[LTHOMPS]

PALMER CNC BEGINS !!!

I have finally decided to build a CNC Router and see it through. After a lackluster attempt about a year ago and some needed research, I am now ready (I think):idea:.
I am new to CNC so this is a big frigging experiment. After my research, I decided to create my CNC using the Ahren 8020 baseframe (I may make some minor modifications along the way). I am also using the bearing blocks from www.finelineautomation.com and adapting the assembly to work with the ball screws. I am also relying the advice of a colleague who has built his own CNC years ago. His machine, "The Ultimate CNC Router" is featured here. After the Ahren frame is said and done, I start to deviate and pursue the PALMER CNC Experiment. I decided to use linear ball screws and rails for motion. I also opted for the NEMA-34 motors. I have no clue at this point what the Z-Axis will resemble. I am not keen on CAD models because they take too long, so don't expect to see any until this project is complete. For right now, I am just digging in and getting 'er done. I always set timelines for myself, which I believe are possible, but everyone else thinks I am crazy. I finally decided to make this CNC 5 days ago, and parts started to arrive yesterday. I give myself two weeks from today to be cutting material using the CNC or this experiment is a failure. I will be posting all of the pictures on my Palmer CNC Blog since I find it easier to manage them there. However, the normal forum updates will be provided here.

Any comments, suggestions and feedback is greatly welcome. So, let's hear it.

Let the experiment begin!!!

[LTHOMPS]

This is as far as I have gotten on day 1 of this project. At this point I can't go any further for the following reasons:

1. 8020 cross member extrusion for upper gantry will not allow for mounting of linear guides. I need a height of 6" to position two rails onto. I will source and pick up locally today a piece of 8020 that I can use for this design.

Update: Could not source locally.....awaiting FEDEX shipment tomorrow.


2. Awaiting FEDEX shipment of rails and guides for X-axis. Just need to bolt them on.

Update: One rail showed up, so still stuck at this point. FEDEX delivery scheduled for tomorrow.


3. Awaiting FEDEX shipment of helical shaft couplings. Can install ball screw and lower gantry after it arrives.

I expect to have both the X and Y installed today as long as my FEDEX shipment arrives and I can find the longer height 8020 locally.

Update: Not gonna happen tonight, but I can prepare the X axis tonight and make some few minor modifications to the baseframe.

[cncbob]

Wow! 2 weeks is pretty aggressive. I can't wait to see her come together. Keep us posted.

[LTHOMPS]

Managed to get the bearing blocks assembled and added in some gussets. They are a pain in the arse to get in, but they square the entire frame with little effort. Definitely adds a few dollars to the overall build (requires 32 T-nuts and screws, but worth the peace of mind that it's square and solid. Since I am using 3/4" ball screws, the couplings are obviously bigger than other CNC designs I have seen with acme screws, and the coupling size has interference with the piece of 8020 that it's mounted to. I have to come up with a modification to the piece of 8020 or find a smaller coupling. FEDEX expected today with the parts (linear guide rails and 3060 piece of 8020 extrusion for upper gantry) I need to go further. Also ordered all of the electronics, and should start seeing those today or tomorrow. Will start to formulate a master bill of material list. Pictures of some components for the X, Y and Z attached.

[LTHOMPS]

Day 3 was a complete wash due to items not arriving and additional modificatiions having to be made to account for switching to a ball screw, linear rail/guide system. I decided to build a wooden table with the new drill press I bought.

Now back in the saddle on Day 4, and things are looking a lot better. Had to modify (shorten) as well as notch (to accomodate large coupling used for 3/4" ball screw) the piece of 8020 the linear guides were attached to. Up-close photo attached. You can see in previous photo this piece of 8020 was 14" and now it is 5". Otherwise the ball screw nut would interfer with the 14" piece and I would lose 9" of travel. Also, finally received the piece of 3060 needed for the uppper gantry. It's not shown in today's latest photo because I still need to drill access holes in it for mounting to the lower gantry. X and Y will be complete today. Six more working days to go and I hope to have something moving. Will be away for a week, so no updates after tomorrow.

[LTHOMPS]

Day 5 was accomplished before I left to go on business travel for the job. Couldn't post the update or would have missed my flight. So here is the update. Finally got the new 8020 extrusion for the upper gantry drilled and mounted (photo attached). Also made and mounted the support plates for the X-axis linear guides. Did a fair amount of work making sure the table was square and the rails were straight relative to table. My colleague who is guiding me in this build is extremely anal when it comes making sure the rails are straight. I had to take pictures to prove it or he won't believe me. I actually used the wrong reference, so I need to go back and check for straightness again......ARGHHHHHH! Can move the X-axis by hand now and I'm pretty impressed I've gotten this far. I think this time I will actually finish the build. I also started to build the controller box. Didn't get very far because I am by no means an electrician, but components are all mounted and just need to do final wiring (day 5 & 1/2 photo attached). Attempted to solder all the connections for steppers, but after I did it, they all fell off. So will need to seek help with this tomorrow from my colleague. Soldering SUCKS AZZ! Now I need to finalize the Y-axis and get a computer to really make this project come to life. Be back soon with updates. Need to catch up on sleep......

