Annoyed with kit manufacturers not including full specs

When shopping for rocket kits, the most annoying thing to me is when manufacturers don't include full specs. It's a rare treat when a kit is shown complete with diameter, height, weight, MMT diameter, materials for all parts, fin thickness, bay length, hardware, etc. Seems like the most commonly-omitted spec is weight (kind of important), followed by overall length.

Note to manufacturers: If I can't easily find the full specs, I will shop elsewhere. Please update your information.

amen

I'm curious, what manufacturers list all of this info?

No one. Estes is closest.

Off the top of my head PML and LOC seem pretty good about it, but Wildman and Madcow in particular have been bothering me lately. I've been looking for a full FG kit and they seem like the place to go, but hell if you can directly compare any two of their kits because each one is missing some crucial spec.

Different strokes for different blokes I suppose.

For me, dry weight of the components is pretty useless since I know my complete build is going to be heavier anyway.
I could potentially see a desire for simulation purposes, but I also don't feel the need to have an incredibly accurate sim prior to even Buying the kit.

You are of course free to purchase from whoever you wish. Maybe have a chat with Tim next time you call about an order?
(I'm not sure I've looked at a kit that didn't list mount diameter...)

Nytrunner said:

For me, dry weight of the components is pretty useless since I know my complete build is going to be heavier anyway.

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Same here, but I know about how much I overbuild. I just want a starting reference. Not listing any kind of ballpark weight is silly. Are the kit components 16 oz? 100 oz? Throw me a bone here...

Nytrunner said:

I could potentially see a desire for simulation purposes, but I also don't feel the need to have an incredibly accurate sim prior to even Buying the kit.

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FWIW I'm looking for a FG kit I can fly on a big I or small J at club launches (3000 ft waiver) that still has the potential for supersonic flights at another site but at a reasonable altitude (6000-8000ft).

I think I like the Wildman Drago 4, although I had to guess the weight since they don't list it. I'm going with 80 oz. for now, but I suspect it could be heavier, which is okay with me. Even at 100 or 120 oz. the numbers look good.

My Drago 4XL is 12.5 pounds minus motor. That's with Recon parachutes and dual Missileworks altimeters running 9V batteries.

muddymooose said:

Same here, but I know about how much I overbuild. I just want a starting reference. Not listing any kind of ballpark weight is silly. Are the kit components 16 oz? 100 oz? Throw me a bone here...

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You're a Level 2 and you can't figure out within an order of magnitude of what a kit might weigh? Or how to find enough info to calculate it, again within an order of magnitude?

Flyfalcons said:

My Drago 4XL is 12.5 pounds minus motor. That's with Recon parachutes and dual Missileworks altimeters running 9V batteries.

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Thanks for the information

Cnorm said:

You're a Level 2 and you can't figure out within an order of magnitude of what a kit might weigh? Or how to find enough info to calculate it, again within an order of magnitude?

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I didn't try to figure it out. At the moment I'm just browsing kits and comparing the listed specs.

muddymooose said:

When shopping for rocket kits, the most annoying thing to me is when manufacturers don't include full specs. It's a rare treat when a kit is shown complete with diameter, height, weight, MMT diameter, materials for all parts, fin thickness, bay length, hardware, etc. Seems like the most commonly-omitted spec is weight (kind of important), followed by overall length.

Note to manufacturers: If I can't easily find the full specs, I will shop elsewhere. Please update your information.

Click to expand...

Take a look at MAC Performance Rocketry.
www.macperformancerocketry.com

Good luck on your L2 Tomorrow!

same can be said about a lot of things...

I was recently looking for an air filter / room purifier. Each seem have their own specs they rate their system to. Looks like there is a standard, but only a few list their rating. SO comparing them is difficult.

Look at cars. some list Bhp, some list torque.. some list cargo space, some list "interior volume" and mileage rating always seem to be under ideal conditions (or that the CPU is programmed to cheat it..)

In advertising, it's either high in one thing, or low in something else.. that's the advantage. list only what numbers are high or low..

Mach one is just getting up and running (hence all the items being out of stock) but they have most of the specs, and even offer .ork files for some of them.
https://www.mach1rocketry.com/store/p52/Messier_65_SR.html
https://www.mach1rocketry.com/store/p7/Portia_SR-1.html

I bought the Portia and Speed Demon from them. Good kits.

swatkat said:

Mach one is just getting up and running (hence all the items being out of stock) but they have most of the specs, and even offer .ork files for some of them.
https://www.mach1rocketry.com/store/p52/Messier_65_SR.html
https://www.mach1rocketry.com/store/p7/Portia_SR-1.html

I bought the Portia and Speed Demon from them. Good kits.

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The photos on the Portia Page are of my rocket (and son).

I'm working on creating my own rocket kit company. I'm working with madcow for the body tubes and Upscale CNC for G10 parts. I cant really talk about it yet because i dont have a vendors account I plan to list the built weigbt, CG, CP etc. If any mods have a problem with me posting this i will take it down.

mperegrinefalcon said:

I'm working on creating my own rocket kit company. I'm working with madcow for the body tubes and Upscale CNC for G10 parts. I cant really talk about it yet because i dont have a vendors account I plan to list the built weigbt, CG, CP etc. If any mods have a problem with me posting this i will take it down.

