Greg's French 75 Mm Field Artillery Model

[gjmontll]

Wheel hub flanges - done!
This photo shows the two wheel hubs, now completed. The pieces are sitting on their corresponding page from the French Army document that was primary source for my CAD work for these components. I tried to come up with a good machining sequence on these parts, but I should have left more material on the ends for holding in the chucks. The tapered D-bit reamers featured in the prior posting worked well, as the inner hub mates nicely to the axle taper, and the outer flange onto the inner flange taper.
Next up: Maybe I can find a few more straight-forward piece to design and build. So far, the axle and hubs have been challenging, maybe I can do a few simpler pieces while I design the wooden pieces for the wheels. (each hub mounts 14 spokes that connect into 7 wooden "fellows".) Then there are numerous small metal brackets and fasteners that tie the spokes and fellows together and a steel "tire"
around the rim.
Greg

 

[Moose53]

Wheel hub flanges - done!
This photo shows the two wheel hubs, now completed. The pieces are sitting on their corresponding page from the French Army document that was primary source for my CAD work for these components. I tried to come up with a good machining sequence on these parts, but I should have left more material on the ends for holding in the chucks. The tapered D-bit reamers featured in the prior posting worked well, as the inner hub mates nicely to the axle taper, and the outer flange onto the inner flange taper.
Next up: Maybe I can find a few more straight-forward piece to design and build. So far, the axle and hubs have been challenging, maybe I can do a few simpler pieces while I design the wooden pieces for the wheels. (each hub mounts 14 spokes that connect into 7 wooden "fellows".) Then there are numerous small metal brackets and fasteners that tie the spokes and fellows together and a steel "tire"
around the rim.
Greg
View attachment 107293

 

[Moose53]

I am watching your project with great interest . You appear to have access to workable build drawings of the French 75 . I am a member of the GBO forums and enjoy building operational 1800's artillery . Tracy and Mike at seacoastartillery on GBO forums may be able to provide you with a scale rifled tube for your project .

 

[gjmontll]

I am watching your project with great interest . You appear to have access to workable build drawings of the French 75 . I am a member of the GBO forums and enjoy building operational 1800's artillery . Tracy and Mike at seacoastartillery on GBO forums may be able to provide you with a scale rifled tube for your project .

Thanks for your interest.
The French drawings are good, but to call them "workable build drawings" is a stretch. Since they are only drawings, lacking dimensions, accompanying text, or any designation of scale, I wonder what their purpose was. Different pages are obviously at different scales, so I derive their scale based on some known dimension(s), then go from there. For example, the axle/wheel drawing shown in my last posting appears to be at 1:7 scale. So I measure each feature as closely as possible, then multiply by 7/8ths to get the size for my 1:8 scale model, drawing in TurboCAD. Since the French drawings have no dimensions or scale, I'm designing and building in inches.
I was unaware of the GBO forums until you mentioned them, they look interesting, but just looking at the list of fora titles, I didn't see anything exactly applicable. Am I missing something?
And I looked at Seacoast Artillery's website. Impressive products. I'm sure they could make a custom barrel for me. However, I want the major pieces to be my creations, and to as much as possible, the minor parts too. (When possible, I may purchase some gears and will purchase most nuts, bolts, rivets ....) But I will ask them about the barrel, maybe I can machine it and have them rifle it, or a barrel liner.
What sort of 19th century artillery do you make? You say operational, what scale? As I researched my project, I see all sorts of other interesting project ideas. As you may know, the French 75 Model 1897 was considered the "first modern" field artillery, belonging more to the 20th century. It's a much more complex project than I should have undertaken, but as I said at the start, this is because of my grandfather's involvement with the AEF's "First Shot."
Back to the machine shop,
Greg

 

[Moose53]

Thanks for your interest.
The French drawings are good, but to call them "workable build drawings" is a stretch. Since they are only drawings, lacking dimensions, accompanying text, or any designation of scale, I wonder what their purpose was. Different pages are obviously at different scales, so I derive their scale based on some known dimension(s), then go from there. For example, the axle/wheel drawing shown in my last posting appears to be at 1:7 scale. So I measure each feature as closely as possible, then multiply by 7/8ths to get the size for my 1:8 scale model, drawing in TurboCAD. Since the French drawings have no dimensions or scale, I'm designing and building in inches.
I was unaware of the GBO forums until you mentioned them, they look interesting, but just looking at the list of fora titles, I didn't see anything exactly applicable. Am I missing something?
And I looked at Seacoast Artillery's website. Impressive products. I'm sure they could make a custom barrel for me. However, I want the major pieces to be my creations, and to as much as possible, the minor parts too. (When possible, I may purchase some gears and will purchase most nuts, bolts, rivets ....) But I will ask them about the barrel, maybe I can machine it and have them rifle it, or a barrel liner.
What sort of 19th century artillery do you make? You say operational, what scale? As I researched my project, I see all sorts of other interesting project ideas. As you may know, the French 75 Model 1897 was considered the "first modern" field artillery, belonging more to the 20th century. It's a much more complex project than I should have undertaken, but as I said at the start, this is because of my grandfather's involvement with the AEF's "First Shot."
Back to the machine shop,
Greg

