View Full Version : Techie Heavy duty axle question.

04-19-2009, 10:08 AM
I've done some searching and reading on topic, but there is a hole in the info.

I don't have dimensions on a 1.5" axle. I'm trying to order parts now and fab my 3" extended myself.

So, a few 3" extended and axle questions for the forum:

1. What size blank do you start with for machining? I plan a 1 5/8 X .188 x 12. But I gotta make sure. Turn down the axle to 1.5" somewhere past the brake mounting flange. I need that measurement too. Might be around 1.7" from some of the spacers I've seen.

2. On 3" extended...Do you change the angle of the axle to keep the same gear track? Or do you keep the same angle(45deg), and accept (maybe want?) the wider stance? I'm pretty sure you do, but I gotta check.

3. I read the axle thread as 16/inch. I think it's right for a standard crown axle nut.

4. How far from the end of the axle (thread end) should the brake flange be mounted?

Thought I'd see what the forum might know so I can proceed with confidence. It's no fun to backstep and redo. Thanks.

04-19-2009, 10:56 AM
Let me check my old gear. I may have a leg that is nfg I can send you.

It may be standard though...

04-19-2009, 07:50 PM

I just built myself a set of 1.5 inch extended gear and used 1/8 inch
x 1.5 inch 4130. I machined a cylinder to slip on the axle shaft for
the seal. That way it is adjustable and removable. That saves a lot
of machining.


Cub junkie
04-19-2009, 08:24 PM
Unless you just really want to machine the axles and cut the threads yourself you can buy nice machined axle blanks from Aircraft Spruce. Then you can make the above mentioned spacer and fabricate a brake caliper mount. I think they are 12 inches long, plenty of material to work with. I built my gear legs 3 inches over stock and kept the same tread width.

04-19-2009, 11:28 PM
I'm following this thread with interest. And, I appreciate all the answers.

I've seen the axles on spruce...I thought I'd make my own for the experience. I even own a lathe. (sans the screw feed) I'm using a friends lathe to learn the screw/thread making. I just don't have a good print for these.

I have the cleveland 6" wheel and brakes.

I figure to get two blanks 1 5/8 by .188 by 12" and machine down to 1 1/2 from the brake flange out...or maybe not. I have some spacers that are 1.7 long that I believe are to offset the wheel from the brake attach flange. I could just machine that spacer in (I figure).

Again, just looking for some exacts, to avoid a "do over."

Cub Junkie, geometrically, I guess the 3" extention only widens the stance by about an inch and a quarter. No sweat.

I know to use some doublers and gussets near the bottom undersides.

As usual, please always pardon my ignorance...it's never intentional.

Thanks, and I'll always take more input.

04-19-2009, 11:28 PM

04-20-2009, 12:11 AM

Looking to 'learn' on your cub axles? :-?

If you don't mind some advice, order enough stock for six blanks, get yourself a REAL comfy stool to sit on while you watch; get a case of cold beer, plus one for yourself (the first for all the guys coming in to see how it is going), and plan on one full day for each try. :oops: :oops:

From experience, you will make lots of scrap pieces in trying to get it correct. These are parts that do not allow being off very much.

Learn how to sharpen you tools well, and keep them sharp. Cut to within .003, and sand from there.

It will take days for the first one to be correct unless you have a jumbo lathe that can cut deep and fast. Then you will find yourself cutting too deep on the last cut :evil: , (I do that on my projects).

When things go bad, like you just cut .005 under allowable tolerance after a full day of machining that part, relax and take a walk. After all, it is experience! :wink:

What type of lathe do you have?

04-20-2009, 08:07 PM

I appreciate the advice. I've learned to pick my fights. Maybe I'll leave this monster lay and pick another job to learn threading. I got many of the same responses from the "smart fellows" at the airport. They are good at most things, but they don't like threading much. I heard a few horror stories today. That said, they did suggest that you thread to the bottom, then reverse the machine out to the top and start the cut again deeper, so you don't lose your index.

I have a friend with a Grizzly 4003 and another has a G406. I don't care to start the "machine" talk. I'm not a professional machinist and neither are my friends. My ignorance would surface immediately. I'd love a bridgeport and a southbend to play with, but it'd be a total waste in my hands and wallet. I have a cheep three in one and I like playing with it, learning machining on my own and from others, and making parts.

Thanks for the info. I may grab a 1.5 axle with a thread on it from wag aero and weld a brake flange and sleeve behind the flange, then start legs.

PS. I never did see any dimensions from posters.

04-20-2009, 08:52 PM
A/C Spruce... P/N 05-02488, 1 1/2" axle with flange welded on. $149. Good place to start.

04-20-2009, 09:19 PM

Check out my photo album and you can see some of my projects... including 2 1/8" internal thread :x and a 2 1/4" internal thread.

There are some great how to instructions on the web for threading, but some practice helps. Also it takes some scrap to learn what not to do :oops: :drinking:

Fly on up here and we can play for an evening and get you threading with ease. The key is the tool cutting edge angle/compound angle and having a threading dial...

Watch reversing out, some old machines have enough slop to mess the thread...

Good luck!

04-20-2009, 09:50 PM
I was worried about a backlash... And I don't know enough about the machines, but I was hoping that the feed and the machine work dependently.

I'll have to take you up on the visit sometime. You live in the part of the county I wish I could be. Farther from Wash. DC and closer to mountains the better.

Internal thread sounds really, really HARD without taps!


04-20-2009, 09:56 PM

Start here:


Cub junkie
04-20-2009, 10:18 PM
Cal, the blank axles from Wag Aero have different threads than the Aircraft Spruce blanks. The wags are more coarse, not sure the pitch I just remember they were. If you go with blanks I would recommend the ones from Spruce.

04-20-2009, 11:18 PM

There are step by step tutorials on the web that will cover threading much quicker than sifting through all the pages on the PM site. I have spent hours reading and picking up tidbits, but will say if you are just learning, the PM site can make you frustrated by showing what you do not know :oops:

Ignorance is bliss often!

Cal, do a search on thread cutting and you will find the step by step! The tough part for me is getting the piece to the exact size to start cutting.

I assume you have the little thread tool angle Gage?

As far as fine vs course... I hate AC Spruce. I just do not go there. I would be careful and get a thread on my axle that is common so when you have a problem you can get a new nut.


Cub junkie
04-21-2009, 12:06 AM
Aircraft Spruce axles use 1/1/2"x16 nuts. Very common.

Jim Miller
05-08-2009, 08:51 AM
My axles are 1 1/2 from Alaska Airframes. Next time you stop by you can photo and Mic.

Jim Miller

05-21-2009, 11:58 PM
I'm going to let this thread go, but I'll say I've learned alot about different models of Cleveland wheels and brakes. No wonder, noone offered specs for an axle. Answer is "it depends...."

I have some 1.5 inch axle, 6" cleveland wheels that needed new brake disks. I'm going to put them on my t/w Glastar for a while until I'm finished building the Supercub. The number of 6" wheels with all their own specs and differences is astounding. They don't sell them by spec, but by production aircraft, or part number relating back to production make and model. Do you need Cessna, Piper or Beach etc. 6 inch wheels. BTW, the Supercub is under 1.25 axles, so we don't have a brake disk for you application.

Well, I think I'm set up with good, tall-hat brake disks (wheel clearance) on the correct wheel, flange, bolt size, pattern etc. Now, I'll just make my own spacers to fit. Experimental does make it challenging to use your own parts. Pheewww!!

Lastly, when I do this next week is to wonder what kind of fit the spacer should give the wheel against a mounted brake reference. If anyone knows, I'll gladly listen. If you don't, I'll figure it out yet.