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Just wondering how you can make much profit when you are buying parts from Mad Cow which will be your competition?

crossfire said:

Just wondering how you can make much profit when you are buying parts from Mad Cow which will be your competition?

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He'll probably lose money on every sale, but make up for it on volume.

crossfire said:

Just wondering how you can make much profit when you are buying parts from Mad Cow which will be your competition?

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Im working with Michael Klet. I'm buying parts in higher volume so he is giving me a discounted rate per part. I will have a different account on TRF that will be for my company.

I can point you to some help with component dimensions...I've been building (over a long period of time) a set of OpenRocket component files with the best available size/mass data for many manufacturers including Estes, Semroc, Madcow, LOC, BlueTube and others. Getting good data is hard, and sometimes almost impossible. Thanks to the prior work of John Brohm and the late Carl McLawhorn we have a lot of information on Estes/Centuri parts, and the Apogee site has much useful information on MPR items. The readme in the git repo plus the XML files contain a huge volume of research notes and discussion about gaps and errors in the manufacturer sites and catalogs.

Here is the git repo with installation instructions for OpenRocket: https://github.com/dbcook/openrocket-database

Kits are a whole other problem. In MPR/HPR, they are made in small batches and are not always the same from run to run.

Weight being at the top of the priority list is kind of a nuisance, considering how much it can vary based on who's building it, how they build it and with what materials. Larger kits, especially.


Braden

mike2wander said:

Take a look at MAC Performance Rocketry.
www.macperformancerocketry.com

Good luck on your L2 Tomorrow!

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Thanks Mike, and thanks for bringing your kits to my attention. I like what I'm seeing.

swatkat said:

Mach one is just getting up and running (hence all the items being out of stock) but they have most of the specs, and even offer .ork files for some of them.
https://www.mach1rocketry.com/store/p52/Messier_65_SR.html
https://www.mach1rocketry.com/store/p7/Portia_SR-1.html

I bought the Portia and Speed Demon from them. Good kits.

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Looks like great stuff...I'll have to check back once there's more in stock.

Nytrunner said:

For me, dry weight of the components is pretty useless since I know my complete build is going to be heavier anyway.
I could potentially see a desire for simulation purposes, but I also don't feel the need to have an incredibly accurate sim prior to even Buying the kit.

You are of course free to purchase from whoever you wish. Maybe have a chat with Tim next time you call about an order?

Click to expand...

I simulate everything before I buy. Yes, my build will be heavier, but give me the dry weight of the components as a starting point. How hard is that? Since many kits don't come with recovery gear, the mass is needed to size a parachute as well.

Let's just say that buying from Wildman's website can be challenging with the lack of details and lack of photos.

Cnorm said:

You're a Level 2 and you can't figure out within an order of magnitude of what a kit might weigh? Or how to find enough info to calculate it, again within an order of magnitude?

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I am sure the "order of magnitude" is an exaggeration, but even 10 lbs vs. 15 lbs is an important distinction. People new to fiberglass or canvas may not know offhand the significant weight increase compared to cardboard. Why should we hunt down data and make calculations when the "kit" maker can simply slap the bag-o-parts on a scale?

Buckeye said:

I simulate everything before I buy. Yes, my build will be heavier, but give me the dry weight of the components as a starting point. How hard is that? Since many kits don't come with recovery gear, the mass is needed to size a parachute as well.

Let's just say that buying from Wildman's website can be challenging with the lack of details and lack of photos.



I am sure the "order of magnitude" is an exaggeration, but even 10 lbs vs. 15 lbs is an important distinction. People new to fiberglass or canvas may not know offhand the significant weight increase compared to cardboard. Why should we hunt down data and make calculations when the "kit" maker can simply slap the bag-o-parts on a scale?

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At the same time I can recall seeing at least one post where someone was crying that the manufacturer of the kit said such & such weight with recommended motors, but his build wouldn't fly on those motors (because it was built heavy)....

Yes dry weight of kit components would be nice, but in my case, the information contained in sims found online is usually close enough....
YMMV

T-Rex said:

At the same time I can recall seeing at least one post where someone was crying that the manufacturer of the kit said such & such weight with recommended motors, but his build wouldn't fly on those motors (because it was built heavy)....

Yes dry weight of kit components would be nice, but in my case, the information contained in sims found online is usually close enough....
YMMV

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I think there are far more posts about sim files posted online that are complete garbage...

muddymooose said:

When shopping for rocket kits, the most annoying thing to me is when manufacturers don't include full specs. It's a rare treat when a kit is shown complete with diameter, height, weight, MMT diameter, materials for all parts, fin thickness, bay length, hardware, etc. Seems like the most commonly-omitted spec is weight (kind of important), followed by overall length.

Note to manufacturers: If I can't easily find the full specs, I will shop elsewhere. Please update your information.

Click to expand...

My main gripe is manufacturers selling PARTS with inadequate specs, specs needed when creating custom designs in Rocksim or OpenRocket for which those parts will be used!