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Jack459
08-19-2008, 06:08 PM
Hi, I'm wondering what the parts are that i would need to order from the Semroc website in order to complete this rocket. (Black Widow)

kurtschachner
08-19-2008, 06:50 PM
Well, you have this:

http://www.semroc.com/Store/scripts/ClassicParts.asp?ID=513

and this:

http://www.semroc.com/Store/scripts/prodView.asp?idproduct=197

which gets you most of the way there. There's also this:

http://www.semroc.com/Store/scripts/prodView.asp?idproduct=1291

but I would email Carl and see just what that has in the pack.

One other thing, Carl is very good at being able to supply parts that aren't listed on Semroc's website. It can't hurt to ask.

Jack459
08-19-2008, 07:05 PM
Thanks. I wasnt certain what parts were included in the sub-assembly package. I sent an email to sales@semroc to be sure.

So far i have the following in my cart
-Balsa Nose Cone #7 Ogive
-Chute Pack 12'' Black and Yellow
-Decal Black Widow
-Engine Hook Standard
-Laser cut black widow fins
-Tube Coupler #7
-Parts Sub-Assembly 13 Black Widow
-Body Tube #7 4''-booster
-Body Tube #7 9''-sustainer
-Thrust Ring #7

I think thats it depending on what is in the sub-assembly. If I'm missing anything, help would be greatly appreciated.

kurtschachner
08-19-2008, 07:08 PM
Hey, wait a second. I'm not the world's foremost expert on Centuri models, but I have this "thing" in my collection that I need to paint. Isn't this a Black Widow? I thought it was. I got it from Semroc so at one time they had the kit. You should ask Carl.

Either that or my early-onset dementia is kicking in again.

Jack459
08-19-2008, 07:14 PM
Thats a beautifully constructed black widow. My brother had one when we were younger. We never did get that booster section to glide.

Ltvscout
08-19-2008, 07:49 PM
Hey, wait a second. I'm not the world's foremost expert on Centuri models, but I have this "thing" in my collection that I need to paint. Isn't this a Black Widow? I thought it was. I got it from Semroc so at one time they had the kit. You should ask Carl.

Either that or my early-onset dementia is kicking in again.
Semroc hasn't kitted it, yet. Carl has had the parts available for awhile now. I thought he did the fins for you originally? Maybe not.

Jack459
08-19-2008, 08:05 PM
Another question. I was looking over the sets of plans on the Old rocket Plans and Jim Z's sites. They seem to be very different. Which one should i be following if i am going to be building the Black Widow?

kurtschachner
08-19-2008, 08:06 PM
Semroc hasn't kitted it, yet. Carl has had the parts available for awhile now. I thought he did the fins for you originally? Maybe not.

Well allrighty then, ring one up for dementia.

I honestly can't remember. Carl must have cut the fins (and fin reinforcements) for me because I am quite sure I didn't do that. I have a whole bag of the passport couplers from Semroc and I remember buying them (just not for the Black Widow).

OK, enough of this nonsense. I went back and looked up my past orders from Semroc and I see that I ordered the nose cone, couplers and body tubes back on 1/2/06. Carl must have cut the fins as a special order.

At least I now know the life of a typical memory :rolleyes:

Carl@Semroc
08-19-2008, 08:14 PM
There have been at least three different versions of the Black Widow. That is the main reason why we have not done it yet. We have been considering an xKit of the earliest version, but it had problems staging and gliding. The later version has better booster fins and the pass-port coupler, but looks different from the original. I think I have the latest version around here somewhere, but I have not seen it in a while. The laser-cut fins are also for the latest version.


PSA-13 is for the latest version of the Black Widow and contains:
A 1 HTC-7B Tubing Coupler #7 Outside 1.0" Long
B 2 TB-7 Thrust Block #7
C 1 LL-122 Launch Lug 1/8" x 2.25"
D 1 SE-10 Screw Eye 1"
E 1 EC-118 Elastic Cord 18"
F 1 SCK-24 Kevlar Thread 100# 24"

Jack459
08-19-2008, 08:20 PM
Thank you i am placing my order now.

Jack459
08-25-2008, 01:02 PM
I have a question about the booster stage and the coupler. I sanded down the booster stage so it will fit into the coupler not too tightly. My question is How far should I insert the booster into the coupler? All the way to the sustainers body tube? or just up to the two holes in the coupler?

jetlag
08-25-2008, 01:15 PM
Hey, wait a second. I'm not the world's foremost expert on Centuri models, but I have this "thing" in my collection that I need to paint. Isn't this a Black Widow? I thought it was. I got it from Semroc so at one time they had the kit. You should ask Carl.

Either that or my early-onset dementia is kicking in again.

It's called 'Pre-senile dementia' :D (ya know, that smiley icon looks a tad demented.....)

Once you pass 40, look out!!!!!!!!

