Slingsby T12 Gull Build - Page 5

davidjensen · Sep 20, 2009, 09:39 PM

Quote:

Originally Posted by Fred China

Mike
Yes I am.
The hobby to me is mostly in the building.

Fred

I watched Fred fly several flights over the weekend and he fly's as good as he builds.

Fred China · Sep 20, 2009, 10:22 PM

First of all, Thank you all for your very kind comments. I have been away this weekend enjoying a very good time with friends, flying at Concrete Wa. USA

Vincent

I am sorry but I can't let it pass. I know we are all human beings but I am Canadian living in Vancouver B.C.

Tom

I drill a hole right through the hose and then enlarge the outside hole.
I push and force a screw through the outside hole and capture a small washer before the screw goes through the inside hole. I then push the screwdriver through the outside larger hole and screw the inside screw to the fuselage. I mount the skid and screw the small bolt through the skid and rubber hose. I position a blind nut with a small pair of needle nose pliers inside the hose and capture it with the bolt. This gives an independant mounting between the fuselage and the skid with the rubber hose and allows the hose to do it's shock absorbing work. I use Robertsons head screws and bolts. I think the USA call them square heads but I'm not sure. They save a lot of slippng and sliding and damage from the screwdriver.

Fred

Lemaquettiste · Sep 21, 2009, 12:03 AM

ouppssss sorry Fred

so, for me, you are one of the best builder of oldtimer in Canada

Barry_Cole · Sep 21, 2009, 10:49 AM

Great building Fred, I guess that you are Canada's answer to Chris Willims here in the UK. Just one thing for you and any others that are going aerotowing. After all that effort, the one thing that always needs to work is the tow release. I like Fred's nice simple idea, but one small thing could improve it. The Photo back on page one, shows the servo operating the release. Try this small modification. When the release is in the closed position have the servo arm pointing forwards, in the 09.00 position. In the open position have the servo arm pointing down in the 06.00 position. Adjust the wire in the servo arm to get just enough movement. The wire should be as close to the ouptut shaft as you can get it. The advantages are. 1:- You are using the full servo travel, and so will get the maximum power out of the servo. 2:- When the servo starts moving to open the release, there is virtually no load on the servo and so the motor can get up to speed easily. As the servo starts to travel down, there is maximum power available to get the rod moving, even under maximum load. Hope this helps. Always test your release by pulling hard on the line and then operating the release. Make sure the servo is fixed well. We tested a release a few years ago on a large scale glider, and the servo had ripped itself out of it's mounting. Remember it's the time it all goes wrong that your release MUST work.

BC Hampshire UK.

SteveR · Sep 21, 2009, 11:01 AM

Well I guess there are as many opinions about setting up releases as there are modelers. I start with the most powerful servo I can fit in the available space and set things up to use about 90 degrees of servo movement to go from full closed to full open. My rationale: I want the release to happen as quickly as possible. The servo arm develops its maximum torque at 90 degrees to the attached pushrod so I split the open and closed positions to 45 degrees on either side. It only takes about 45 degrees of movement before the line actually releases.

Steve

SZD16 · Sep 21, 2009, 02:59 PM

Quote:

Originally Posted by SteveR

Well I guess there are as many opinions about setting up releases as there are modelers. I start with the most powerful servo I can fit in the available space and set things up to use about 90 degrees of servo movement to go from full closed to full open. My rationale: I want the release to happen as quickly as possible. The servo arm develops its maximum torque at 90 degrees to the attached pushrod so I split the open and closed positions to 45 degrees on either side. It only takes about 45 degrees of movement before the line actually releases.

Steve

What he said.

Barry_Cole · Sep 21, 2009, 03:52 PM

Steve,
Not wishing to Hi-Jack Fred's thread, but I must put a short answer.
The servo produces the same amount of Torque wherever the arm is. The pull exerted on the rod, is actually at it's MINIMUM when the arm is at 90degs. Your comment about the speed is however correct, but I would give up a little speed for a positive release. If you want to discuss this further either start a new thread, or e-mail me direct at modelgliding@aol.com

Live long and prosper..

Barry Cole..

davidjensen · Sep 21, 2009, 04:40 PM

I did some serious testing of the tow release on my 4M. It has one of the tube type releases and when I bought the ship it came with a JR 507 std servo. I was very skeptical. So I tested it many times. With my feet up against the leading edge of the wing and pulling on the string with about 80 lbs of force I flipped the release switch and every time it pulled out sending me flying backwards. The servo never sounded like it was straining at all. The design of the moment arm and how it pivots produces very little stress on the servo.

