Mars Lander Finished!

This one has been sitting in my build pile for quite a while.
I'd like to fly it with an 18mm D. Any suggestions?

I bought the Semroc kit a few years back. This one was #15. I screwed up the landing gear and one shroud and set it aside for a few years. Recently, I made an order to Semroc for replacement parts and two weeks later, here are the finished pictures.

I'd forgotten what a involved build this was. I built the Estes original in the 1970s. This model is one of the reasons they are called "classics".

Taking cues from other threads, I painted the legs separately before gluing the whole thing together. When the shrouds were stacked, the fit was okay. There is a small step at the joint of the mid and upper shroud.
Decals didn't stick as well as I would have liked. I tried to go light with the white body spray paint, that gave me a semi-gloss finish which probably didn't help adhesion. But it's done!
Onto the next half finished bird.

Wow it looks awesome. Put up pictures of it flying

Looks great, but it don't count till we see flying pics.

Don't listen to him, Landers always count! Very nice.

Nice job, I am waiting on a nice calm day to fly mine. I think the D will work,
I suggest double checking the center of gravity before flying and the Lander
does not like wind.

hcmbanjo said:

This one has been sitting in my build pile for quite a while.
I'd like to fly it with an 18mm D. Any suggestions?

I bought the Semroc kit a few years back. This one was #15. I screwed up the landing gear and one shroud and set it aside for a few years. Recently, I made an order to Semroc for replacement parts and two weeks later, here are the finished pictures.

I'd forgotten what a involved build this was. I built the Estes original in the 1970s. This model is one of the reasons they are called "classics".

Taking cues from other threads, I painted the legs separately before gluing the whole thing together. When the shrouds were stacked, the fit was okay. There is a small step at the joint of the mid and upper shroud.
Decals didn't stick as well as I would have liked. I tried to go light with the white body spray paint, that gave me a semi-gloss finish which probably didn't help adhesion. But it's done!
Onto the next half finished bird.

Click to expand...

WOW! When you fix 'em, you really fix 'em good. Now I know who to ask for pointers after I get one. How much of the build was all ready completed when you decided to fix 'er up?

On the first attempt, I built the landing gear first. I tried to fill the dowel / balsa joint on the leg's trailing edge without sucess. If you look closely at the pics, I had better luck with the second try.

I tend to jump around instructions and made the lowest exhaust nozzle. Be careful with your build - I used a little too much glue on the nozzle. The wet, white glue can distort the shroud cardstock. You don't want to have any of these cardstock shrouds "force fitting" on the internal rings.

I was frustrated and set it aside for a couple of years. I've done in the past and when I come back I usually get better results.

Looks really nice Hans! I flew my Outlander on a D24 for a great flight..The Mars Lander should do as well! MAYBE about 100-115 foot altitude, almost stuck the landing too!

Excellent job, Chris! I'm trying to decide if I'm an awesome-enough builder yet to take on this kit. I'm pretty sure that the answer is no, not even close. But what the heck, why let that stop me? Every time I see an ML build thread, I get closer to ordering one. This may finally push me over the line.

MK

I 've never seen a Mars Lander other then pictures. Do the legs really "give" when it lands?

The closest that I have to one is an all-plastic #1826 Mini Marz Lander RTF, the only ready-to-fly that I own that is not designed for Micromaxx. The legs on it are sprung to give them some shock absorption, but the elastic only has about half the tension that it needs to be really functional. My flight record for it: launches = 4; successful parachute deployments = 0. (It's a durable little guy, though, and is completely undamaged.) The Semroc Mars Lander, like the original, does much better, I understand.

MK

Yes, the legs are rubber band loaded. They travel up that rounded slot in the housings. It has a really wide stance and should land upright.

I've only seen a Mini Mars lander recently. A former Estes emplyee was flying with our Orlando R.O.C.K. section. This was before the RFT and was a kit, as I understand it. It flew great with a A10-3T.

I think the Semroc re-issue is buildable by anyone with experience. Estes rated it at a Skill level 5, Semroc rates it at a Level 4 Master. I was probably 16 when I built the original Estes kit.

Check out the Semroc instructions so you know what you are getting into:

https://www.semroc.com/Documents/pdf/Mars Lander.pdf

hcmbanjo said:

https://www.semroc.com/Documents/pdf/Mars Lander.pdf

Click to expand...

Yes, I've looked at them before. Hence my caution. :shock:

MK

hcmbanjo said:

This one has been sitting in my build pile for quite a while.
I'd like to fly it with an 18mm D. Any suggestions?

Click to expand...

I bought the 18mm reload hardware. Check out Aerotech's ValueRockets website. The D reloads are only $7.90 for a 3-pack. Most places charge about $12-14.

Trident said:

I bought the 18mm reload hardware. Check out Aerotech's ValueRockets website. The D reloads are only $7.90 for a 3-pack. Most places charge about $12-14.

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The critical question is, will it need nose weight for stability? The shape suggests that it has a good deal of base drag, which could potentially pull the CP rearward by an appreciable amount. I know that there was a build article of the Semroc ML in Sport Rocketry last year, in which the author described his struggle with getting it statically stable with 18mm AT motors, but I don't recall if he factored in the base drag.

MK

MarkII said:

Yes, I've looked at them before. Hence my caution. :shock:

MK

Click to expand...