Nice Black Widow! Kurt, can you get the booster to glide?
Allen

dtomko
08-25-2008, 10:54 PM
I cloned one with Semroc parts a while back:

http://forums.rocketshoppe.com/showthread.php?t=232&page=1&pp=10&highlight=black+widow

You can see where I messed up the booster BT length. Use the Semroc fins with the cut out as a guide for the engine hook lock ring, and ignore the measurement on the instructions.

I had to sand the coupler quite a bit to get a decent fit between stages. I've flown it about 8 times. The coupler gets charred, but a little sanding fixes most of the damage. I also coated the coupler with CA.

When I fly it, I insert the booster until I can just see the BT through the ports. The booster glides, but hand launching it didn't help me much. I fiddled with the clay weight after the first 3 flights.

Good luck and post pictures.

Drew

Jack459
08-26-2008, 08:12 AM
Thanks dtomko. I think I was reading your review on EMRR. Im going to post a picture today after some paint. I know this is going to sound pretty stupid but im not sure how the decals work. They arent the usual peel and stick ones that im used to.

Jack459
08-27-2008, 09:35 AM
I know its not a great paintjob (or picture) but here it is. I still have to put on the decals.

http://i88.photobucket.com/albums/k176/Jack459/DSCN0400.jpg

http://i88.photobucket.com/albums/k176/Jack459/DSCN0399.jpg

Carl@Semroc
08-27-2008, 11:48 AM
I LIKE that box! :D

Jack459
08-27-2008, 11:53 AM
I LIKE that box! :D

Lol yea. Thanks for all the parts. It doubles as a display stand.

Jack459
08-28-2008, 02:04 PM
Ok so i got the decals on now. Ill have to take another pic. What motor combinations would you guys recommend? I was thinking some B6-0's (if i can find them) with some A8-5's. If i cant find any B6-0's would the C6-0's be overkill?

Solomoriah
08-28-2008, 06:49 PM
How big is your launch area?

I don't know, but I'd bet you'll see a 1,000' of altitude with a B6-0 to A8-5 on a Black Widow. That's not too bad (I think the upper stage alone is good for probably more than 1,600' on a C6-7). C6-0 to A8-5 should be a bit more than the upper stage by itself on a C6-7.

Jack459
08-28-2008, 07:55 PM
I have a 100+ acre field to play with upstate New York at my brothers. There is a forested area that starts on the southern part though. Im just worried about not being able to see it. I picked up some B6-0's and C6-0's just before along with some A8-5's and B4-54's. Im probably gonna start with the B6-0's and move up from there.

One more thing. The parachute is pretty tightly packed into the tube and im worried it might not deploy. Would a streamer suffice for the upper stage? It dosent seem to weigh much and I dont think it would sustain any/much damage.

Solomoriah
08-28-2008, 08:10 PM
I'd fly it either on a streamer or on a chute with a spill hole. That said, you can generally get a 12" plastic or mylar chute into a ST-7 tube if you are careful. DO pack it right before flying (unpack and repack) as it might get sticky otherwise. Sometimes you have to try folding it different ways to get the best fit.

Nah, on second thought, I'd go with a streamer. It's going UP there, and even with a hundred acres to work with, you still don't want to have to walk too far.

Your two-tone dark/light paint job should help with recovery.

Also, before launching, make sure at least one person is detailed to track the booster and at least one to track the sustainer, lest you lose one or the other. The more parts that come down separately, the more likely it is you'll lose one.

Jack459
08-28-2008, 08:18 PM
I'd fly it either on a streamer or on a chute with a spill hole. That said, you can generally get a 12" plastic or mylar chute into a ST-7 tube if you are careful. DO pack it right before flying (unpack and repack) as it might get sticky otherwise. Sometimes you have to try folding it different ways to get the best fit.

Nah, on second thought, I'd go with a streamer. It's going UP there, and even with a hundred acres to work with, you still don't want to have to walk too far.

Your two-tone dark/light paint job should help with recovery.

Also, before launching, make sure at least one person is detailed to track the booster and at least one to track the sustainer, lest you lose one or the other. The more parts that come down separately, the more likely it is you'll lose one.

Thanks solomoriah. Im probably gonna go with the streamer. Less drift is always better and less walking sounds good. Theres going to be at least 5 people there more than likely so im going to make sure two watch the sustainer. Although, they might get distracted as I finally got the booster to glide rather nicely. =D

dtomko
08-28-2008, 10:22 PM
I like the black and white paint job as well.

I've only flown mine with B6-0s in the booster and A8s in the second stage. It's never gone to 1000'; the B6-0 gives it a not-too-fast boost. I lost track of the second stage once at NERRF 3, but someone found it - it was a pretty windy day, though. Definitely get another pair of eyes to track it, especially if you get any glide out of the booster.

Haven't had much problem packing the 12" chute; just fold it over once to get a long spike out of it.

