Sydney Harbor Bridge

[WoodMarvels.com]

Hi guys, I want to make a CNC table router version of my laser cut Sydney Harbor Bridge but I have one small issue, my ShopBot Desktop isn't big enough to make the spans - I need to at least 2-3x the size to make it router friendly along with a lot of other adjustments due to the pushing/pulling forces that will be present.

http://cncking.com/sydney-harbour-bridge.html

I remember seeing a video of a ShopBot Desktop with a type of indexing mechanism that allows you to to make very long things accurately in "steps" - I think Ted and Bill were in the video but I can't find it or documentation on how to go about building one for my ShopBot Desktop.

Does anybody on the board know where I can get this so I can start making projects bigger than my ShopBot Desktop?

It's been almost a year since I packed my ShopBot Desktop for a one way trip to Oz... I want to make my first project with it a BIG one to celebrate the return of the Bot!!!

Jon

[Bob Eustace]

Jon cant help you with your exact problem however my dear old dad made me an eight foot model of the Sydney Harbour Bridge all from Meccano! He made up a special press to cut it out with. The thing was so strong that we used to turn it upside down and use it as a see saw. Used to always win prizes at fetes etc. it is such a shame that he didnt live long enough to see the Bot as he spent his life making special purpose machinary mainly for the optical industry and he would have taken to this technology like a duck to water. He made us an automatic record changer before they were invented with all the gears cut on a South Bend lathe copy he made himself. I wouldn't know where to start without the bot!

Jon you could think about adding the approaches as the curved one looks stunning. Beautiful work as usual!

[WoodMarvels.com]

I'm sure I can figure it out but if ShopBot already has all the plans and kinks worked-out - no point reinventing the wheel.

Jon

[chiloquinruss]

In Apsire the feature is called 'Tiling' (tile) and is also covered in a few of the Vectric tutorials. I think this may be what you are after. Russ

[Shane]

In Toolpath operations there is an icon called Tile Toolpaths. That lets you tile your jobs between the x or y axis. This is available in Partworks and Aspire.

To make alignment easier and spot on, I would create guide holes to realign the new 0,0 and also create another so the whole job would remain parallel. Unless they have updated the tutorial videos, the videos never really explained how to setup the physical tiling of the job.

Shane.

[myxpykalix]

maybe your answer is in this post?
http://www.talkshopbot.com/forum/showthread.php?t=17425

[WoodMarvels.com]

Thanks guys - at least now I know the more technical term for it so I can read-up on how to do it!

Jon

[khaos]

Are you talking about a "power stick"? This allows one axis to be extended. Like Rick show here? (http://www.youtube.com/watch?v=zNJww8xFAdE)

[WoodMarvels.com]

That would be AWESOME Joe but that's for a buddy, not a ShopBot Desktop. My bed is fixed... the original prototype for ShopBot Desktop worked sort of that way. What I think I'll do is create my own system - I finally found a picture of what I'm after.

http://www.shopbotblog.com/index.php/2013/02/indexer-spinning-for-autodesk-university/

top picture, shows an extended bed size - I remember seeing a video where Ted or Bill would have leavers on the side to move the bed "up" a knotch and continue working. Think you guys call it tiling. Should be pretty straight forward... will get a few other models out of the way first then tackle this Sydney Harbor Bridge.

Jon

[CNYDWW]

Jon,

The two larger signs in the attached pic are 6ft long. These and the sample from wood were milled on a 24x24x4 cnc router. There is a sled method i used to index the material through the machine.

I first attached a fence and milled off the edge to get a good square reference to the x axis. I then took and attached a 3/4" strip of material to a 3/8" piece of plywood. I set the "sled" in the machine to the fence and drilled a 1/4" hole through the 3/4" material and ply into the bed of the machine. This was centered in the strip on Y and at zero on the X. I then did the same at x 24".

From there i indexed the sled in the machine down 24" and aligned it with the second hole of the sled with the first hole in the spoilboard. Clamped it down and drilled the hole at X 24" again. I did this one more time to give me 4 holes on the sled that was +72" so that i had two dowel pins to use for indexing reference.

Worked like a charm even with a textured background.

Hope this helps
Regards
Randy

[WoodMarvels.com]

that's cool Randy, do you mind posting a few pictures of your set-up? I got the general idea but really want to see... how did you get the indexing to work 100% perfect for cutting? Engraving letters if you are slightly off isn't a big deal but cutting an outer or inner edge is quite another. I didn't think of building a sled that moved, but that's a great idea... I was thinking just having the sheet move but your system is better for consistency and hold-down.

Jon

[genek]

Hi guys, I want to make a CNC table router version of my laser cut Sydney Harbor Bridge but I have one small issue, my ShopBot Desktop isn't big enough to make the spans - I need to at least 2-3x the size to make it router friendly along with a lot of other adjustments due to the pushing/pulling forces that will be present.

http://cncking.com/sydney-harbour-bridge.html

I remember seeing a video of a ShopBot Desktop with a type of indexing mechanism that allows you to to make very long things accurately in "steps" - I think Ted and Bill were in the video but I can't find it or documentation on how to go about building one for my ShopBot Desktop.

Does anybody on the board know where I can get this so I can start making projects bigger than my ShopBot Desktop?

It's been almost a year since I packed my ShopBot Desktop for a one way trip to Oz... I want to make my first project with it a BIG one to celebrate the return of the Bot!!!

Jon
send me a e-mail at eking1953@yahoo.com tj sent me a link for someone else the other day about indexing.. he is getting ready to teach a class on it.

[WoodMarvels.com]

email sent but no reply - do you mind checking your spam box Eugene?