KRMx01 Build Log
Chapter 10 - Installing the ACME screws
Admittedly this is a short chapter compared to the last, but it marks a point where I feel the machine is getting close to looking and soon to be running like it should. As always, here is a picture of the parts required to install the lead screws.
Installing the Z-Axis Lead Screw
Just like the book, I started with the lead screw installation on the Z-Axis. Well, let's just say that it didn't quite go off without a hitch. When I run the screw down to the first nut, it threaded just fine, but going into the second wasn't so easy. Even with the spacers I made for the Z-Carriage, I still didn't have enough clearance on the Z-Beam. I mean it was close, the nut just barely rubbed the Z-Beam. Still it was unacceptable. So, I got out the callipers and went through a bunch of 3/8" washers until I found four that were the same size. I added one to each carriage bearing to give me a little more clearance between the nuts and beam. Next, I didn't really have enough wiggle room on the bottom nut to prevent it from binding when I run the lead screw into it. To remedy this, I removed the 5/16" socket head screws and replaced them with 1/4-20 x 1" long bolts as recommended in the book. After all that, I finally had enough room to shift things around and line up the lead screw. WHEW, hope the rest are not that bad!!!
Installing the X-Axis Lead Screw
Installing the Y-Axis Lead Screws
When I built the Y-Carriages I used the supplied 5/16" socket head cap screws that came with the anti-backlash nuts. After the issues with the Z-Axis, I went ahead and replaced them with the 1/4-20 x 1" bolts before I even started on the lead screw installation. Also, Zachary and I found it helpful to grind down part of the head of the inside motor mount bolts to give a little more clearance for the opposite nut that attached the angle down to the extrusion. This is a tight fit there. Otherwise the Y-Axis lead screws installed just fine.
The machine in its current state
The machine is coming along just fine and I will be starting the electronics portion soon. I think I will turn my attention to the computer rack that will be built into the table next. I have put it off long enough. See you in the next chapter.
Chapter 9 - Motor Mounts
Like every other chapter so far I try to gather all the parts I will need to finish the chapter before I start. This one is no exception. You may want to get a drink of your choice and hunker down for this chapter. If you have been following along you know that I had to make some modifications to the carriages because of the new anti-backlash replacement nut from cncrouterparts.com. I will have to make changes to the bearing blocks and motor mounts to compensate for it. I will lead you through what I will have to do to get it all back on track.
Starting at the top with the Z-Axis
I am going to try to save you a lot of the boring detail as I go along in this chapter. I am starting with the Z-Axis motor mounts and bearing blocks and will progress on. Additionally, I am going to wait until I know the modified blocks are going to work before I paint them. The first image shows the parts for the Z-Axis motor mount and bearing block all marked and punched. The second shows where they have been cut and drilled. I forgot to include the angle pieces in the picture. Sorry about that.
I have the bearing blocks installed on the Z-Axis. Note that I have not painted them yet because I want to make sure that my modifications are all correct. This way I don't waste any paint if a need arises to make new blocks. Zachary climbed on the machine and done an eyeball through the bearing and the two anti-backlash nuts. He seems to think that they will be just fine. We will know for sure when in the next chapter we attach the lead screws.
Recall that I had to move the bearing centers by 1/8" to accommodate the spacer. I have redrawn these for your convenience and can be downloaded by clicking either ICON to the left. Both DXF and PDF versions are available. These are for the Z-Axis.
Doing the Y-Axis bearing blocks and supports
Zachary "The Drill Master" Hildreth
What can I say, Zachary is a drilling machine. After drilling all the holes for all the supports, bearing blocks and motor mounts for both the X-Axis and Y-Axis, I am sure he has mastered the Drill Press!!! Thanks Zach for all your help and hard work today!!! Not to mention that he cut the slots too!
Doing the X-Axis bearing blocks and supports
Here the X-Axis Bearing blocks are assembled and attached to the machine. One thing I noticed was that a hole was missing for the X-Axis motor mount. I was a little confused by it at first. Anyway, I have fixed the DXF and PDF files below. One further note, because the Y-Carriage supports extended past the X-Beam by a very small amount, 3/64" I notched the block that goes against the beam so the bearing assembly would rest against the X-Beam extrusion.
The machine at this stage
Well here is the machine as it sits at the end of this chapter. I must admit, it would look a lot better with the bearing blocks painted, but I want to wait and see how the lead screws go. So that's it for this one. See you in the next chapter!
