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Very Hot Topic (More than 25 Replies) DeHaviland Canada Dash 8-300 (Read 34810 times)
thymekiller
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Re: DeHaviland Canada Dash 8-300
Reply #22 - Jan 18th, 2011 at 6:33pm
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Adding depth to the nose block might make handling it a bit easier. Good idea.
  

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Sky9pilot
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Re: DeHaviland Canada Dash 8-300
Reply #21 - Jan 18th, 2011 at 3:44pm
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thymekiller wrote on Jan 18th, 2011 at 6:52am:
Excellent work on the props Tom. Truly. The whole plane is great, but I am in awe of those props.  Shocked  First rate work. My fingers are crossed for you.
Are they mounted straight ahead? I bookmarked a good thread on prop angles on twins over at HP. Hollar if ya' need it.
I think you are building the first twin on this site. I'm rootin' for ya'


Thanks Thyme...
The plans call for 2 degrees positive (up angle) on the wing as attached to the fuselage.  The nacelles will have 4 degrees negative (down angle) incidence when attached to the bottom of the wing.  The noseblocks will have approximately 1 degree negative down thrust giving me a total of 3 degrees down thrust.  With the counter rotating props there's suppose to be no need of off set to counter tork.  This is all proposed. Execution will determine what trimming will be necessary when it comes down to testing.  

Had to add a spacer to the nacelles to clear the intake at the bottom of the nacelles so I'm reworking the nose of the nacelles.  Looks like I'll build the spacer into the nose block instead of the nacelle so they will come off with the noseblock prop hub and prop.  Here's the latest pics of the corrections and fixes...

Thanks for your interest...
Tom
« Last Edit: Jul 12th, 2017 at 1:24am by Sky9pilot »  

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If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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thymekiller
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Re: DeHaviland Canada Dash 8-300
Reply #20 - Jan 18th, 2011 at 6:52am
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Excellent work on the props Tom. Truly. The whole plane is great, but I am in awe of those props.  Shocked  First rate work. My fingers are crossed for you.
Are they mounted straight ahead? I bookmarked a good thread on prop angles on twins over at HP. Hollar if ya' need it.
I think you are building the first twin on this site. I'm rootin' for ya'
  

",,,The road goes on forever, and the party never ends..."
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Re: DeHaviland Canada Dash 8-300
Reply #19 - Jan 18th, 2011 at 12:52am
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Thyme,

I did order some sticks from Alan back when I was building the Koutney birds.  They are great.  You're right about him being a good builder.  Gonna have to build a Javelin I guess to see how it flies.

Well, I've made a bit more progress on the Dash 8 ...Counter rotating props with Laribee profile.

Had to make some revisions on the nacelles to clear the props.

 Made the tube in a tube free wheeling setups and filed the right and left hand ramps for the props.  

I had some challenges with the ramps. I mockedup both props to check the setup and see how they looked.  Then disassembled them to prep for soldering.  Got them all back together soldered and noticed that the tip tube with the ramps were on the wrong prophubs.  So with a bit more heat and needle nose pliers this was quickly rectified.
The nacelles need some more work and the wings is just balanced on the fuselage so the angle is off in the pictures.  This will be fixed when I get ready to attach the wing.  

Tom
« Last Edit: Jul 12th, 2017 at 1:21am by Sky9pilot »  

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If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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thymekiller
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Re: DeHaviland Canada Dash 8-300
Reply #18 - Jan 17th, 2011 at 6:27am
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  You are very welcome. You are doing very well.
 
  I noticed on more than one occasion you have mentioned brittle wood. Where are you getting your wood? I have found that light weight wood and strong wood don't necessarily correspond. Have you considered buying wood from Alan Cohoen? I bought a couple "sample packs " and WOW is it different than what I can get from Hobby Lobby. Its not to expensive and worth every penny. It comes marked for weight and the pieces are uniform in strength. By that I mean that all the blue tipped sticks bend and break the same. No weak spots which brings with them "Surprises".  He also sells laminating strips. I haven't tried them yet but I will soon. The man is a fanatic about balsa wood and good wood makes a difference. I recommend buying at least one sample pack. At the least, you can hold each different density in your hand, one at a time and compare side by side. It was an eye opening experience for me. You can contact him via HP. He is a great guy to deal with. He is also an excellent modeler.
  

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Re: DeHaviland Canada Dash 8-300
Reply #17 - Jan 16th, 2011 at 6:44pm
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thymekiller wrote on Jan 16th, 2011 at 3:48pm:
Nice work Tom. Thanks for the pics. They help a lot.

