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PML MR-1

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JAL3

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Now on to the lug.

The linear rail lug is wider at its base than the standoff molded into the transition.

I took the lug over to the bench sander and sanded away the flanges on the base until it took on the narrower profile of the standoff.

The lug was still longer than the standoff so I ground down the back end until it was the same length.

My plan is to get some screws, much smaller diameter than normally used for rail buttons, and drill some pilot holes in the standoff. I woud then epoxy the base of the lug to the standoff, insert the screws and fill the screw holes with epoxy.

Does that sound reasonable?

MR1-lug-1.jpg


MR1-lug-2.jpg


MR1-lug-3.jpg
 

n5wd

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I need to find some 29mm Hs, preferably smokey ones.

I don't have a LEUP and I need to find a launch I can get to that will have an on site vendor. Then I need to find out what line that vendor carries. THen I need to buy the hardware.
PM Stu Barrett here on the forum - he runs APCP Services out of Austin, and is usually at Tripoli-Houston launches at Hearne (near Bryan) and the Austin AARG launches, possibly some others, and can help you out.
 

JAL3

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PM Stu Barrett here on the forum - he runs APCP Services out of Austin, and is usually at Tripoli-Houston launches at Hearne (near Bryan) and the Austin AARG launches, possibly some others, and can help you out.
Thanks.

I've actually exchanged emails with him a time or too. I didn't realize he is a dealer.
 

cjl

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Very nice :)

Should fly really nice on something like the H97J :)
 

nburns

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I too have this kit. I really like it but haven't flown it on anything larger than a G. Last time I flew it the piston cracked so need to either repair it or just remove it. Hope you like if once you've flown it.

Nate
 

JAL3

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I too have this kit. I really like it but haven't flown it on anything larger than a G. Last time I flew it the piston cracked so need to either repair it or just remove it. Hope you like if once you've flown it.

Nate
This is my first piston system. I like the idea and hope it works out.
 

AndyC

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Isn't that a 38mm?
Nope. 29/240. Its a great motor. A bit less total thrust than other motors that fit in that case. PML lists ~3500' with the H97J which seems a bit high. Using winroc I only get ~2400' using 3" as the diameter - maybe this is wrong since after the transition the tube is 2.1"?. The truth is probably somewhere inbetween.

Anyway, if you are worried about altitude, the H165 or H128 (both for the 29/180 case) would give you about 15% less than the H97.
 
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JAL3

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Nope. 29/240. Its a great motor. A bit less total thrust than other motors that fit in that case. PML lists ~3500' with the H97J which seems a bit high. Using winroc I only get ~2400' using 3" as the diameter - maybe this is wrong since after the transition the tube is 2.1"?. The truth is probably somewhere inbetween.

Anyway, if you are worried about altitude, the H165 or H128 (both for the 29/180 case) would give you about 15% less than the H97.
You've sold me. Now I have to buy the hardware and find a place to fly, find a way to get the reloads, etc.

I wish there was an easier way!!!!!!!!!!!!!!
 

AndyC

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Keep watching e-bay and the for sale areas here and at rocketry planet, and maybe other places, and you might find someone selling hardware for less. I've picked some hardware up that way and saved a few bucks.
 

JAL3

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Keep watching e-bay and the for sale areas here and at rocketry planet, and maybe other places, and you might find someone selling hardware for less. I've picked some hardware up that way and saved a few bucks.
Can't do Epay anymore but I will be looking out at the rocketry auctions.

I need to save the bucks for the reloads.

Thanks,
 

JAL3

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Finishing began with the scruffing of all exterior surfaces with Sandpaper. I started with #220 and then went to #400 because I didn't like some of the gouge.

Then it was into the booth for the first of 2 coats of Kilz.

MR1-primer-1.jpg


MR1-primer-2.jpg
 

JAL3

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Doesn't anyone have any comments/advice about my lug idea?
 

cjl

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The lug idea sounds like it should work. I'd add some filler to the epoxy if you're going to use it to fill the screw holes - I've had good luck with colloidal silica for that kind of application, but even if you don't do that, I'd bet that it would work fine.
 
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JAL3

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The lug idea sounds like it should work. I'd add some filler to the epoxy if you're going to use it to fill the screw holes - I've had good luck with collodial silica for that kind of application, but even if you don't do that, I'd bet that it would work fine.
Thanks....er....colloildal silica?

What is it and where is it obtained.:eek:
 

H_Rocket

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Doesn't anyone have any comments/advice about my lug idea?

Stop shouting...

I did exactly what you did (without trimming the sides). and just used JB-Weld (because I had some mixed for something else and did not want to waste it. Worked fine until I lost it.

Colloidal Silica is a filler used to thicken epoxies so you can sculpt them. You can also use Phenolic Micro balloons, Fairing Compound, or even talcum powder to essentially the same effect. You can get any of them where you buy commercial epoxies.
 

