一种新型8020 extrusion直线运动系统

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ahren                                 登录/注册后可看大图 Join Date: Feb 2004 Location: USA Posts: 270                                 登录/注册后可看大图

登录/注册后可看大图 CNCRouterParts -- New linear motion system for use with 8020 extrusion. Now on sale, a new linear motion system from www.cncrouterparts.com! These unique components turn a standard 1/4" thick steel rail into a linear rail. No angled mounting or fussing with alignment of gas pipe -- just bolt a piece of steel to your extrusion, and use these for square, rigid, trouble-free motion. Pre-load the bearings using the integrated nylon set screws and the t-slots on the extrusion. Cost wise, these are designed to be very competitive -- everything you need, aside from the rail itself, is included in the price. No eccentric bushings, and no custom machining. Mount these straight to 8020 as an integrated part of your frame. A complete linear motion solution for your machine can be had for as little as $120, plus the price of low cost steel rails. Want greater stiffness? Just add more carriages to spread the load -- they're completely modular. Like all the parts we sell, these are designed to work with 8020 15 series aluminum extrusion, forming an integrated system with the other parts sold on the site. Attached Thumbnails                                 登录/注册后可看大图                                    登录/注册后可看大图                                    登录/注册后可看大图                                    登录/注册后可看大图                                    登录/注册后可看大图                                    登录/注册后可看大图                                    登录/注册后可看大图                                    登录/注册后可看大图

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dsquire     Join Date: Nov 2006
Location: Canada
Age: 66
Posts: 50


1/4" thick steel rail into a linear rail

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"These unique components turn a standard 1/4" thick steel rail into a linear rail."

These look very promising. Could we please have some overall sizes? I am suprised that this is the first post on this new item.

Thanks

Don

qinsdau

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Sure! Here's a pdf file of the dimensions. I also have a .STP file for use in 3-D modeling, but CNCzone doesn't support that format -- let me know if you want it. I'll try and create a Google Sketchup file for it as well, since I know a lot of people are designing in that.

Thanks for your interest!

Ahren

qinsdau

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Sure! Here's a pdf file of the dimensions. I also have a .STP file for use in 3-D modeling, but CNCzone doesn't support that format -- let me know if you want it. I'll try and create a Google Sketchup file for it as well, since I know a lot of people are designing in that.

Thanks for your interest!

Ahren

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Hi All,
Prices haven't officially "gone up" yet -- I just wanted to show the regular price (as opposed to the sale price) of the items while I'm away on vacation for those with longer-term budgetary plans. The linear carriages have only been up on the site for a week or so, so you can expect a least a few more weeks of introductory pricing once the store re-opens mid January. So the long and the short of it is, it isn't Jim's fault .

Happy New Year Everyone!

Ahren

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WillyInAus     Join Date: Feb 2007
Location: Australia
Age: 36
Posts: 14


Good work ahern,

I have bookmarked your site as I be starting a new build late Jan of a larger unit.


Sean in Aus

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All,
I'm back from vacation, and the online store is back online. Those of you waiting to order parts, thanks for your patience! Also, for those wondering, introductory pricing on the linear motion products will be good through Feb 25th.

Best regards,

Ahren

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Nice, I am gonna check into the 1/4 steel and try a complete set of these on my new homebuilt.
Steve

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Great! I'd love to see pictures of your machine, and I'm sure others would too. FYI, I added some steel companies to my links page. It looks like www.discountsteel.com is one of the cheaper places for material, but I'm sure it depends heavily on shipping.

Ahren

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Sketchup Files Now Available!

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I have updated the CAD file section of my website. PDF files are available for 2D drawings of all cncrouterparts.com parts, as well as .STP and .SKP (Google SketchUp!) for 3D modelling. Hope this helps out those of you working on designs!

Best regards,

Ahren Johnson

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All,
I have had multiple people comment that they like the system, but would like to see more spacing between the bearings for X and Y axis parts. While this could certainly be done (at higher cost), I want people to be aware that you actually CAN get greater spacing by simply using two bearing trucks, connected by a piece of 8020 (or steel/al tube, plate, etc.) using the existing mounting holes on the carriage. One set of bearings on each carriage is fixed, so you can actually use the steel rail itself to get the two carriages aligned during assembly. This way, you can set the span between bearings to fit your needs. See picture below -- I hope this makes sense.

