Author Topic: ARF adhesives (Read 6986 times)

Andrew Hathaway · « **on:** March 17, 2006, 01:00:09 PM »

Anyone know exactly what kind of adhesive the Top Flite ARFs are stuck together with? I want to do some minor disassembly and knowing what they used might save me some trouble.

Thanks!

Louis Rankin · « **Reply #1 on:** March 17, 2006, 02:02:35 PM »

The Chinese ARF builders use Hot Glue guns.

frank carlisle · « **Reply #2 on:** March 17, 2006, 02:33:14 PM »

i don't know what they use for glue but a little wrigging and prying should do the trick. try using a heat gun on it.

Andrew Hathaway · « **Reply #3 on:** March 17, 2006, 03:19:27 PM »

Thanks for the replies, here's what I've found so far...

I'm still not sure what this stuff is, but its not like anything I've dealt with before. It penetrates like a mother, and is soft but brittle...

Weird.

I cut the fillets between the parts with a sharp #11 blade, and then followed by carefully prying apart with a #2 X-acto handle with the large curved carving blade. I also used some minor brute force.

My conclusion is that the Nobler ARF front end is built a lot stronger then it appears. The plywood firewalls are keyed into the plywood doublers, and here's the part that threw me... The doublers are keyed, and the motor mounts key into them. The mounts as they extend out the front of the fuselage look like 5/16" x 7/16", then they taper back to 1/8" x 7/16" at the rear, but in reality the taper is more like 1/4" x 7/16" because 1/16" of the width is keyed into the plywood doublers. Hope that makes sense. Seperating the oak(?) motor mounts from the fuselage sides took quite a bit of balsa along for the ride. At any rate, even with minimal and substandard adhesives the motor mounts, front doublers, and the firewalls, aren't going anywhere. Much the same as the Veco kits with everything keyed and the lesser cements of the time period.

I'm already on the downhill stretch. I've got new 5-ply birch firewalls cut, an authentic Nobler landing gear bent, 3/8" x 1/2" hard maple motor mounts cut, and it's slowly going back together.

frank carlisle · « **Reply #4 on:** March 17, 2006, 03:24:56 PM »

can you show us pictures?

Andrew Hathaway · « **Reply #5 on:** March 17, 2006, 03:27:18 PM »

Sure, I'll post some in a couple minutes.

Andrew Hathaway · « **Reply #6 on:** March 17, 2006, 03:46:00 PM »

In the first picture you can see how the doublers are relieved and keyed for the firewalls and motor mounts, as well as the mounts themselves and the OEM firewalls. The second shot shows the new plywood firewalls and motor mounts.

I chose to remove a section of the new motor mounts to allow them to key into the original doublers. Also it took some sanding to get them to fit the cutouts since the original mounts are probably a metric size, slightly smaller then 1/2" tall.

Edit: Removed hyperlinks, thanks for attaching them for me, I missed the option when I posted the original message.

Ironbomb · « **Reply #7 on:** March 17, 2006, 04:27:52 PM »

Use fuel. Fuel dissolved my Noblarf quit nicly

. And at an inopportune time as well.

I never would have thought a fuel compartment would be assembled with fuel dissolvable glue

.

Good catch fixing it now. Enjoy the rebuild

Seriously, dont use fuel

Greg

frank carlisle · « **Reply #8 on:** March 17, 2006, 05:35:57 PM »

good pics andrew. you're making arf assembly look real serious.

Lyle Spiegel · « **Reply #9 on:** March 17, 2006, 05:48:58 PM »

I have ARF Nobler - when i got it i checked the wing & stab incidence to verify alignment to the engine thrust line- the stab was dead nuts but the wing cut out was way off- I checked multiple times to be sure- then I called TopFlite and complained- they said it couldnot be off- refused to acknowledge my feedback that they had to recheck the layout of wing cut out. With help from Bill Hummel we fixed the problem and got it together with everything zero- zero- and it flies like a dream.