Thanks Thyme... Grin Wink Cool
  

If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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Re: DeHaviland Canada Dash 8-300
Reply #16 - Jan 16th, 2011 at 3:48pm
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Nice work Tom. Thanks for the pics. They help a lot.
  

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Re: DeHaviland Canada Dash 8-300
Reply #15 - Jan 15th, 2011 at 10:21pm
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Hi all,

I decided to show you how I plunge my spinners from plastic.  The plastic is from the plastic picnic plates from Dollar Tree Store locally.  Here's the stuff (that's a technical name for the various tools and supplies used to make the spinners).  I made the mold from 1/4 balsa discs cut with a circle cutter.  I laminate these together and then glue the discs on a barrel sander attachment for hand drills. It's 1/2 inch diameter.  I glue the disc on with CYA in 4 spots for easy removal after sanding.   Once sanded I mount it on a bamboo skewer and hold it in a clamp so the heated plastic plate can be plunged over the mold and held down till it cools Shocked you must move quickly.  I heat the plastic plate with a Monokote heat gun I have from my RC days. Heat the plate till the plastic begins to sag.  Depending on the size of the mold, make sure you heat enough of the plastic to cover the mold.  If it doesn't work...fret not! just re-heat and plunge again.
Here's the picture of the stuff.  I should have shown a new plate because I had already made six or seven spinners already so the plate is worse for wear Roll Eyes Shocked Grin...

Here's how the spinner is trimmed...leave it on the mold and using a single edge razor blade carefully start the cut and gently move around the mold keeping the blade flat on the bottom of the mold...

Here's the finished spinner on the mold...just pop it off and heat some more plastic plate...as you can see the plate can make several spinners or whatever else you're molding as long as you can hold on to the plastic plate or whatever is left of it...

I always make extra because you never know when you can use it for something else or you mess up one you've got a replacement.

Tom
« Last Edit: Jul 12th, 2017 at 1:16am by Sky9pilot »  

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If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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Sky9pilot
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Re: DeHaviland Canada Dash 8-300
Reply #14 - Jan 13th, 2011 at 11:56pm
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Hi all,

Latest work on the Dash 8...props and spinners....

I have made the prop blades on the Laribee/Boor style from info provided me by Don McLellan on HPA.  The blades are cut from 1/32 balsa two sheets marked with a center line for the blades.  This blade line is then aligned with a mark on a two liter soda bottle.  The mark is 12 degrees off vertical to the right for the righthand prop and 12 degree to the left of vertical for the lefthand prop (they are counter rotating props) they rotate over the top to the outside of the arc away from the fuselage.

I molded the individual lamination on the 2 liter soda bottle (filled with water to keep it firm for the laminations) to set the shape of the blades.  I then took the dry shaped blades and began the laminations.
I have laminated the blades with a 50/50 Duco/acetone glue mixture.  I spread it liberally on both laminations making sure all the mating surfaces are coated.  I let them dry to a tacky texture and then apply more glue to one surface and them press the two together and then press them with rubberbands on the 2 liter bottle to cure 24 hours.  With the same alignment of the 12 degrees left and right. This is my first try with this and so I'll have to wait to see how it turns out.  

While the blades were drying on the bottle I turned my attention to the spinner.  I've decided to plunge mold the spinners from plastic picnic plates from the dollar store.  These come in red, yellow, white, and black.  I'm using the black so I don't have to paint them.  I made extra in case I botch one.  I heat the plates with the Monokote Heat Gun left over from the RC days.  Once the plastic begins to sag under the heat I immediately plunge it over the mole which has a bamboo skewer in the base and is held by a racheting clamp to hold it up.  I hold the plastic down over the mold till it cools and then trim the base with a razor blade even with the bottom of the mold.  

Here's a picture of the spinners and the mold and also with a couple stuck on the nacelles in mockup to see how they look.

now the mockup of the spinners on the planes nacelles...

The blades are drying now and will be mounted on bamboo shafts that will fit in the brass hub made from brass tubing as you saw in the last post of the tube in a tube freewheeling prop hub.


Sorry the Photobucket link nolonger works...so those photos were lost.  I'll try to post new pictures later.
Tom
« Last Edit: Jan 17th, 2018 at 4:41pm by Sky9pilot »  

If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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Re: DeHaviland Canada Dash 8-300
Reply #13 - Jan 13th, 2011 at 2:41am
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thymekiller wrote on Jan 12th, 2011 at 4:20pm:
Thanks for the link. My power supply for my confuser is out and I am without links of any kind. Am using mommas machine.
Feels good to be back. Will get better into things this spring. Cant decide what to build first. Something new, or finish an old one.

