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Very nice loking all aluminum machine, from what I gathered from your post you are NOT using the V-groove bearings?
It's been a long time sense I've scrapped the idea of using V-Groove bearings and rails. That decision cost me a small fortune, and has left me with a big pile of unused parts. So I have spent many hours in CAD trying to find an economical solution, one that will let me use as many of the leftover parts as possible!
The solution is in 1/2" dia. mounted rails with open ball bushings. So with a new CAD file, I have been acquiring rails and bushings one piece at a time! Then I placed an order at dumpster CNC, as I like the idea of using their anti-backlash Delrin nuts along with a 5-start acme screw from McMaster-Carr. The screws are heat-treated 4140 steel with a nice black oxide coating. They mate well with the dumpsterCNC nuts!
Hopefully, when I'm finished with this retrofit upgrade, I will have a nice router with a 24x24 t-slot plate. This router will go up for bids on eBay. Whatever it's final sales value is, the money will be used to build as many Blue Midi-Router's as I can afford! This is in response to the multitude of emails requesting them! Word is, there's a shortage of them in Australia! The new Midi-Routers will also be redesigned to incorporate the dumpsterCNC anti-backlash nuts and 5-start acme threads!
So far I've made the new acme screw and it's fixed-end thrust bearing block. Then I band sawed the old ends off y-axis slide block.
All the aluminum has been ordered for the new slide block ends, and the tall side plates.
To be continued.......
Very nice loking all aluminum machine, from what I gathered from your post you are NOT using the V-groove bearings?
No, my experience with V-Groove bearings was not good, I will never build a machine using them again!
This morning I setup my big mill with two vises, dialed them in so they were both aligned parallel with the machine's axis, and centered within the mill's travel. Then I bolted on my long soft-jaws, and closed the vises on a 1" dia. steel bar. Then I milled a 1/16" x 1/2" step in both jaws.
Next I mounted the 24" long rail supports, and milled off the boss from the previous design. Then I dialed in the dowel pin hole in the end of the rail, as this is gives me the centerline for the new linear rail. Next I milled both sides & top of each rail, leaving .010" for the .2500 Radius.
With a .500 Dia. ball end mill, I milled a radius down the center of the new support track. Using a 1-2 micrometer, I was able to measure over a short section of linear rail and a gage pin in the dowel pin hole. This gave me the other center location for the linear rail.
Lastly I drilled and C-bored the six holes for #6-32 SHCS needed to fasten the linear rails to the support base.
With the two vises setup on the mill, I started on the y-axis front & rear plates. First I had to add a solid stop to one vise, so the plates would have a point of reference. Then I placed one plate in the vises, and dialed in the dowel pins protruding form each end. Then I calculated the center distance between both pins, and set the DRO to x-zero. Now, with an edge finder, I established the y-zero and set the DRO.
With an under size drill, I made a hole on each end of each plate. Then I used a boring head to make the hole .5005" dia. Now I have the base frame and y-axis linear rails finished!
Last edited by widgitmaster; 08-31-2009 at 03:53 PM. Reason: added pics
From the start, I was going to work on the Y-Axis slide block first, then I realized it was possible it would get damaged or deformed in the process!
So 1st thing this morning, I made a plug out of aluminum to fit in the center bore snuggly. This bore must be plugged, as the new screw & nut assembly were much smaller!
After making the plug about .0005" bigger than the bore & c-bore, I put it in a cooler full of ice! Then I heated the block with oxy-acetylene until it was nice and hot! The plug had shrunk in diameter from the cold, and the hole expanded from the heat! Just enough for the plug to fall in about 1/4" from bottom, so with a swift smack from a 10-lb sledge, it hit bottom
Now that the hole is plugged, I will re-machine all surfaces until the part is flat, parallel & square. Then I can re-bore the hole to fit the new nut, and mill the ends to accept the new ball bushing adapter blocks.
Hopefully the rest of the material will arrive when I'm finished with this part!
The UPS guy was here, and left with a sore back!
All the material is now in house, all $374.87 worth!
Poor UPS guy, wow look at all that aluminum goodness.
