Spruce strips for Jurca Replica

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

Dana LaBounty

Active Member
Joined
Mar 29, 2019
Messages
44
I have both the 2/3 scale P-51 and the 3/4 scale P-40 drawings from Jurca. I've been an airplane mechanic, fabricator and homebuilder for going on 5 decades. Currently I am restoring my Great Lakes Sport Trainer biplane then I'll start on the Jurca P-40. The Jurca warbirds are not good projects unless you have successfully built at least one other plane to flying status.
To speed up the build do the metal tube fuselage version, it'll also save $'s compared to building with wood. It will weigh less and perform better as well. The plans are still available with the last updates Marcel added while he was alive. Having a full set of plans will save you much time and money as well.
 

wiloows5050

Well-Known Member
Joined
Jul 28, 2007
Messages
349
Location
Elk Grove Ca
I have both the 2/3 scale P-51 and the 3/4 scale P-40 drawings from Jurca. I've been an airplane mechanic, fabricator and homebuilder for going on 5 decades. Currently I am restoring my Great Lakes Sport Trainer biplane then I'll start on the Jurca P-40. The Jurca warbirds are not good projects unless you have successfully built at least one other plane to flying status.
To speed up the build do the metal tube fuselage version, it'll also save $'s compared to building with wood. It will weigh less and perform better as well. The plans are still available with the last updates Marcel added while he was alive. Having a full set of plans will save you much time and money as well.
Dana, we’ll said. I tried to tell him that a jurca project was way way over his skill level. He’s asked these questions on other groups as well.
My opinion he would be better off doing a kit plane and building up his skill level. If you don’t know how to read the drawings you probably should be trying to build that plane.
 

marianmadalin32

Well-Known Member
Joined
Aug 9, 2018
Messages
64
Location
Bucharest
Cutting parts by hand is a waste of precious time. All the parts I actually cut and you can see them in other threads were automatically cut on the CNC machine. This way we save time.
 

Shayde

Well-Known Member
Joined
Jul 8, 2022
Messages
62
Location
New Zealand
Cutting parts by hand is a waste of precious time. All the parts I actually cut and you can see them in other threads were automatically cut on the CNC machine. This way we save time.

I think the bigger issue than cutting the parts is that you seem to struggle with reading the plans. Constructing a plane is going to be very, very tricky if the plans are nonsense to you. I'm guessing you're going to be wanting someone to put the parts together for you?
 

Yellowhammer

Well-Known Member
Supporting Member
Joined
Feb 21, 2020
Messages
821
Location
Born In Alabama, reside: Louisiana (unfortunately)
Cutting parts by hand is a waste of precious time. All the parts I actually cut and you can see them in other threads were automatically cut on the CNC machine. This way we save time.
Building an airplane is not a fast process at all. It takes time and many times a part has to be built twice or even three times to get it correct. I appreciate your passion. The reason you, me and many many others joined this forum was to get rock solid and trusted advice along with like minded fellowship from those that have been there and done that.

I trust what these gentleman have told me over the years and they have never once led me astray. Members here on HBA are just trying to get you to understand that things have to be done a certain way when building aircraft for a plethora of reasons. If it as easy everyone would be building an airplane. I had to learn many new skills when I first started building ( I still have more skills to learn) and for me that is one of the most rewarding aspects of building your own airplane.

The main reason is the safety of you and others around you when and if the time comes to take to the skies.

Never give up on your dreams but truly listen to the advice you are asking for and follow it. You will have much less heart ache down the road.

-Yellowhammer
 

marianmadalin32

Well-Known Member
Joined
Aug 9, 2018
Messages
64
Location
Bucharest
I think the bigger issue than cutting the parts is that you seem to struggle with reading the plans. Constructing a plane is going to be very, very tricky if the plans are nonsense to you. I'm guessing you're going to be wanting someone to put the parts together for you?
No, mister/lady ! I want someone to look at them and simply tell me how many spruce strips I need, to know exactly the number of strips I order, before placing the order, not after. But I think you have no idea. So please remove yourself from this thread !
 

marianmadalin32

Well-Known Member
Joined
Aug 9, 2018
Messages
64
Location
Bucharest
Building an airplane is not a fast process at all. It takes time and many times a part has to be built twice or even three times to get it correct. I appreciate your passion. The reason you, me and many many others joined this forum was to get rock solid and trusted advice along with like minded fellowship from those that have been there and done that.

