Motor Retension and removing aft centering ring

Motor Retension and removing aft centering ring

Post by BigEmo1 » Wed, 20 Dec 2000 11:36:58



I am beginning the construction of my Rocketman Rocketboy and I ran into a
small problem with the motor retention.  I am wondering what the "Timberman
Nuts" are and how they attach to the rear centering ring.  Any suggestions?
Also, does anyone know of a good way to remove the aft centering ring after you
tack the fins in to do teh interior fillets?  Thanks

Alex Immerman

 
 
 

Motor Retension and removing aft centering ring

Post by Peter Cl » Thu, 21 Dec 2000 00:21:07


Quote:

>I am wondering what the "Timberman Nuts" are and how they attach to the rear

centering ring.  Any suggestions?
Quote:
>Also, does anyone know of a good way to remove the aft centering ring after

you tack the fins in to do teh interior fillets?  Thanks

I'm not sure what a "Timberman" nut is unless it's a T-nut -- I thought they
were called that because they're T-shaped viewed from the side. They have a
round flat plate on one end of a tube that is threaded on the inside.  You
drill a hole big enough for the tubular part and epoxy it in with the flat
plate on the inside surface of the centering ring. Obviously this has to be
done before assembly.

Another choice is a "Threaded insert" which has fine threads on the inside and
big coarse threads on the outside. You drill a hole big enough for the coarse
threads and***it in, anchoring it with epoxy. This can be done after
assembly, so it's good for a retrofit or oh-my-gosh-I-forgot application.

In either case, if you put the T-nut or insert in first, then put long screws
in the inserts during test fit, you can grab hold of the screws to pull the
retaining ring out.

Hope this helps,
Peter W. Clay NAR 18619 SR L1 OREO 555
If it dies, it's biology; if it blows up, it's chemistry; if it breaks, it's
physics.

 
 
 

Motor Retension and removing aft centering ring

Post by Jim Yan » Thu, 21 Dec 2000 00:41:01




Quote:
>I am beginning the construction of my Rocketman Rocketboy and I ran into
>a small problem with the motor retention.  I am wondering what the
>"Timberman Nuts" are and how they attach to the rear centering ring.
>Any suggestions? Also, does anyone know of a good way to remove the aft
>centering ring after you tack the fins in to do teh interior fillets?
>Thanks

>Alex Immerman

Those would be 'Tinnerman' nuts,and not the type you want to use. What you
want are 'T-nuts',and you can buy them (larger sizes) at Home Depot,smaller
ones at good hobby shops. you drill a hole and tap in the T-nut,it has two
prongs to bite into the wood to prevent turning.It's best to use a little
epoxy ,too. If you mount your T-nuts in the ring first,then you can run
screws into them to use as handles to help pull out the CR after the
front/center CR's glue sets up.

Tinnerman nuts are made from a flat piece of steel,and stamped with a hole
and two tabs flared out for the***threads to follow.Not good for
repeated use.

T-nuts have a threaded collar and a flat 'top hat' with prongs bent
down,making the 'T' shape.

Jim Yanik,NRA member

 
 
 

Motor Retension and removing aft centering ring

Post by Bob Kapl » Thu, 21 Dec 2000 03:12:43


Quote:


>>I am wondering what the "Timberman Nuts" are and how they attach to the rear
> centering ring.  Any suggestions?
>>Also, does anyone know of a good way to remove the aft centering ring after
> you tack the fins in to do teh interior fillets?  Thanks

> I'm not sure what a "Timberman" nut is unless it's a T-nut -- I thought they

I think he's talking about a Timmerman Nut, which is a stamped piece of
spring steel that will engage a bolt. They are often used in mounting stuff
in racks and other blind mounting situations. I don't see them as useful for
motor retention.

As to removing the aft centering ring, don't glue it in in the first place!
It's easier with a 3 ring MMT, as I use in my baffle system, the other 2
rings will allign the mount fine. But for a conventional 2 ring MMT, just
don't glue the aft ring in place. Slip it on the tube, then glue the MMT
into the tube, gluing only the forward ring. Now glue the fins, fillet
inside at the MMT and the airframe, then glue in the aft centering ring.

