Dalotel Build
12-08-2012, 01:53 PM
#1
Dalotel Build
A week or so ago I posted asking the question if a Dalotel would be considered a classic pattern airplane or not. I got a bunch of responses giving me support for the project so I drew up some rough plans and have begun the build. The first step was to clean up some old cowl molds and lay up a cowl. I am going to make the build as detailed as I can so I have detailed the lay up process. First pic is plans with the cowl mold.
12-08-2012, 02:06 PM
#3
RE: Dalotel Build
Once the PVA has dried we are ready. I first cut a cloth kit. The first layer is a 2 oz Crowsfoot cloth. This cloth has a fairly tight weave, will add some strength but not much. It is mainly used as a surface layer to reduce pinholes. The second layer is an 8 oz plain weave cloth. This will be the bulk of the strength and the final layer. The front of the cowl has some details that the cloth will not be able to negotiate. An application of paste made from epoxy and cab-o-sil softens the corners so the cloth can flow smoothly. This is followed by the first nose layer.
12-08-2012, 02:10 PM
#4
RE: Dalotel Build
Then the main portion of the 2 oz cloth is applied followed by the 8 ozlayer. At this point I like to blot the excess resin out with a paper towel. After the two halfs have cured, they are popped out of the molds and joined together. Now I have a cowl and can start sizing the firewall.
12-09-2012, 10:55 AM
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RE: Dalotel Build
Thanks for posting. I will be watching with interest.
Are you going to run the pipe inside like Chip had on his Hanson Dalotel?
Doug
12-09-2012, 11:13 AM
#10
RE: Dalotel Build
Doug, yes the pipe will be located in a tunnel at the fuse bottom. If you look at the plan picture you will notice the wing has been moved up to accomidate this. I am fortunate enough to have access to a co-worker that can weld up any header I may need. Not sure it will be fully enclosed but should be close.
12-09-2012, 11:38 AM
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RE: Dalotel Build
SRT,
nice build you've got going here!
Doug,
SRT's Dalo build looks like it will be very similar to our Chippy build in terms of planform and moments. Our model will just be a tad larger.
It looks like the engine will be inverted and setup with the pipe in a similar way to most of Hanno's post Magic designs (and many of the later Japanese classics) in a tunnel under the wing. Well, the Calypso and Supra's were low wing so no tunnel but the same concept. Actually, Hanno's Mystic might be the best "equivalent" in setup. With the Dalo being a pretty square type design (square as in angular), going with a rectangular type tunnel recess in the fuse bottom, Bridi Dalo style, is not a bad option. Of course, e-power (comment tailored to Doug specifically...
) would simplify all that. It looks like even the wing/stab airfoils are similar to the ones we'll be using, pronounced LE entrance...
The Dalo is another ideal e-power model! Maybe in a years time when the Chippy's are done...
Following with interest!
David
nice build you've got going here!
Doug,
SRT's Dalo build looks like it will be very similar to our Chippy build in terms of planform and moments. Our model will just be a tad larger.
It looks like the engine will be inverted and setup with the pipe in a similar way to most of Hanno's post Magic designs (and many of the later Japanese classics) in a tunnel under the wing. Well, the Calypso and Supra's were low wing so no tunnel but the same concept. Actually, Hanno's Mystic might be the best "equivalent" in setup. With the Dalo being a pretty square type design (square as in angular), going with a rectangular type tunnel recess in the fuse bottom, Bridi Dalo style, is not a bad option. Of course, e-power (comment tailored to Doug specifically...
) would simplify all that. It looks like even the wing/stab airfoils are similar to the ones we'll be using, pronounced LE entrance...The Dalo is another ideal e-power model! Maybe in a years time when the Chippy's are done...
Following with interest!
David
12-09-2012, 04:10 PM
#12
RE: Dalotel Build
I managed to get the fuse sides and doublers seamed and cut. The next step is to laminate them together. I will be using epoxy for this so I can add some CF tow between the sides and doublers. I just need to break out the bagging equipment and supplies.
12-09-2012, 05:30 PM
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RE: Dalotel Build
SRT,
Does the Partall and PVA work the same regardless of whether the glass is laid up on a male plug rather than a female mold?
I'm planning to lay up a single piece glass cowl atop a male plug made of foam and ply, glassed and then painted to smoothness. Would the PVA attack the paint? I assume the wax wouldn't.
David
Does the Partall and PVA work the same regardless of whether the glass is laid up on a male plug rather than a female mold?
I'm planning to lay up a single piece glass cowl atop a male plug made of foam and ply, glassed and then painted to smoothness. Would the PVA attack the paint? I assume the wax wouldn't.
David
12-09-2012, 05:52 PM
#16
RE: Dalotel Build
David, yes the wax and PVA will work for that application. Make sure that the wax you use is compatable with the PVA. Both products I have pictured are made by the same company. The nice thing about making a part off a male mold is that you can sand the part smooth before removing from the mold.
12-09-2012, 06:14 PM
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RE: Dalotel Build
Good stuff.
