FYI: I found the receipt, I paid $2.35 a lb for a total of 13 lbs ($30.55 total) that was enough aluminum to do 4 plates with scrap left over
I just bought one on sale from their outlet store 
Nice. Read the directionsā¦ there is a little muffler thing that needs to be attached to get the ultraquietness. I fired it up immediately and was a little dissappointed until I read the directions.
1 Like
I began installing the new gantry. I had to use the V Wheels form the old gantry on the new.
It went together fairly well. To fit the current Y rail spacing I had to mount the V wheels right against the plate, just like they are for the standard gantry. So the eccentric spacers are on the outside, just like the eccentric nuts are.
This is how I mounted it:
Bolt ->Spacer->Plate->Washer->Wheel->Locknut
Though I suppose reversing the bolt would have worked as well:
Locknut ->Spacer->Plate->Washer->Wheel->Bolt
This means that I did not need to countersink those holes. In fact the counter sink is a problem as I had to grind down a wrench to be thin enough to slip under the bolt head and adjust the spacers.
I could have put the spacers on the inside of the plate, which I suspect is better for supporting the wheel, but that would involve repositioning the Y rails and trimming the waste board. A lot of work, so unless it becomes a problem I will wait to do that until I redo the y rails.
So far I got 2 upper wheels mounted on one side and 2 sets of upper and lower wheels mounted on the other. It rolls nice and smooth. And the gantry is exceptionally solid. A definite improvement over the maker-rail.
It will take me a couple more evenings to compete the changeover. I should be ready to run some test cuts this weekend. 
In retrospect I wish I had ordered up new V wheels as well. I would have cost more but I could have test fit and mounted the new gantry without disabling the machine. But I think these plates will work good enough that I can get the machine running even if I find a flaw that requires me to cut a updated set of plates.
More progress made, I got all the V wheels and motors installed, and one set of upgraded belts on.
So I just have the last belt and then redo the wiring and homing switches.
Taking apart the old gantry I noticed that the pulleys on the Y axis motors were really hard to remove while the X and Z pulleys just came right off. I donāt know if this is normal or a sign that I had the Y belt tension too high?
A few of the lower X axis and Z axis V wheels were really chewed up. It seemed to be on the outer ridges, I am not sure what caused it or if it would have any effect on their performance.
Also the Z axis eccentric bolt holes were really messed up as well. I think this may have been part of the reason for the sudden increase in āflexā I was seeing?
It looks like replacing the Z axis eccentric nuts with eccentric spacers is a really good idea. Adding a extra pair of wheels might help distribute some of the load. As all the force on the bit that is causing the gantry to flex is being held by those 4 bolts and wheels.
Progress Pics:
There is the upgraded belt and pulley as well as 8 V wheels (4 upper, 4 lower). They all lined up no problem. The wheels just clear the tie wraps on the belt. They used to hit before. But I got extra thin tie wraps and adjusted how I lined them up to get this to happen.
The edge of the wheel just barely sticks out past the bracket. I will update the bracket design so that it sticks out instead to better protect the wheel
Here is the outside. With this setup the wheel holes donāt need to be countersunk. So I will be removing it from the design.
The limit switch holes are too far back from the edge to directly mount the switch. I need to move the holes closer on the design.
Here you can see the X and Z axis. That is a LOT of wheels!
It is pretty stable. There is still a tiny bit of flex, but that is the c-beam twisting, not the mounts.
Because the whole rail moves up and down, not just the router mount, I will need to figure a new way to set up the limit switch. (Maybe have it trigger on the lock bolt of the bottom wheel?)
I was able to reuse the original router mount but it is only held in place with 2 screws.
I have new 2 new router clamps on order to replace it.
The gantry bracket takes up more space under the gantry rail, but the Y brackets are taller so I have the same amount of usable Z height. I plan on making new Y rail brackets as well to increase the Z axis height. Once I know what Y rail setup I am going to use.
1 Like
So overall, are you happy with the C beam and linear drive for the X?
Any thoughts about changing both Y axis rails to C beam and linear as well? I was considering that, however when I think about my X, Y and Z upgrades Iām really just better off building a brand new machineā¦
1 Like
So far it seems to be a much more solid setup. Even if you do not go as far as I did, I HIGHLY recommend replacing the Z axis. The C beam is so much stronger.
(though I am sure an e-bay linear bearing and rod setup would be just as good if you are just swapping the Z)
I have only done simple motion testing. I need to run some stress tests to see how much more load the new setup can take. Though I want to wait until I get my new spindle mount before I do any real carving. (I should have it by this weekend)
After that I will have to run some speed tests to dial in the feed, rpm and acceleration settings. The R7 kit seems to be using mostly default TinyG setting and I want to see if I can fine tune it a bit.
If you are considering upgrading all 3 axis to a c-beam with screw drive setup look at the R7 kit. The biggest expense in the kit is that it comes with a water cooled spindle. I am sure you could order one without a spindle to save on cost. I used the gantry brackets from it as well as the bill of materials to make my part list. (So far I have spent about $600 on the upgrade spread over several orders.)
I thought about just going with a new build and getting the full kit myself, but decided to go with the hybrid option because I really want to have a longer Y axis work area. And 1000mm is the longest you can go with a screw drive.
I have yet to settle on what rail system I am going to use though.
I can keep my current setup and just get longer maker rails - 1800mm max
I could go with a belt drive c-beam - 1500mm max
I could go with a belt or rack and pinion steel rail - unlimited
My plan it to give it a few months of use with the current maker rail setup. See if I have any issues. Though I was not before. If it holds up I will just swap out the Y rails with longer ones. The cheapest and easiest option.
1 Like
Do you feel this is any better/worse/different than the openbuilds c-beam linear actuators? They seem to have an all in one bolt on solution thatās got a screw drive built into it. I was thinking about getting one of those to upgrade my X axis with.