MK,

Don't worry, buy it and build it! If I can do it anyone can.

It's really not that bad. Just take it in sections. There are really no show stoppers. The Semroc kit even has laser cut fins. You do have to cut the dowels and glue the shrouds, but it's really not that bad.

Just build it!



Hans,

Great lander! I love the 2 tone legs. Mine flys great on a C6-3. Are your legs 13 1/2 inch spread? Do your legs have much side play? Lastly is it less that 4 Oz empty? Those are the biggies.

PLEASE PLEASE PLEASE post a flight photo!

hcmbanjo said:

I'd like to fly it with an 18mm D. Any suggestions?

Click to expand...

I've flown my on D24's. Always a great flight.

tonypv said:

I've flown my on D24's. Always a great flight.

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Was that the launch in Tewksbury when it spit the case and we spent quite a while searching for it?

BobH48 said:

Was that the launch in Tewksbury when it spit the case and we spent quite a while searching for it?

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Yes.

But we found it.

tonypv said:

Yes.

But we found it.

Click to expand...

The motor or the ML?

MK

MarkII said:

The closest that I have to one is an all-plastic #1826 Mini Marz Lander RTF, the only ready-to-fly that I own that is not designed for Micromaxx. The legs on it are sprung to give them some shock absorption, but the elastic only has about half the tension that it needs to be really functional. My flight record for it: launches = 4; successful parachute deployments = 0. (It's a durable little guy, though, and is completely undamaged.) The Semroc Mars Lander, like the original, does much better, I understand.

MK

Click to expand...

If you have one of the RTFs with red legs, cover them with tape, paint the rest white, and apply decals found here:

https://www.tangopapadecals.com/$10_oop.htm

That's what I did (see my avatar).....

Tom C.

MarkII said:

The motor or the ML?

MK

Click to expand...

The motor.

conleyt said:

If you have one of the RTFs with red legs, cover them with tape, paint the rest white, and apply decals found here:

https://www.tangopapadecals.com/$10_oop.htm

That's what I did (see my avatar).....

Tom C.

Click to expand...

I have one that I did the same thing too.

While I do not have the Mars Lander, I did build the Outlander which I am told has very similar characteristics. While it has flown on a C6-3 with a mix of success and failure, I did fly it on the aerotech D21-4T once and it was by far its best flight. It ripped off the pad with a loud roar and boosted to a nice altitude. It did not stick the landing which I have yet to do but a great flight nonetheless. I did not have to add noseweight. So I would guess the 18mm D motor would do very well for your Mars Lander if it seems a bit underpowered on the C.

Glenn

Thanks GlennW,
That's the information I'm looking for!
I had a feeling the D21-4 would be the way to go, but I was waiting for input from those with experience from the "Lander" series.

I've got both the Outlander and ML sitting on the shelf beside me. The Outlander is considerably heavier than the ML and more draggy to boot. I wouldn't try the Outlander on any 18mm BP motor, but the ML flies decently on a C6-3.

The old catalogs call for a B4-2 on the first flight, but I don't think I'd try it with my current ML. I might build a second one with a lot less finishing effort and try it with a B6-2 one of these days.

I've flown mine on a B6-2. It flew great, but it does not get a full 'chute until close to the ground! It made maybe 75-90 ft altitude.

I like the C6-3.

My Mars Lander weighs in at 4.8 Oz empty, My Outlander comes in at 5.8 Oz and it is much more draggy than the ML.

I was really tempted to use a 18mm D in my Lander.
I'm glad to know the C6-3 is okay. I've got plenty of those!
I've heard stories about unsuccessful flights with a B6-2 and C6-3. Who knows, those could have been built a little heavy or flown in gusty winds.
Just looking at the cross section, I don't think I'd ever use a B4-2 or B6-2.

In answer to Mach7 -
The legs are right at a 13 1/2" span.
There's not any real side play in the legs. There's just enough side clearance to move up and down in the housings.
When I get access to a good scale (mine isn't very accurate) I'll weigh it. If it's above 4 oz. I will probably go with the D.

Sounds like your on the right track.

I've flown mine in 10 mph winds on a C6-3 and it did just fine and mine comes in at 4.8 Oz.

Carl of Semroc posted a great piece on the M.L. stability. I think its on YORF, if I find it I'll post a link.

Mach7,
I went back to some older Mars Lander threads looking for the stability posts. May be I should have read more build threads before tackling the ML. I came across build thread by a great modeler named Leo.
Scroll down to post #7:

https://forums.rocketshoppe.com/showthread.php?t=787&page=1&highlight=mars+lander

This is the same issue I had with mine. My model was an early #15. It wasn't a big deal. Certainly not a complaint directed at Semroc, Carl has corrected the problem. It just took some trimming to get it close.

The first shots I took were outdoors with sunlight directly overhead. The bright upper lighting really made the upper shroud joints look way out of whack.
I painted the shrouds separately then glued them together. This didn't allow paint to get on and into the upper shroud's seam. Some of the brown laser cuts show at the edges which only makes the joint more evident.
I know - to some these are moot points. But, it does explain some of the problems I had with the shroud fit and could help a builder who has an early run kit.

Here's a few more pics, taken indoors in a more flattering light.

That looks great!

Hans, your being too critical of your work, but I guess we all do that to some extent.