I made a "pull tab" cut into one of the ply plug formers with the idea that once the layup has cured, I could simply pull the plug out of the cowl bottom. Is some "wiggling" usually required with the wax and PVA or will the cowl simply slip off the plug?
I also want a light but firm part. I plan to put a couple of lite ply rings at either end, the front to provide a little thickness and a contour to open the front to (I realize this one is usually not needed) and the rear to keep the shape and provide a flush mount point to the fuse (possibly with magnets but likely screws). I was thinking two layers of 2oz cloth followed by a top layer of 3/4 oz to close the weave. How does that sound?
David
I made a "pull tab" cut into one of the ply plug formers with the idea that once the layup has cured, I could simply pull the plug out of the cowl bottom. Is some "wiggling" usually required with the wax and PVA or will the cowl simply slip off the plug?
I also want a light but firm part. I plan to put a couple of lite ply rings at either end, the front to provide a little thickness and a contour to open the front to (I realize this one is usually not needed) and the rear to keep the shape and provide a flush mount point to the fuse (possibly with magnets but likely screws). I was thinking two layers of 2oz cloth followed by a top layer of 3/4 oz to close the weave. How does that sound?
David
12-10-2012, 02:03 PM
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RE: Dalotel Build
ORIGINAL: speedracerntrixie
You will have to pull them apart. Sometimes it is possible to get a corner started and then shoot some air in the gap to blow off the part.
You will have to pull them apart. Sometimes it is possible to get a corner started and then shoot some air in the gap to blow off the part.
Thanks, I thought that technique might work.
I managed to dig up the old Dalo plans I have been working over but haven't touched in a while. Originally they were 60 size and had some features which I found a little complex and perhaps unnecessary so I changed things a bit. I then scrapped the glow power idea and decided that I was interested in a TOC size (i.e., 90-120) electric version which led me to closing up the fuse bottom and going with plug-in wings as well as a removable canopy section. There were a lot of CAD details which I needed to clean up (probably due to different software interpretations of the drawings) and I didn't quite get finished on the fuse plans. The wing plan ought to be good to go. The airfoils used here are quite different from the airfoils you will be using.
Below are the scaled down plans for the "proof of concept" 30 size model. The TOC version would be the same in design with slight mods to wood sizing and whatever else I decided would be beneficial and learned from the 30 size model. The TOC version would be a 136% scale up from the 30 size or 6' in span.
I thought you might find them of interest.
David
12-10-2012, 02:48 PM
#20
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RE: Dalotel Build
ORIGINAL: doxilia
Good stuff.
I made a "pull tab" cut into one of the ply plug formers with the idea that once the layup has cured, I could simply pull the plug out of the cowl bottom. Is some "wiggling" usually required with the wax and PVA or will the cowl simply slip off the plug?
I also want a light but firm part. I plan to put a couple of lite ply rings at either end, the front to provide a little thickness and a contour to open the front to (I realize this one is usually not needed) and the rear to keep the shape and provide a flush mount point to the fuse (possibly with magnets but likely screws). I was thinking two layers of 2oz cloth followed by a top layer of 3/4 oz to close the weave. How does that sound?
David
Good stuff.
I made a "pull tab" cut into one of the ply plug formers with the idea that once the layup has cured, I could simply pull the plug out of the cowl bottom. Is some "wiggling" usually required with the wax and PVA or will the cowl simply slip off the plug?
I also want a light but firm part. I plan to put a couple of lite ply rings at either end, the front to provide a little thickness and a contour to open the front to (I realize this one is usually not needed) and the rear to keep the shape and provide a flush mount point to the fuse (possibly with magnets but likely screws). I was thinking two layers of 2oz cloth followed by a top layer of 3/4 oz to close the weave. How does that sound?
David
The cured epoxy will no stick and it pops right off with minimal effort. But before you pop it off, sand it and prime it at least.
As you suggested, 2 layers of 2 oz with a top coat of 1/2 oz will produce a reasonable outcome. It will be heavier than necessary but would be hanger rash proof too. Vintage models only need maybe 1 layer of 2 1/2 oz and maybe 1 layer of 1/2 oz as fill for canopies or chin cowls. Some strips of balsa layed inside maintain the shape. You can get a little fancy if you want by laying the second layer on bias. Produces more stability over time, but isn't absolutely necessary
I make fairly large canopies for the EF 78" Extra for example. Not apples to apples since mine is a cavity mold but it is close in comparison. The canopy is laid-up with 1 layer of 1/2 oz as fill and 1 layer of 3 oz, close weave glass. This is very large compared to vintage canopies, about 9" wide, 19" long and 7" deep. I lay in balsa strips to hold the shape while the canopy is curing. The cavity mold also allows me to shoot the primer first into the mold. The ready primed and otherwise readyto install canopy comes in at less than 5 ozs. Balsa-glass composite done this way, is surprisingly stiff and strong but super light
12-10-2012, 03:21 PM
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RE: Dalotel Build
ORIGINAL: MTK
Suggestion... If you have the male mold ready but not quite finished yet, you can do a quick finish job with adhesive backed Teflon tape. Just stick it to the male mold, smoothing as you add more pieces. For simple molds, I use 2'' wide material and for more complicated, I use 3/4'' wide, striping the tape if you will. You want a reasonable surface underneath that won't telegraph too much
The cured epoxy will no stick and it pops right off with minimal effort. But before you pop it off, sand it and prime it at least.
