Lathe work

[orchardair]

Builders,

I've compiled the required threaded tube endings that are required to be manufactured for one Hatz Classic.
This does not include the PEM nuts that you can buy ready-made.

I changed the design a bit from the plans, in a way that I think will make them easier to weld to thin-walled tubes:

lathe.PNG (109.08 KiB) Viewed 6127 times

The depth of the widest part is not critical, but let's say it is 0.050". This is the lip that stops the plug from sliding further into the tube.
Total height of all the plugs should be 0.75".

I've tried to find someone locally that would make a set for me unsuccessfully, and one non-local manufacturer (an on-line service) quoted me $800. I can buy a lathe for that!

In the past, the group has come together with good solutions for issues like this one. If several of us can commit to buying a set of these plugs, maybe someone can help out?

Hopefully.

[jptowey2]

Still far from there.. but depending on costs would be up to participate in group purchase. PM me as we might have vendor at work who could do.
Thanks

[dougm]

Do you have a vocational school/college nearby? It might be possible to enlist them in making these. They aren't that complicated and would be a good project for someone. Just a thought.

[Bitshifter]

I bought a small Grizzly lathe and it worked great. I didn't need it for much else but it doesn't take up any room under my table. it is nice to have around.

[orchardair]

I bought a small Grizzly lathe and it worked great. I didn't need it for much else but it doesn't take up any room under my table. it is nice to have around.

Which model did you get?

[Bitshifter]

I have the 8688, 7" x 12" mini lathe. Its not perfect and I had to rebuild the transmission but I would still buy it again. The internal gears are plastic and the spindle bearings are not tapered. It got jammed and a plastic drive gear broke, I ordered replacement parts from the LittleMachineShop.com. While replacing the internal gears I converted it to tapered spindle bearings and it is a much better lathe. It is easy to jam, especially if you are using it to part tubing. If it jams you need to be quick on the e-stop or you will blow a fuse, get some spares. So far I have been able to make everything that I need. It has the biggest spindle bore of all the mini lathes which comes in handy.

[mmarien]

You can find weldable rod end adapters on the internet. Just search for rod end adapters. Here is one source: https://www.qa1.net/rod-ends-and-relate ... e-adapters. Price is good.

I decided to use aluminum control tubing so I needed different adapters that can be riveted to the aluminum tubing. I'm not sure why they are so rare as RV's and my Glasair use the same type. The design shown below is copied from my Glasair plans. I did find a source that had a half dozen of each thread direction. They sold me those but said they weren't getting any more in. I had a local guy make a few more for $8 ea. I'll probably buy the rest of the inserts I need to weld to the tubing on the Internet.

Tube Inserts 0.75 6160 x 0.065.png (68.77 KiB) Viewed 6075 times

20180114_152345large.jpg (256.12 KiB) Viewed 6075 times

[orchardair]

Murray,
You are correct that there are weldable tube ends for sale, but the only ones I could find were for 0.058" tubes, or thicker. I actually contacted the manufacturer http://www.fkrodends.com/WELD44.html to see if they would make some for 0.035 tubes, they said not for such a small order.
Amit.

[JBMoore]

Not having built a Classic, I'm going to make an assumption the inserts go into the end of the control rod tubes and not the compression tubes in the wing.
If so, you can switch to a female threaded rod end bearing, buy weldable threaded inserts that will fit 0.035" tubing and weld (or rivet) them in.
I didn't do the math for the cost difference.
Jeff Moore

[mmarien]

Murray,
You are correct that there are weldable tube ends for sale, but the only ones I could find were for 0.058" tubes, or thicker. I actually contacted the manufacturer http://www.fkrodends.com/WELD44.html to see if they would make some for 0.035 tubes, they said not for such a small order.
Amit.

Right. When I switched to aluminum the A&P next door suggested that I just double the wall thickness. I used 063 shown in the drawing above. Although the plans for his RV4 show 3/4" 035 aluminum tubing. The RV4 drawing also show male rod ends. Note the optional 1.125" version.

RV4 bell crank drawing (cropped).jpg (665.65 KiB) Viewed 5914 times