We have painted the bearing blocks and motor mounts. I thought the 1/8" piece would be kinda cool looking if it was painted red. Sort of like a racing stripe. Anyway, here are a couple of images so you can see the results.
Chapter 8 - Z-Carriage
Gathering the parts for the KRMx01 Z-Carriage
Marking and drilling the Z-Carriage parts
Here are a couple of images of the Z-Carriage parts. The first showing them marked and punched and the other after all the parts have been drilled. Note the spacers. The Z-Carriage sides require attention to detail. If you look close you will see that I had miss marked one. Luckily I caught my mistake and corrected it.
Painting the Z-Carriage parts
Here are the steel parts painted for the Z-Carriage. These will need to dry a while to harden up then I can start the assembly. I am leaving the router mounting plate bare aluminum like the other aluminum parts of the machine. I just think it looks better. Besides, I have always had problems with aluminum taking paint and holding it. Has anyone tried baking Krylon 2 in 1 paint in the oven? If you have send me a message through the contact link from the main menu at the top please and let me know how it worked.
I just realized that I did not drill the holes in the supports for the anti-backlash nuts to 3/8". I plan on using the 5/16" socket head screws that came with them. I will have to take these back to the drill press and correct that error. Suppose it will need a bit of touch up on the paint too. :-(
Assembling the Z-Carriage
The Z-Carriage is assembled as outlined in the book, except for the spacers that are placed under the Z-Carriage support pieces. The images show the completed Z-Carriage assembly. Note the arrows for the location of the spacers.
I feel there are a couple of things to point out. The 1-1/2" bolts that attach the router plate to the carriage sides seem just a a little long. Bolts 1-1/4" long may have been a better selection. The longer bolts will work, but I had to loosen a couple and make sure they were pushed as far to the outside edges they would go to prevent them from interfering with the Z-Rails.
Adjusting the Z-Carriage
This wasn't too bad of a job. Rest the carriage on the bolt you place on the bottom of the Z-Beam and manipulate the bearing adjusters until it is square. I was fortunate that I had only a minuscule adjustment to make. The images to the left are the Z-Carriage installed and adjusted.
The machine at this point
Well the machine is really starting to take shape! Next comes the bearing blocks and motor mounts. These items will have to be altered to accommodate the changes in the carriages for the new anti-backlash nuts. I will make updated drawings available. See you in the next chapter! :-)
Chapter 7 - X-Carriage
This chapter probably should have been called X-Carriage and Z-Beam since the two parts are integral. But I digress.
Gathering the parts required for the X-Carriage
I have gathered together all the stuff I need to build the X-Carriage / Z-Beam and Rails. If you look at the second image with the hardware you will see that I have washers and nuts all on one bolt. These have been set aside to use for the bearings. All these washer measure the same thickness as do the nuts. This helps assure that the bearings are all the same distance from the angle.
Just like the Y-Carriages, I expect to have to make spacers because of the height difference between the original anti-backlash nut and the new one. I will tackle that when I get there.
Marking and drilling the carriage top and bottom
Here I have used my little flat white paint and height gauge trick to mark the X-Carriage top and bottom pieces. For an old guy with poor eyes, this is a nice contrasting method for me to mark these items. One thing I have noticed using this method is that if you let the paint dry a long time, the line chips out a bit where if you wait till it is dry enough to handle the lines stay crisp.
Marking and Drilling the Z-Rails
Here are the KRMx01 Z-Rails. When I mark aluminum, I find the best contrasting mark is to use a blue Sharpie or other permanent marker. The resulting scribe mark is quite easy to see. The marker can be removed with mineral spirits. The image on the left shows the opposing pairs marked and punched. The right shows them drilled.
Painting the X-Carriage top and bottom
The X-Carriage top and bottom pieces have been painted. I want to give them a little time to dry. I am sure that I will need to make spacers for these as well. I plan on picking up some 1/8" x 2" strap to make these with to ensure that the whole width of the carriage pieces are supported. I will do some trial assembly to confirm, but I am sure that they will be needed.
Making the spacers
The spacers for the X-Carriage are a little different than the Y-Carriage. I wanted to make sure that the carriage top and bottom were fully supported. These spacers are made from 1/8" x 2" strap. They are cut 4" inches long and have the same drill pattern as the carriage pieces do. The holes start at 1/2" from the edge. I have included a DXF drawing for you if you are doing something similar.
