Sopwith Snipe Project - Page 24

Nick · 22 July 2008, 05:53 AM

Quote:

Originally Posted by brinesharks

I think David's approach is good, but I would round over the nose first with a quarter round bit top and bottom, slightly larger than you need. This way the piece can be fed through the router table easily as it still has flat faces. cut the angled grooves using a table saw (blade thickness TBA!). From the drawings it looks like you could still lie the LE flat on a bench. Mark out the areas you want routed out then set you router table fence to the required depth (1/2"?) and manually feed the piece in sideways, then move it along the required (marked) distance. Repeat along the length as required. Clean up the LE profile with a hand plane and check with a template (of the rounded section). Remember to be well rested and not distracted!!! Being a symmetrical cross section you could cut it fairly rapidly as you only have to turn the piece around while leaving the saw/router set.

Testing on pine is a great idea - I plan to do this too! Also, I thoroughly recommend reading through all the back issues of Shopnotes and the whole process should seem a lot more achievable.

Do you want an extra pair of hands/eyes when you try it out? Happy to come down if you think it would help (certainly would help me to learn more!).

Thanks Bryan for your suggestions, like lots of jobs it's not the time taken doing it, it's knowing how to set it up in the first place & those are good suggestions. I look forward to making a mess of some pine and seeing how it goes.
Those shopnotes you sent me on cd are excellent, might take me a while to get through all of them though. Thanks for your offer of help, might just take you up on that.

Thanks again Bryan & David for your input.

Nick

Nick · 22 July 2008, 05:59 AM

This is some of the work on the centre section so far.
I made the ribs about 3 years ago. This is the capstrip for the outer box rib being clamped after steaming.

Then getting glued up

After finishing all the ribs I just had to see what it might look like together so slide them on to an old bit of pine

Finally getting back to this part again. The Spars have a tie strap built into the centre of them. Here it is before gluing up after routing up the slots for the strap.

This is where I’m at now after almost finishing the spars. Once glued together I put them through the thicknesser again at a slight offset angle as they are 1/16” off rectangular.
They are then tapered down to the joint box size which are rectangular. This caused a few headaches but got there in the end.

Nick

Nick · 22 July 2008, 06:26 AM

Quote:

Originally Posted by brisfitworks

Nick:

When we made this stock for our Camel, one of our more creative members took up the challenge.

I was just reading through the e-mails he and I exchanged to remind myself of how he did it and an important note: the Camel LE on the stab is the same shape but a smaller size, so once you "tool up" for the wing you may want to do the one for stab at the same time.

One thing you can see in the dimensions is they planned a sequence - the cap of the mushroom is 1/16" narrower than the base. Sounds a lot like you start with 7/8"x1" and do the angled stem first just as we did. Here is our Bruce's e-mail of what he did (sounds like you could do a similar thing on your mill):

"I have been working on a plan for making the L.E. for the wings. It is more
complicated that I thought at first, but should be OK. I have a moulding
head for use on my table saw, but don't have 13 feet in front and in back of
the saw to push the raw stock through. Instead I'll mill the pieces on one
of the milling machine at work. I made up a mandrel to hold the moulding
head in the mill. The head is just a single interchangable cutter that
mounts in a slot in the circmference of a 5 inch diameter aluminum disc.
With the mill head tilted, I can machine the the top and bottom of the
leading edge with a flat cutter at the proper angle to accept the rib
capstrips. Although the moulding head came with cutters for shaping about
twenty different profiles, the one for Sopwith Camel wing leading edges was
must have been declared obsolete and was hence not one of them. With the
help of some excellent machine shop guys, I've made a cutter to fit into the
slot in the moulding head which will cut the proper shape on the nose of the
leading edge. While I was sick, the guys in the shop finished making the
cutter for me, honed and oil-hardened it and the tried it out on some scrap
pine. I'm told it worked fine although I haven't seen the results yet. The
nose of the leading edge will be slightly oversize to allow for some sanding
after fitted to the ribs."

The one thing he didn't describe was that he machined up a guide in UHMW plastic to feed/pull the spruce through. Clamp the guide in the table vise and feed away!

Bill.

P.S. I just was shocked, Bruce's e-mail was almost 9 years ago to the day! Our poor Camel has been put on the back burner so many times it will be 10years old before it even flies. Thankfully, we've finished up and got flying a Dr.1 and a Strutter and rebuilt every plane in the fleet in that time. It's hard to keep these guys focused

Bill,
Many thanks for posting that. There seems to several ways of achieving the result. I think I might have the reverse problem to Bruce in that I don't have 13 foot spare each side of my mill but I like the idea of making a cutter which would be another good project to do at trade school.
I've certainly got something to think about now.

Thank again, Nick

Nick · 22 July 2008, 11:09 PM

Today I routed up the slots on the spars so the joint box fitting will slide on. There is a reinforcement spacer brazed each side on the inside which link with a strap .

The Joint box can then fit properly. The holes through the spars will be drilled later in situation. Just have to make a jig up to do it

Sorry this pic is a bit blurred, hard to get clear photos of the black fittings but
it shows the spacer. It also shows how the spar is offset if thats the right word but the part where the box is, is square on.

Cheers, Nick

j ferguson · 23 July 2008, 04:02 AM

Hi Nick,
It is wonderful to see the drawings, ponder them, and then see the thing itself. it looks as though the ends of the boxes bear on the ends of the center-spar section so that if you want to have the 51 inches center to center of the rod holes, the overall length of that assembly has to be dead-on.

BTW is "in situation" the proper form of "in situ?" I ask because term"in situ" comes up occasionally in construction in US, mostly on the literate side of the business, but "in situation" is new to me.

