20mm paper tube to hold Quest D5-0 motor

[WillMarchant]

Has anyone found a source for 20mm inside diameter paper tubes for the Quest D5-0 motors? Thanks in advance!

 

[bob jablonski]

Semroc was talking about making motor mounts when Quest brought out there "D" so they may have some. With Quest coming out with cool motors we may have to start making motor mount kits for those motors. Cluster E and F in BT80 anyone?
Mr. Bob
Starlight Dude
www.starlightrocketry.com

 

[spacecadet]

Make your own out of rolled-up card. I've never bought a motor mount (or any other purpose-made item, for that matter).

 

[Chrisn]

^that

Model rocketry parts cost alot more than they should, compared to recycling stuff at home.

 

[rstaff3]

I'm too lazy to make the large quantity of standard sized tubes that I use...but that's what I did for the D5. Heck, a motor mount doesn't even have to be pretty

 

[powderburner]

Heck, a motor mount doesn't even have to be pretty

True, but it does have to be pretty close to the right size.

Until we can all get hold of these motors, and use an old expended casing as a starting point, does anyone have good data (factory specs?) on the outside diameter of the new motor, or any tips on what to use as a mandrel to wrap cardstock around?

 

[Chrisn]

I dont have any problems with size, even with the very few kits I have built at the beginning a bit of masking tape is needed for a proper friction fit.

Unless you have a lathe or access to one im not sure what could be used as a mandrel OR there is some Aluminium or brass tube/rod which comes close to 20mm diameter depending on where you get it from.

 

[MarkII]

The as-yet unreleased motors (E and F) that were announced at NARAM 50 are supposed to be 28mm in diameter. Roll a sheet of cardstock around one a couple of times, hold the cardstock in place with a wrap or two of masking tape, and stick it in a standard 29mm mount.

If you wrap the 20mm D5's with a enough tape to make a layer that is just a smidgen less than 1mm thick, you can fit them securely into Semroc Series 085 (LT-085) tubing (ID=0.865" or 21.97mm, OD=0.945" or 24mm). The LT-085 tube will then fit perfectly into a 24mm motor mount.

MarkII

 

[rstaff3]

True, but it does have to be pretty close to the right size.

Until we can all get hold of these motors, and use an old expended casing as a starting point, does anyone have good data (factory specs?) on the outside diameter of the new motor, or any tips on what to use as a mandrel to wrap cardstock around?

Since the question was concerning the D5, all you have to do is go to Quest and buy some. I can sell ya' some spent motors

As others have mentioned tape works as an adapter.

 

[zog139]

Hey Dick

I took some S-8 ? Tube the one that is smaller then BT-50 simply cut out a strip and glued it back together . Not major difficult.

 

[WillMarchant]

Hey Dick

I took some S-8 ? Tube the one that is smaller then BT-50 simply cut out a strip and glued it back together . Not major difficult.

The Semroc series 8 tubing looks like it might be a pretty good fit without modification. Is that what you used? If so, I guess the fit wasn't as close as the specs made it look...

 

[MarkII]

I think BMS has what we need, though it's a tight fit-dead on ID:

T20Q-34: .787x.748x.039x34 MPC/Quest T20

I've got a length of that from my last order (don't know what possessed me to order it)

I've got some Quest Ds on my order, so we'll see how that fits.

Cheers,
Jon

Yes, but that's simply an equivalent version of Quest's T20 tube. The outside diameter of this tubing is 20mm (0.787"), whereas a motor mount for the D5 requires a tube with an inside diameter of 20mm (actually, just a smidgen larger). The inner diameter of the BMS tubing (0.748") is a bit too small for it.

I posted this a couple of weeks ago on YORF. It seems to me that you could make a nice, good-fitting 20mm motor tube by taking a length of BT-40, slitting it down one side along its length, spreading it open slightly and then gluing it inside a length of Series 085 tubing (LT-085). You will have constructed a tube that will fit around a 20mm motor like a glove. The tube will have a small gap running the length of the inner wall. To provide a gas seal, simple plug or fill a small section of this gap at the aft end of the tube. (You won't need to fill in the gap along its entire length, just at the rear end.) This motor tube will fit perfectly into a 24mm motor tube, so it can function as a 20mm to 24mm adapter. You can obtain both BT-40 and LT-085 from Semroc.

MarkII

 

[Carl]

I have ordered some of the Quest D5 engines. Does anyone have one that can measure the actual diameter? Euclid needs a little better spec than just over 20mm.

 

[zog139]

Carl

Maybe someone else can chime in to back up what I got.

I have one of the early release D5-P motors, it measures 0.785 with my dial calipers.