I trust what these gentleman have told me over the years and they have never once led me astray. Members here on HBA are just trying to get you to understand that things have to be done a certain way when building aircraft for a plethora of reasons. If it as easy everyone would be building an airplane. I had to learn many new skills when I first started building ( I still have more skills to learn) and for me that is one of the most rewarding aspects of building your own airplane.

The main reason is the safety of you and others around you when and if the time comes to take to the skies.

Never give up on your dreams but truly listen to the advice you are asking for and follow it. You will have much less heart ache down the road.

-Yellowhammer
Mister, if you're nothing but a talker, talking does not help anyone. Please remove yourself too from this thread ! Many thanks.
 

Shayde

Well-Known Member
Joined
Jul 8, 2022
Messages
62
Location
New Zealand
No, mister/lady ! I want someone to look at them and simply tell me how many spruce strips I need, to know exactly the number of strips I order, before placing the order, not after. But I think you have no idea.

The plans had a very concise table indicating the lengths of each size strip of wood you needed. Someone even clipped that table out for you and attached it. Yet you still couldn't read / understand it. Here's the information from that table again:

TypeLength required
25mm x 19mm spruce60 metres
38mm x 19mm spruce13 metres
19mm x 19mm spruce20 metres
19mm x 12mm spruce10 metres
25mm x 19mm ash5 metres
38mm x 19mm ash5 metres
140mm x 19mm ash2 metres
65mm x 19mm ash2 metres
19mm x 19mm ash4 metres

Is that not the information you're after?

So please remove yourself from this thread !

I don't think you realise we're all trying to help you here.
 

wiloows5050

Well-Known Member
Joined
Jul 28, 2007
Messages
349
Location
Elk Grove Ca
No, mister/lady ! I want someone to look at them and simply tell me how many spruce strips I need, to know exactly the number of strips I order, before placing the order, not after. But I think you have no idea. So please remove yourself from this thread !
You have missed the whole point of what everyone is trying to tell you. The plans tell you how much you need. The only way to know the length is to look at the plans! You, not some random stranger have to determine how much material each part will use. Let’s talk material for a minute, the 19x25 capstrips are probably used for wing rib capstrips. Each wing rib will use two pierces of both different lengths. You will need two of each (right and left side). You can’t order the capstrips in exact lengths. No company is going to cut them in length exact feet and inches. Besides I can guarantee you will screw something up and have to recut something. (The example of the 19x25 comes from the MJ9). I promise you that there will be waste, you can’t avoid it. Most people order long lengths to try and minimize waste.
If you don’t want advice or aren’t going to listen to people trying to help you maybe you should stop asking questions. That’s why I quit responding to you on messenger. Start studying the plans, not everything but the individual pieces and approach how you are going to build or assemble it. That will go a long way the answers your questions. I look at my plans multiple times before I cut or assemble pieces. I notice new things almost every time I look a a sheet of plans. You seem to be in to much of a hurry to put things together. That’s why I suggested that you make some of the part by hand there will be plenty of part you can’t make using CNC. The spar on a jurca is one of the more complicated one to make. If you can’t work with the material your building with you will NEVER be able to assemble the spar. You need to enjoy the journey otherwise in my opinion you are missing the joys of the accomplishment that comes from build an airplane.

One last item. You need to apologize to those people who were trying to help you and you were rude too.
 

marianmadalin32

Well-Known Member
Joined
Aug 9, 2018
Messages
64
Location
Bucharest
The plans had a very concise table indicating the lengths of each size strip of wood you needed. Someone even clipped that table out for you and attached it. Yet you still couldn't read / understand it. Here's the information from that table again:

TypeLength required
25mm x 19mm spruce60 metres
38mm x 19mm spruce13 metres
19mm x 19mm spruce20 metres
19mm x 12mm spruce10 metres
25mm x 19mm ash5 metres
38mm x 19mm ash5 metres
140mm x 19mm ash2 metres
65mm x 19mm ash2 metres
19mm x 19mm ash4 metres

Is that not the information you're after?