Craftsmanship looks really good.

Thanks, John

Nick · 23 July 2008, 06:03 AM

Quote:

Originally Posted by j ferguson

Hi Nick,
It is wonderful to see the drawings, ponder them, and then see the thing itself. it looks as though the ends of the boxes bear on the ends of the center-spar section so that if you want to have the 51 inches center to center of the rod holes, the overall length of that assembly has to be dead-on.

BTW is "in situation" the proper form of "in situ?" I ask because term"in situ" comes up occasionally in construction in US, mostly on the literate side of the business, but "in situation" is new to me.

Craftsmanship looks really good.

Thanks, John

Hi John,
You're right about the fittings. Typical of most Sopwith fittings it performs many functions so has to be accurate. This one fitting braces the tie rods within the centre section, then the tie rods (flying wires) between the cabane struts, one of the main flying wires, it attaches the wing, has a socket for the cabane strut and another socket for the drift strut.
Thanks for the English lesson too, I was crap at English in my school days so don't know where I got that idea from. Hey isn't that called malapropism? Maybe I learnt something at school, maybe not!

Cheers, Nick

Joe Perkel · 23 July 2008, 06:28 AM

Excellent Nick, truly helpful to actually see this detail up close like this!

I have good news, with many thanks to Bill, my missing drawing details are en route from the U.K. as we speak!

Nick · 23 July 2008, 06:38 PM

Quote:

Originally Posted by Joe Perkel

Excellent Nick, truly helpful to actually see this detail up close like this!

I have good news, with many thanks to Bill, my missing drawing details are en route from the U.K. as we speak!

Good news about your plans Joe. Great to be able to look at as much detail as possible and resolve issues and draw it out as you are doing before building. I’m finding I keep stumbling across differences to be resolved as I progress which means I may have to remake something or modify it to be correct.
I’ve been looking at the original centre section plans again now I’m getting closer to start assembling it and have noticed a few things. There are some notes on it which I can’t really make out and they have not been included on the Replicraft plans. I’ve circled them on this . I can make out what looks like item 1A and another showing dotted lines between the centre ribs. I have no idea what they are referring to, fabric detail maybe.

The other differences are regarding the short centre ribs. The Replicraft plans show 4 centre short ribs (D2507) the same (2 left and 2 right) . The original plan shows 2 different styles of rib, the centre ones and the ones with a cut out to the front section capstrip.
I thought I’d resolve this by looking up the part numbers in the schedule and presto it’s different again It shows a different rib B2719, called a Special fabric rib, (listed on the plate here as drawing 1116/1117) which is only attached to the rear of the front spar.

I suspect I’ll probably go this way and modify 2 of the centre ribs I’ve already made as it makes sense this way.

Any ideas anyone what those item notes are?

Cheers, Nick

brisfitworks · 24 July 2008, 05:57 AM

Nick:

On Barker's Snipe there is a tube bolted in between the spars on the centre-line and it looks like an Aldis sight mount. The fabric between the two, central stub ribs was not installed to clear this tube. Just ahead of this, in the image I am looking at, is a big bump like a block of wood fabric'd over for mounting something. In a more frontal view and zoomed in it almost looks like the fabric is missing between these two central ribs ahead of the front spar.

When I originally looked at your drawing I thought the piece installed ahead of the front spar at ctr-line was a front aldis sight mount - it is very similar to a piece on F2b centre-section for the Aldis.

I have a scan of a photo of a post war Snipe with a Guardian Angel parachute installed and the empty clips for an Aldis sight hanging down and the fwd one looks like it might be ahead of front spar.

Are these just details of a variety of Aldis sight mounts? I have already found three very different installations of Aldis sights for the F2b as made by the factory.

I am at a loss about the other two notes.

I will go through my microfilms some more for any more clues.

I will have some of my darkroom back together soon so I will print off some of the more useful drawings for you and make up a package to snail mail to you with the two disks promised previously.

Nick · 24 July 2008, 02:35 PM

Quote:

Originally Posted by brisfitworks

Nick:

On Barker's Snipe there is a tube bolted in between the spars on the centre-line and it looks like an Aldis sight mount. The fabric between the two, central stub ribs was not installed to clear this tube. Just ahead of this, in the image I am looking at, is a big bump like a block of wood fabric'd over for mounting something. In a more frontal view and zoomed in it almost looks like the fabric is missing between these two central ribs ahead of the front spar.

When I originally looked at your drawing I thought the piece installed ahead of the front spar at ctr-line was a front aldis sight mount - it is very similar to a piece on F2b centre-section for the Aldis.

I have a scan of a photo of a post war Snipe with a Guardian Angel parachute installed and the empty clips for an Aldis sight hanging down and the fwd one looks like it might be ahead of front spar.

Are these just details of a variety of Aldis sight mounts? I have already found three very different installations of Aldis sights for the F2b as made by the factory.

I am at a loss about the other two notes.

I will go through my microfilms some more for any more clues.

I will have some of my darkroom back together soon so I will print off some of the more useful drawings for you and make up a package to snail mail to you with the two disks promised previously.

Hi Bill,
Many thanks for that, It hadn't occured to me about a different type of Aldis sight mount. I think you're right there. Here's a photo of Barkers Snipe
(thanks to Edward and Johnathan again) which shows the mounting. Your suggestion makes good sense that at some stage it was mounted forward of the spar.

The other notes are a mystery, can't think of anything that would match the dotted line patterns.

Many thanks once again Bill, your input is always much appreciated.

Cheers, Nick