Questions about JGRO Router

[ignatz]

I have a couple of questions about the JGRO router plans that I'm hoping someone can help me with.

1. Is the assy04 connected to the base support structures? How?
2. Are the base supports connected to dtl05? How?
3. What is the single wood screw used for?

[The Wizard]

Originally Posted by ignatz I have a couple of questions about the JGRO router plans that I'm hoping someone can help me with.

Here's how I did mine......

1. Is the assy04 connected to the base support structures? How?

Yes, my 'cutting bed' (det'l 04) is a seperate piece to the 'bed support' (det'l 06) and the 'bed support' is bolted through the end frames (det'l 1 & 2) in four places (between the support rails). It was aligned flush with the top of the end frames and clamped into position and then the bolt holes were drilled right through both pieces to ensure correct alignment. The 'cutting bed' was installed after I had the machine up and running so that I could set the 'grooves' parallel to the gantry travel using a DTI. Once the 'cutting bed' was correctly aligned I 'spot drilled' through the ends into the end supports and then removed the 'cutting bed' again. I used three CSK head machine screws at each end between the 'grooves' and 'dry wall' screws in the small outer pieces. The machine screws are going into 'blind nuts' that I installed in the end frames using the 'spotted' marks to establish the correct location. By doing it this way everything can be unbolted if I ever have to replace a leadscrew, A-B nut or if I have to dismantle the machine if I move house.

2. Are the base supports connected to dtl05? How?

Yes, mine is bolted through the end frames in four places (between the support rails) too. I aligned the bottom of det'l 05 with the bottom of the end frames and then clamped and drilled through both pieces to ensure correct alignment. This was done prior to fitting the upper bed as described above. I also made four 'towers' out of MDF that were glued to the inside corners of the frame structure on det'l 05. The face of the 'towers' had a 'blind nut' inserted and my entire machine sits on four hockey pucks (with a CSK hole in the centre) that are screwed into the 'towers'. These act as vibration dampers and help to keep the noise down (my machine is currently in my living room as I have no workshop to work in at the moment!)

3. What is the single wood screw used for?

I didn't bother with that but it can be used as a reference point when establishing X/Y/Z zero.

If you want to have a look at my construction progress check out my build log here....... http://cnczone.com/forums/showthread.php?t=6244

I really need to update that as I have made some major changes/improvements since then and I am just about ready to start 'real' cutting jobs with it instead of test cuts and tweaks.

Hope the above is useful to you.

Larry

[ignatz]

Hi Larry, Thanks very much for the post and the link to your thread. Your answers let me know that the pieces needed to be connected and gave me some direction. I don't think I'll be using the blind nuts because it exceeds my capacity. The thread answered some questions I didn't even know I had yet around alignment. You have a very nice machine. Cheers!

[The Wizard]

Originally Posted by ignatz Hi Larry, Thanks very much for the post and the link to your thread. Your answers let me know that the pieces needed to be connected and gave me some direction.

No problem, glad you found the information useful.

I don't think I'll be using the blind nuts because it exceeds my capacity.

I am not sure I understand the above? They do not require any special tooling to fit as they just screw into a drilled hole. I drilled mine with a hand held power drill and they are fine. If you are not familiar with them they have a large, coarse wood type thread on the outside diameter and a metal machine screw thread on the inside diameter. They are fitted with either an Allen hex head or a slotted head (depending on type/size) and you simply drill a hole the correct size in the MDF, add a drop of wood glue for strength and screw them in. You can see an example at the following link.... http://www.mcfeelys.com/subcat.asp?subcat=20.15.1

The thread answered some questions I didn't even know I had yet around alignment.

When it came to aligning the assemblies I used a length of 1/2" CRS inserted through the holes for the leadscrew bearings (I used bearings at each end of the leadscrews) to make sure that the frames and the carriages were truly in line and then roughly set up the pipes from there. I then removed the CRS once the pipes were roughly aligned and put in the bearings and leadscrews. The final alignment of the pipes was done once I had the machine powered up but 20/20 hindsight says it would have been easier and faster to do that before I mounted the leadscrews as I could have simply 'rolled' the carriages along the pipes with a DTI clamped to them rather than 'feeding' them along the pipes under power.

You have a very nice machine. Cheers!

Glad you like it and good luck with your build .

Larry

[ignatz]

Originally Posted by The Wizard I am not sure I understand the above? They do not require any special tooling to fit as they just screw into a drilled hole. I drilled mine with a hand held power drill and they are fine. If you are not familiar with them they have a large, coarse wood type thread on the outside diameter and a metal machine screw thread on the inside diameter. They are fitted with either an Allen hex head or a slotted head (depending on type/size) and you simply drill a hole the correct size in the MDF, add a drop of wood glue for strength and screw them in. You can see an example at the following link.... http://www.mcfeelys.com/subcat.asp?subcat=20.15.1

Wow! Thanks again... I didn't even know about those fasteners. I thought you cut a hexagon shaped hole in the wood and then glued a regular nut in it. The only way I could imagine doing that would be with a mill and a dividing head (which I don't have access to). Now the trick is going to be finding the fasteners locally.

My process for alignment seems cruder than yours. I started with the large gas pipes and leveled one to set the up/down alignment. I used a try square on both ends to make sure that the pipe was square to the base supports and set the left/right alignment. I put the gantry in place and inserted the other gas pipe. I leveled and squared the new pipe and across the gantry. I added the leadscrew and made sure that it aligned properly (I have two flanged bearings for the non stepper side so I used one in each end for alignement). At this point, the gas pipes needed a little more adjustment to make sure that all 4 bearings were touching the gas pipe. With this alignment, I was able to move the gantry by turning the leadscrew by hand. I repeated this process for the other axises and then removed all of the lead screws. I taped a piece of paper to the table and taped a pencil to the Z axis. I manually moved the machine in the X and Y directions (got that idea from you) and used a square to see how close I was... and I was pretty close. I am going to attach the motors and do some paper tests next. We'll see...