Electronics bay/Entacore

This is my 8" "BlueTube" bay for my 3" rocket.I have a dual deploy/data Entacore altimeter on order that I'm going to use.Has anyone have any experience with these or suggestions? I have 3 1/8" holes drilled in it ,is that enough,or too much?My payload section is 3" X 18" so 2g's of BP should do the trick.:confused2: Plan on doing a ground test first anyways but looking for advice since this is my first HPR rocket.Also are epoxy fillets enough on the sled or something more? First launch will be with H128 but plan on stepping up to LVL 2 with same rocket with a J350.

No experience with the Entacore unit..

3 1/8" holes..Hmmm, I would go with 3/16" or even 1/4" holes to be on the safe side. You don't want ANY type of pressure differential between outside/inside the avbay.

2G's of BP should do the job..Is it FFFFg or FFFg black powder?

Sled looks good..Is there any movement fore/aft of the rods on the all thread?

Pantherjon said:

No experience with the Entacore unit..

3 1/8" holes..Hmmm, I would go with 3/16" or even 1/4" holes to be on the safe side. You don't want ANY type of pressure differential between outside/inside the avbay.

2G's of BP should do the job..Is it FFFFg or FFFg black powder?

Sled looks good..Is there any movement fore/aft of the rods on the all thread?

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Well from what I have been reading FFFFg is what I should use,haven't got it yet but here in PA gun shops are everywhere.So I shouldn't have a prob picking it up in the next 2 weeks before my cert attempt.

ohh an I was wrong on my holes they are 3/16" not 1/8

The sled is nice n tight no movement at all when placed inside tube

I like my Entacore a lot. I have about ten flights on mine this year.

I used it along with an RRC2 mini in my L3 project and it supplied altitude,speed, time, ejection charge firing, voltage to altimeter and pressure. And it recorded al of these every 1/10 of a second. This is my altimeter of choice now. I love all the info I get. There's enough memory for three or four flights before downloading.

Crashed it pretty hard once. Not the altimeter's fault. A three engine cluster only lit one engine. Upon inspection the sensor had pulled a couple of legs loose when the rocket went in ballistic. A little straightening and a little heat from a soldering iron to make sure all the contacts were good to the board (followed by lots of ground testing) and the first flight after the crash was this past Saturday and was a complete success. Pretty tough unit.

The only thing I don't like is that it only beeps out continuity one time before it goes into launch mode. If you miss the beeps you have to shut it down and start over.

Good luck with yours.

I think all the other questions have been handled.

Thats a great looking rocket guy. I have the same rocket as you and my came out to 84 oz completed, but I have 2 LOC shock cord protectors and 2 parachute protectors and so it was a little heavier. My word of wisdom to you is that the smallest motor that I would fly on mine is an Aerotech I161 and it went to an altitude of 1235ft with main deployment at 400ft. So if I was you first go weigh it and if it is similar to my weight than I think you should go look at the Newtons and use a motor that has about the same newtons as the I161. With that motor and that altitude for a level 1 cert flight it is pretty good.

andrewlathrop87 said:

Thats a great looking rocket guy. I have the same rocket as you and my came out to 84 oz completed, but I have 2 LOC shock cord protectors and 2 parachute protectors and so it was a little heavier. My word of wisdom to you is that the smallest motor that I would fly on mine is an Aerotech I161 and it went to an altitude of 1235ft with main deployment at 400ft. So if I was you first go weigh it and if it is similar to my weight than I think you should go look at the Newtons and use a motor that has about the same newtons as the I161. With that motor and that altitude for a level 1 cert flight it is pretty good.

Click to expand...

Well since I'm a lil "gun-shy" almost made up my mind to do first launch without the bay for my cert. flight just to make sure I get it.Still waiting on 9v holder that I ordered (didn't notice its comming from Hong Kong LOL) so if it doesn't get here I'm going to just bolt battery down with some M3's an small peice of 1/8" plywood.Working on bay today so will post some pics lator this eve.
8 days till lift off!!
Stay tuned....op:

Well this is what I ended up doing to hold my charges so they don't flop around,also had a push button switch that I bought at Radio Shack but found a key on/off for $4.80 an free shipping on below link.I ordered one set an it came with 3 switches and 2 keys.:confused2: Guess they have extra's. LOL It comes from Hong Kong air-mail in lil over a week an the threaded shaft is metal NOT plastic like others I have seen.
3 days till lift-off:w:
https://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330414981722&ssPageName=STRK:MEWNX:IT

I received a PM,so figured would share some more info on this thread,asking why I used 2 terminal blocks on one end of bay.I did this so I could swap over the altimeter easier at the launch site.Maybe in the future can afford a second altimeter.So these are pix of my 2nd E-bay and different way I set it up.Haven't done all the J-B weld on holder screw points and bolts yet.
pix description:
1.Battery holder,holes drilled on either side so zip-tie can be used for extra insurance.Also used a quick connect from key switch,battery,altimeter.
2.The binding posts I used instead of blocks.
3.Fiber washer should hold back gases.
4.The holes to insert ignighter leads.

5.Switching over takes less than 5 minutes(long as you don't drop the small bolts).
6.Showing the ends of both bays before bolting together with wing nuts.
7.A note too self when setting it up.
8.Aft,red for hot end,bottom,etc...
9.Fore,pointy end,top,etc...ohh an the center holes are for venting...just kidding!!Plan on picking up some https://www.blastcaprocketry.com/ at Red Glare IX so that will be there home.

Hope this helps...I might even use a micro connector on those removable ends to make it a little easier if I can find some I like.The Radio Shack near me is very limited on selection for things like that though.