter001
 
Posts: 181
Joined: Wed Jul 03, 2013 7:03 pm
Location: Heidelberg GP

Re: Pieter Visser

Postby Pieter001 » Mon Jan 15, 2018 7:16 am

Setup the angle grinder with a 1mm steel disk on the workbench at the correct height to cut the elevator pulley on the silver cut lines I've drawn. Once this was done, I removed the foam and pulled off the bottom layer of peel ply to get the part material free.
The general rule of thumb for 300-400gr bi-ax is 0.5mm for each layer. The material thickness measures 5.6mm for the 11 layers ;)
20180115_172601.jpg
Clamping the angle grinder at the correct height to make straight cuts
20180115_172601.jpg (293.58 KiB) Viewed 51 times

20180115_180218.jpg
Foam and bottom peel ply removed with the vernier showing the material thickness
20180115_180218.jpg (271.84 KiB) Viewed 51 times
Pieter001
 
Posts: 181
Joined: Wed Jul 03, 2013 7:03 pm
Location: Heidelberg GP

Re: Pieter Visser

Postby Pieter001 » Tue Jan 16, 2018 1:40 am

To make the elevator bracket the simplest way was to take the bracket drawing and to get it resized to the correct scale through trial and error. Then cut the out the template, which I changed slightly to make it simpler and it will add a bit more strength where the alu parts did show hairline cracks. This carbon part is already over engineered, but the cutting is going to be simpler too.
Then rough cut the two parts with the angle grinder. The template was used to mark the drill holes, which I drilled into one part, making sure the pulley and pins won't foul. I then lined up the parts back to back and clamped them together to drill the holes into the second part. Only 4mm drill bit used for this. Now all that is left is to sand the parts on the belt sander while bolted together.

20180116_122514.jpg
Correctly scaled drawing to cut paper template to transfer onto the carbon sections
20180116_122514.jpg (175.14 KiB) Viewed 40 times

20180116_122739.jpg
Drilled holes from template and transferred to both parts while clamped and now bolted together for final sanding
20180116_122739.jpg (164.9 KiB) Viewed 40 times
Pieter001
 
Posts: 181
Joined: Wed Jul 03, 2013 7:03 pm
Location: Heidelberg GP

Re: Pieter Visser

Postby Pieter001 » Tue Jan 16, 2018 11:31 am

Done the shaping ;) Now need the AN5 bolts to complete this job. I will need a slightly longer bolt as my layup is thicket, so AN5-22 should work well.
Attachments
20180116_192127.jpg
Elevator Pulley bracket completed and in need of AN5 hardware to complete the installation
20180116_192127.jpg (188.17 KiB) Viewed 36 times
Pieter001
 
Posts: 181
Joined: Wed Jul 03, 2013 7:03 pm
Location: Heidelberg GP

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