Cox TD 020 question

If you can fit your retainers to the myriad TD 020's you have access to then I have to admit that the issue might be particular to my example which I got second hand with no knowledge of it's history. The anodising is still fine over the threads so I doubt they've been tampered with.

To be honest I think the crankshaft fit is the more interesting of the two issues. Obviously I would very much like to use my new crankcase instead of the old one. Hopefully the shaft fit can be resolved when one or two kindly souls dissasemble their TD 020's and share if their crankcases are anodised inside the crankshaft sleeve or not. My old case is not but is anodised everywhere else and the new one is anodised absolutely everywhere. The difference in internal diameter is 0.1mm as far as my calipers can determine which is quite a bit when we're talking about these little engines.

I have never run into any collets not fitting between new or old crankcases. I have had issues with the new drive plates on your site and older TD 020 crankshafts not fitting. If you ever make a new run of TD .020 drive plate please add about 100 of the smaller inside diameter version to the order. I'll buy 10.

I have 2 new of the gold Tee Dee .020 prop plates that are too small to fit the crank and I have no idea why.

Jason_WI wrote:I have never run into any collets not fitting between new or old crankcases. I have had issues with the new drive plates on your site and older TD 020 crankshafts not fitting. If you ever make a new run of TD .020 drive plate please add about 100 of the smaller inside diameter version to the order. I'll buy 10.

Jason,

The drive-plates for the TD 020 we sell are still old Cox stock. We have such a large amount of them that we doubt there will ever be a need to manufacture them

Bernie I got a couple from you last week. Any Idea why these won't fit. This not the first time I have seen this issue with the .020's.
Joe

I would say that being Manufactured in 1957 to 1994 with 1968 and 69 different engines just as the Babe Bee were not all the same , maybe some testing or product change wrong size parts run ? Car engines , Heil. airplane , application may have had the need for a heavy spline or decided the spline they were using for some reason needed beefing from the beginning ?? Just guessing I don't Know either , Eric

jsesere wrote:Bernie I got a couple from you last week. Any Idea why these won't fit. This not the first time I have seen this issue with the .020's.
Joe

Joe,

I am out of the office until Tuesday but will check upon my return. They are NOS Cox but perhaps some have defective threads?

Shall get back to you on Tuesday.

Bernie,
As you well remember, back in 2009, a very large quantity of Cox inventory became available including a hugh amount of material from the Cox R&D department. The R&D stuff was massive and acquired by a young guy (CEF member) here in Georgia through his classmate, now Cox engineer. I bought many items for use/collection not resale and I know Reggie(VGE) and I think you and Matt did also.
After I bought a few of the new TD.020 crankcases, I decided to assemble one but the NOS stock crank was too large for the case bore.
I measured the crank with my digital caliper and got an OD of .217 inch/5.51 mm.
The crankcase bore in question is front ID .2115 in/5.39 mm and rear ID is .2145 in / 5.45 mm. It is tapered.
It appears me that it did not go thru the final machine process or final hone process at the factory. The collet threads were fine.
I have concluded that many items that were incomplete or unfinished ended up in the big pile in Cox R&D in the last days of operation. I also had bought a large number of Killer Bee drive plates that had not been finish broached so would not spline onto an .049 crankshaft. Too much trouble to try to get my money back now.
Don't know if this has helped answer your concerns but these were my experiences FWIW..

Steve...............

66 Malibu, this is invaluable information. It means that I can now stop wondering whether or not to look for a crankshaft that might fit since the problem is actually with the crankcase. I got the exact same measurements as you did and VGE was my source for the crankcase. From your description I now need to decide whether to modify the crankcase to suit my crankshaft or keep it as a curiosity. Some have previously suggested I grind down a crankshaft to fit but I'm not sure about that. I don't have the tooling or experience to do either option right now.

PS. I'm going to assume that the problem with the carb retainer's threads are specific to my old crankcase. Sorry to cause you stress about that one Bernie. I still can't see why it won't work but if everyone else is happy with them it makes sense it's just my example.

Thermalsniffer,
It's a high probability that your TD.020 crankcase may have been part of the same batch/production run as the ones I bought.
You can do want you want with your stuff, but I can tell you that a TD.020 crankshaft is about 50X harder to find than a good crankcase ( most moving parts are now days) from my experience.
I believe that turning down the crank would remove any and all of the heat treating it may have , therefore wear out fast.
Getting that taper down would  require machine work and tolerances well into .0000 and .00000 of an inch to keep the crank from binding in the case.
I would either try to drill and hone case as close as possible and know that it may fail anyway because hobbyists can never match Leroy Cox's level of tolerances, or put it on the shelf as a reminder of what might have been.
Speaking again about TD.020 crankshafts, the last one I saw on eBay was about 7 years ago and I bought it.
Others may disagree but this has been my experience..YMMV'
Steve...

