Jart - Old School

isoarthenland · Aug 10, 2006, 09:51 AM

Can there ever be enough Jart Build threads?

I can't say I'm new to sloping, I was doing it back in the 70's in Seattle with a Dodgson Design Todi...4 channels...rudder, elevator, ailerons, flaps, flaps to elevator mixing....all mechanical, no electronic mixes....but I degress...

I recently moved from Seattle to within a few minutes of Point of the Mountain in Utah and have been lurking around the RC Groups Slope site for a few months now. I submitted an entry to the SDCC thread, but really wanted to build a Jart, so I have abandoned the SDCC plane http://www.rcgroups.com/forums/showthread.php?t=527662

My TD flying has been limited since I live so close to POM, and frankly, flying a 3.7 meter Sharon F3J on such a great slope is getting a little boring...I need something FAST and for BIG AIR

Here are the things that took me down the built-up Jart path:

1) Picked up a lot of skills building 2 Harley Michaelis Genie LT/S TD planes a couple years ago and wanted to try them on something else http://genie.rchomepage.com

2) I had some left over materials from the Genie builds.

3) I wanted to have removeable stabs and wings

4) It didn't look like anyone has done it.

5) My new shop is mostly done and I wanted to put it to work

What to call it?

Jart-to-go
Jart Lake City
Have Jart, will travel
Crunchie Jart

I'm a ways into it because I didn't know if there would be any interest, but I decided to go ahead and put it out there just in case.

Russ

isoarthenland · Aug 10, 2006, 10:39 AM

Fuse materials:

1/16 Ply sides

.014" x 2" x 36" thick uni-carbon laminate http://www.acp-composites.com/acp-ucfl.htm - Side doublers

1/8" bulkheads

Basswood block - pointy nose

1/2" balsa planks

slopemeno · Aug 10, 2006, 11:01 AM

Cellulo-Jart...? nah.

Have you ever seen Reeds FU-2? It was sort of a pre-proto-Jart, and it was a balsa fused plane, though the glass reinforcements probably outweighed the balsa by a 2-to-1 margin. So its totally do-able, just try to keep the weight in the same range.

infopimp · Aug 10, 2006, 11:11 AM

> Can there ever be enough Jart Build threads?

No.

isoarthenland · Aug 10, 2006, 11:13 AM

I haven't seen the FU-2...I'll keep the weight thing in mind. The fuse, when ready, will have 2 layers of 3/4oz glass layed on with poly resin.

slopemeno · Aug 10, 2006, 12:44 PM

Go heavier. 2 layers of .75 oz will be fairly easy to punch through. I would PM Reed and ask him what he used on the FU-2, and maybe go a little lighter if you are concerned about overall weight.

isoarthenland · Aug 10, 2006, 12:55 PM

I just looked back on my Genie instructions and it actually calls fo 1.5oz glass. My Genie fuse survived a 100ft straight in crash into hard-packed dirt without issue last year at Visalia. The fuse is 3/4" wide at the point where the fin starts.

slopemeno · Aug 10, 2006, 01:36 PM

I think (and this is just one guys opinion..take it for what its worth) you'll end up under weight, and then be tempted to add weight, and there goes the durability. Shoot for at least 45 oz weight once done. Reeds is 55? oz and it rips. You have the hills and wind.

isoarthenland · Aug 10, 2006, 02:20 PM

I've got to get over my "lighter is better" TD mentaility. It cracks me up when I see bondo being slathered on these small planes. I wonder what the fuse should weigh without radio gear?

isoarthenland · Aug 10, 2006, 03:55 PM

I made some bulkheads out of balsa to experiment with thickness and adding holes for my balast tube and radio gear wires. When I thought I had them right, I made them out of 1/8" ply.

slopemeno · Aug 10, 2006, 03:57 PM

Swag here, but I would say 36-38 ounces for the bare airframe.

Reed · Aug 10, 2006, 05:20 PM

Love this build! Funny, I was just thinking as I woke up today that I should do a built-up JART thread. Now I don't have to! Great stuff, Russ.

slopemeno has good advice here - shoot for 45oz and you'll have a very versatile medium/big air machine. She's all about speed, so keep the nose down and let her run.

greyhound flyer · Aug 10, 2006, 05:35 PM

Looks good, Russ. But why does that Genie have all those extra formers?

samotage · Aug 10, 2006, 06:03 PM

Go Russ!

How about Jart-OSV (Old Skool Version)?

Sam.

isoarthenland · Aug 10, 2006, 06:48 PM

Reed...I'll take all the advice I can get!

Greyhound...apparently these little slope planes go really fast, which means, I suppose, that they land fast too

....hench the extra formers

Sam...I've been lurking around your Jart build....when I grow up I want to make a Jart just like yours

Aug 10, 2006, 09:51 AM	#1
isoarthenland Registered User Join Date: Mar 2006 Location: Utah Posts: 347	Jart - Old School Can there ever be enough Jart Build threads? I can't say I'm new to sloping, I was doing it back in the 70's in Seattle with a Dodgson Design Todi...4 channels...rudder, elevator, ailerons, flaps, flaps to elevator mixing....all mechanical, no electronic mixes....but I degress... I recently moved from Seattle to within a few minutes of Point of the Mountain in Utah and have been lurking around the RC Groups Slope site for a few months now. I submitted an entry to the SDCC thread, but really wanted to build a Jart, so I have abandoned the SDCC plane http://www.rcgroups.com/forums/showthread.php?t=527662 My TD flying has been limited since I live so close to POM, and frankly, flying a 3.7 meter Sharon F3J on such a great slope is getting a little boring...I need something FAST and for BIG AIR Here are the things that took me down the built-up Jart path: 1) Picked up a lot of skills building 2 Harley Michaelis Genie LT/S TD planes a couple years ago and wanted to try them on something else http://genie.rchomepage.com 2) I had some left over materials from the Genie builds. 3) I wanted to have removeable stabs and wings 4) It didn't look like anyone has done it. 5) My new shop is mostly done and I wanted to put it to work What to call it? Jart-to-go Jart Lake City Have Jart, will travel Crunchie Jart I'm a ways into it because I didn't know if there would be any interest, but I decided to go ahead and put it out there just in case. Russ