JAL3

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Stop shouting...

I did exactly what you did (without trimming the sides). and just used JB-Weld (because I had some mixed for something else and did not want to waste it. Worked fine until I lost it.

Colloidal Silica is a filler used to thicken epoxies so you can sculpt them. You can also use Phenolic Micro balloons, Fairing Compound, or even talcum powder to essentially the same effect. You can get any of them where you buy commercial epoxies.

Sorry about raising my voice. I was just trying to capture a bit of attention.

Thanks also for the info on the fillers. My experience with them is rather limited and fairly messy. Its one of the many reasons I am no longer allowed to build at home.
 

cjl

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Stop shouting...

I did exactly what you did (without trimming the sides). and just used JB-Weld (because I had some mixed for something else and did not want to waste it. Worked fine until I lost it.

Colloidal Silica is a filler used to thicken epoxies so you can sculpt them. You can also use Phenolic Micro balloons, Fairing Compound, or even talcum powder to essentially the same effect. You can get any of them where you buy commercial epoxies.
Microballoons weaken the epoxy though, while colloidal silica actually strengthens it somewhat. West system sells it - it's their number 406 filler.
 

H_Rocket

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Microballoons weaken the epoxy though, while colloidal silica actually strengthens it somewhat. West system sells it - it's their number 406 filler.
Really? Interesting. I tend to use milled glass for strengthening. Is there an advantage of the silica over glass?
 

FROB

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The silica turns the epoxy int a smooth jell like tooth paste that wont run & is easy to apply.
Milled glass is much stronger but messier & hard to get smooth.
 

cjl

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Really? Interesting. I tend to use milled glass for strengthening. Is there an advantage of the silica over glass?
Milled glass is stronger than the silica (though slightly heavier). I find the silica to be easier to work with, but either is excellent. I tend to use whichever I happen to have at hand actually. Never had a problem with either milled glass or colloidal silica.
 

JAL3

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I am not overly fond of flat paints so I decided to go this something similar too, but not like the "publicity photo". I proceeded to give the forward section a coating of flaky metallic silver. I had gotten a case of the stuff for another project and it has worked well for me.

MR1-masked-for-silver.jpg


MR1-silver-1.jpg


MR1-silver-2.jpg
 

GaryT

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John:
Here's a Scratch built upscale of a PML MR1 I did, Well it's not really scale as I just eye balled it, The BT is a 75mm MM I had, The Transition is made up of an old middle section of a 4" NC, 4" BT & 6oz Fiberglass, NC I got out of a junk pile at RG5 form Jeff Taylor, The (2) ¼" CR's and 1/8" Birch Fins I made myself. Here are its specs:

Height- 36"
Weight- 33oz
BT- 3"NC- 4"
Motor Mount- 54mm With an Aeropack Retainer.
CP- 29" From Tip.
Test Photos 038.jpg

I'm Now thinking about doing a Bigger one that will naturaly be DD. That one would be.

NC- 7.5"
BT- 5.5"
MM- 75mm
Height- Approx 90"
 
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JAL3

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John:
Here's a Scratch built upscale of a PML MR1 I did, Well it's not really scale as I just eye balled it, The BT is a 75mm MM I had, The Transition is made up of an old middle section of a 4" NC, 4" BT & 6oz Fiberglass, NC I got out of a junk pile at RG5 form Jeff Taylor, The (2) ¼" CR's and 1/8" Birch Fins I made myself. Here are its specs:

Height- 36"
Weight- 33oz
BT- 3"
NC- 4"
Motor Mount- 54mm With an Aeropack Retainer.
CP- 29" From Tip.
View attachment 1691View attachment 1692

I'm Now thinking about doing a Bigger one that will naturaly be DD. That one would be.

NC- 7.5"
BT- 5.5"
MM- 75mm
Height- Approx 90"

Thanks for sharing. It really looks nice and I like the non-khaki/drab paint job too.

I'm hoping to finish mine except for the lug mount this afternoon. Then I have to wait for an opportunity to fly it.
 

JAL3

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The silver had a couple of days to dry and then I peeled off the masking and reversed it. The bottom of the rocket was then sprayed with a glossy, dark green. I don't know where I got the can from. I didn't even know that Valspar made rattle cans.

MR1-masked-for-green.jpg


MR1-green-1.jpg


MR1-green-2.jpg
 

JAL3

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When the green had dried, the masking was peeled off and the results inspected. I was satisfied and needed only to get to work on the lug.

MR1-painted-1.jpg


MR1-painted-2.jpg
 

JAL3

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Wow. Your MR-1 looks very familiar. You need some yellow "detonator" on the tip of the nose though :p

Its uncanny.

I do like the "Detonator". I might have to do something about that.
 

Pem Tech

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Wow. Your MR-1 looks very familiar. You need some yellow "detonator" on the tip of the nose though :p

WOW!!!
That is a killer photo!!
I am much envious of your skills...
 
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