vbearings

[cxixer]

I am looking to upgrade my wood router. I currently have the vxb fully supported 20mm rails under the gantry (y axis). I originally built the x axis with skate bearings. I've never really been satisfied. A combination of this plus the weak z axis gives a jagged cut at 20ipm. I'm cutting mostly MDF by the way. I'm looking to get 55" rails to attain 48-49" of travel.

I would like to strengthen everything up and be able to cut at 60-80ipm smoothly. I was thinking about getting the same vxb bearings, but the delay has been spending the money. I would also like to get new z axis bearings at the same time ~50-$80 off ebay. I have been looking for other options for the x axis bearings. I keep finding THK or similar bearings on ebay for around the $250-300 range which is better than vxb's $320+S&H. But I took a look at imservice (superiorbearing)'s v-groove bearings, the total cost on this would be about $160+S&H... which I definitely can afford right now.

My question is... would these vbearings work? Are these sturdy enough? The Mechmate is a great design, but uses heavier duty bearings. I would be worried that these wouldn't offer the rigidity I'm looking for. I'd hate to spend that plus the money for the THK's. Would I be better off just getting the THKs?

[ger21]

I believe that ShopBots use the same size bearings that imservice sells.

[cxixer]

That is good news. Has anyone here had success with these bearings on a y or x axis? That would certainly be nicer on my wallet!

Another thing. I would like to strengthen the gantry where the sidewalls meet the axis support. Currently the setup is a 1x3" steel beam with angle iron welded to either end on both sides (it would look like a capital I if you looked at it from above), which is then bolted to the sides of the gantry. This is not as stiff as I would like it. It is rock solid as is (1/2"-10 ACME) and stays square, but I am wanting to go back to the original setup with R&P driving it, and when it was like that, it tended to get out of square because if one side moved just a smidge when the motors were off, the other side would not go with it. I can do other things, like put stoppers at the end of the rails to square it up each time, but I would still like to make it more rigid.

I've seen others who have this support bolted to the gantry sides, I'm assuming this is not my problem. I do have another 1x3" beam the same length, if I welded/bolted these together and welded them to the sides of the gantry, would it help?

I would like to stiffen up everything, so this thing cuts solid and will allow me to cut aluminum when the need arises.

[ger21]

Joe's Hybrid use the V bearings as well, I believe.

[dertsap]

check this out http://www.cnczone.com/forums/showth...ght=rock+solid


i use v bearings on both x and y , for the x i have the bearings riding on square tubing and the y runs on angle iron , it works great and is an economical way to build solid slides

[cxixer]

Where did you find that shopbot info? All the pictures look like they use the THK type bearings. And on most big routers I see this type of bearing used more than anything else, is there a reason for this? These tend to be more expensive (brand new) than the vxb bearings/pillow blocks, are they better quality?

The original Joe Hybrid used the vbearings on the z axis. But again, I don't know that I've seen anyone use them for the x with a bigger machine.

I guess I'm still concerned with the strength, would I get the same results with the vbearings as I would with the THK bearings?

[ger21]

http://www.shopbottools.com/files/do...sembly0901.pdf

Joe's hybrid uses them on all three axis as well.

[ger21]

THK's are far stronger than V bearings, but that comes at a far greater price. Sure, they'll make you're machine stronger, but there are thousands of Shopbots using them, and I've seen some impressive aluminum parts cut on Shopbots.

[dertsap]

Originally Posted by cxixer I guess I'm still concerned with the strength, would I get the same results with the vbearings as I would with the THK bearings?

to put it simple no

but the price diffrerence is huge , i have no problems with the v bearings and i'll cut aluminum .05" deep at 50 ipm easily with a .5 endmill , for fun i will cut .01-.02 at 500 ipm with no work for the machine and it cuts out a pocket fairly qiuickly
a guy just has to use a little common sense and utilize the machine to the best of it's abilities

this is the build i did http://www.cnczone.com/forums/showth...=23120&page=12

[cxixer]

Originally Posted by dertsap to put it simple no but the price diffrerence is huge , i have no problems with the v bearings and i'll cut aluminum .05" deep at 50 ipm easily with a .5 endmill , for fun i will cut .01-.02 at 500 ipm with no work for the machine and it cuts out a pocket fairly qiuickly a guy just has to use a little common sense and utilize the machine to the best of it's abilities this is the build i did http://www.cnczone.com/forums/showth...=23120&page=12

Nice router. Did you just use angle iron for the rails for your vbearings? Did you do anything to them other than bolt them on? If I went that route, I would save another $100 instead of buying the expensive version. Also, did you use the imservice vbearings with concentric/eccentric bearings?

So now I decide between ~$150 or ~$350 for all of my upgrades.. And I would also really like a nice aluminum z axis ... if only I could already machine aluminum...

[dertsap]

i needed to do a little shimming to the angle but nothing major , i used eccentric bushing , the y the bearings are mounted to an aluminum plate and the z is mounted to that , there are pictures of the x axis assy in the link , i did use imservice vbearings , they are cheaply priced , well other than the gouging they hit me with on shipping to Canada which was nearly 50 bucks alone for a dozen bearings thru the mail .

[cxixer]

Just reading through the joe hybrid thread. I see where he switched to vbearings on all axes. That and dertsap's router have just about got me convinced on the vbearings.