Semroc Goblin launch lug question

The plans for the Semroc Goblin sat to place the launch lug "4 inches from the bottom". In the picture it shows the top of the launch lug at the 4" mark, but that would put it in the way of the black band decal. What if I put the bottom of the launch lug at the 4" mark instead?

I'm not an expert on this, so you may want to someone else's :2:. Anyway, from just logic and experience (I built an Excelsior Goony Goblin) I don't think the launch lug should be in the way of the stripe.

Do you think that it would matter being higher up on the body tube than lower?

I'm also building the Semroc Goblin as we speak.

If you were to glue the lug in postition like the illustration in Step 17, the decal would run into the lug.
If the lower end of the lug was 4" from the bottom as the step 17 description says, the decal won't hit the lug.

Or, you can build it like the original kit. Instead of a single long 3/16" lug, use two smaller 1/8" lugs:

https://mrjoem.htmlplanet.com/Estes/planK55.html

I know, a 3/16" rod and single 3/16" lug would help with rod whip.

If you want to go to extremes like the original plan, turn the "3" fin decals on their side. (The second picture is my older Goblin.)

hcmbanjo said:

I'm also building the Semroc Goblin as we speak.

If you were to glue the lug in postition like the illustration in Step 17, the decal would run into the lug.
If the lower end of the lug was 4" from the bottom as the step 17 description says, the decal won't hit the lug.

Or, you can build it like the original kit. Instead of a single long 3/16" lug, use two smaller 1/8" lugs:

https://mrjoem.htmlplanet.com/Estes/planK55.html

I know, a 3/16" rod and single 3/16" lug would help with rod whip.

If you want to go to extremes like the original plan, turn the "3" fin decals on their side. (The second picture is my older Goblin.)

Click to expand...

I'll glue the 3/16" lug higher then. I knew about the "3" before and I'll put them that way.

hcmbanjo said:

I'm also building the Semroc Goblin as we speak.

If you were to glue the lug in postition like the illustration in Step 17, the decal would run into the lug.
If the lower end of the lug was 4" from the bottom as the step 17 description says, the decal won't hit the lug.

Or, you can build it like the original kit. Instead of a single long 3/16" lug, use two smaller 1/8" lugs:

https://mrjoem.htmlplanet.com/Estes/planK55.html

I know, a 3/16" rod and single 3/16" lug would help with rod whip.

If you want to go to extremes like the original plan, turn the "3" fin decals on their side. (The second picture is my older Goblin.)

Click to expand...

The "3" might be a stylized bat in a "head on" position.

hcmbanjo said:

I'm also building the Semroc Goblin as we speak.

If you were to glue the lug in postition like the illustration in Step 17, the decal would run into the lug.
If the lower end of the lug was 4" from the bottom as the step 17 description says, the decal won't hit the lug.

Or, you can build it like the original kit. Instead of a single long 3/16" lug, use two smaller 1/8" lugs:

https://mrjoem.htmlplanet.com/Estes/planK55.html

I know, a 3/16" rod and single 3/16" lug would help with rod whip.

If you want to go to extremes like the original plan, turn the "3" fin decals on their side. (The second picture is my older Goblin.)

Click to expand...

Totally agree with Chris on this one!

Split the lug in two or use two smaller 1/8" diameter lugs.
Personally I always mount the aft lug just below the foreward edge in a fin/body fillet with the forward lugs rear end touching the loaded CG line.

Launch lug.......you don't need no stinkin launch lug.
Just hand launch it.:wink:

I think it is better to have 2 launch lugs with some separation. Put one close to the back end of the airframe and put the other at or slightly in front of the CG. And since you have a 3/16" lug you could just cut it in half and use both pieces that way.

Just last weekend I launched my Silver Comet converted to a V2. It has a single lug, about 2" long or so. If the rocket tries to wobble around on the launch rod it puts a lot of stress on the rod surface at each end of the lug which translates to more friction. When I loaded the rocket on the rod it slid down easily enough so I didn't think about it, and we had been using the 1/8" rod on that position so the 3/16" rod might not have been used that day. Anyway it was a windy day and the rocket was wobbling around on the rod a lot. At launch the rocket moved a couple of inches and got stuck on the rod. I checked the rod afterwards and it felt smooth and clean. I think with separate lugs some distance apart it would not have had a problem.

I have glued it on at 3.5" from the bottom. It is a 3" long lug, so we'll see what happens when I send it up.

I think I goofed it. I just put the Goblin on my 3/16 guide rod with a "D" engine in it and slid it up by using my finger on the nozzle. The aft section angled away from the rod and the lug caught and dragged along it. :cry:

I can either try to dissolve the glue (Elmer's Glue-All) or get another lug to position at the bottom. I'll probably go the lug route as removing this lug would be messy.

So it looks like my Goblin will have to wait to be finished until I get another lug. Oh well, live and learn.:bangpan:

I decided to try to remove the lug with a fresh hobby knife blade and with some patience it came off just fine. I put a little FnF on the body tube where it was and will sand that smooth, then I am going to cut the lug into two shorter lugs and place them like hcmbanjo did above.

I'll get this Goblin in the air soon enough!

Got the lugs on and tested them before I added the fillets. Much better. One more step toward me losing it on a "D: flight.

Spacepirate R said:

Got the lugs on and tested them before I added the fillets. Much better. One more step toward me losing it on a "D: flight.

Click to expand...

How long is each lug?

Just over an inch each.

Haven't seen the Semroc instructions but, on the original Estes kit the 1 1/4" inch launch lug was cut in half making each lug 5/8" long. The bottom edge of the bottom lug was glued on even with the bottom edge of the body tube. The top of the top lug was 1 3/4" from the top edge of the body tube. Just my 2 cents worth.

I just finished a Semroc Goblin and built it like the instructions said. The black stripe does go across the launch lug, but I didn't use the decal for the stripe, I just painted it on....

I got one of these at NARAM, but I haven't had a chance to build it yet (also picked up a New Way Goblin as well!). I have built one using BT-56 tubing and a Cosmic Cobra nose cone (actually, it's a kitbashed Cosmic Cobra). If you don't want to lose it, just remember that the Goblin LOVES the C11-5!

I finally launched my Goblin today!!! I used the adapter and put it up on a B6-4. Decent alt and very straight (phew!). The streamer worked very well and it landed with no damage. I need to order some C11-5s soon so I can see what it really can do. I won't have it use a D at my local field as my Blue Ninja goes very high up on one and has a tendency to drift out of the park.

Oh, I had some problems with the paint wrinkling (I sanded it and re-painted. I think I have my masking technique down now though.) but it looks good. I did get a little creative with it though. I'll post pictures in the Gallery soon.