Suggestion... If you have the male mold ready but not quite finished yet, you can do a quick finish job with adhesive backed Teflon tape. Just stick it to the male mold, smoothing as you add more pieces. For simple molds, I use 2'' wide material and for more complicated, I use 3/4'' wide, striping the tape if you will. You want a reasonable surface underneath that won't telegraph too much
The cured epoxy will no stick and it pops right off with minimal effort. But before you pop it off, sand it and prime it at least.
I don't want to take this fine Dalo build down a turn with my questions but I appreciate the reply and suggestions. I can appreciate wanting to sand the part on the male plug but what's the need to prime it at that point? I was considering laying up 2-3 in a row one after another and then paint them at a later point in time.
The part I have in mind is a small conical shaped cowl. The plug would be made from a frame of lite-ply filled in between with white foam sanded to contour. I take it no glass or paint on the plug itself is needed if I stick on some Teflon tape? That would save some time... Do you have a link for the Teflon tape stuff? I know plumbers use it but it's not the sticky backed kind.
David
12-10-2012, 04:06 PM
#22
RE: Dalotel Build
David, thanks for sharing the plans. I'm sure I will use some bits and peices. Not too much to show today. My time tonite will be setting up for some laminations. I need to set up a couple glass plates that will support the fuse sides ( I will be doing the firewall and fin parts too ). Then I will simply put a single layer of plastic that is sealed to the glass and pull vacuum. Should be able to do that tomorrow or the next day. Obviously will post some pics of the process.
12-12-2012, 02:22 PM
#23
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RE: Dalotel Build
ORIGINAL: doxilia
Matt,
I don't want to take this fine Dalo build down a turn with my questions but I appreciate the reply and suggestions. I can appreciate wanting to sand the part on the male plug but what's the need to prime it at that point? I was considering laying up 2-3 in a row one after another and then paint them at a later point in time.
The part I have in mind is a small conical shaped cowl. The plug would be made from a frame of lite-ply filled in between with white foam sanded to contour. I take it no glass or paint on the plug itself is needed if I stick on some Teflon tape? That would save some time... Do you have a link for the Teflon tape stuff? I know plumbers use it but it's not the sticky backed kind.
David
ORIGINAL: MTK
Suggestion... If you have the male mold ready but not quite finished yet, you can do a quick finish job with adhesive backed Teflon tape. Just stick it to the male mold, smoothing as you add more pieces. For simple molds, I use 2'' wide material and for more complicated, I use 3/4'' wide, striping the tape if you will. You want a reasonable surface underneath that won't telegraph too much
The cured epoxy will no stick and it pops right off with minimal effort. But before you pop it off, sand it and prime it at least.
Suggestion... If you have the male mold ready but not quite finished yet, you can do a quick finish job with adhesive backed Teflon tape. Just stick it to the male mold, smoothing as you add more pieces. For simple molds, I use 2'' wide material and for more complicated, I use 3/4'' wide, striping the tape if you will. You want a reasonable surface underneath that won't telegraph too much
The cured epoxy will no stick and it pops right off with minimal effort. But before you pop it off, sand it and prime it at least.
I don't want to take this fine Dalo build down a turn with my questions but I appreciate the reply and suggestions. I can appreciate wanting to sand the part on the male plug but what's the need to prime it at that point? I was considering laying up 2-3 in a row one after another and then paint them at a later point in time.
The part I have in mind is a small conical shaped cowl. The plug would be made from a frame of lite-ply filled in between with white foam sanded to contour. I take it no glass or paint on the plug itself is needed if I stick on some Teflon tape? That would save some time... Do you have a link for the Teflon tape stuff? I know plumbers use it but it's not the sticky backed kind.
David
Try McMasterCarr http://www.mcmaster.com/#76475A34or http://www.mcmaster.com/#76475A35. Yes the tape is a little pricy and possibly beyond what you wanted to spend. You may request a sample from some folks like St.Gobain who make the material.
BTW, this isn't plumber's tape. Plumbers may not release the way you want because it is porous, expanded PTFE (Teflon)
If you wanted to do several parts from a mold, then maybe a cavity type is the better way to go. That's much of what I do even if I pull only one part. The prep work is a bit heavy but the final outcome requires comparatively little work to finish.
12-12-2012, 05:49 PM
#24
RE: Dalotel Build
I found the time to do some laminating today. The fuse sides were masked with some scrap trim Monokote where I did not want epoxy. Then a thin layer of epoxy was spread out on some craft paper. The fuse side was layed on top of the epoxy and then carefully removed. The result was a thin film of epoxy on the fuse side and no epoxy where I didn't want it. The fin is 5/32 thick Nomex honeycomb with 1/16 basla skins and the firewall is a couple laminations of 3/32 ply. Last pic shows all the peices in the bag with peel ply top and bottom after vacuum is pulled. This will make for very strait parts.