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Old Dec 20, 2007, 05:46 PM
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The best/quickest I have found is a 60 watt hot knife ... You can get them at hardware stores sometimes .. I bought mine here at this ebay store for 33.00 shipped . Don't get the 15 -20 watters as they barely will do it and you waste a lot of time letting the tip reheat ... it needs to be over 40 watt anyhow .

hotknife

I grind the width of the exacto knife blade to about 1/8 " wide and up the blade about 3/8" to 1/2 " ,,and this allows sharper turns and also less heat loss on the tip . You can cut a plunging slot the thickness of an exacto knife blade ... remove the door .... CA the fuse and door edges to seal the fiber and then sand to an exact fit .
This works really great when you have to do compound curve areas .
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Old Dec 20, 2007, 06:01 PM
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Cool V, I'll have to see if they have one at the hobby store.

I can't believe I threw my erasing guard away, got to go see if they still carry those ancient artifacts.
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Old Dec 21, 2007, 11:06 PM
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Quote:
Originally Posted by v22chap
I too apreciate the amount of work that goes into this stuff ... My son who is a programer for Northrop Grumman aircraft company does flight sim stuff for a hobby and I have seen some of the stuff he writes to get the job done .


Keep the pix coming arb ... this should be great ,, I am just in awe of guys that can do this stuff with computer programs ... I can barely get around in them some times .... :O
Yes, the process of creating aircraft from scratch for G3.5/G4 simulator is quite time consuming especially the way I am doing it with DOS based converter and Deep Exploration but the results are worth the effort ...
It feels really good to see something done from scratch actually flying ....
As far as difficulty of above process ... it is terrible at the beginning until you make your first properly functioning model, later on, it's basically time.

I was trying to post a little video shoving retracting gear doors but there is size limit so please visit my test website and clik link below

http://groups.google.com/group/rc-mo...3-5-g4-related

I am also doing it as test if you can redirect viewers to different website, some places will not let you do that.

Next on the bench is going to be main gears.
Watching Max's video shoving retracting gears, I assume that motion is just a pivoting action around axis that is "crooked" , meaning that is at the angle in both views, side and top.

BTW, my name is Andrzej, I am originally from Poland and I will be using my name from now on ... it is just more natural to me.
Also as a part of introducing myself, I am attaching picture of me and my Great Planes Yak 54 25% just after maiden about two weeks ago.

Just in case I do not get to the Forums before ...

Merry Christmas to you all

Andrzej
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Old Dec 21, 2007, 11:31 PM
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Thanks for posting Andrzej.

You can also upload to Youtube then embed a video. I've posted this before, but I guess it's appropriate to post it here also.

The mains are at 30 degrees and retract 110+ degrees.

Gear and Gear Doors in SolidWorks
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Old Dec 21, 2007, 11:45 PM
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Shanghai
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Max,

Have you actually prototyped your main gear?. The BA609 is similiar and although I have a working model, I am not 100% stisfied with it.
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Old Dec 22, 2007, 12:18 AM
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Max,

I just tested embeding video from youtube and it worked.
From now on I will be using this way to present videos, seems to be much easier for viewers.
I was trying to erase that reply after I tested the video but I do not know how ... sorry.

Andrzej
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Old Dec 22, 2007, 07:42 AM
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Quote:
Originally Posted by shanghai_fool
Max,

Have you actually prototyped your main gear?. The BA609 is similiar and although I have a working model, I am not 100% stisfied with it.
Not yet. I hope I can get the gear doors working next week and start on the main gear by the first of the year. I'll definitely let you know how the work, they should scale pretty good. I was also thinking BA609 models when I was designing the gear.
Quote:
Originally Posted by arb6591
Max,

I just tested embeding video from youtube and it worked.
From now on I will be using this way to present videos, seems to be much easier for viewers.
I was trying to erase that reply after I tested the video but I do not know how ... sorry.

Andrzej
No problem Andrzej, linked videos are still good. I still use them if I have them on my website already and just don't want to download to YouTube.
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Old Dec 22, 2007, 08:27 AM
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Andrzej

Yes the linked to another website worked for me just fine ... and that just has to be awesome to see your work pop to life ... A few yrs back when my son was starting I played a little with just writing code to do a website ,,and even though I didn't get good at it or go far in his book ,,it was still fun to type this long string of commands and then see it pop up on the internet as my website .

Great to meet you and your two hobbies It is always nice to put a face and name to the forum names
I hope that you and yours have a very Merry Christmas and a prosperous and Happy New Year ... and the same to all the rest of you VTOLers
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Old Dec 24, 2007, 10:39 PM
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v22chap,

I know the feeling you described about programming ....
Some time ago I made few AutoLisp programs for use at work, I spent hours and hours of debugging and editing the code but the final effect was worth the effort, just a plain satisfaction that it worked what you did...

