Quantcast

Port Holes

The Rocketry Forum

Help Support The Rocketry Forum:

kandsrockets

Well-Known Member
Joined
Jan 18, 2009
Messages
3,006
Reaction score
0
When you drill your port holes do you chamfer the hole or do you just leave the hole square. I like to chamfer mine but was wondering if this may cause any problems with air flow.
 

Handeman

Well-Known Member
TRF Supporter
Joined
Jan 18, 2009
Messages
7,721
Reaction score
315
Location
Stafford, VA
I've always left mine flat, without a chamfer, at least on the outside surface. Usually I put some CA in and re-drill and then sand the inside flat with the tube.

The way I do mine, chamfering would be an extra step and I just don't bother. I don't know if it would mess with air flow, it might. Maybe a little venturi affect.
 

Gillard

Well-Known Member
Joined
Jan 18, 2009
Messages
1,970
Reaction score
1
i leave them square, have not thought about air flow issues, i'm too lazy to chamfer them.
 

Pantherjon

Well-Known Member
Joined
Jan 19, 2009
Messages
7,347
Reaction score
1
I leave my port holes square..Same with my starboard holes..:roll:
 

WillMarchant

Well-Known Member
TRF Supporter
Joined
Jan 15, 2009
Messages
2,327
Reaction score
55
I try to make the holes "square" and clean the edges as much as possible. CA does seem to help get those edges nice and smooth. And remember to read the recommendations in your altimeter's technical manual...
 

Bill P

Well-Known Member
Joined
Mar 29, 2009
Messages
204
Reaction score
0
Mine are square.

In cardboard tubes, the holes are soaked in CA and drilled again then sanded.
 

kandsrockets

Well-Known Member
Joined
Jan 18, 2009
Messages
3,006
Reaction score
0
I guess I should explain little more about the type of tubes I am using. All of my DD rockets are glass covered cardboard tubes or they are composite tubes. Also when I am saying about chamfering them it is a very small amout just enough to clean the edge of the hole.

As far as effecting the alt performance I have not seen any ill affects. All of mine have deployed at apogee. It was just something that I was wondering about.
 

quickburst

Well-Known Member
Joined
Jan 20, 2009
Messages
1,683
Reaction score
24
I don't think it would matter. Chamfered or not, as far as portholes go .... size matters.

Did you get my email?
 

Sailorbill

Well-Known Member
Joined
Jan 25, 2009
Messages
1,283
Reaction score
0
On cardboard I drill the holes then I wick in CA followed by re drilling then sanding. On Phenolic I just drill the holes and sand smooth same with composite covered tubes. I have used a countersink or center drill to clean up the edges.
 
Top