Tuesday, December 18, 2012

Huntsville Record Trials 2012

Huntsville IMBPA Record Trials November 24-25, 2012:

Martin Truex Jr        A Hydro 1/3 OVAL           19.019 sec
Martin Truex Jr        D Hydro 1/3 OVAL           16.999 sec

David Hall                B O/B Hydro SAW            2.939 sec    76.556 mph
David Hall                B O/B Hydro 1/3 OVAL   24.168 sec
David Hall                P Hydro 1/3 OVAL          19.964 sec
David Hall                S Hydro 1/3 OVAL          20.164 sec

Mark Bullard            Twin Hydro 1/3 OVAL     18.423 sec

  • A = 2.1 cc
  • B = 3.5 cc
  • C = 4.9 cc
  • D = 7.5 cc
  • E = 11 cc
  • F = 30 cc
  • N = 1.2-7.4V
  • P = 8.4-14.8V
  • Q = 15.6-22-2V
  • S = 22.8-29.6V
  • T = 33.3-37.0V
  • The 1/3 mile oval course has 100.58 m long straights
  • The radius of the corners is 10.66 m
  • Total length: 268.22 m


Truex quite fast with his 2.1 cc hydro.


Hall's record run with a JAE OB 21 hydro. Novarossi power.



Hall's record oval S-hydro run.



Truex oval record run with his Novarossi 46DD powered JAE45 - 8 second laps! :)

 

Wednesday, December 5, 2012

T2-21 Build-Series #6

Time for the stuffing tube, cowl-mounts and the remote needle base.

Previously:
KEP's T2 .21 Presentation
KEP's T2 .21 Freebie
KEP's T2 .21 Build Series #1
KEP's T2 .21 Build Series #2
KEP's T2 .21 Build Series #3
KEP's T2 .21 "Inspirational" Article
KEP's T2 .21 Build Series #4
KEP's T2 .21 Build Series #5

BBH lightweight motor mount rails are installed with suitable spacers.

Here you can see a "dry-fit" of the stuffing tube that will be glued inside the tub and the flex tube that runs inside that. We have also made an aluminum flex adapter that is used when aligning the flex tube vs the engine flex coupling/collet. The adapter has two diameters - one that fits inside the flex collet and the other end that fits inside the K&S 1/4" flex tube.

Open up the hole through the tub bottom. Use the side view template of the tub sides as a guide where the stuffing tube will go through... Here it's dry-fitted with the flex tube installed as a reference to check that it will be straight.



Push the flex tube up and over the adapter (if you have made your own) or close to the flex collet and do a visual alignment...


Tack glue the stuffing tube with 5-minute epoxy.

Add milled fiberglass to epoxy glue and make a fillet around the stuffing tube.

Make a stuffing tube cover from some 1.5 mm plywood scrap and glue it with 5-min epoxy.


Use a mix of milled fiberglass and epoxy glue to make a filling inside the radio room where the stuffing tube meets wood. I also add the same filling under the "wedge" area under the stuffing tube tube as reinforcement.

Small pieces of 25 g fiberglass cloth is cut-out to make extra reinforcement on the inside and outside. These are "brushed" in place with laminating epoxy.

When the laminating epoxy has set the edges of the tub-bottom cloth is sanded down smooth.


The fiberglass cloth over the stuffing tube inside the radio box is done the same way. The lower tub in the picture has only the epoxy-glue & milled fiberglass mix added. The upper tub has the cloth in place.


The front cowl mounts are made from 0.7-0.8 mm thick polycarbonate ("Lexan") sheets that are cold bended. The lower one has one leg that is a bit longer. See the PDF's for more info.

Personally I use SS 4-40 screws for mounting so I drill the holes at 3mm. Note that there should be about a 1 mm gap between them as the cowl will be there... Note also that these angles will be fixed later on with smoother corners etc.



The lower cowl-mount angle is aligned so its about 1-1-5 mm below the tub deck. And the holes are marked out with a pen and the holes drilled. For 4-40 threads I use a 2 mm drill bit and then use a 4-40 tap to start a thread so to speak - then thread in the 4-40 screw.

Use one of these gadgets when drilling these holes. Don't drill too deep!

The cowl is fitted with the only the lower angle installed. Make small markings on the cowl where the edges are on the lower cowl mount.

Then the rear is fitted.

With the markings as a guide do a slot in the front of the cowl. See the above pics as reference.

Drill 4 mm holes through the cowl and the rear cowl rests in the tub. Use a drill press so the holes will be straight!


These 4x4 & 4x2 mm neodymium magnets will be glued with epoxy glue.


Dry-fitted magnets in the cowl and tub.



Sand the outside of the magnets and clean them. Make sure the magnets will be facing the right side of each other and glue them flush with 5 minute epoxy.

The protruding upper part of the magnet will be smoothed out with a mix of epoxy glue and milled fiberglass (as a putty).



Here the pipe-mount is also installed (will be a later article) and the hole/slot for the NR exhaust adapter is opened up.





The holes are drilled for the VictoSport needle base and also the pipe-mount (will be an later article). Note that you can only use 2 of 3 holes in the VictoSport needle base as the lower hole is covered by the lower banjo-nipple.

Done for now. :)

Next: KEP's T2 .21 Build Series #7