Steve, after running a few OK Cubs and Testors McCoy Red Heads, I am no longer concerned about "fit and finish". Nor "metallurgy".
- George

Yea George,
I have way more than my share of all flavors of OK Cubs and Testors/McCoy/Wen Mac engines and the they all make noise.....
However, a good double handful of those are worth about what one TD.020 is worth.
I hate to give advice, but I ( for the love of the hobby) didn't want to see good TD parts bite the dust.
You know the " you don't know what you have until it's gone " story...
Matter of fact, I just picked up an extraordinarily well built Ace Littliest Stick plane for $5.00 from a friend recently set up for a TD.020, that will get a good Pee Wee instead if or when it flies.....
Steve.............

Steve, I was being facetious. Prior to Estes, I enjoyed the fit and finish of all Coxes I purchased. They all ran well. I have a Littlest Stick with .020 Pee Wee, may put the Ace Adams Baby Twin built it 30 years ago, repaired it a couple years ago. That engine powers it just fine.

Good to hear that the Pee Wee had plenty of power for the Littliest Stick. My problem is that once the thing is in the air you might not get it back for whatever reason.
A good example is a Pee Wee that I rebuilt for a friend of mine last season that was probably the strongest one I ever built. On it's first RC flight the little plane caught a pre Storm thermal and quickly got out radio range. My friend said he could hear the PW screaming along well after it was out of site. It headed toward about 100 miles of forest and was never found....
Steve....

I lost a Goldberg 1/2-A Skylane Junior with Golden Bee and pulse rudder back in 1977 to a prestorm thermal. I learned a hard lesson, never fly on the eve of a thunderstorm. That was in North Little Rock, Arkansas. It was headed west, probably landed somewhere in Kansas.

Loved that plane, was tedious building it but a beauty once built. Even with full rudder to attempt spiralling it down, it kept climbing and climbing. Then rain drops the size of quarters started pelting me. By the time I made it to the truck 75 feet away with all my gear, I was drenched.

The Littlest Stick is small enough, that even on rudder only, you can only let it out so far to keep oriented in flight. Unless you fly around thermal activity, usually spiralling it into the ground will keep it from getting away. I lost another to the swamps at edge the model plane park on the other side of the Pali on Oahu, Hawaii back around 1980. Engine sagged, it went down into the reeds never to be found. I had it made up nicely to look like Red Baron's plane, red with white squares and Maltese crosses.

Similar sized plane, Ken Willard's Roaring 20 (downsized Top Dawg) flew really well on Pee Wee with Ace Pulse, loved to fly that bugger back in the early 1970's.

The Littliest Stick I just acquired has the same red covering with white panels and black Iron Cross on each. The white fuselage band has the black ace of spades, really nice build. It is set up for R/E which I'll keep.
Didn't think I could go too wrong since the original kits on ebay go for $70-$100.
I was going to build one of my Das Not Ugly kits from Select Hobbies with the same motif but rtf for $5 is way easier.
Hope see airborne with a PW shortly...........

Dave Frizke has plans, the LA Stick which I believe is similar if not the Littlest Stick, both are Ace R/C products. I think it may be on either Outerzone or Hip Pocket Aeronautics, too. $70 - $100 is quite a bit since the LS is an easy scratch build, plus one can better QA the wood used.

There are a good number of plans in the 20" wingspan range, for the Pee Wee power. Back in the late 1960's / early 1970's, Nick Ziroli made a 12" wingspan Spad and Fokker DVII either Pee Wee or Tee Dee .010 powered as single channel escapement. Today, those are regulars on electric power with at least 3 channels.

Good to hear from you, Steve, I actually named you in another thread about Li'l Satans the other day. I hope all is well. How's that hotrod engine coming along?
Rusty

Hi Rusty,
Thanks for the shoutout !! Been following your great adventures and fun but staying low key...After our visit at your house a couple of years ago, I had another total knee replacement which has a long recovery time and then bout with type 2 diabetes which beat me down pretty good. I have been accumulating hypereutechtic pistons, moly rings,new bearings, special rocker arms, cam, and special con rods for my project engine. Pretty much at special gift times like Christmas, Birthday, Fathers Day somebody gets me some more parts. Of course the heads and the rest of the other stuff I got from you will be used. I have all the new parts to rebuilt the Muncie 4 speed trans I got from you and will do so as my health gets me back to my sub-normal self ( wife sarcasm ) and the temp moderates some.
Hope you got some use out of that Lil Satan kit although you already had a flyer as I recall. I actually got another Lil Satan nicely built flyer with a stout reedie at Perry this year. As I get stronger, I'll teach my 13 year old grandson the joys of U/C.
Maybe I'll be able to come over you way in the not too distant future so I can watch a real pro fly !!
Anyway, hope all is well !!
Steve....

Hi George,
Thanks for the plans info. I had printed the tiled plans off Dave Frizke's website 6 or 8 years ago for the Littliest Stick and put them away totally forgotten until you reminded me... I believe that I have saved all the plans he had at the time on my old computer so I need to go back to the site and update everything....
Thanks Again, Steve...

Yes, large lots of R&D rejected items ended up in the marketplace and we, in-turn, ended up with many of them. Some items had to be scrapped and others reworked; whereas others seemed to be fine.

We just tested 20 randomly selected collets and they all fit fine. As posters have pointed out, the issue may lie with the crankcases.