Joining Shapeoko 3 rails

Talk about all things CNC
krtwood
Posts: 26
Joined: Tue Jun 16, 2015 4:01 am

Joining Shapeoko 3 rails

Post by krtwood » Fri Sep 02, 2016 9:50 pm

Given the lack of news of any larger versions coming out and the feeling that anything bigger is going to have so much more to it that an upgrade from the stock machine no longer makes sense, I decided to get the XXL and experiment with joining the stock rails onto the longer rails for the Y axis. I've started out by trying to join the two short rails together before I do anything to the new ones since they are useless at this point otherwise anyway. A picture is worth a thousand words and I think this picture tells the story of my approach clearly
extend rails.jpg
extend rails.jpg (72.72 KiB) Viewed 1217 times
I didn't get the alignment perfect vertically at the joint but it still seems to run okay through the gantry, which was encouraging in that I hope to get it better when I try again but even a less than perfect alignment seems like it will work. I'm not so worried about a little loss of accuracy, especially in the Z axis, at the joint for what I will do with it.

Short video on it:

Next up: Build a 6' x 4' torsion box.

Is 9mm as wide as the GT2 belt goes? Since I have to get longer belts anyway it would make sense to upgrade that now if possible.

CastIrony
Posts: 650
Joined: Mon Jul 21, 2014 10:21 pm
Location: Portland, OR

Re: Joining Shapeoko 3 rails

Post by CastIrony » Sat Sep 03, 2016 3:59 am

Is 9mm as wide as the GT2 belt goes? Since I have to get longer belts anyway it would make sense to upgrade that now if possible.
12mm GT2 belt is available, but IIRC there was trouble finding any pulleys that wide without having them be custom manufactured.
Shapeoko 3 #192 - Complete! Needs limit switches.

WillAdams
Posts: 8488
Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15
Contact:

Re: Joining Shapeoko 3 rails

Post by WillAdams » Sat Sep 03, 2016 1:29 pm

lngenious! I'd worry about the MDF deforming under load but you should be able to add side supports as was done for Makerslide to minimize that. Some folks did join MakaerSlide --search the forums.

Is there a V- extrusion profile which matches the V on the SO3 rails? What would be the cost on having such machined?

If you couldn't afford that why not mill out a butterfly pocket and matching aluminum key along both sides? Make the key thick enough and you could have a matching through hole in the side support as well.
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

krtwood
Posts: 26
Joined: Tue Jun 16, 2015 4:01 am

Re: Joining Shapeoko 3 rails

Post by krtwood » Sat Sep 03, 2016 8:36 pm

I will definitely support the joint as there's really no reason to not do it. I thought about getting a plastic 2"x3" block to use instead of mdf as something more stable but the last time I did that was the fence faces on my router table and they inexplicably keep warping worse than cheap plywood. So I figure keep it simple until it proves to be a problem.

I was going to cut the original end plates and then add some bracing to them because I want more Z height and I don't want the end plates sticking up above the spoilboard. Now I'm thinking I will just make new ones out of 18mm baltic birch and have those and the middle support all notched at the same height to fit under the extrusion to ensure it's level.

krtwood
Posts: 26
Joined: Tue Jun 16, 2015 4:01 am

Re: Joining Shapeoko 3 rails

Post by krtwood » Tue Sep 13, 2016 2:35 am

So I have the torsion box ready and have the new rails joined to the old rails. Still a lot to do between that and a functioning machine. There were a couple surprises in joining the rails.

1) While all the ends of the old rails were as square as a I cared to measure, none of the ends of the new rails were square in both directions. 5 out 6 were square one way but not the other way (but some one way and some the other) and one was out both ways. I used a sanding disc in my table saw to get them pretty close. Pretty disappointing to have to do this since if the ends of the Y axis rail aren't square that's a real problem for a normal machine.

