BT-50 Thrust Rings - What to use?

I'm in the middle of building an Estes Goblin clone with a baffle and realized I don't have any thrust rings (engine blocks). What can I use instead?

I don't have any spent D engines and could order some but was hoping to give this thing a test lunch later in the week.

OK here is what I just used...BT-50 centering rings for 18mm engine mounts...
Perfect fit >>>> https://www.hobbylinc.com/htm/sfr/sfr825024.htm

Apply several wraps of 1/4" masking tape to the base of the motor for an external thrust ring

I'd go with the external thrust ring. Engine blocks limit the size of a motor that can be flown.
DOWN WITH ENGINE BLOCKS!!!!:kill:

The baffle I was going to make was like what was used in the old Estes Bandit kit with and extended engine holder tube, holes in the side of it and a solid bulkhead in the end. The tape idea made me think. How does wrapping some tape backwards around an engine to the proper thickness sound and using that? everything will then get coated in epoxy.

Aksrockets said:

I'd go with the external thrust ring. Engine blocks limit the size of a motor that can be flown.
DOWN WITH ENGINE BLOCKS!!!!:kill:

Click to expand...

Don't know if a Goblin with larger than a D is such a good idea in my area. Field sizes would be an issue.

Scode68 said:

I'm in the middle of building an Estes Goblin clone with a baffle and realized I don't have any thrust rings (engine blocks). What can I use instead?

I don't have any spent D engines and could order some but was hoping to give this thing a test lunch later in the week.

Click to expand...

Roll up a strip of cardstock until it's the same size as a thrust block. Glue it in.

The standard Goblin motor block is an AR-2050 adapter ring: https://www.semroc.com/Store/scripts/prodView.asp?idproduct=1070

There are lots of other usable alternatives already listed in this thread...

I can't imagine putting anything bigger than a D in a Goblin unless one simply wanted to get rid of it.

bradycros said:

Roll up a strip of cardstock until it's the same size as a thrust block. Glue it in.

Click to expand...

Yeap that's exactly what I was going to recommend if you don't have a spent D12 casing laying around. cut a 1/4" strip of cardstock and rolled around a 3/4" dowel until it's the same ID as your BT-50. smear a bit of white glue on the strip and re-roll. when dry they work like a charm.

bradycros said:

Roll up a strip of cardstock until it's the same size as a thrust block. Glue it in.

Click to expand...

I've done this too. Just takes a minute to fabricate a thrust ring like this. I like to smear a little extra glue on them to protect from ejection gas.

Micromeister said:

Yeap that's exactly what I was going to recommend if you don't have a spent D12 casing laying around. cut a 1/4" strip of cardstock and rolled around a 3/4" dowel until it's the same ID as your BT-50. smear a bit of white glue on the strip and re-roll. when dry they work like a charm.

Click to expand...

Or you can wrap it around a 18mm engine case...:wink:

Since I was a little impatient or anxious I made one from masking tape and covered it in epoxy but next time if I don't have any spent engines I'm going to wrap the card stock.

Thanks guys!:clap:

I keep a bag full of spent engines downstairs in my rocket lab. Very useful things, spent engines!

Have plenty from C and below but I haven't launched a D in probably 20 years.

Long ago we used to have a great time launching Goblins on AVI blackpowder E's. An Estes E11 would not quite be the same performance but probably a wee bit more reliable Just be sure to do it from a big field and have an experienced rocket flight watcher on hand, it will really haul #!$%. For that kind of stuff we always used the CHAD method of a masking tape ring at the back of the engine.