# Bogstandards twin DXF files



## rickharris (Feb 23, 2008)

Hello, We have now managed after much time and effort to complete (we think) the 3D CAD exercise we started oh BS's PDF documentation for his open column twin.

We offer the DXF files here for others to use BUT please be aware nothing has as yet been made from these drawings. The 3D CAD animation seems to work so they should be OK.

Also be aware that some of the work was done by 14 - 15 years old school kids. We have tried to maintain good quality control.

I do note that we inadvertently reversed one of the valve fittings and I am unable to flip it until I get back to school - bear this in mind if you make them.

If this works we will use some other plans we have for further 3D design exercises and post the DXF files accordingly.

Many thanks to John for the original PDF documentation.



View attachment componant sheet 1.dxf


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## rickharris (Feb 23, 2008)

Second file 

View attachment componant sheet 2.dxf


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## rickharris (Feb 23, 2008)

third and final file

IF anyone needs more please let me know and I will try to oblige. As with all 3D CAD work this is a virtual build and so every part has been created and we can easily produce relevant 2D or 3D drawings from the original prodesktop CAd files. 

View attachment section view.dxf


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## Bogstandard (Feb 23, 2008)

Hi Rick,
I suppose now I will have to get myself a cad package just to look at my own engine (chuckle).

Looks like you have done a good job there. 

I can assure you that if made to my dimensions it will run, even with a bit of bad machining it should still function. When I designed it, it was with beginners in mind, with only a couple of areas that need to be fairly accurate. They were the eccentrics and the spool valves.

It is so nice to know that my feeble sketchings are helping to create artisans of the future.

John


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## rake60 (Feb 23, 2008)

John I've tried many of the free viewers that are available 
for Auto Cad files. The one I use is from Information Graphics.
Their free dwg viewer will open DWG, DWF and DXF files.

Very nicely done Rick!


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## Bogstandard (Feb 23, 2008)

Rick Admin, 
Thanks for the info, have downloaded and looked at the files. I must get my Solidworks reloaded.

Rick Piccies,
Looks good.
Do you mind if I put them into the archive on the original site that I built the engines on?
It just might help people to make one.

John


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## rickharris (Feb 23, 2008)

Please do with them what you like. All to help!

I might suggest add a warning that they are not as built drawings but should be to your dimensions.


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## malcolmt (Apr 29, 2008)

Hi Rick
Excellent work, :bow: :bow: it was johns original drawings and writings that brought me to this site and very grateful i am for it.
Just one question. Does any one know where i can get drawings of 600 inches by 430 inches printed out. :big: :big:

All the best

Malcolm


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## flathead (May 5, 2008)

How does one go about downloading a set of drawings?


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## rickharris (May 5, 2008)

The original drawings were A3 in size 600 x 400 sound about right. Many print shops will be able to print at A3.


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## ianjkirby (May 6, 2008)

Hi guys,
 I'm with Malcolm! When I loaded the drawings into my package ( ViaCAD 2D/3D ), they ended up approx 15 metres long x about 10.7 metres high!!??!! I see they are dimensioned in mm, and I selected mm for units prior to downloading, but clearly something is amiss. Does anyone have any suggestions?
Regards, Ian Kirby.
Wollongong NSW Australia


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## rickharris (May 6, 2008)

The dxf files load OK here into both of the programmes I have that read DXF. In one I have to resize but that is the way that particular programme deals with DXF files.

As said, the originals are A3 in size 297mm × 420mm.

Hopefully the dimensions remain correct even at vast sizes! This could be a BIG model otherwise.

Please remember that the drawings were done as a CAD exercise and to date have not been used for a build. They are AFAIK correct to the original PDF file though.