Keep us posted. I enjoy seeing your work. It is inspiring.


Thyme,
I giving this link to HPA catajets because you said you didn't have links due to the confuser power supply, so here's HPA catajet link:
http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=3985.240
Be sure and check the cataprops as well got some neat stuff from So. America group, multi prop and single prop stuff.  

To stimulate your building in the cataprop area you might check out this site...solid model plans...these give profiles that you can convert easily to cataprop models ...may need to enlarge the horizontal stab etc and adjust the incidence of wings and stab but will get you thinking, here's the link: http://www.ualberta.ca/~khorne/solid/solid.html
Tom
  

If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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Re: DeHaviland Canada Dash 8-300
Reply #12 - Jan 12th, 2011 at 4:20pm
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Thanks for the link. My power supply for my confuser is out and I am without links of any kind. Am using mommas machine.
Feels good to be back. Will get better into things this spring. Cant decide what to build first. Something new, or finish an old one.

Keep us posted. I enjoy seeing your work. It is inspiring.
  

",,,The road goes on forever, and the party never ends..."
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Re: DeHaviland Canada Dash 8-300
Reply #11 - Jan 12th, 2011 at 3:14pm
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thymekiller wrote on Jan 11th, 2011 at 7:10pm:
Cool. If anybody can do it, you can. Your plane looks great.  
Do you have a link to that website? Does Bill still come around? I noticed he ventured over to HP. Did he come back? Noticed Black lion has been gone to. It happens in this hobby.


Thyme...
Thanks...I'm looking forward to getting this one in the air.  Working on props now.  Will tissue soon.  

Here's that link: http://www.vintagemodelairplane.com/pages/Downloads/CRB_dl.html
You need to click on the tube in a tube link.

Bill was pretty active before the holidays...everybody gets wrapped up in family activities thru these holidays.  I spect he'll be back soon with finished pics of his AT-6 Texan/Harvard...

Great to hear from you.  

Tom
  

If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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Re: DeHaviland Canada Dash 8-300
Reply #10 - Jan 11th, 2011 at 7:10pm
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Cool. If anybody can do it, you can. Your plane looks great. 
Do you have a link to that website? Does Bill still come around? I noticed he ventured over to HP. Did he come back? Noticed Black lion has been gone to. It happens in this hobby.
  

",,,The road goes on forever, and the party never ends..."
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Re: DeHaviland Canada Dash 8-300
Reply #9 - Jan 11th, 2011 at 6:14pm
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Thyme thanks for the compliments....

This is a great hobbie and with the net the opportuntiy to meet some great people, like the guys on this site and HPA and SFA in this hobbie...

After looking at my Dash 8 and Don's on HPA and all the pictures I've been surfing on the net I realized my cockpit windows were too large.  I began thinking on how to rectify the problem.  In discussion with Don through emails, he mentioned he had a plane he built a while ago and everytime he brings it out he sees the too larger cockpit windows.  No one else ever says anything but he sees it.  I know just what he means.  soooooo  to fix this I decided I would measure the windows on the plan (13mm) deep/high.  So I placed a 1/16 strip of balsa at the top of each opening and then relocated a lower sill that is 13mm from the top of the new window top.  I relocated the six stringer on the nose and blended them into the nose block.  I am quite pleased with the way it turned out and now the cockpit windows will look correct when finished with tissue and finish.  I think I'm going to go with paint airbrushed on.  That way I can keep it light and control the amount that goes on.  Basically two tone, white and black.  I have what appears as gold mylar tissue that I will cut into strips to apply as the gold trim.  Should turn out nice.  Here's the latest pics...
Closeup of cockpit... Cockpit left side... Closeup of the nose and nacelles...

Couldn't wait to mockup her up again but this time I tried to get the angles aligned a bit better.  Shimmed the nacelles approximately 4 degrees of negative incidence.  Looks a bit better.

Left side ... Upper rear right quarter... Upper front right quarter... Lower right side...

Upper left front quarter ...like she's banking left...

Getting ready to start on props next...going to try to make counter rotating props to cancel tork roll...will be using 3/32 tan rubber and trying all this with tube in a tube free wheeling propshafts.
Here's a pic of the prop hub I found on Vintagemodelairplane.com FF site ...


Tom
« Last Edit: Jul 12th, 2017 at 1:11am by Sky9pilot »  

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If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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Re: DeHaviland Canada Dash 8-300
Reply #8 - Jan 7th, 2011 at 12:58pm
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Thanks Thyme had a great holiday season...mostly just with family.
Still building, what you got on the table?

Tom
  

If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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