On with the show Fred

Fred China · Sep 23, 2009, 12:15 AM

The canopy
Rather crude right now but hang in there.

Fred

SteveR · Sep 23, 2009, 07:48 AM

Fred, the facets you created on the nose are a work of art. Are those representative of the full size? Done in plywood?

Steve

Fred China · Sep 23, 2009, 03:13 PM

Thanks Steve
Yes, they follow the full size in number etc.

I used a round head chisel gouge and made a gouge in a piece of pine then rounded off the end of a hardwood dowel and then burnished the small wedge shaped piece of ply in the gouge. This forced a SMALL amount of compound curve into the ply and then did the rest of the bending with the heat gun. The nose block underneath was squared off a minimum amount with a sanding block for each piece before gluing. Really not hard just time consuming.

Fred

Fred China · Sep 25, 2009, 01:35 AM

More on the canopy

The frame is stained and varnished then 1/64" ply over the frame so there is more area for glueing the plastic. Plastic stuck on with contact cement.
Next is the outer ply facing which will be pre stained and I haven't decided to pre varnish or not.

Fred

SteveR · Sep 25, 2009, 06:55 AM

Total puuuuuurrrrrrfection, Fred! As I recall, you usually get one shot to get it right with contact cement. What's your secret??!!

Steve

suirendoujin · Sep 25, 2009, 08:03 AM

Fred,
I have also noted the faucets on the nose and was impressed, to say the least. English IS second language to me, and I was, honestly, not able to understand the method you have described to make those faucets into the nose block. If possible, can you show some pictures of the tools you have fabricated for the task, and how you did it?? I am sure MANY others would appreciate this visual input.

LGE · Sep 25, 2009, 11:04 AM

Fred,

Great build thread.

Are you using similar contact cement that is used for gluing counter top laminates? I think I recall you thin the contact cement with lacquer thinner and I am assuming you are coating both the canopy and the supports, let dry before gluing both parts together, is this correct?

I was wondering about brand and type of contact cement. This is the brand I am finding(DAP WELDWOOD 00105 Contact Cement
) ? What do you use?

Thanks
Larry

Sep 23, 2009, 12:15 AM	#69
Fred China Registered User Join Date: Jul 2006 Posts: 70	The canopy Rather crude right now but hang in there. Fred Attached Thumbnails Just the framework right now. There will be a layer of 1/64" ply just covering the framework then the clear plastic will be held on with contact cement. Then another layer of 1/64" ply to finish the canopy. 28.9 KB · Views: 115 26.8 KB · Views: 94 28.1 KB · Views: 89 32.6 KB · Views: 101

Sep 25, 2009, 01:35 AM	#72
Fred China Registered User Join Date: Jul 2006 Posts: 70	More on the canopy The frame is stained and varnished then 1/64" ply over the frame so there is more area for glueing the plastic. Plastic stuck on with contact cement. Next is the outer ply facing which will be pre stained and I haven't decided to pre varnish or not. Fred Attached Thumbnails 3 panels of plastic side to side 25.2 KB · Views: 113 28.0 KB · Views: 107

Sep 20, 2009, 10:22 PM	#62
Fred China Registered User Join Date: Jul 2006 Posts: 70	First of all, Thank you all for your very kind comments. I have been away this weekend enjoying a very good time with friends, flying at Concrete Wa. USA Vincent I am sorry but I can't let it pass. I know we are all human beings but I am Canadian living in Vancouver B.C. Tom I drill a hole right through the hose and then enlarge the outside hole. I push and force a screw through the outside hole and capture a small washer before the screw goes through the inside hole. I then push the screwdriver through the outside larger hole and screw the inside screw to the fuselage. I mount the skid and screw the small bolt through the skid and rubber hose. I position a blind nut with a small pair of needle nose pliers inside the hose and capture it with the bolt. This gives an independant mounting between the fuselage and the skid with the rubber hose and allows the hose to do it's shock absorbing work. I use Robertsons head screws and bolts. I think the USA call them square heads but I'm not sure. They save a lot of slippng and sliding and damage from the screwdriver. Fred

Sep 21, 2009, 12:03 AM	#63
Lemaquettiste Registered User Join Date: Aug 2003 Location: Béziers France Posts: 96	ouppssss sorry Fred so, for me, you are one of the best builder of oldtimer in Canada

