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Electric Stunt => Gettin all AMP'ed up! => Topic started by: builditright on July 29, 2019, 03:07:52 AM
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Hi all.
I have decided since the one part of model building I personally have stayed as far away from as I could and also
since the Predator has molded parts and we want / need to make sure that we got the mold bucks right I should
start there. So please bare with me.
Okay here we go...
Below are the four main fuselage and also the two leading edge mold buck/s frames.
**Please note that some parts may be adjusted or modified for the actual kit.
edit: Sorry but the first photo says balsa on it but it is actually plywood, I copied the balsa part for the buck but forgot to change the text in the file when I cut it in ply... Oops! :-[
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More pictures...
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Few more.
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What material-technique are you going to mold the pats?
Here is a stupid question. I understand that you are copying the original predator. So most likely there is a central box with the molded parts on top and bottom nose etc. My question is wouldn't it be easier to just mold two halves with parting line in the vertical plane and have a whole fuselage? With that you mold 2 parts instead of 3 and you make it easier for the end user to make the plane and eliminate most of the formers aft of the wing trailing edge.
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I used different types of foam only because I didn't had enough of each to
do them all plus I wanted to see how easily workable each one was.
Here's the turtle deck with blue foam, from start to wrapped.
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Rather than flood this post with too many pictures, so..
let me jump to the leading edge mold which is the part
that I used two different types of materials
Here I used thick styrofoam and at the wingtip end of the
one mold I used thick insulation. I got this stuff from Lowes.
It came in a 4'x8' sheet and has an outer layer that I stripped
off the foam.
I think this stuff was actually the easiest to work with when
considering that I don't have a foam cutter.
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Walter, it appears that you're doing a super job. Especially as I believe, you are doing a lot of the CAD work these days. Keep up with your usual excellent work on the Prededator.
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Here are some views of the T.E. parts and assembly
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More on the T.E.
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When I buy the kit will it have molded parts or will I have to carve the bucks from templates in the kit. I'm trying to understand what the end user has to do.
I have carved my own bucks for a leading edge sheeting just like you're doing and, as you may already know, you have to be very careful not to get the sanding board sideways and create a scoop. Mine came out ok but it was tedious work.
Thanks,
Motorman
Hi MM,
You are right; it has been somewhat tedious making the completed bucks for the molds but then again it is my 1st time making them, but then again I did not have instructions to go by. Now I do believe that I have learned a lot already by just doing them. I used a longboard sanding block plus some long thick pieces of wood as sanding blocks, so I am hoping the finished molded parts will be okay.
As far as me pre-making (molding) the parts, I am sorry to say that I don't plan to include the parts pre-molded. My thoughts here are mainly cost effectiveness because I think it would take an awful lot time on my end to make them for each kit, plus it would take a bigger or even a separate box and then a bunch of protection to prevent them from getting damaged in transit plus, there would obviously be extra postage, so basically I am not planning to pre-mold the parts for these reasons.
Because I have to still figure out what the overall cost of the kit is going to be I have not decided if I am going to include the molds with the kit or offer them as an add-on to the kit.
I hope this post doesn't change your mind about getting a kit.
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Sorry for gap in time on some pictures, we had some orders to fill.
Here's a little more on the progress.
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and some more
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and some more
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Here I am working on the inboard side.
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Here I am working on the inboard side.
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Here's more.
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More and now I flipped the wing over and a couple of last minute things I added.
A plywood doubler to one gear rib.
A basswood and plywood B.C. mount brace spanning across the first 3 main ribs on both sides
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and some more.
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here's the last of this batch, see you in a week or so.
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May I make a suggestion here?
If you added tabs to the rear side of the ribs in places where there is no LE or TE sheeting then you can make a simple plan with only the rectangular spots where the ribs go. The idea is 3M77 the plan with rib location to a building board (particle board). Glue the ribs directly in position and after that there is access to finish the whole thing including the leading edge sheeting (minus cap-strips and center sheeting on the building board side) without any additional fixtures. I hope it makes sense. For sure it will use more material but the build will be greatly simplified.
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More progress pics...
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More progress pics...
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Here's more
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more pics...
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Phew... that was a bunch.
These are the last for today.
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Hi Walt,
That is one terrific job you are working on. Lots of engineering and manufacturing decisions to
be made....great job.
One thing that has me puzzled, is how the landing gear wire is supposed to be captured in the
landing gear block.
In your photo #....161425.jpg, the landing gear wire is not clamped in anyway, and is easily
removed.
I'm wondering if the laser cut parts were intended to be assembled in a different sequence, i.e.
the LG wire being in the middle of the 3 piece sandwich, with a solid panel on either side of it.
Please see my crude sketch below for what I had in mind.
Am I missing something??
Keep up the great work, Walt....it's inspiring, and I learn a lot besides. You are a major
asset to this hobby.
Cheers.
Warren Wagner
Clay, NY
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HI Warren. The LG blocks are glued (epoxied) in place in the ply reinforced ribs, just like any other similar set up. The actual LG wire comes out of course and is held in place with a top cover. Walt just hasn't got to that point yet. I interrupted him to get some spare ribs, er extra ribs, for a trainer I am assembling. H^^
Hi Ty & Warren,
This photo was taken just after I had assembled the gear mount and inserted the gear for adjustment in the track, so basically both of you are correct. I just had not installed the cover yet. The slotted bolts were temporarily used and will not be used in the final assembly. Shorter allen head bolts will be used.
I sincerely want to thank you both (and others) for opinions and questioning me in the midst of the build. Things can always happen and I could have been saved from a very serious mistake at a point that could saved me from needing a lot of aspirin. Thank you H^^
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Hi guys...
I know it's been a long time since I've been able to make any progress on the Predator prototype
but I caught a little break from making kits this week end.
That said, here's a few photos from the past two days I have been able to work on it.
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here's a few more photos.
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here's a few more photos.
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And a few more..
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Next will be to drill the torque block and then the sheeting...
More photos to come.
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Okay guys,
Before we drill the torque blocks I thought I should fit the L.E. sheeting.
The last picture was a tough one because the inspector came in the shop.
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Okay..
Here are the torque blocks drilled out, make sure your's can be removed easily.
Afterwards I noticed that the front L.O. wire had the potential to jam if it would flip over the gear mount wing while I would
move the wing around, so I added a small piece of thin ply as a blocker/wall to help keep the L.O. wire from jamming up. why but
Okay, I don't know why but the the first two photos are rotating when expanding them, so I posted them backwards rotated to see
them correctly when expanding them.
Go figure...
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More Pics..
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More Pics..
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Okay now prepare to cut the bottom sheeting out for the gear block openings.
First I cut out the gear doors on the plan and then turned the plan upside down and then placed the cut plan piece over the wing.
If you are not comfortable with working on the back side of the plan then make a mark the back side which panel you're working with.
Either way mark the sheeting through the cut out/opening in the sheet and then carefully start cutting the gear door openings starting in the middle of the box as shown.
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Wingtips are next.. I am starting with the outboard first and will also just show it first for clarity and less confusion.
I am adding some thin ply centers to the prototypes wingtip and would really appreciate some feedback on whether
this would be a welcomed add-on to the kit since it is not already a part of the kit.
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Walter, thanks for doing this kit, should be a winner! If the thin plywood is 1/32" that would be good. I like it. At 1/16" ply maybe not so much. Plenty of holes though, either way would work out Ok.
Dave