Aug 10, 2006, 10:39 AM	#2
isoarthenland Registered User Join Date: Mar 2006 Location: Utah Posts: 347	Fuse materials: 1/16 Ply sides .014" x 2" x 36" thick uni-carbon laminate http://www.acp-composites.com/acp-ucfl.htm - Side doublers 1/8" bulkheads Basswood block - pointy nose 1/2" balsa planks Attached Thumbnails Draw outline of fuse "box" 1/4" smaller than plan 25.4 KB · Views: 251 Cut out sides and stick to 1/16" plywood 39.8 KB · Views: 160 Here's that uni-carbon laminate...nice strong stuff (not quite old school) These will be epoxied to 1/16" ply sides----strong 91.2 KB · Views: 177 Hmmm, a little skinny 48.8 KB · Views: 199 Laminated ply and carbon 41.1 KB · Views: 152 Future pointy nose 50.6 KB · Views: 181 49.6 KB · Views: 227

Aug 10, 2006, 12:55 PM	#7
isoarthenland Registered User Join Date: Mar 2006 Location: Utah Posts: 347	I just looked back on my Genie instructions and it actually calls fo 1.5oz glass. My Genie fuse survived a 100ft straight in crash into hard-packed dirt without issue last year at Visalia. The fuse is 3/4" wide at the point where the fin starts. Attached Thumbnails Back end of Genie fuse...single edge blade shown for size 18.5 KB · Views: 196

Aug 10, 2006, 03:55 PM	#10
isoarthenland Registered User Join Date: Mar 2006 Location: Utah Posts: 347	I made some bulkheads out of balsa to experiment with thickness and adding holes for my balast tube and radio gear wires. When I thought I had them right, I made them out of 1/8" ply. Attached Thumbnails 26.7 KB · Views: 198 77.9 KB · Views: 212

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Aug 10, 2006, 11:01 AM	#3
slopemeno Registered User Join Date: Jan 2003 Location: the Alameda gall bladder refrigerator Posts: 5,461	Cellulo-Jart...? nah. Have you ever seen Reeds FU-2? It was sort of a pre-proto-Jart, and it was a balsa fused plane, though the glass reinforcements probably outweighed the balsa by a 2-to-1 margin. So its totally do-able, just try to keep the weight in the same range.

Aug 10, 2006, 11:11 AM	#4
infopimp PNF Join Date: May 2005 Location: Los Gatos, CA Posts: 4,422	> Can there ever be enough Jart Build threads? No.

Aug 10, 2006, 11:13 AM	#5
isoarthenland Registered User Join Date: Mar 2006 Location: Utah Posts: 347	I haven't seen the FU-2...I'll keep the weight thing in mind. The fuse, when ready, will have 2 layers of 3/4oz glass layed on with poly resin.

Aug 10, 2006, 12:44 PM	#6
slopemeno Registered User Join Date: Jan 2003 Location: the Alameda gall bladder refrigerator Posts: 5,461	Go heavier. 2 layers of .75 oz will be fairly easy to punch through. I would PM Reed and ask him what he used on the FU-2, and maybe go a little lighter if you are concerned about overall weight.

Aug 10, 2006, 01:36 PM	#8
slopemeno Registered User Join Date: Jan 2003 Location: the Alameda gall bladder refrigerator Posts: 5,461	I think (and this is just one guys opinion..take it for what its worth) you'll end up under weight, and then be tempted to add weight, and there goes the durability. Shoot for at least 45 oz weight once done. Reeds is 55? oz and it rips. You have the hills and wind.

Aug 10, 2006, 02:20 PM	#9
isoarthenland Registered User Join Date: Mar 2006 Location: Utah Posts: 347	I've got to get over my "lighter is better" TD mentaility. It cracks me up when I see bondo being slathered on these small planes. I wonder what the fuse should weigh without radio gear?

Aug 10, 2006, 03:57 PM	#11
slopemeno Registered User Join Date: Jan 2003 Location: the Alameda gall bladder refrigerator Posts: 5,461	Swag here, but I would say 36-38 ounces for the bare airframe.

Aug 10, 2006, 05:20 PM	#12
Reed Vitruvian JART Join Date: Mar 2003 Location: San Francisco Posts: 4,715	Love this build! Funny, I was just thinking as I woke up today that I should do a built-up JART thread. Now I don't have to! Great stuff, Russ. slopemeno has good advice here - shoot for 45oz and you'll have a very versatile medium/big air machine. She's all about speed, so keep the nose down and let her run.

Aug 10, 2006, 05:35 PM	#13
greyhound flyer Genie Builder Join Date: Aug 2004 Location: Portland, Oregon, United States Posts: 260	Looks good, Russ. But why does that Genie have all those extra formers?

Aug 10, 2006, 06:03 PM	#14
samotage find me @samotage Join Date: Jul 2005 Location: Melbourne Australia Posts: 8,298	Go Russ! How about Jart-OSV (Old Skool Version)? Sam.

Aug 10, 2006, 06:48 PM	#15
isoarthenland Registered User Join Date: Mar 2006 Location: Utah Posts: 347	Reed...I'll take all the advice I can get! Greyhound...apparently these little slope planes go really fast, which means, I suppose, that they land fast too ....hench the extra formers Sam...I've been lurking around your Jart build....when I grow up I want to make a Jart just like yours