Sep 21, 2009, 10:49 AM	#64
Barry_Cole Registered User Join Date: Apr 2007 Location: Hampshire UK Posts: 12	Great building Fred, I guess that you are Canada's answer to Chris Willims here in the UK. Just one thing for you and any others that are going aerotowing. After all that effort, the one thing that always needs to work is the tow release. I like Fred's nice simple idea, but one small thing could improve it. The Photo back on page one, shows the servo operating the release. Try this small modification. When the release is in the closed position have the servo arm pointing forwards, in the 09.00 position. In the open position have the servo arm pointing down in the 06.00 position. Adjust the wire in the servo arm to get just enough movement. The wire should be as close to the ouptut shaft as you can get it. The advantages are. 1:- You are using the full servo travel, and so will get the maximum power out of the servo. 2:- When the servo starts moving to open the release, there is virtually no load on the servo and so the motor can get up to speed easily. As the servo starts to travel down, there is maximum power available to get the rod moving, even under maximum load. Hope this helps. Always test your release by pulling hard on the line and then operating the release. Make sure the servo is fixed well. We tested a release a few years ago on a large scale glider, and the servo had ripped itself out of it's mounting. Remember it's the time it all goes wrong that your release MUST work. BC Hampshire UK.

Sep 21, 2009, 11:01 AM	#65
SteveR Registered User Join Date: Feb 2002 Location: New York Posts: 1,872	Well I guess there are as many opinions about setting up releases as there are modelers. I start with the most powerful servo I can fit in the available space and set things up to use about 90 degrees of servo movement to go from full closed to full open. My rationale: I want the release to happen as quickly as possible. The servo arm develops its maximum torque at 90 degrees to the attached pushrod so I split the open and closed positions to 45 degrees on either side. It only takes about 45 degrees of movement before the line actually releases. Steve

Sep 21, 2009, 03:52 PM	#67
Barry_Cole Registered User Join Date: Apr 2007 Location: Hampshire UK Posts: 12	Steve, Not wishing to Hi-Jack Fred's thread, but I must put a short answer. The servo produces the same amount of Torque wherever the arm is. The pull exerted on the rod, is actually at it's MINIMUM when the arm is at 90degs. Your comment about the speed is however correct, but I would give up a little speed for a positive release. If you want to discuss this further either start a new thread, or e-mail me direct at modelgliding@aol.com Live long and prosper.. Barry Cole..

Sep 21, 2009, 04:40 PM	#68
davidjensen Will fly for food Join Date: Dec 2003 Location: Bellevue WA Posts: 3,031	I did some serious testing of the tow release on my 4M. It has one of the tube type releases and when I bought the ship it came with a JR 507 std servo. I was very skeptical. So I tested it many times. With my feet up against the leading edge of the wing and pulling on the string with about 80 lbs of force I flipped the release switch and every time it pulled out sending me flying backwards. The servo never sounded like it was straining at all. The design of the moment arm and how it pivots produces very little stress on the servo. On with the show Fred

Sep 23, 2009, 07:48 AM	#70
SteveR Registered User Join Date: Feb 2002 Location: New York Posts: 1,872	Fred, the facets you created on the nose are a work of art. Are those representative of the full size? Done in plywood? Steve

Sep 23, 2009, 03:13 PM	#71
Fred China Registered User Join Date: Jul 2006 Posts: 70	Thanks Steve Yes, they follow the full size in number etc. I used a round head chisel gouge and made a gouge in a piece of pine then rounded off the end of a hardwood dowel and then burnished the small wedge shaped piece of ply in the gouge. This forced a SMALL amount of compound curve into the ply and then did the rest of the bending with the heat gun. The nose block underneath was squared off a minimum amount with a sanding block for each piece before gluing. Really not hard just time consuming. Fred

Sep 25, 2009, 06:55 AM	#73
SteveR Registered User Join Date: Feb 2002 Location: New York Posts: 1,872	Total puuuuuurrrrrrfection, Fred! As I recall, you usually get one shot to get it right with contact cement. What's your secret??!! Steve

Sep 25, 2009, 08:03 AM	#74
suirendoujin Registered User Join Date: Jan 2006 Location: The Far East Posts: 596	Fred, I have also noted the faucets on the nose and was impressed, to say the least. English IS second language to me, and I was, honestly, not able to understand the method you have described to make those faucets into the nose block. If possible, can you show some pictures of the tools you have fabricated for the task, and how you did it?? I am sure MANY others would appreciate this visual input.

Sep 25, 2009, 11:04 AM	#75
LGE Registered User Join Date: Oct 2007 Location: Seattle Posts: 28	Fred, Great build thread. Are you using similar contact cement that is used for gluing counter top laminates? I think I recall you thin the contact cement with lacquer thinner and I am assuming you are coating both the canopy and the supports, let dry before gluing both parts together, is this correct? I was wondering about brand and type of contact cement. This is the brand I am finding(DAP WELDWOOD 00105 Contact Cement ) ? What do you use? Thanks Larry