Jim

 

[tomar]

Has anyone found a source for 20mm inside diameter paper tubes for the Quest D5-0 motors? Thanks in advance!

Quest Aerospace sells both 20mm motor tubes and 20mm airframe tubes. And best yet, they are having a sale yesterday and tomorrow on all merchandise on their web site.

 

[WillMarchant]

​

Quest Aerospace sells both 20mm motor tubes and 20mm airframe tubes. And best yet, they are having a sale yesterday and tomorrow on all merchandise on their web site.

That's the outside diameter, Mark. I asked Nettie and she said those wouldn't work.

 

[shreadvector]

That's the outside diameter, Mark. I asked Nettie and she said those wouldn't work.

Correct.

The 20mm motor tube is basically a BT-20J (2.75 inch long BT-20) which will accept an 18mm motor inside, and it is about 19mm outside diameter. Also Known As (AKA) T-19. it fits inside the T-20 tube which is 19mm ID and 20mm OD.

We need 20mm ID which would be 21mm OD and known as T-21. Or maybe it would be a thick walled T-22?

 

[artapplewhite]

Carl

Maybe someone else can chime in to back up what I got.

I have one of the early release D5-P motors, it measures 0.785 with my dial calipers.

Jim

I have a couple of D5-0s (That how they're marked) and the labels, which are white, light-weight paper wrapped around the brown, kraft-paper casings are not flat all around. There are wrinkles which could make a tight fitting motor mount problematic. If you look closely you can see a small gap between the label and the casing at the bottom of the motor.

The gaps are much bigger at the top because the casing is not a perfect cylinder either. At the nozzle end, my calipers (which are metric) read 20.00 mm (0.787 inches) but at the top end they read 19.42 mm(0.765 inches) .

The walls of the D5 casing are between 1.80 mm and 1.96mm thick. This compares to an Estes D12 casing which is 2.9 mm and a C6 casing thickness of 2.7 mm.

The thin casings cause pronounced burn through when the D5-0 motor is used in a monocopter.

Art Applewhite

 

[WillMarchant]

The thin casings cause pronounced burn through when the D5-0 motor is used in a monocopter.

Art Applewhite

Bummer. Sounds like a sad story there, Art.

 

[MarkII]

I remember a thread about this issue awhile ago, probably in TRF 1.0. I think that longer burning motors seemed to be more susceptible to it than others. In my monocopter flights with relatively short-duration 13mm motors, I have never seen any evidence of unusual off-center burning. Others reported seeing it with Chinese-made Quest C6s, but there were also descriptions of it with Estes C6s.

MarkII

 

[ScrapDaddy]

The propellent was mede in Germany; but the casing was made in China


Note: i am chinese :y:

 

[MarkII]

The propellent was mede in Germany; but the casing was made in China

Well, that's odd. :shock:

I thought that the new Quest motors were made entirely in China.

MarkII

 

[FlyBack]

Unless you have a lathe or access to one im not sure what could be used as a mandrel OR there is some Aluminium or brass tube/rod which comes close to 20mm diameter depending on where you get it from.

I roll my own. After a great deal of experimenting with different papers, glues and wax mold releases... I found that plain old copier paper and Polycrylic works just fine. The mandrel is a 20mm glass tube from a science supplies house. A spray on mold release is used on the mandrel.

Regards,

FlyBack

 

[patelldp]

...Why doesn't Quest make a tube? Doesn't this seem bass-ackward?

 

[MarkII]

...Why doesn't Quest make a tube? Doesn't this seem bass-ackward?

They have plans to start selling them, I believe. The lack of a ready-made tube for the 20mm diameter motors is no big deal right now. It's easy enough to adapt exisiting tubes to take them or to roll your own motor tubes for them.

MarkII

 

[ScrapDaddy]

Well, that's odd. :shock:

I thought that the new Quest motors were made entirely in China.

MarkII

I was using a metaphor

 

[BigRiJoe]

QCR (https://www.cybertravelog.com/qcr/) make a 21mm tube and a thrust ring for it

 

[WillMarchant]

QCR (https://www.cybertravelog.com/qcr/) make a 21mm tube and a thrust ring for it

I found the thrust rings but not the tubes. Were they on the same page?

 

[BRS Hobbies]

Which rockets are the Quest D-5 motors designed for? I looked at the Quest line of rocket kits and didn't see any of the rockets that are recommend to use a D-5 engine.

Best regards,
Brian

 

[GrossApproximator]

I roll my own. After a great deal of experimenting with different papers, glues and wax mold releases... I found that plain old copier paper and Polycrylic works just fine. The mandrel is a 20mm glass tube from a science supplies house. A spray on mold release is used on the mandrel.
FlyBack

How strong are the tubes when polycrylic is used? I'd like to try out your method.