Both my X and Z axis are the openbuilds c-beam linear actuators, using their acme screws and anti-backlash nuts.
The only difference is the custom gantry plates to allow both mini v-wheels on the inside of the c-beam (standard as per the bundle) and Full sized V wheels on the outside.
I could have ordered up the full 1000mm and 250mm bundles but ordered them as individual parts to not waste the standard bundle gantry plates for both axis or the bundle end plates for the X axis.
The only parts of the R7 hardware that are not standard openbuild components are the plates (gantry, Y axis and endplates) and a 20x20 1000mm Openbuilds V-Rail that has been cut and squared to match the 1000mm c beam rail.
Originally I was considering just using the default bundles and bolting the X and Z gantry plates directly together. But discovered I could order just the R7 gantry plates by themselves. It was a more expensive option, both for the plates as well as all those extra wheels (they add up fast). But I think well worth it. The gantry assembly is SOLID. No wiggle or flex in the assembly.
There is a slight flex in the gantry as a whole when I pull on the router, but that is the actual c-beam twisting very slightly under load. And I think, a limitation of the material rather than the design.
The plates are open source so you could easily cut your own and order everything else from openbuilds.
I decided to go with precut for the gantry plates as I wanted to know they were accurate. I was having some waste board level issues and getting a correct countersink depth is important on the c-beam inner channel wheels. Although with the success of my custom Y plates I probably could have managed it.
Oh, gotcha. That makes a bit more sense now. I bet that thing is ridiculously solid with wheels inside the c-beam and out.
Yep. It may be overkill but I think it is worth it. 
It was tricky to assemble and adjust. I just kept re watching the assembly video until I got it. Also the wheels are not as tight. You want them to have a little āslipā. With all those wheels donāt need them be super tight to keep things aligned.
Updates on the build:
I did a test cut last night and my mm per revolutions were way off for the Y axis with the new belts, so everything came out elongated.
I got it roughly dialed in. Accurate to about .5mm per 100mm. I will do a more refined calibration once I get the new router mount setup
Also while the gantry rides higher, the bottom of the Z axis sits a lot lower. Reducing my z height a lot more than I expected. Giving me about 75mm of clearance. With bit height and my extra MDF sacrifice sheet it worked out to less than 20mm of cut depth. As it was I had to raise the spindle mount up to get enough clearance for my 1/4" bit. So new end plates are a must.
I considered redoing the Y plates so the gantry rides higher. But I think it may better for the gantry to be closer to the Y rail for stability? I think it will be easier to stabilize taller end brackets instead.
One of the upper fixed V wheels is slightly out of alignment so it doesnāt make good contact with the rail. I am not too worried about it as the other 7 are fine. I need to re-check to make sure the hole is properly laid out in my design.
The original v wheel bolts are just a tiny bit too short on my bracket when used with the eccentric spacers. I have longer ones on order.
I need to re-calibrate the Y motor currents for the new setup as well the acceleration jerk settings. After that cut new end brackets and redo the waste board.
I got the spindle mounts last night. I installed them and used the 3D printed adaptor rings for my Makita router. (I will post pics later)
There is a lot of play in the corner brackets that I used to mount it to the C-beam so I may need to mess with it to make sure the spindle mounts hold the router perpendicular to the waste board.
I did a quick cut last night. The project is a box frame that will be covered with foam and paint so any flaws would not matter. A good test project:
First I did not have enough z height.
With my sacrifice sheet in place and the 1/4" bit inserted as far as it could go (too far actually) I have about 2 mm of clearance. I made it work but it took me a while to figure out I needed to remove the 10mm safety height from my cut file. And of course I hit my clamp. (I am going to have to cut a few new ones.)
First it started with the rabbit joints. It cut beatify, powering through the plywood no problem. No notable flex in the gantry. Then cutting the holes. Here I made a mistake, I did the holes as profile cuts not pockets. So each hole had a small āplugā of remaining wood in the center. The bit would hit the plug as it moved out of the pocket. Sometimes jamming the plug against the wall of the hole. Now before this would guarantee missed steps. Not this time.
The impact would just make the whole thing shake, but no slipping belt, no flexing gantry. On a particularly bad hit, the work piece would move under the clamps! That right the clamps failed instead of loosing steps. That is a first.
I went ahead and finished the cut, knowing that this didnāt need precision. The work piece tended to shift back into the original position so it was not that bad. I just kept a careful eye on it, hoping nothing got too bad.
The final profile cut went just fine, no issues. Just lots of sawdust. (I need to make a new dust shoe asap. )
So after this unintentional torture test I feel very happy with this upgrade.
One weird thing happened that I canāt figure out.
One of the rabbit cuts was shifted 12mm too far in the X axis.
I thought it was a error in the print file as everything else lined up as expected.
If it was missed steps it should have shifted everything as it was one of the first cuts.
The only thing I can think of is that the work piece got shifted when doing the cut, the shifted back after? It was doing it for the holes, but they were only shifting a couple of mm. (I fixed the part by widening the rabbit joint with my table saw)
I am hoping this was a one time thing and not a symptom of some issue. I am tempted to re-run the cut file (after fixing the holeās cut strategy) just to see what will happen.
I really need to redo my end brackets to give me a more workable Z height.
I have a new 1/8" collet for my router on order. As soon as that comes in I will cut some new plates.
Iāve got new Y and X end plates Im cutting out of 1/4" alum tonight and tomorrow, provided all goes well ill most likely mass produce some if others are interested. my biggest question is whether people would prefer taller Y plates, or taller X plates. Iām on the fence, Iām thinking Y, since X has far more holes for mounting pulley etcā¦
What do others prefer?
How about both?
