Arbor Support Shape?

[Uglydog]

The factory VN arbors all have an arc.
My shop made arbors do not have an arc shape. Instead, they are straight, fashioned them from 1018, carefully bored them to fit the arm, and use the 3bolt fastener which Cal Haines recommended in a different thread. I still need to improve the bearing assembly.

Is there an advantage to the arc shape?

Daryl
MN

 

[Cal Haines]

Daryl,

I'm not sure what arc are you referring to?

Can you post photos of your arbors?

Cal

 

[Uglydog]

Cal,
Thanks for asking me to clarify.
I made this one for the VN6. As I make progress toward slowly getting the 22LU together I'm thinking about how I should construct the missing OEM arbor support arm. While this one seems to be working very well, as you can see I still need to shorten her up a little, and I need to work on the bearing assembly.

The larger question is overall design. Is the sweeping arc of the OEM supports (last pic) advantageous?

Daryl
MN

 

[David VanNorman]

I may be wrong but the sweeping arm might let you see more.

 

[Cal Haines]

Just a guess, but the arc may have to do with the reservoir for the one-shot oiler; it needs to be a the same level as the bearing. The No. 12 has a straight arbor support with a dead center. The No. 16 (which is the direct descendant of the No. 12) has a curved support with a live bearing support, instead of a dead center.

Cal

 

[Uglydog]

Got it I was thinking that perhaps there might be some trigonometric engineering concept which somehow optimized support, and reduced vibration.
So the follow up question is bearing assembly and lubrication. I'm not finding threads on this on any forum.
Anyone have ideas?
I'm working with a retired local pattern maker to have multiple 24inch scraping triangles cast. Turning out very affordable, I hope he will let me post some here in FS at hobby machinist.
I'll see him tomorrow, and ask what it would take to build some forms for some supports. If he is game I'll start a thread.
I've already asked him how they made castings with reservoirs. He lost me in the explanation.

Does anyone think that the 6, 12, and 16 could all take the same support?
The 22s and up would likely require something larger.
Ideas?
Opinions?

Daryl
MN

 

[Cal Haines]

If I were making one, I would just use permanently lubricated bearings and not bother with the elaborate one-shot oiler system.

You could make up a nice arbor support out of a stack of steel or aluminum plates. (The support on my No. 16 is an alumimum casting.) Have them water-jet or plasma cut if you can.

No. 12 and No. 16 should use the same size support. IIRC, the No. 6 is a little shorter. The No. 22 would have come with two arbor supports and they were not at all the same shape.

Cal

 

[Uglydog]

Cal,
How does the aluminum casting work out? This past fall I "inherited" a small commercially made foundry suitable for aluminum and brass. I could cast one myself!!
Your comments on permanently lubricated bearings, they confirm the direction I was thinking.
Two supports for the 22? Not the same. Ok, more research!!
Thanks!

Daryl
MN

 

[Cal Haines]

Daryl,

My No. 16 is still apart, waiting for me to install new bearings. I have not used it in horizontal mode. However, the aluminum casting is very substantial, I can't see any reason that it wouldn't work just as well as the cast iron arbor support for the No. 12. It has a thicker cross section, so should be as stiff or stiffer, etc.

The larger machines, No. 22 and up, have a second arbor support that can be positioned in the middle of the arbor, for additional support. It looks like some No. 22 machines had a dead center arbor support and others had the pilot type arbor support, with the bearings. Note that a special arbor is need for the pilot type support: the arbor has a pilot on the end that sticks into the bearing. The sleeve support uses a special sleeve on the arbor to provide additional support the arbor in the middle. For heavy milling setups, there was also an outer brace that connected the dovetail on the knee to the outer arbor support, providing additional support. The newer version of the 22L/M manual shows the ball bearing arbor supports and the outer brace. Let me know if you need a copy.

Cal

 

[Uglydog]

All I've got is the free manuals from Vintage Machinery and Van Norman Yahoo. The manuals there only show one support with no break out views. I wasn't even aware that there were additional manuals.

Sounds like critical information. Do you have a manual or a scan available or for sale?

Daryl
MN