 

[Moose53]

It will take a while to get used to how this forum works so please excuse the extra posts. I have to wait a bit more before I can post links to some of my cannons . Because I know how easy it is to set this up as a operational piece I would make a suggestion. Because of the complexity of this project you could make the wow facture over the moon if you could model it in 1/3 scale with a bore of 1 in . Because the ATF considers any artillery piece made before or during 1898 an antique you should have no problem getting it ok'ed . I would be more then happy to show you some ways to make it shoot and even how to make cases . No one I know of has been able or willing to tackle the French 75 because of the complexity or lack of workable information . So you can understand our enthusiasm , if you are unable to make a shootable model , someone here will be able to with your helpful information . Thank you

 

[Onit12345]

Here's the link for GBO cannon section

http://www.go2gbo.com/forums/blackpowder-mortar-and-cannon-sponsored-by-seacoast-artillery/

 

[gjmontll]

Thanks to Moose53 and Onit12345 for your interest and the info you've provided.
That URL in the previous message is very useful, interesting to see how the Seacoast experts do their barrels. And it led me to two other sites that I was not yet aware of:
http://passioncompassion1418.com General WWI artillery info, (with English translation pages available)
http://canonde75.free.fr/index.htm Dedicated to the Modele de 1897 (only in French), this looks like a great resource, pictures, diagrams and descriptions on various assemblies. I know enough French that I can (with the help of Google Translate) make good use of their info. And their list of surviving 75's says there is one just an hour away, in Santa Ana, CA. Another field trip in the offing after I find exactly where it is. It is supposed to be an actual 1897, my April trip to Camp Roberts revealed a US Army later model, as I posted here a few months back.
My plans remain unchanged, I am endeavoring to make a 1:8 scale non-operational replica.

 

[gjmontll]

Status Update: Axle, Wheel Hubs, Sleeve
I've been doing some rework. My original set of hub spindles were too long and I needed to redo one of the hubs. Rather than that complex process for turning the spindle taper at the camber angle that I did first time, I turned the taper using the compound slide set to 1°. Then I heated and bent the spindles for their 3° of camber. (Made a bending fixture by drilling and reaming the spindle taper into the end of a piece of 1/2" steel rod. I was pleased to see that my homemade dbit reamer worked fine on the steel too. If I had known that, I'd have made the hubs from steel, not aluminum.
In my 19June2015 posting, you can see the axle, and see that the diameter is different at each end of the threaded portion. The larger diameter is actually the major diameter of the threads, and the smaller diameter matches the threads' minor diameter. This is how it is in the real gun, I believe it is to facilitate assembly and maintenance. After installing the axle into the trail, a sleeve then shims the narrower portion back out to the major diameter. On the full size gun this sleeve would be a substantial piece of metal. But at 1/8th scale, I worried about being able to drill a 0.297 hole through a 1.125 inch long 0.368 steel rod. But that is close enough to 3/8" that a 3/8" collet still holds it and would hopefully be less likely to crush the thin walls than my lathe's 4jaw chuck. But it went well, as shown below.
Pictures:
1: Drilling the axle sleeve, holding in a collet vise on the lathe.
2. The assembled axle, with its spindle tapers and the sleeve, and the two wheel hubs. Notice the 3° camber, (it looks like it's more.)
3. Separate parts: axle with spindle tapers, wheel hubs.
Note: Laying parts on the French drawing, they look a bit small. That's cause the drawings are 1:7 scale, my project is 1:8 scale.
\
Now I'm almost ready for the woodworking part: making the 28 spokes and 14 fellows. I should design/build some jigs and fixtures for the odd angles involved.
Greg

 

[sanddan]

I just found your build, great work so far.

There is a technic I used on SolidWorks that could help you with translating the non dimensioned original drawings into at a minimum 2D and possibly 3D solid models. PM me if your interested. Not trying to disrupt the build.