        Bob Kaplow      NAR # 18L       TRA # "Ctrl-Alt-Del"

Kaplow Klips & Baffle:      http://www.nira.chicago.il.us/Leading_Edge/MayJun00.pdf
NIRA:   http://www.nira.chicago.il.us  NAR:    http://www.nar.org





 
 
 

Motor Retension and removing aft centering ring

Post by Bob Kapl » Thu, 21 Dec 2000 03:34:21


Quote:



>>>I am wondering what the "Timberman Nuts" are and how they attach to the rear
>> centering ring.  Any suggestions?
>>>Also, does anyone know of a good way to remove the aft centering ring after
>> you tack the fins in to do teh interior fillets?  Thanks

>> I'm not sure what a "Timberman" nut is unless it's a T-nut -- I thought they

> I think he's talking about a Timmerman Nut, which is a stamped piece of
> spring steel that will engage a bolt. They are often used in mounting stuff
> in racks and other blind mounting situations. I don't see them as useful for
> motor retention.

Make that tiNNerman as in http://www.tinnerman.com/ which has several
pictures of them.

        Bob Kaplow      NAR # 18L       TRA # "Ctrl-Alt-Del"

Kaplow Klips & Baffle:      http://www.nira.chicago.il.us/Leading_Edge/MayJun00.pdf
NIRA:   http://www.nira.chicago.il.us  NAR:    http://www.nar.org





 
 
 

Motor Retension and removing aft centering ring

Post by BigEmo1 » Thu, 21 Dec 2000 04:05:08


This is kinda wierd because in the instructions it says "TIMBERMAN" and not
"T-nut" or "TINNERMAN."  These match Jim Yanik's description in the previous
message so they must be "t-nuts."  However, the problem of the middle centering
ring still remains. The rocketboy is slightly different than most HPR kits in
that it has a forward centering ring, as usual directly in fron tof the fins, a
middle centering rins, directly behind the fins, and a rear sentering ring,
inside the end of the alluminum nozzle.  The rear centering ring is the one the
"t-nuts" are attached to.  The mid-centering ring is the one I am having the
problem removing.  This ring has no "t-nuts" or anything to grab hold of. Also,
the t-nuts' prongs are as long as the threaded recepticle for the screw.  They
look like they will stick out of the end of the aft centering ring.  Is this a
problem?

Alex Immerman

 
 
 

Motor Retension and removing aft centering ring

Post by Pete Dav » Thu, 21 Dec 2000 07:02:17


Hi Alex
If the prongs on the 't-nut' are too long simply file them down.  You can do
this before fitting to the centering ring or after if space allows.

Regards the removal of your middle centering ring (assuming that you havn't
glued it in place, can you***one or preferably two wood screws into it?
you may need to drill small pilot holes so as not to split the ring.  Once
you have got the wood screws in you can use pliers/grips to pull out your
cenering ring.

Regards Pete
Pete's Rockets.
http://www.FoundCollection.com/


Quote:
> This is kinda wierd because in the instructions it says "TIMBERMAN" and
not
> "T-nut" or "TINNERMAN."  These match Jim Yanik's description in the
previous
> message so they must be "t-nuts."  However, the problem of the middle
centering
> ring still remains. The rocketboy is slightly different than most HPR kits
in
> that it has a forward centering ring, as usual directly in fron tof the
fins, a
> middle centering rins, directly behind the fins, and a rear sentering
ring,
> inside the end of the alluminum nozzle.  The rear centering ring is the
one the
> "t-nuts" are attached to.  The mid-centering ring is the one I am having
the
> problem removing.  This ring has no "t-nuts" or anything to grab hold of.
Also,
> the t-nuts' prongs are as long as the threaded recepticle for the screw.
They
> look like they will stick out of the end of the aft centering ring.  Is
this a
> problem?

