It's Hedley, Hedley Babar !

[kjhambrick]

This is Hedley Babar:


Attached below is a preliminary design based on @Alan R's BMSSchoolRocket17.ork File.

I am going with the short 17-inch airframe so maybe I can translate what I learn with Hedley into smaller rockets.

The only real mod to the standard BMS 3-inch School Rocket is that I will install a Featherweight 38mm Av-Bay in the nose and MAYBE add a screw-on retainer to the 29mm MMT instead of the standard BMS motor clip.

I've never flown an HED Rocket but I've wanted to try it ever since I read about it here on TRF.

Thanks to everyone on TRF for all the HED designs along with the best practices and gotchas !

I am sure I'll have LOTS of questions and I'll post follow-ups here as the build progresses.

-- kjh

Gratuitous Video Clip:

 

[Rschub]

 

[kjhambrick]

@Rschub --

Where in the world did you find my portrait ?

--kjh

 

[lakeroadster]

@BABAR takes offense at your blatant and unprovoked use of his avatar...

 

[kjhambrick]

@BABAR takes offense at your blatant and unprovoked use of his avatar...

Maybe I should rename this one Hedley Rebar ?

EDIT: can't afford a Lawsuit

-- kjh

 

[bad_idea]

MAYBE add a screw-on retainer to the 29mm MMT instead of the standard BMS motor clip.

Drat, I won't make it to Apache Pass this weekend, else I could bring you an Estes 29mm retainer, of which I seem to have a gazillion or so gathering dust. If you'll be at Hearne on the 13th, I could probably send you one by sneakernet (too late to arrange that this week), or if you're taking your time with the build, I could get one to you at Seymour at the end of the month or Apache Pass next month. (Like a neutron, there is no charge. I have these things running out my ears.)

 

[kjhambrick]

Thank you, Stephen !

The Estes plastic 2-fer retainer is the one I was thinking about trying -- I'll remove it from my Hobbylinc cart !

I don't imagine I'll even start the build for a few weeks ( I still need to order the BMS Rocket and find a pair of line-cutters ).

I bet I will see you before I even have the parts on hand for Hedley ...

As for this month's launch ... Jim changed the AARG launch from Saturday ( Mostly Cloudy with 19 mph S wind ) to Sunday ( Partly Cloudy with 8 mph NW wind )

I will 'un-scrub' my flight and try to launch T'Pring's P'Toy on an I161W at Apache Pass on Sunday.

Thanks again, Stephen, I'll be in touch !

-- kjh

 

[bad_idea]

Thank you, Stephen ! The Estes plastic 2-fer retainer is the one I was thinking about trying

You're quite welcome. There's now a 2-pack in my range bag waiting for the next time I see you.

I've used those Estes retainers extensively. For the thicker thrust rings of high-power motors that have fewer turns to engage the retainer, I usually add a patch of blue tape to the threads to tighten them up. It comes off easily after the flight. @AeroTech suggested taping the thrust ring to the retainer, which I've also done.

I still need to order the BMS Rocket and find a pair of line-cutters.

Re. the line cutters, you and me both. While realistically my design/print/test/iterate/finalize/build loop is slow enough that there's nearly no chance of my flying a new cable-cutter HEDD design by the Shootout next month, I'd really like to get a set cable cutters in-hand to get further into that design. Improved Piranhas are an obvious choice, but if they're not available soon, I may wander off onto a tangent and try to develop some of my own. @rocketace makes some tiny ones, I believe. Tagging him so he'll know to hide from me if he doesn't want to be peppered with questions when next we meet.

As for this month's launch ... Jim changed the AARG launch from Saturday ( Mostly Cloudy with 19 mph S wind ) to Sunday ( Partly Cloudy with 8 mph NW wind )

If it weren't that I expect I35 to be clogged with eclipse traffic by Sunday evening, I'd probably attend even though I don't have as much ready to fly as I should. As it is, I'm passing on this month. Hope that great weather Sunday gives y'all a lovely day of flying.

 

[BABAR]

Maybe I should rename this one Hedley Rebar ?

EDIT: can't afford a Lawsuit

-- kjh

No worries.

For the less educated among us (like me)this may be helpful

Head End Deployment

https://www.rocketryforum.com/threads/hed-vs-traditional-dual-deploy.181956/

 

[bad_idea]

Improved Piranhas are an obvious choice, but if they're not available soon, I may wander off onto a tangent and try to develop some of my own.

Barely an hour after I posted this, I heard from @Cameron Tinder that more Piranhas will be available in a few weeks. That's plenty of time for me to avoid a tangent this time around.