I don't think you realise we're all trying to help you here.
Correct, but seems to be a very big language barrier here. Can anyone tell me indications like this: 4 strips of 25x19, 6 meters long, 3 strips of 12x19 2 meters long. Is that hard ???
 

marianmadalin32

Well-Known Member
Joined
Aug 9, 2018
Messages
64
Location
Bucharest
You have missed the whole point of what everyone is trying to tell you. The plans tell you how much you need. The only way to know the length is to look at the plans! You, not some random stranger have to determine how much material each part will use. Let’s talk material for a minute, the 19x25 capstrips are probably used for wing rib capstrips. Each wing rib will use two pierces of both different lengths. You will need two of each (right and left side). You can’t order the capstrips in exact lengths. No company is going to cut them in length exact feet and inches. Besides I can guarantee you will screw something up and have to recut something. (The example of the 19x25 comes from the MJ9). I promise you that there will be waste, you can’t avoid it. Most people order long lengths to try and minimize waste.
If you don’t want advice or aren’t going to listen to people trying to help you maybe you should stop asking questions. That’s why I quit responding to you on messenger. Start studying the plans, not everything but the individual pieces and approach how you are going to build or assemble it. That will go a long way the answers your questions. I look at my plans multiple times before I cut or assemble pieces. I notice new things almost every time I look a a sheet of plans. You seem to be in to much of a hurry to put things together. That’s why I suggested that you make some of the part by hand there will be plenty of part you can’t make using CNC. The spar on a jurca is one of the more complicated one to make. If you can’t work with the material your building with you will NEVER be able to assemble the spar. You need to enjoy the journey otherwise in my opinion you are missing the joys of the accomplishment that comes from build an airplane.

One last item. You need to apologize to those people who were trying to help you and you were rude too.
"No company is going to cut them in length exact feet and inches"... Really ???
Are you being serious right now ? That's why I was telling you most of you need to remove yourself from this thread. You have not even a clue how a woodworking company works, you never seen a CNC cutting router close in your life !
 

BJC

Well-Known Member
Supporting Member
Joined
Oct 7, 2013
Messages
15,619
Location
97FL, Florida, USA
"No company is going to cut them in length exact feet and inches"... Really ???
Are you being serious right now ? That's why I was telling you most of you need to remove yourself from this thread. You have not even a clue how a woodworking company works, you never seen a CNC cutting router close in your life !
If you know, why are you asking for others to explain it to you?

Language barriers are no excuse for rudeness. And rudeness will discourage knowledgable people here from trying to help you.

Good luck.


BJC
 
Joined
Nov 14, 2009
Messages
8,603
Location
Rocky Mountains
So please remove yourself from this thread !
Maybe there is a significant language problem here? If not then................I'll be very blunt:

You are in WAY over your head, even for a static display.
With an attitude like you have displayed you will not find many here that will help and run the risk of being banned by the moderators.*

If you would go back and fill in some of the blanks on your profile page some of us that might still be willing to help will have a better idea of your background and experiences so we can give better responses.

* you are just about 2 more rude posts from going into my personal ignore file .............. and I'll never return to this thread.
 

Shayde

Well-Known Member
Joined
Jul 8, 2022
Messages
62
Location
New Zealand
Correct, but seems to be a very big language barrier here. Can anyone tell me indications like this: 4 strips of 25x19, 6 meters long, 3 strips of 12x19 2 meters long.

To answer your question, you would need roughly the following lengths of 25 x 19 spruce:
  • 5.1m x 4 strips
  • 4.7m x 4 strips
  • 3.1m x 4 strips
  • 2.2m x 4 strips
That allows for a bit of leeway. That all adds up to a little bit (40cm) over the recommended 60m of spruce. If necessary you can scarf shorter lengths together, 3m from the end as suggested by the plans. These strips all go into the fuselage longerons. Half of the strips can actually be 20 cm shorter if needed, as the upper longerons aren't as long as the lower ones. All but four of them require tapering.

For 12 x 19 spruce, you need two 5m strips.

The rest becomes harder to work out without doing some calcs (or putting it in CAD). The drawing also indicates quite a few 19 x 19 transverse strips, the lengths of which can't be determined from this drawing - they'd be in the top-down plan.

Does that help?
 
Top