[LTHOMPS]

I'm quoting this as day 6, but it's more like 6.5 with daylight savings time. But whose counting! I lost a bet that I would have the X and Y controlled by the computer by day 6. Cost me lunch and some beer. Anyway, got the soldering help I needed and finished the controller (minus the E-stop). Will do that later. Verified all my connections were providing the correct voltages (took a few tries, but finally got it). Sourced a computer and loaded Mach3, VCarve and Cut 3D. As for the CNC build itself, got the X ball screw cut and installed. Had to make extensions to accomodate the ball screw flange (shown in photos). I ran out of t-nuts to finish mounting the second Y rail, so I am waiting for a FEDEX shipment. I am also waiting for a new piece of 80/20 extrusion that I will use as my Y axis mounting bracket. Once FEDEX arrives the Y will be complete (hopefully). Today I need to source rails for the Z axis and a router and I also need to cut my Y axis ball screw to length. We're getting close.

[LTHOMPS]

Day 7 & 8 have been the most frustrating. Day 7 I managed to get 'er all hooked up and tried moving the X-axis, only to find out the breakout board has separate power (not the DC) that I hadn't hooked up. I took the unit to show my colleague this day and he decided to run one of the steppers at 450 IPM. Later that day I hooked it up to the X-axis gantry and re-ran it under the same conditions. I will post the video once I figure out how to shrink it. Day 8, I thought I would be running the Y and Z axes. That didn't happen. It was a little more complex and lot of drilling and tapping. Ultimately, I cut the 80/20 for the Y-axis too short and it screwed up my Z-axis travel. The Z-axis travel currently is only 4", so I need to source a new piece of 80/20. Should have it in a few days. I also rigged up the Y-axis just for giggles and ran that today. I will post that video as well. I probably won't work on the machine until I get my 80/20. Think I'll go fishing.

[LTHOMPS]

OK. I said I wasn't going to mess around with this machine until I procured my new 80/20 for the Z-axis to make it greater than 4" of travel.....well I was bored and wanted to see something move. I had to make the Y-Z-axis interface(I drilled and tapped so much aluminum today). That took me about 2 hours. Photos attached. This Z-axis is temporary so please don't tell me how crappy it looks. I think I will try to machine better brackets for the new Z-axis with this machine. I know I will need to take very small cuts, but I will see how it turns out. I have not procured my router and mount as of yet. As I was cleaning up, I noticed an old dremel and table top attachment and thought I could use it for a trial run. GOOD IDEA! It actually worked with some minor modifications. Grabbed a cigar, beer and turned 'er on. Took a few passes manually just to see 'er cut. Surprisingly it worked.

[LTHOMPS]

Well on day 10 I did get my router (Porter Cable) hooked up with a nice mount from K2-CNC. As far as I am concerned, I built a router in 2 weeks (same as 10 working days....well I am close anyway). I didn't bother installing the new piece of 80/20 to make my travel greater than 4" because it didn't arrive when it supposed to. Since then I have only been making minor modifications (none of which you may notice from the pics). One major change was turning the gantry 180 degrees. This bought me an extra 2" of travel (putting me at 35" in the X). One major problem I have is getting the coupler on the X-axis to completely grab onto the ball screw (it keeps coming loose). I may weld 'em together today or drill and tap for set screws. I have also been trying to rid myself of what I think is noise when running the X-axis at 400+ IPM. Noise doesn't seem to go away even at 300 IPM. I am thinking of trying to re-align the entire system. I believe the gantry is sagging down a little too low. The noise worsens as the gantry nears the X-axis stepper which doesn't have room to move, thus increased friction=noise. The problem isn't apparent on the opposite end of the X stepper which has a little room to move inside the bearing. If I do a total re-alignment this will also give me a chance to insert T-nuts (hindsight during the original build) for mounting the MDF table I plan to use. This should only take an hour or so. I have been cutting material and am overall pleased with the CNC performance (eventhough I have nothing to compare it to). It should only get better with the upcoming adjustments.

[cnctoolman]

Looking quite nice there. Are you experiencing any flex out of the upper gantry that you can tell?

[cindy cheng]

Later that day I hooked it up to the X-axis gantry and re-ran it under the same conditions. I will post the video once I figure out how to shrink it. Day 8, I thought I would be running the Y and Z axes. That didn't happen. It was a little more complex and lot of drilling and tapping. Ultimately, I cut the 80/20 for the Y-axis too short and it screwed up my Z-axis travel.
Your oppion is nice,can i take part to my feed hammermill blog ?

[LTHOMPS]

Looking quite nice there. Are you experiencing any flex out of the upper gantry that you can tell?

Toolman: There have been many of these machines built based on the Ahren 80/20 design using 3.0" aluminum for the upper gantry. I used 6.0" (which I think is overkill) and there is absolutely no flex that I can see.

[LTHOMPS]

It's been a week and I haven't gotten anything done because I was out of town. So now, back at it. I finally changed the Z-axis and used the new piece of 80/20 I procured to make my Z-travel greater than 4". I actually went overboard and used the entire length of 80/20 I had. My Z is now 6+ inches. I say 6+ because the true Z can only be as large as the piece of stock that the gantry can move freely over. I can move freely over 6", but it can travel at least another 5". I also got rid of the noise I was experiencing. It was due to the ball screw having too much play inside the linear bearing. The biggest change I made since last week was making a new Z-Axis plate and side plates to attach it to the linear guides. The Z-axis plate I purchased from FLA was slightly undersized because it was intended for the rack and pinion setup. I simply made my own and made it conform to the design. I'm quite impressed I was bale to do it with some plate aluminum stock, mitre saw and a drill press. I also started installing a table so I can finally get something cut. One of the slots is backordered so I am 90% done with this. I went with slots from Incra-Track (mainly because they had some sweet looking table clamps).

[LTHOMPS]

It's been a year and I hven't posted any updates because I have been busy cutting and routing things with the machine. IT IS A BEAST! Here's one example of something I cut for a friend.