Andrew Hathaway · « **Reply #10 on:** March 18, 2006, 09:14:26 AM »

I don't want to give the impression that the ARF Nobler really needed the changes I'm making. I should probably mention this is my second. The first was built pretty much exactly per the instructions, except for a Sig bellcrank, Sullivan leadouts, ball link controls, and a 25FP. It flies very nice. I just didn't like the departures from the green box layout. The ARF Nobler's nose is 1" shorter, the gear is narrower and isn't installed at an angle, and the rudder loses the charisma that the green box Nobler had... Also the fibreglass cowl never agreed with me. So I came across this one in Tower's scratch and dent bin. I saved some money since the instruction book was missing, so I can justify modifying to my hearts content.

So far the fuselage has been stretched back to the original length, the firewalls have been replaced with 5-ply birch, and the motor mounts have been upgraded to maple. The main landing gear has been replaced with a new GB Nobler style gear. The tailwheel also will be installed per the GB Nobler plans. The wing now has a 4" delrin bellcrank and .021 leadouts. I also removed the OEM lead bird shot tip weight. Now I know what is causing the mystery rattle in the wing of my other ARF Nobler. All the Monokote has been stripped and the final finish will be dope and silkspan.

I'm still not sure if addressing all these issues is really worth the trouble, it flies just fine out of the box, I just wanted something just a little bit better.

john e. holliday · « **Reply #11 on:** March 18, 2006, 03:15:40 PM »

Good luck. DOC Holliday

Andrew Hathaway · « **Reply #12 on:** March 18, 2006, 11:43:43 PM »

Here's a shot of the mock-up as it sits now.

Landing gear issues have been addressed
4" bellcrank is installed
Hinge pockets have been opened up to accept standard pin hinges
Engine crutch has been completed and installed in fuselage
Rudder/Fin has been constructed per the original plans and modified to fit the ARF structure.
Tip weight has been removed

Plenty of work left, but so far its been rewarding. Still cheaper then any currently available Nobler kit, and probably a lot less work. The weight is going up a bit, but still within reason.

Andrew Hathaway · « **Reply #13 on:** March 21, 2006, 12:03:55 PM »

I'm not sure if anyone is still following this, or is interested, but I've come this far, I might as well keep updating.

All the principle construction is done. The top blocks and cowl are all carved balsa, per the green box TF Nobler. Weight box is installed in the outboard tip. I've got to do the fillets and minor detail work then its time to start applying dope and silkspan.

Bill Little · « **Reply #14 on:** March 22, 2006, 07:15:51 AM »

Outstanding job, Andrew! I like the looks just a *little* bit better.

Now THAT looks like a Nobler.
BTW: I would have a HARD TIME during appearance judging telling that it wasn't a real GB Nobler.
Good Luck with it!

Andrew Hathaway · « **Reply #15 on:** April 04, 2006, 12:34:27 PM »

Couple more progress shots...
I'm still working out the trim in my head, not sure how its going to look when its finished.

RC Storick · « **Reply #16 on:** April 04, 2006, 04:58:05 PM »

You have done a fine job! Good to see so much craftsmanship.

john e. holliday · « **Reply #17 on:** April 04, 2006, 06:38:31 PM »

Looks great, you going to have it done in time for Topeka? DOC Holliday

Andrew Hathaway · « **Reply #18 on:** April 04, 2006, 10:54:17 PM »

That's the plan... I had another project in mind for my primary stunt effort for this season, but the bottom dropped out and I decided to do this one instead. Somehow I always end up at Topeka with my backup that almost always results in an over-run and loss of pattern points. I planted the old Banshee last summer and have sworn off schneurle ported .40's. This one is going to have a OS Max-S 35. Hopefully it flies as good as I think it will.

RandySmith · « **Reply #19 on:** April 04, 2006, 11:29:50 PM »

Great post Andrew !
The photos are very good for show n tell
we need more post like this , your plane looks very nice

Randy