I have just DL the first file - I note that the radius measurements have lost their R lable to indicate radius although the numbers are there - will look at that



Following on from the discussion about metric vs imperial below is the rational for the metric series of paper sizes:

"The ISO paper size concept

In the ISO paper size system, the height-to-width ratio of all pages is the square root of two (1.4142 : 1). In other words, the width and the height of a page relate to each other like the side and the diagonal of a square. This aspect ratio is especially convenient for a paper size. If you put two such pages next to each other, or equivalently cut one parallel to its shorter side into two equal pieces, then the resulting page will have again the same width/height ratio. "


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## SandyC (May 6, 2008)

Hi Guys,

This sounds like the sort of thing that would happen if the original DXF files were saved from 'MODEL SPACE' layout in the CAD package, rather than 'PAPER SPACE'

I use 'TurboCad' here and if I forget to change a 'MODEL SPACE' file/drawing into a 'PAPER SPACE' one, prior to saving the final drawing DXF file (or trying to print it) then the overall size is determined by the 'MODEL SPACE' boundary limits, which is much the same as you are getting...i.e. 15 metres x 10 + metres.

In other words...the file does not contain the paper dimensions, which the 'PAPER SPACE' version does.

It' is an easy trap to fall into,....don't ask how I know this : : :fan:

'AutoCad' works in much the same way....so just a thought.

Hope this is of some help.

Best regards.

SandyC ;D ;D


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## SandyC (May 6, 2008)

Hi guys, me again....

I have just tried the first component file on my TurboCad package..... interesting...

It actually loads as a 'WORLD ('MODEL SPACE) type.

If the CAD setup is in IMPERIAL format (@ 1" = 1") then the drawing manages to confuse the CAD...since it shows the size of the drawing is 595" x 420"..... in other words...the mm (UNIT) values get converted to direct inch UNIT values..... 1mm = 1".

This is not an error with the CAD...it is doing exactly what it says on the tin.....you need to tell it that 1" should be converted to 25.4mm or vice versa.

Changing the CAD 'SPACE UNITS' to METRIC (mm) instead of IMPERIAL inches, the drawing comes out at 595mm x 420mm&#160; which is ISO A2&#160; not A3 (which is 420mm x 297mm).

At this setting if a drawn part is actually measured (using the CAD distance tool) it comes out exactly ON SIZE&#160;&#160; i.e&#160; a 10mm part actually measures 10mm. So... I believe this to be a true 1:1 drawing size.

Printing it at this size is another matter though......unless you have an A2 printer (or a plotter)

Most good print shops would probably have a plotter (or an A2 printer), so...as long as you specify METRIC (mm) then the results should come out fine.

An A3 print would show all components at reduced size, (not 1:1) however the dimensions given on the print would remain correct for work to procede.

Hopefully this will help some of you.

Best regards.

SandyC ;D ;D ;D


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## rickharris (May 6, 2008)

Not at work at present but I will attend as soon as Poss - I could reduce this to more sheets but A4 or Letter size if you like - will take a little time.


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## Bogstandard (May 6, 2008)

Flathead,

Rick from admin kindly allowed me to host my 'internet' ramblings about making my engine, which was turned into a booklet form.

If you go to this post, 
http://www.homemodelenginemachinist.com/index.php?topic=615.0
it describes a bit about the engine, and a bit further down it shows the links to Ricks' site to download from. If you really want to build the engine, it is the book that is required, the cad files on this post are a good reference help to what is shown in my sketches in the book.

All I can say, even if you don't build it, it is worth reading just for some of the lateral thinking machining ideas and techniques that are used, and a lot of standard basic ones as well.

John


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## Brass_Machine (May 7, 2008)

Bogstandard  said:
			
		

> All I can say, even if you don't build it, it is worth reading just for some of the lateral thinking machining ideas and techniques that are used, and a lot of standard basic ones as well.
> 
> John



I agree. It is worth the read, even if you only pick up one technique.

Eric


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## flathead (May 7, 2008)

John-
Thank you for the reply. I have already downloaded and read your booklet. I am a novice at metal working and just received my "new" South Bend lathe and Clausing mill and am excited to start making some chips. I enjoyed your writings and found them very rewarding - especially since this is all a learning experience for me.


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## esteam (May 9, 2008)

John 

Thank you for plans and booklet. It's really excellent job. 

I'm so impatient to build it but the only problem is micro screws. It's impossible to find them in Turkey. I saw the url about micro screws that you post. I'm gonna try to buy.

Regards

Erdem


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