> Alex Immerman

 
 
 

Motor Retension and removing aft centering ring

Post by BigEmo1 » Thu, 21 Dec 2000 07:23:43


I was thinking maybe just glue a dowl or***onto it and just pull it out
then when i put it back in ust make it facing the opposite direction.  Either
way it doesnt really matter because the nozzle with the rear centering ring
will cover it up.  

Alex

 
 
 

Motor Retension and removing aft centering ring

Post by Jim Yan » Thu, 21 Dec 2000 09:18:04




Quote:
>Hi Alex
>If the prongs on the 't-nut' are too long simply file them down.  You
>can do this before fitting to the centering ring or after if space
>allows.

>Regards the removal of your middle centering ring (assuming that you
>havn't glued it in place, can you***one or preferably two wood
>screws into it? you may need to drill small pilot holes so as not to
>split the ring.  Once you have got the wood screws in you can use
>pliers/grips to pull out your cenering ring.

>Regards Pete
>Pete's Rockets.
>http://www.FoundCollection.com/



>> This is kinda wierd because in the instructions it says "TIMBERMAN"
>> and
>not
>> "T-nut" or "TINNERMAN."  These match Jim Yanik's description in the
>previous
>> message so they must be "t-nuts."  However, the problem of the middle
>centering
>> ring still remains. The rocketboy is slightly different than most HPR
>> kits
>in
>> that it has a forward centering ring, as usual directly in fron tof
>> the
>fins, a
>> middle centering rins, directly behind the fins, and a rear sentering
>ring,
>> inside the end of the alluminum nozzle.  The rear centering ring is
>> the
>one the
>> "t-nuts" are attached to.  The mid-centering ring is the one I am
>> having
>the
>> problem removing.  This ring has no "t-nuts" or anything to grab hold
>> of.
>Also,
>> the t-nuts' prongs are as long as the threaded recepticle for the
>> screw.
>They
>> look like they will stick out of the end of the aft centering ring.
>> Is
>this a
>> problem?

>> Alex Immerman

I suggest using super glue to temporarily attach a couple of Q-tip
sticks(minus the cotton tip) to the CR,to use as pull handles. Then break
them off afterwards,and sand off the residue.

Jim Yanik,NRA member

 
 
 

Motor Retension and removing aft centering ring

Post by Leonard Fehske » Sat, 23 Dec 2000 03:04:30



wrote

Quote:
>Make that tiNNerman as in http://www.tinnerman.com/ which has several
>pictures of them.

Can we leave the TinMan's nuts out of this?  I used to think The Wizard of
Oz was such a wholesome movie...

len.

 
 
 

Motor Retension and removing aft centering ring

Post by Peter Cl » Sat, 23 Dec 2000 12:45:55


(snip)>I used to think The Wizard of

Quote:
>Oz was such a wholesome movie...

Tom Lehrer sang in 1964:
"When correctly viewed, /anything can be lewd.  /I could tell you things about
Peter Pan,  Or the Wizard of Oz/ (there's a dirty old man!).
(Oh, back to rockets... that same album has a great sendup of Werner von
Braun.)

Peter W. Clay NAR 18619 SR L1 OREO 555
If it dies, it's biology; if it blows up, it's chemistry; if it breaks, it's
physics.

 
 
 

Motor Retension and removing aft centering ring

Post by Lewis Garro » Sun, 24 Dec 2000 02:20:23


pay no attention to the man behind the curtain............


Quote:

>(snip)>I used to think The Wizard of
>>Oz was such a wholesome movie...

>Tom Lehrer sang in 1964:
>"When correctly viewed, /anything can be lewd.  /I could tell you things
about
>Peter Pan,  Or the Wizard of Oz/ (there's a dirty old man!).
>(Oh, back to rockets... that same album has a great sendup of Werner von
>Braun.)

>Peter W. Clay NAR 18619 SR L1 OREO 555
>If it dies, it's biology; if it blows up, it's chemistry; if it breaks,
it's
>physics.