I like to see faces behind screen names because it makes the conversation more "human" if I can use this word
Before the "computer" age everybody had a name and a face ...... you know what I mean, that's why I like being not so anonymous ... they are not going to steal my SS# or my health insurance just because I showed my face under my avatar.....

I better get back to work on Max's VP-124 and post some updates.

Till soon.

Andrzej
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Old Dec 28, 2007, 02:52 AM
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Max,

Because of your inspiration, I have been working on my plug (3rd version). I do not have your CAD capabilities so I used RCad and the extremely small bitmaps to develop a reasonably close form. I added formers where the fuse changes shape or where mounting gear, etc. I then printed the sections and glued them to 1/8" balsa and then sandwiched them at appropriate spaces to 2x3" balsa blocks using carbon tubes to keep them straight and aligned. After filling in the spaces, I sanded down the blocks to the formers. So, its basically a solid balsa plug. I just need to fill and fine sand.

I wanted the plug to be the inside dimensions plus the thickness of the fiberglass skin so I will cover the plug with FG. What weight do you recommend and should I paint the plug before FG? I hope to be making the mold next week.

Donald
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Old Dec 28, 2007, 04:42 AM
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Signing on.
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Old Dec 28, 2007, 08:56 AM
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Donald
That is looking good ... and is exactly how I would have to do it also .. love that RCcad program ... does a lot for being a cheapy .
Good luck and keep us posted ..you guys are inspiring me enough I may have to try one this next time ,,balsa takes a long time to build ..and I think once the plug is made the rest would be quicker than a balsa build up .
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Old Dec 28, 2007, 10:10 AM
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Quote:
Originally Posted by shanghai_fool
I wanted the plug to be the inside dimensions plus the thickness of the fiberglass skin so I will cover the plug with FG. What weight do you recommend and should I paint the plug before FG? I hope to be making the mold next week
Donald that looks fantastic! I think about 3 oz would give it a little extra strength and should drape pretty easily over the curves. I have some of this 3.16 oz fiberglass and should work nicely. I think any "crowfoot weave" pattern in that weight should work.

Edit: I wouldn't paint it before FG.
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Old Dec 28, 2007, 07:22 PM
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What I have is 5.8 oz. that came with the M2000 kit from CST. I think that is for the mold along with the coremat to build mold thickness. I need to go shopping and I don't know how they measure that stuff here. On to my next questions.

How many layers for the fuse and how thick should I make the mold?

I suppose the first mold layer would be the fine mesh 5.8 oz since that needs the detail then build up with the coremat.

I think I have figured out how to make the opening in the mold where the wing goes and its large enough to get my hand in and with some tools, I should be able to get to the seams. The top of the fin will also be open to get to that seam. I will do like you did and wait to cut the openings for battery and gear until fuse is assembled.

EDIT: BTW, the power plane is really super for carving the square blocks down to shape.

The only epoxy I have at the moment is a 6oz size Z-POXY finishing resin. I thought I would use that for the plug. Then I have to shop for the mold epoxy. That should be fun. I looked at one store that I think sells epoxy but all the labels are in Chinese so I'm not sure what kind it is. My wife speaks Chinese but doesn't speak epoxy. Trying to figure out type, viscosity and time should be a trip.

I have never used epoxy before except as glue and only know what I have read here. I'm not sure when to put the 'gelcoat'. Probably the first thing in the mold when making the part. I am assuming that 'gelcoat' is just thinned 2 part epoxy with color pigment that is about the viscosity of paint. I don't have enough materials to make many mistakes so any suggestions will be appreciated.
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Old Dec 28, 2007, 11:40 PM
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Donald, If you put the epoxy on thick enough when you wet out the FG so you don't have to worry about sanding through the FG, I would probably just use one layer of FG on the fuse plug. It's just to keep the epoxy on the plug and from coming off in pieces when you release the mold. More wouldn't hurt, 2 if you think the plug might get abused.

The epoxy I use has a pot life or at least 30 min (temp dependant), that will give you enough working time to use what you mixed up. I use the West System 105 epoxy and 206 hardner, but any epoxy that would wet out the fiberglass should work.

The gelcoat is a THICK layer of epoxy that becomes the mold surface and is the first thing to go onto your prepared plug. The stuff I use goes on about 1/8th" thick. I think that graphite powder and colloidal silica in your kit is what you would use to thicken it. That's a neat kit, it should have that in the instructions, see what it says about the colloidal silica. I think I used too much on one of my replacement plugs. I wish I had started with a kit like that.

The rule of thumb I heard was 3 times as many layers for the mold as the number you plan on using for the part. Since the part will be 2, the mold should have at least 6, I think I used 7 or 8. Yes, the 5.8 oz would go next to the gelcoat. The coremat will build up thickness quick, so I don't know how that relates to number of layers, probably at least a couple or 3.
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