Painting the spacers
Finally the spacers are painted up and ready to go. As soon as they dry a while so they are not so soft, I will do some trial assembly. Remember, these spacers will go between the extrusion and the top / bottom carriage pieces.
Assembling the X-Carriage
Here is the fully assembled X-Carriage component. The X-Carriage is assembled exactly as in the book with the exception that the spacers are located between the carriage top and/or bottom and the aluminum extrusion. Looking at the second image, I have drawn some arrow to indicate this. One other thing I would like to point out is that I started the assembly process by attaching the rails first. This allowed me to easily get them in position and fastened down without fighting gravity and try to do it while it was on the machine. I also conditioned the rails after I had the assembly completed. I just figure it would be easier to do that while it was on the table.
Attaching and adjusting the X-Carriage
Setting up the X-Carriage takes time and patients. The first thing I done was set the height of the carriage from the top of the beam. To do this I clamped the plate that will be used as the router plate to the beam and then my height gauge to the plate to create a constant surface. Next I adjusted the carriage top until it was the same height on both sides until it was within .001" of each other.
Next I used a square to make sure that both outside edges of the rails were square to the table. To do this I had to loosen the bolts and nudge the top of mine over about 3/64" to get it square. Once it was square on both rails on both sides of the table, I re-tightened the bolts and checked frequently during the process. Finally, I used the square to make sure the face of the rails were square with the table. Only the rail on the right side needed a little adjustment. About 1/32".
Chapter 6 - X-Beam
Materials for the KRMx01 X-Beam
Installing the X-Beam
The beam has the bolts slid on for the rails and has been bolted to the Y-Carriages. I must admit, the bolts on the inside of the angles of the carriages are fun to get at if you have large hands. Also, I would recommend having a helper when it comes time to square the beam to the carriage and tighten the nuts. Thankfully, my son Zachary helped me, and on his birthday too. Happy 18th Birthday son. I love you.
NOTE: The extrusion for the X-Beam should hang over about an inch or so on each side. The important part is that it clears the Y-Carriage supports. With the modification I made to the Y-Carriages using the spacer for the new anti-backlash nuts, I ended up with the supports extending past both ends of the X-Beam by about 1/16 of an inch. To rectify this, I may need to modify the bearing supports further. I will detail what I done in the section on the motor and bearing mounts. On a new build, I would recommend cutting the table top a 1/4" narrower than the plans call for and move the left Y-Beam in by 1/4".
Zachary and I could not help but to test out the newly installed Y-Carriages and X-Beam. This is a nice smooth rolling assembly. You can watch it in motion in the video below. Zachary is playing the part of the CNC drive motor. As I recall, at two years old he made a really good tricycle motor too!! :-)
Preparing the rails for the X-Beam
Next in line is preparing the X-Beam rails. The little height gauge I bought is really starting to pay for itself on this project. I have always marked the aluminum angle from the outside forcing me to sit the inside of the angle on some stack wood to drill it. This way, I can mark it from the inside and just lay it on it's face to punch and drill. Now, I still want to lay it on some wood when I drill to support the aluminum so it does not distort. But I digress. The first image shows the rails marked, punched and ready for drilling. The second image shows the rails drilled and deburred, ready for installation.
Installing the rails
Here Zachary is tightening the bolts on the rails. We started by clamping a piece of 3/4" MDF across the entire face of the X-Beam. Next the rail is clamped to the MDF at the center and towards the ends. The bolts are progressively tightened starting from the middle and working our way to the ends moving the clamps on the rails as we go along.
Conditioning the rails
Next the rails are conditioned to make them ready for the X-Carriage. This little device used to condition the rails works quite well. You can see some information on the construction of the rail conditioner in chapter 1 of the build.
For the fun of it, we have included a short video showing Zachary using the conditioning board on the rails. GO ZACH GO!!! :-D
Adjusting the X-BEAM to the table
Next, we make sure that the face of the X-Beam is perpendicular to the table. Ours was spot on on both side making no adjustment necessary. I don't know if that is SKILL or just dumb luck. But it was a good sign nonetheless.
The completed KRMx01 X-Beam Assembly
Here are a couple of shots of the completed X-Beam and the machine. Next up is the X-Carriage. I suspect that there will be modifications to it like there were to the Y-Carriages because of the new nuts. Tune in to the next chapter where we build the X-Carriages and find out! See you there.
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