Drew

barone
08-28-2008, 10:36 PM
Just a little advise on the tracking....as if you're not getting enough. The guy assigned to watch the booster WILL watch the sustainer. Assign two to the booster if you can. Also, if you expect a really high altitude (for me over 1000 feet), it's best to have someone posted in the general area of where you expect the rocket to come down. It's easier to keep track of the rocket from a side angle to the launch site as opposed to standing within 50 feet of the pad. A two way radio will keep him/her in contact with the range so they can watch for the launch. Heck, with five people....two to watch the booster, two about 500 feet down range and one to launch. Man you are set! :D

Jack459
08-29-2008, 09:18 AM
Thanks barone. I just found out I might have more than 5 people. (I think im looking at upwards of 10!) Im gonna set some of them up downrange and assign them booster or sustainer. Do you by any chance have an estimate of the altitude when it stages?

Solomoriah
08-29-2008, 09:33 AM
On a B6-0, what? 500'? Maybe 750'?

Just guessing. Rocksim would give you a guess, possibly better, possibly not...

Jack459
08-29-2008, 10:02 AM
Yea a B6-0. I was just curious.

barone
08-29-2008, 10:21 AM
Actually, the staging should occur at a relatively low altitude. Most of the altitude acheived by model rockets is from coasting as opposed to power boost. Check out the Frick'n' Frack launch video somewhere in this forum. I think they used a B6 booster. Although the FnF is much more draggy than the Black Widow, it'll give you some idea of the altitude.....yours will go higher. I thought there might be a RockSim file somewhere but I couldn't find it.... :o

dtomko
08-29-2008, 10:22 AM
I don't have Rocksim, but from my observations staging with a B6-0 occurred at 200' at the most, and probably lower. My builds tend to be a bit heavy, but those big fins on the Black Widow may also be a factor.

Drew

Doug Sams
08-29-2008, 11:40 AM
Actually, the staging should occur at a relatively low altitude. Most of the altitude acheived by model rockets is from coasting as opposed to power boost. Yes, I agree with you and Drew. Not only will the booster burnout not be too high, but because the booster is so draggy, the sustainer ejection altitude will only be higher by the added booster burnout height.

The booster burn imparts mainly velocity (and hence, kinetic energy) on the sustainer, but not gobs of alititude. Typically, then, a C booster, with its longer burn, should impart more velocity than a B. But I suspect with the Black Window and its draggy booster fins, that rocket will hit a terminal velocity during booster burn. This means that the C motor will burn out higher, but the rocket won't be going any faster, than on a B booster.

Thus, at sustainer ignition, it will be going the same speed in both cases, just at a higher altitude.

Therefore, the sustainer burn profiles should be about that same for either booster (given the same sustainer motors). The sustainer will add the same amount of altitude in both cases. IOW, if the C booster burns out 200' higher than the B, then the subsequent ejection event will be 200' higher.

OTOH, if the booster weren't so draggy, the longer booster burn of the C motor might add not only height but speed, resulting in the sustainer traversing more distance during its burn and coast phases. And thus getting considerably more added altitude than just the added staging height.

At least, that's my take :)

Doug

.

Maniac BAR
09-03-2008, 12:54 AM
I just finished the build of a Black Widow clone myself. If was flown about two weeks ago on a B6-0/A8-5 combo. The booster sep. was about 100 to maybe 150'. Nice straight climb for the sustainer. It did go almost out of sight! I used a 30" long X 1" wide streamer which just barely fit into the tube and it came down not far from the pad with no landing damage on our hard desert. The booster was actually trying to glide. :p Had a large amount of stalling but it did sort of fly.

The only thing was I had some trouble with the build about the coupling. The way the instructions showed it was glued to the sustainer with the motor way up inside the tube. How the heck were you suspossed to get the motor friction fitted into the tube and how the heck were you suspossed to get the motor back out!!!! :confused: :confused:

Since mine was a clone, I glued a motor block into the sustainer with about 1/4" of the motor still outside the tube and glued the coupler to the booster instead. Thin CA was used all over the coupler and the bottom of the sustainer to help keep the charring to a minium.
The coupler was placed just far enough onto the booster to still leave the vent holes clear. The sustainer fins were clearence notched for the coupler. This left about the size of the vent hole (1/4") as the gap. The first flight was great with no staging problems. I think the coupler on the front of the booster may have helped it to glide better. The thin CA was also used to add a little weight to the front of the booster as well as sealing it. Now I can use a little clay to get the booster balance just right.

And you are right about the helpers. :eek: I had three or four and we all lost the sustainer for a little while because we ALL just had to watch the booster try to glide down!!!!!

Very fun rocket!!!!

Jack459
09-03-2008, 07:47 AM
Flight Report: September 1st

First flight was great. I did not see the booster detach but it came in ballistic about ten feet from the pad. The sustainer went out of sight and was recovered about 400 feet from the pad. C6-0/A8-5

Second Flight was even better. I didnt see the booster detach but boy did it glide. It glided a good 300 feet from the launch pad. The sustainer got tangled in the shroud lines on descent but no damage was taken. After this flight i inspected the severly charred coupler and notices it cracked. While prepping for the final flight of the day.... a certain someone stepped on the booster and broke a fin and the third flight was scrapped.