 

[kjhambrick]

Barely an hour after I posted this, I heard from @Cameron Tinder that more Piranhas will be available in a few weeks. That's plenty of time for me to avoid a tangent this time around.

@bad_idea --

@Cameron Tinder let me know over in the Piranha Cutter Thread that you canceled your order so I could buy it !

I purchased your pair of Improved Piranha Line Cutters from Cameron yesterday afternoon.

I've also ordered the BMS goodies that I will need so if all goes well, I should be ready to fly Hedley next month !

THANK YOU !

-- kjh

 

[bad_idea]

Anytime, Konrad. You're closer to when you need these than I, and you'd been looking for them longer than I had, so I was happy for you to have them. Looking forward to this build, and to seeing the finished rocket!

 

[kjhambrick]

Anytime, Konrad. You're closer to when you need these than I, and you'd been looking for them longer than I had, so I was happy for you to have them. Looking forward to this build, and to seeing the finished rocket!

Thanks Stephen !

The Piranha Line Cutters arrived today.

They're BEAUTIFUL and there is a nice little box to keep the parts together.

Can't wait to ground test it and then to fly them in Hedley -- just need to receive my BMS order and do a little building.

I really want to fly them in other rockets without a payload bay too.

For example in a 2.6 inch Nike Smoke with a big, beautiful hollow Glass nose cone

-- kjh

 

[kjhambrick]

Woo Hoo !

My 29mm x 3-inch BMS School Rocket and a few parts for the Av-Bay arrived today !

Great service from BMS ( ordered Saturday / received Thursday ).

I'll unbox the parts and weigh them tomorrow and maybe take a pic or two ...

Woo Hoo !

-- kjh

 

[bad_idea]

My 29mm x 3-inch BMS School Rocket and a few parts for the Av-Bay arrived today !

Great service from BMS ( ordered Saturday / received Thursday ).

BMS are great. Very few of my mid- and high-power rockets to date haven't had at least some BMS content. Good quality, great prices, and fast to ship.

If you start building before I can get the retainers to you, leave at least 11mm of motor tube exposed. My notes say the depth inside the threaded half of the retainer is 10.5mm with a 5mm ledge at the back that wraps around the back end of the motor tube.

 

[kjhambrick]

BMS are great. Very few of my mid- and high-power rockets to date haven't had at least some BMS content. Good quality, great prices, and fast to ship.

If you start building before I can get the retainers to you, leave at least 11mm of motor tube exposed. My notes say the depth inside the threaded half of the retainer is 10.5mm with a 5mm ledge at the back that wraps around the back end of the motor tube.

Thanks Stephen.

Yes, I've modified the MMT / CRings in OpenRocket so the 29mm MMT extends 9/16 inch ( ~ 14 mm ) past the aft CRing.

I couldn't help myself -- I opened the box and fondled my parts

The parts are all first class !

The 11-inch polystyrene nose cone is BEAUTIFUL and I will be able to bond a pair of internal plywood CRings with epoxy for the Av-Bay ( I was worried that it might be HDPE and I would need screws ).

EDIT: the 11-inch HDPE nose is still BEAUTIFUL but I will need to use flat-head screws thru the shoulder to secure the Featherweight 38mm Av-Bay ( shucks ).

And I didn't realize the aft CRing includes a pre-installed blind-nut for the #6-32 motor clip screw.

I've used that method before and it's very secure except that I once lost the clip in the sand at Fiesta Island and had to go with tape

Tape works too

Anyhow ... I am very pleased ... the BMS 29mm / 3-inch School Rocket is a BARGAIN at $30.00 !

-- kjh

p.s. I just might order a pair of 24mm 3-inch School Rockets for Ellie and Evie.

Looking at the instructions, about all they would need is a ruler, wood glue masking tape and paint ( and stickers -- gotta have stickers ! )

 

[kjhambrick]

Parts is Parts ...



Extra parts are at the top right next to the instructions:

2 x CR38300-W ( 38mm motor mount in 3-inch airframe CRings for the Av-Bay )
2 x BHC300-W ( 3-inch Coupler Bulk Plates for the aft-end of the Av-Bay )
1 x TopFlite 24-inch chute ( purple - main )
2 x TopFlite 9-inch chutes ( green and yellow -- great colors for finding a rocket in a corn field )

Next is measuring and weighing parts and learing the state of the art for bonding wood to HDPE

-- kjh

 

[manixFan]

Looks like a great project using a lot of good techniques. I must admit, I was a bit surprised you'd post a link to a Blazing Saddles clip, that can be quite risky. When we watched that movie with my son a few years ago (he was in his mid 20's), he kept asking: "are they allowed to say that!?"

