Warbird Information Exchange

This is the CAF's SB2C based in Houston, TX (not that there are many flying around these days.)
Other queries have not been very fruitful, so now it is a broad request.
(It seems likely will need to get a generic store brought, or even custom)


While we where doing the pain touch up on SC2C I discovered the ring the rear gunners seat is on is missing bushings, and now I am tasked to look for them.

Installation:
The gunners seat and machine guns is mounted inside an aluminum ring that is held by 2 bolts at opposite ends to the fuselage.
Thats it!
Their is an adjustable brace to change the tilt, so the gunner will have optimal position of the machine guns for defense.
Did I mention the fact the MG was also mounted on the ring?

Yes, that is a lot of weight rattling around on the bolts.


Details:
According to the parts book below, the bushing seems to be a Curtiss part, as the part number does not match anything I know, and of course a bushing is not a high tech part.
Regardless, any info anyone can find about this will be appreciated.

Meanwhile I will go with Plan B.
I will find the basic dimensions of a bushing. The length needed, outside diameter, and diameter for the bolt. The bolt looks to be a standard AN bolt, or has an AN equivalent so that is easy.
The major issue is the hole in ring for the bolt. I am sure the aluminum ring will have an elongated hole in it, so it is likely we will need a reamer to clean out the hole for a good fit. Of course we could be lucky and no need it.

If I need to ream out the hole, who can I talk to about the tools and matching bushing to get this fixed?

I will get more information ASAP.


This is what the manual said about the ring mount for the gunner seat:

Curtiss Manual AN 01-25AD-4
Parts Catalog
15 April 1946
P 252, Fig. 140 Flexible Gun parts list sheet.

Item:
#9
Bushing 84-58-825 Bushing <- This seems to be Curtiss part by the number, however we can find a replacement with searching.

#10
84-58-827 Bolt <-- again a unique number, but an AN type bolt will fill the requirement.
AN380C3-3 Cotter Pin
AN310-6 Nut
AN960-616 Washer

#11
84-58-843 Bushing
84-58-835L Fitting Assembly -Upper

Thanks
Joe Kudrna

Flying Pencil wrote:If I need to ream out the hole, who can I talk to about the tools and matching bushing to get this fixed?

You need to measure the size of the existing hole (or the outside of the bushing). You can probably go 1/16" diameter oversize with no ill effect. You may need to make a custom bushing on a lathe if you can't find something in the parts bin that will work (or can be modified).

There are plenty of places that sell drills and reamers. You might try Rutland Tool for mail order if you can't find anyplace close.

https://www.shoprutlandtool.com/catalog/ and enter "reamers" in the search window.

FP: I would bet that the bolt listed in item #10 is a sholder bolt. You should be able to cross over to the current MStd. to get a replacement. Just a guess, but it will probably need to be a high strength spec.

If you need, pm me and I'll wander through some of our stuff and locate some possible specs for you.

Have you contacted "Helldiver" here? I would think he might be able to help you out with some of that info.

Also "Yanks Air Museum" in Chino has a Helldiver, you might try to contact them.

Tim

Call Nelson.....

Lynn Allen wrote:Call Nelson.....

Or perhaps even the folks at Wichita Air Services.

Querstion? What are the dimensions of this bushing...unless, as Cvair mentioned you're actually in need of a shoulder bolt?

Well, after too many distractions, this is what I have found and can finally post:

All that I need is a simple bushing. I am not sure if it is missing, or because the bushing in the ring is wore out (but it nicely round).

The bushing needed will have an OD no bigger then 0.497", and an ID of no less then 0.375" (direct caliper measurements, dimensions smaller for clearance), and 11/16 long (however 5/8 may be better fit)

The bolt that fits in is (custom due to low profile head) is:
0.374", or 3/8" equivalent, diameter
4.629" (4 5/8") long, with 3 3/4 long shank (4.5" long will fit as well)
Head is 0.16" (5/32) at its thickest.


I do not believe I need a new bolt, it does not have much ware or damage.

Who is "Nelson"?

Thanks for your input.
Cheers!

Flying Pencil wrote:
Who is "Nelson"?

Nelson Ezell

http://www.ezellaviation.com/

Flying Pencil wrote:The bushing needed will have an OD no bigger then 0.497", and an ID of no less then 0.375" (direct caliper measurements, dimensions smaller for clearance), and 11/16 long (however 5/8 may be better fit)

FP, have you taken the bolt and your dimension requirements around to local sources? Or have you been approaching this from an "original part" point of view? One of the good things about the industrialization in Houston is if you can't find the exact bushing you need..you can often find the stock from which it is made and trim it to OD on a lathe or drill press and ream the core to allow for shank clearance.

Sounds like you need a stick of 3/8" Porous Sintered Bronze-Cored Bar Stock(google this), so you can make your own..or given the length is 11/16..you may find it off the shelf...or stack several of what you do get?

Another possibility..have you considered trying a modern replacement like Delrin or some such? The new stuff often
surpasses original bearing life. It also can be found in "bar" or "stick" form.
www.igus.com/show_bronze.asp

If you are not looking for origional, try McMaster Carr . I order bushings thru them for work. The have a nice web site and are reasonable in price for all sorts of tooling components.

Kenn

Dan K wrote:

Flying Pencil wrote:
Who is "Nelson"?

Nelson Ezell

http://www.ezellaviation.com/

He's the guy that rebuilt that thing after it was crashed and brought to his shop on three trucks. He's also the one that's been annualing the airplane ever since (well, his employees anyway).

Kinda interesting to hear of someone that is working on/with the airplane and doesn't know Nelson. But it's no big deal I reckon. However, I'd make it point to at least meet him if you're gonna work on the airplane. I would doubt there's anyone who knows it better.

Lynn wrote "Call Nelson" and had me scrambling for my magic box to see if I had one and then Gary said he meant Ezell. Oh well I didn't have one anyway, maybe one in Breckinridge.

retroaviation wrote:

Dan K wrote:

Flying Pencil wrote:
Who is "Nelson"?

Nelson Ezell

http://www.ezellaviation.com/

He's the guy that rebuilt that thing after it was crashed and brought to his shop on three trucks. He's also the one that's been annualing the airplane ever since (well, his employees anyway).

Kinda interesting to hear of someone that is working on/with the airplane and doesn't know Nelson. But it's no big deal I reckon. However, I'd make it point to at least meet him if you're gonna work on the airplane. I would doubt there's anyone who knows it better.

Thanks for the info, and thanks the rest for all their help!

Mail sent!

As I get free time I get things done, much happening for me.
Will give Nelson a call soon.

Thank you all!

You better call real quick as he is about to leave for Austria..... He has to go check up on a twin engined, twin tailed, beauty of a P-38 ... Alan