Best choice of motor for L1 on a LOC IV?

[aviator172rr]

Hello everyone,

Just ordered a LOC IV and will be attempting a Level 1 flight next month in Lucerne Lake!

I want to fly it on an H motor and want to go with the safest and single-use option for this flight. I was thinking Aerotech H100W-14A but not sure if it would handle it well. Especially right as it's leaving the launch rod in case there are strong winds that day. My understanding is that we want the rocket to go straight up 90 degrees if possible so not sure if this motor would have enough power to fight the wind (if there is any).
I will also be fiberglass wrapping the fins so that will add a bit of weight too.

Any suggestions?

 

[SkyFire]

Looks good on RockSim. Delay should be reduced to 10 seconds.
Suggest using RockSim or Open Rocket simulations before using any motor.

 

[aviator172rr]

Thanks!
I used Open Rocket for my mid-power rocket and I will certainly be using it for this too once I am done building this with all the correct weight data, etc.
Just wanted to order the motor in advance since it takes time for shipping.

 

[T-Rex]

You can get a .rkt or .ork file in several places on the net for free. No it won't be exact, but it will be close enough for you to chose a motor and get it ordered. You might need a second choice if the H100 is unavailable.

 

[aviator172rr]

I actually looked for it but couldn't find it. I will keep looking. Thanks

Update: Just found it

 

[teepot]

When you get a final weight put that info into Thrustcurve. That will give you multiple motor options. the information will include speed off the rail, projected altitude and suggested delay, to name a few.

 

[bobbyg23]

Any of these will work great. Don't go too small on the motor. H135 or h282 would be great choices.

 

[bobbyg23]

I175 would be a great choice. Plenty of oomph of the pad and right around 2300'. Would be a perfect flight.

 

[ThirstyBarbarian]

I like a lot of the 29mm single use motors, but you would need an adapter, which is a great thing to have in general. H115 is a great L1 motor, plus it’s sparky. H135 and H182 are also nice.

 

[PayLoad]

The H182 would give you the grunt off the rod & not too high of an altitude

 

[T-Rex]

I flew my L1 using a similar rocket on an H238T. Great flight to 1500ft.

 

[Sandy H.]

My choice, assuming 38mm motor mount would be:

Any 38/480 RMS option that is normal (i.e. not endburn or plugged). They are all I motors, but on a 4" LOC should be in the 3000-3500ft realm, I imagine (no sim/check, just field flying recollection). The 38/360 RMS options are similar, but lower altitude.

I know a lot of people cert on the H128 (29/180) but that would be a little soft for my preference on a 4" rocket (vs 2.6" which I've done on and H128 safely and easily in the 2500ft range, no fiberglass).

I've never flown a DMS motor, but I would guess an H or I with an average thrust of 170-300+ would get you off the rail pretty well and still be in the 2000-4000ft range on a 4" rocket.

No need for fiberglass at this size on an L1 motor, but if you choose to go that route, tend toward harder hitting motors off the pad.

Sandy.

 

[Scott_650]

I used an Aerotech DMS H100 drilled to about an 8 second delay for my L1 in a Discount Rocketry 4” Crayon Rocket, similar in weight (but a bit draggier) than a LOC IV - perfect motor for my successful attempt, the altimeter data almost matched my Open Rocket sim perfectly, apogee 1550 feet. I set my Chute Release to 500 feet so I didn’t have to walk too far but in low wind conditions recovery would’ve been fine without it. Good luck on your attempt!

 

[mrwalsh85]

The best motor? Whatever you want.

 

[OverTheTop]

^^^ This. It is your flight so you get to choose how you want it to fly!

If it were my choice I would probably go the H182 because I love red motors. YMMV.

 

[Donnager]

A 38mm H-219 is pretty sedate compared to a lot of them, and should be great for what you are doing. That is what I got my L1 on in a LOC Goblin.

Most of the college students getting their level 1 use the proverbial H100 at our site.

If I was just looking for an H to check the high power box, I'd choose the H115 DM or the H135, both 29mm. There is not much difference between an H-115 and a G-80 or G138.

 

[DaHabes]

I used an H219T for mine (Madcow Super DX3). It has nice pop off the rail, being Blue Thunder, easy to light, being Blue Thunder, and it's a baby H, so it will keep the bird in sight and won't go too high, so drift won't be an issue, even without a chute release. In the grand scheme of certification you have to retrieve the rocket and have it be flight worthy, the best of all options is to use a big chute for a soft landing and a Jolly Logic Chute Release. If you don't have a JLCR, someone at a club launch surely will (they are very common now at both clubs I launch with) and will likely let you borrow it. Just make sure you get good instruction from the owner on how to use it and bench test it on your parachute folding to ensure it opens.

 

[Terry Habegger]

A lot of good advice here
Loc IV and DMS H100 was my choice and worked well.
Build your rocket strong with good epoxy and you can use same rocket for L2.
I did L2 with a DMS J425R.
My advice if you have room in your budget buy and use a chute release.
As always talk to your senior club members.
Terry L2

 

[aviator172rr]

Wow. Great responses. Thanks, everybody.

 

[Michael L]

I flew my LOC IV on a Cesaroni I350 for the L1 cert flight (I wouldn't do that again but it was a very nice flight). The 2nd flight was on a Cesaroni I540 I used motor deploy. I used a larger chute than what it came with. It took forever to come down but the landing was nice and soft. I might still do that again but the 2nd flight had the LOC suppled chute and it did just fine.

Think of this post as a "it worked but I wouldn't make that choice again" post.

L2 (all fiberglass) rocket is purchased but I haven't started building. I have converted the LOC IV to dual deploy with backup and I need to make sure I know how to do that correctly first. My LOC IV has turned into a test bed.

Best wishes for a successful launch and certification.

 

[teepot]

I used a scratch built 3" with a 38mm mount. I put an adaptor in and flew it on an AT DMS H195. Flew to 1800'. A soft landing and a 500 yard wind blown drag across the lake bed. They took that into consideration. It was pretty scratched up but still flyable.

 

[rdrown]

I used a scratch built 3" with a 38mm mount. I put an adaptor in and flew it on an AT DMS H195. Flew to 1800'. A soft landing and a 500 yard wind blown drag across the lake bed. They took that into consideration. It was pretty scratched up but still flyable.

The true definition of "Scratch Built"