2007/10/21 - {Filename?} Re: a quick BT-7 [TANKS] (Stacy Hilton)

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Chrys,

I'm not sure that you will be able to directly drive a BT5's tracks. Even the original tank had an offset drive. Take a look:

Those disk shaped things on the back are housings for the final drive gears. I was confused about how these shafts were driven until I got a good look at a drawing in"Steel Steeds Christie" a biography of J. Walter Christie written by his son J. Edward. This drawing clearly shows the layout of the major components in the M-1931 Christie tank that was the basis for the BT series. The drawing shows the transmission and clutches in front of the final drives and what looks to be a gear arrangement between them. Later!

Paul Hilton.

----- Original Message -----

From: Chrysanthos Kanellopoulos

To: tanks-at-rctankcombat.com

Sent: Sunday, October 21, 2007 1:24 PM

Subject: a quick BT-7 [TANKS]

Actually, Paul, you've made me want to build a BT-7 just for the heck of it. If I could just start with 12 mm steel shafts bent to right angle Z for suspensions at an ironsmith's with a torch. I hope that works and they won't break at the corners after they are overheated. (I never trusted suspension arms built out of 2-3 parts and heavy loads, but that's just me, I overengineer everything to be on the safe side because I know so little). It has a rear drive system too! I am drawing a 1:8, 70 cm long BT-5 on CAD during breaks at work. 18 V DeWalt drills (500 RPM) fit into the 1:8 hull and anvilus' M01 motors fit inside the 1:6 hull, and positioned so they are directly connected to the rear drive shaft (388 RPM). It should be easy for me if I transferred Tankette's DeWalt drills drive and axle systems into the 1:8 Christie. No transmissions and pulleys for me....

It is supposed to have two Z -active suspension arms with springs for teh two front ground wheels (finally) and a bell crank system like the Locust and my Ha-Go for the rear, closely spaced, ground wheels, and be done with this problem in my usual quick, crude, and primitive style.... I think I've mirrored the first Z suspension arms. Ahhh! but a Christie is not to be taken lightly and crudely! She is as mystical as a Luger in teh sense that she always looked like a prototype (with her casket shaped hull ) yet with sophisticated systems. This coffin looking thing hops gracefully over obstacles.

That's only a recipe for building an all aluminium and stainless steel model quickly.

Perhaps in a year or two from now...

Chrys

PS . In the last attachments, Christie / T-34 type tracks with tiny 3 mm screws. MOst of teh conical head goes into the holes. Large, 5 - 6mm thick bolts in the middle are the guide horns. Only these are 65 mm wide tracks. In scale 1:6 a BT-7 would require hinges that are 5 cms wide and with two holes. You'd have to drill the middle hole for the guide horns yourself. IT is possible if you started with 3 mm cobalt drill bits, then with 5 or 6 mms. 5 horns make a drive wheel 9 cms diam. and 6 of them about 107 mms diam.

. IN the other type , little angles come exactly to the middle of the hinge. Two of them from either side, and both bolted together with tiny screws, to form the guide horn. Think Meccano.

suspnsion_Z.jpg

Christie_print screen3.jpg

Christie_print screen2.jpg

Christie_print screen.jpg

T34 track 65 side.jpg

T-34 65 mm inside.jpg

T34 track 65 inner.jpg

T34 track 65 outer.jpg

T34 track 65 outer2.jpg

T-34 65 mm front.jpg

T34 track 65 side2.jpg

From:	"Stacy Hilton" <stacyj-at-defnet.com>
Subject:	{Filename?} Re: a quick BT-7 [TANKS]
Date:	Sun, 21 Oct 2007 17:57:34 -0400
Reply-To:	tanks-at-rctankcombat.com