Here in my town we have a guy who does scrap metals but he almost always has a nice stock of l=aluminum...I just wish I had a way to mill it.
Tried to PM you but that did not work, what size are your old v-groove bearings?
I am interested in them for another router project.
Beautiful work and thanks for sharing,
Tom L.
Because the mill is setup with two vises, I decided to make the two X-Axis rail supports!
Starting with two 2" x 2 1/2" x 24 1/4 bars of 6061 aluminum, I placed one on the floor of the vises and used two pair of Starrett "Hold Downs" which forces the bar downward when the vises are closed. Then I used a 3" face mill, and took a light cut across the top of the rail. After flipping the bar a few times taking light cuts, I successfully removed what ever twist or crown that was in the bar stock.
Now that two sides are perfectly parallel and to size, I placed bar in the soft jaws, again rocking the bar slightly as I closed the vises to ensure it was seated properly. Then I took a light cut across the top and flipped it a few more times.
With the bar flat, parallel & square, I started milling the web down the center of each bar using a 1/2" dia. 2-flute endmill.
Last edited by widgitmaster; 09-02-2009 at 05:02 PM. Reason: typos
Next I used a .500 Dia ball end mill to make the radius down the center of the web. Then I milled the bars to length, and using an edge finder I centered the part and set the DRO to X-zero.
With a center drill, I spot drilled the locations for all six holes on each bar. Then I drilled through using a #29 drill. Now I can flip the part, and use a 2-flute counter bore to recess the #6 SHCS which hold the linear rails on.
The end holes will be done later.
This morning I worked on the Y-Axis slide block, first by milling off all the excess from the big plugged hole, then by milling the jagged end and making the bottom flat.
With both the vises removed from the mill, I propped the slide block off the table with 1-2-3 blocks. Then I dialed one side in until it was parallel with the mills table. With a big end mill, I removed the jagged ends until the top surfaces were all co-plane. Then I set the DRO so zero was in the center of the square hub in the middle of the slide block. Then I moved over and milled each end until the saw marks were removed. Then I measured the final dimension.
Next I flipped the part over, and re-dialed it in parallel. Again I set the DRO to zero in the center of the slide block for both X&Y axis. Now I can mill the step on each end, drill some 1/4" dia. holes, and ream some 3/16" dia. holes for dowel pins.
After deburring, I pressed in the dowel pins.
All that is left to do is the center bore for the lead screw nut. That will be done after the end blocks are bolted on, to ensure the ball bushing bores and the lead screw bore are all in line and on location.
Last night I was bored, so I went out to the shop and squared up the end blocks!
First I deburred the blocks, then I sprayed some blue DyKem all over. Then with my little height gage, I scribed a line around each block indicating where the excess material was. Then I put a 10-tooth blade in the band saw, and set the motor pulleys to maximum RPM. When finished cutting, I placed the 1st block in the vise, and used my Starrett Hold-Downs to ensure the block was flat on the floor of the vise. Then I used my big fly-cutter to finish two sides perfectly parallel.
Then I placed one of the blocks between the hard jaws, and machined the next two sides. As long as the mill's head is trammed true, the blocks will be perfectly square. Next I rotated the block 90 deg. and placed the 5th surface down, and used a knife edge square to align the blocks prior to closing the vise. Then I milled one surface on both blocks. Now I Rotated the blocks again, and milled the 6th surface till it just cleaned up. By rotating the block, I can get the 5th & 6th surfaces perfectly square, even if the knife edge square was off just a bit!
Next I drilled and tapped 6 holes for 1/4-20 UNC around 1" deep, then I drilled & reamed two .1876 dia. holes for dowel pins in each block. Then I drilled and reamed one 3/8" dia. hole through each block.
Next I drilled a .825" dia hole through each block, which gets bored later on to .18745 dia. for the Ball Bushings. But before I can bore the holes, I need to modify a big 3/4" shank carbide tipped boring bar so that it will reach through the 4.00" thick block, and fit in the .500" dia. hole in my little boring head. These heavy boring bars work much better than the skinny ones, as they do not chatter at higher RPM.
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