2) The extrusion changed. The v-rails don't come to a point anymore. No big deal. The wall thickness increased by somewhere between .005" and .010", so the outside dimensions have increased. This is a problem. No matter what I do the gantry is going to be loose on the old section of rails. Won't know how much of a problem it is until I get it finished.

schafe94
Posts: 13
Joined: Wed May 25, 2016 2:51 pm
Location: Duyên Hải, Vietnam

Re: Joining Shapeoko 3 rails

Post by schafe94 » Thu Sep 15, 2016 3:49 am

krtwood wrote: 2) The extrusion changed. The v-rails don't come to a point anymore. No big deal. The wall thickness increased by somewhere between .005" and .010", so the outside dimensions have increased. This is a problem. No matter what I do the gantry is going to be loose on the old section of rails. Won't know how much of a problem it is until I get it finished.
Would you be able to get around this by joining new with new and old with old?
So if you joined two of the new rails together for the X axis, you would have a smooth transition side to side.
If you have 3 new and 3 old you might have one side of the Y axis that is a little loose when you are on the area where the gantry is on the old rail.

Just a thought.
Awesome work on this project by the way.

krtwood
Posts: 26
Joined: Tue Jun 16, 2015 4:01 am

Re: Joining Shapeoko 3 rails

Post by krtwood » Thu Sep 15, 2016 10:04 pm

schafe94 wrote:
krtwood wrote: 2) The extrusion changed. The v-rails don't come to a point anymore. No big deal. The wall thickness increased by somewhere between .005" and .010", so the outside dimensions have increased. This is a problem. No matter what I do the gantry is going to be loose on the old section of rails. Won't know how much of a problem it is until I get it finished.
Would you be able to get around this by joining new with new and old with old?
So if you joined two of the new rails together for the X axis, you would have a smooth transition side to side.
If you have 3 new and 3 old you might have one side of the Y axis that is a little loose when you are on the area where the gantry is on the old rail.

Just a thought.
Awesome work on this project by the way.
Good thought. The new rails are the 40" XXL rails and the old rails are the 23.5" standard ones so they aren't interchangeable. Since I'm not doing anything to the X axis I have one short rail left over. I could theoretically join the 3 old rails for one Y rail and two of the long rails for the other one. I'd have to cut one of the new rails though and there would be an extra joint on one side. I don't want to do anything to prevent it from being converted back to a regular XXL machine. I'm sure I could get a hold of two new short rails if I really needed them.

krtwood
Posts: 26
Joined: Tue Jun 16, 2015 4:01 am

Re: Joining Shapeoko 3 rails

Post by krtwood » Sat Sep 24, 2016 10:35 pm

The patient has a heartbeat. I was a little worried when I got the gantry on the rails moving it by hand it really shook the gantry moving over the joint in the rails. But under its own power it seems to pass over it without any issues. We'll see when I start actually running jobs but I'm optimistic.

End supports for the rails made, still need to do the middle supports. Belts tensioned. Wiring done. I used the two longer extensions for the Y motors and spliced in new wires for the X and Z.
shapeoko1.jpg
shapeoko1.jpg (115.32 KiB) Viewed 941 times
Combined the two drag chains (with a bunch leftover) for the Y axis and bought another 1m chain for the X. Made a wood U channel to keep the drag chain where it's supposed to be and give an easy attachment point for the end of the chain.
shapeoko2.jpg
shapeoko2.jpg (94.04 KiB) Viewed 941 times
Power strip, power supply, and relay for controlling the router mounted.
shapeoko3.jpg
shapeoko3.jpg (66.57 KiB) Viewed 941 times
Need to make the enclosure and mount the monitor on it and do the spoilboard. Still deciding whether to buy t tracks or make them integral in the mdf

JeromyReno
Posts: 225
Joined: Mon May 04, 2015 11:28 pm

Re: Joining Shapeoko 3 rails

Post by JeromyReno » Wed Oct 12, 2016 4:31 pm

amazing

WillAdams
Posts: 8488
Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15
Contact:

Re: Joining Shapeoko 3 rails

Post by WillAdams » Thu Oct 13, 2016 1:46 pm

Yeah.

This does bring up something I've been wondering about at the back of my mind --- what are the upper limits of the various machine components? And societal limitations of making and shipping these machines?

- Inventables is now doing a 750mm wide X-axis since they came out w/ their wide MakerSlide --- suspect there was an underlying engineering consideration here (or maybe some customer research which hasn't been made public?)
- only the two smallest SO3 expansion options from the poll were addressed by the XL and XXL --- suspect that there's some monstrous shipping charge hit for rails which are long enough for 4' of cutting area, or there's some limitation in the system --- interesting to me that there was a simultaneous switch to 9mm wide belts (and kind of bummed that there isn't a wider option which doesn't carry a hit on positioning precision) --- what is the option after belts?
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

Post Reply