Looking forward to seeing you and the rocket at Seymour, hopefully sooner than later.


Tony

 

[bad_idea]

Parts is Parts ...

View attachment 640269

Is there enough motor mount to engage both centering rings and still leave enough room for the Estes retainer? I have plenty of BT52H on hand if you need a long piece.

 

[kjhambrick]

Looks like a great project using a lot of good techniques. I must admit, I was a bit surprised you'd post a link to a Blazing Saddles clip, that can be quite risky. When we watched that movie with my son a few years ago (he was in his mid 20's), he kept asking: "are they allowed to say that!?"

Looking forward to seeing you and the rocket at Seymour, hopefully sooner than later.


Tony

Thanks Tony.

I didn't mean to offend anyone ...

I don't often agree with Woopie Goldberg, but she is an intellegent person and I do agree with her assessment of Blazing Saddles ( Whoopi Goldberg Rejects Claim That ‘Blazing Saddles’ Is Racist: ‘Leave the Movie Alone, Don’t Make Me Come for You’ )

... “It deals with racism by coming at it right, straight, out front, making you think and laugh about it, because, listen, it’s not just racism, it’s all the isms, he hits all the isms,” Goldberg said (via Entertainment Weekly). “‘Blazing Saddles,’ because it’s a great comedy, would still go over today. There are a lot of comedies that are not good, okay? We’re just going to say that. That’s not one of them. ‘Blazing Saddles’ is one of the greatest because it hits everybody.”

“If you’ve never seen ‘Blazing Saddles,’ you should do yourself a favor, get some popcorn, get a glass of wine, and put it on, because it’s magnificent,” Goldberg added before telling the film’s critics: “Leave my ‘Blazing Saddles’ alone. Don’t make me come for you!” ...

I meant to go to Seymour last month but I missed the announcement that the launch was moved forward a week for Easter.

Anyhow, I hope to come to Seymour this month ( Apr 27 / 28 ) to watch some rockets fly and so I can learn the site.

That way I should be ready to fly something or other at the Texas Shootout in May.

-- kjh

 

[kjhambrick]

Is there enough motor mount to engage both centering rings and still leave enough room for the Estes retainer? I have plenty of BT52H on hand if you need a long piece.

Thanks Stephen.

The stock 5.65 inch MMT will be fine because the TTW fin tabs are only 2.5-inch long so they only span the aft 3.0-inches of the 5.125-inch root chord:

I've been adjusting weights and measures now that I have the parts on hand.

I am not done yet but the latest .ork is attached ... She's gained about 50 grams over the original .ork I attached to post #1 above.

There will be more with Glue and Paint and after I figure out how to bond the Av-Bay Rings to the HDPE nose.

I am researching exotic adhesives before I decide ... Materials Science sure has progressed while I wasn't looking

-- kjh

EDIT: This will likely be a slow build because I was thinking I might put it together with my granddaughters to decide whether or not to get a pair of BMS School Rockets for them to build.

 

[bad_idea]

Thanks Stephen.

The stock 5.65 inch MMT will be fine because the TTW fin tabs are only 2.5-inch long so they only span the aft 3.0-inches of the 5.125-inch root chord

Nice!

BTW, Estes retainer should be about 13.4g.

 

[kjhambrick]

Nice!

BTW, Estes retainer should be about 13.4g.

Thanks, Stephen !

I needed that

Updated HEDLEY-3.0.ork is attached ( dry mass now 487 grams ).

-- kjh

 

[kjhambrick]

Stephen --

After trying the 29/40-120 and HP 29mm reload casings as well as RMS 24/40 and 24/60 casings in an adapter, I decided to use the supplied BMS motor clip.

This meant we had to build the MMT with the recommended 1/4 inch overhang so the short-ish Z-clip would reach the end of the motor or adapter.

So ... here is Hedley.ork modified for the BMS Z-clip:



We put together the booster with Titebond III Ultimate over the weekend.

The sum of the same parts in OR is 200.63 grams. The actual booster mass on a scale is 200 grams ... I am surprised it is so close !

I'll need to make allowances for filler and paint and maybe a 'HEDLEY' sticker ...

I'll be doing the nose cone next without the girls to keep them away from Epoxy Goo

-- kjh( trying to get her flyable for Seymour or AARG-May )