Replacing V Wheels with Linear Guide bearings

Long story short I have some HGH15CA Linear Guide bearing on the way to me. Toying with the idea of how to install them on my xcarve. So I pulled the model from grabcad and set to work. What I came up with was 2"x2"x6" 3/8 aluminum angle. With the guideway on the top of the y rail. Looks like it would fit no problem. Attaching to the original plates (plus a few new holes). This will increase the height by about 50mm and require 12mm spacers between the y plates and the x rails. Would love to get the community input before I take my machine apart (again).

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I would mount the guide on the outside of the machine to help prevent debris clogging it up, or even on the underside with a guard on the wasteboard side.

I would need to make sure they can handle that kind of load for the underside but it is a good idea as it would be easy to hide from dust. I was going to put come guards on the side anyway. The side would push it out really far forcing me to either reduce my cutting area or have big spacers. I am planning.

edit. Underside wont work, the plates I use to stiffen Y and the waste board get in the way.
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totally overkill, but, hey no more v-wheels to adjust. :stuck_out_tongue_winking_eye:

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In your place, I’d personally prefer to put the rails on the outside and not use spacers. Advantages: no need for angle brackets, easier mounting to side plates, less dust, no need for additional riser plates for the belts, fewer parts, cleaner. Disadvantages: about 50mm of less X travel (total for both rails).

What about the X? Is there room for even one rail inside the X carriage with the idlers in place? No question for a second.

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If you mount the rails to the outside, then you’re widening the X axis and thus your gantry would be too short. As shown, the angle bracket will also widen the X-axis. The wide maker-slide will be too short and not reach from side to side. However, you could move your end-plates inward along the X-axis to completely make-up for all of this and it would all fit just fine. :wink:

Now, how does the belt system work if you’re utilizing the top of the rails like that? If you move the rails to the outside, then the belting paths wouldn’t change at all. But you’d have to move your end plates and thus your X-axis would be narrower.

@EliasPolitis said the same thing with less words. :wink:

Keeping things clean, I made short wood sides that go right up under my X axis beam and my side rails stay completely clean.

I LOVE this approach and would be all over this if it works. Can you tell me where you sourced your rails and bearings?

I agree there are advantages to the outside. I would really not want to lose 2" on my X. It would also mean I have to take the whole machine apart, cut the wasteboard, square the machine again. I redesigned the base to be 2 2060 running the length to allow me to attach 1/8 steel plates running from the bed directly to the Y-axis as supports and 1.5" angle attached to the plates to help with lateral movement and still have room for the waste board. This also gives me mounting points for the dust shields. I lost some x in that process 31 to 29, that would drop me to 27 and make it harder to square the machine. As for the X, the new wide maker slide only has to mounting points front and bottom or back and top depending on how you have it installed. So I think that would be replaced and new x plates made when that time comes.

They were a gift, so I have no clue about quality and only one review. Thats the other advantage to this design, if they are crap I can switch back easily and not waste a ton a cash/time.

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Do you see “Hiwin” stamped on the blocks and rails?

not here yet, but lets be honest, at that price they are cheap knockoffs. It was a gift so at worst its a proof of concept.

If you decide to go for it, try to make it reversible, That is, if it doesnt work, you can return your machine to it’s original state.

Don’t be worry about dust and debris problem. They are sealed on both end. They always works that way.

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That is the plan, I plan to try it with the existing holes on the y plates, no damage to anything. if it works I will add holes for support. Even then it should be completely reversible.

Even if they are clones, they should be an order of magnitude stronger than v wheels.

However, the most critical question here is how do you get your friends to buy you mechanical components for gifts. Amazon wishlist? Innocent hints? Ah… these damn v wheels got loose again. If I only had some linear rails. Oh no, Santa forgot to bring the HGH15’s.

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TIL I have 2 forum accounts…

bth

M5 tnuts to the top of the rail? Am I missing something?

If your rails are HGR15 clones, they are designed to take DIN912 M4 screws. So, M4 T-nuts is what you’ll need. M5 are for the bigger brother, HGR20. Look under column “d” below.

Profile T-nuts will work the best as they will provide more threads and more length (Y length in your case), as opposed to drop in T-nuts or plain flat T-nuts. In the latter there’s no “T”, but some people tend to call them all T-nuts. Also, pay attention to the profile selection. You will need “20 series” or “2020”.

UPDATE:
A note about the screw lengths. M4x12 is on the short side, M4x16 will kiss the channel floor (not such a big problem). Ideally you need M4x15. If you are OCD and cannot find M4x15, grind and file the tip of a M4x16 (having threaded a regular nut beforehand helps with deburring). My local fastener supplier goes from 12mm to 16mm in M4 lengths. Just to keep in mind.

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I will check with my local supplier as well, I suspect I will run into the same thing with the M4. I cannot thank you enough for that catch! Looks like I will need qty 25 for each side as well. small washer should save me some time

Ok now someone needs to tell me I can get away with 1/4 in angle vs 3/8.

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Well, this will solve one problem (screw length), but will create a new one (not enough space for the dust caps).

hg_dust_cap

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Ok then the grinder it is. They are here!

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