Additionally, the mounting holes drilled through both sides of the blocks are sized for 5/16-18 bolts (used with the 8020 15 series). However, this sized hole also happens to be the right size for the inner diameter of a tapped 3/8-16 bolt, so if you'd rather have a nice big tapped hole, you can just tap the existing hole, giving you even more mounting flexibility.

Ahren
www.cncrouterparts.com
Attached Thumbnails

qinsdau

I think people are trying to avoid doubling their cost. Since it seems that the difference in cost between a truck of a standard length and a longer one would be the incremental cost of the additional aluminum, one could save a lot by not having to buy twice as many trucks for their gantry axis.

How are people using these? Are they using one truck on either side of each linear rail or one truck on either side of the whole axis?

John

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Join Date: Feb 2004
Location: USA
Posts: 270


John,
Thanks for your feedback -- that's fair enough. As it is right now, the system really requires two trucks per side for the gantry axis anyway (except for very small machines, or plasma cutters with not much load on the bearings). Depending on the orientation of your rails you sort of have two options. Option A: two on one side (with the rail laying horizontally), which provides greater resistance to racking, or Option B: wrapping the rail (with the rail oriented vertically), which gives you a stiffer vertical gantry for taller Z axes.

KingJamez is almost done with a system using option B, so it will be interesting to see how well his design works once he starts his project log here.

So I'm interested to know -- what would people ideally like to see in terms of spacing? I think the current design accommodates all but the gantry axis pretty well with a single pair of trucks, but I'll look into doing a run of larger ones for gantries. The current bearings are 3" and 4" apart respectively. Would 11" and 12" work for most people's designs? I welcome your input.

Best regards,

Ahren

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Stepper Monkey     Join Date: Jan 2007
Location: USA
Posts: 571


I'm not much of a router guy, more work with mills myself, but I have to say - This idea completely kicks ass. So does Ahren apparently. Useful website, definitely an asset to the community.

This makes it look easy enough I'm actually contemplating building a simple router table now that I went to his site and eliminated the two big reasons I hadn't bothered before. Not actually needing a router enough to actually mess with scratch building either the system of bearing/screw mounts or the bearing/rail system I sort of ignored the idea up until now even though I always thought it would be a neat addition to my mills. Looks like thats taken care of nicely now, so time to clear space in the garage again for a build.

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Thanks for the compliments, Stepper Monkey! I'm glad my parts are inspiring you to build a machine! I'll keep you all posted as new parts become available. Next order of business for me is a way of mounting drive nuts to extrusion -- once that's done, there's reallly nothing left to machine. An extrusion machine should be a bolt-together system at that point.

Ahren

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Hi Ahen - Thank you for offering this very interesting linear motion setup. I have been very torn with what to do on a limited budget and frankly only hand tools to work with. Buying these trucks could help a lot.

Could you tell us a bit more about what quality of skate bearings are being used ? If I understand the load capabilities of them better, this will help me answer your question about spacing, at least for my application.

I am tempted to suggest that you (also) offer a truck with at least 12 inches between the bearing pairs, but another real consideration (for me) is the ability for each truck to deal with 100 plus lb loads in each direction. Does this seem viable ?

Also, a question on the pre-load method. It looks like the moveable bearing is held by a nut that is "partially tight", and then a nylon screw tightened to make the pre-load. Is there any spring to this preload - or is it all based on how tight that nylon screw is ?

BTW, I am not planning to use these with 80/20, at least at this point, so I appreciate them having extra attachment holes.

Thank you

Harry

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Harry,
The bearings themselves are nothing special -- just regular ABEC 1 skate bearings. I don't have quoted load ratings from the manufacturer, but equivalent bearings have dynamic load ratings of 611 lbs and static ratings of 255 lbs. The static rating is probably more appropriate, given the low speed the bearings will be running under, so conservatively I would say each bearing can probably withstand 150-200 lbs. You should have at least 2 bearings working in each direction, which puts each truck at around a 300-400 lb capacity. I haven't tested one of these to failure (they're darn tough!) so take this with a grain of salt.

As for the pre-load method, the nut is all the way tightened once you get it set. The nylon screw creates a small fulcrum that the bolt going through the bearings rotates against as you tighten it. You just make minor adjustments to the set screw and tighten the bolt until you get a decent pre-load, and then tighten the bolt all the way. Once the main bolt is tightened, the nylon screw is almost irrelevant.

Oh, and thanks to all for their feedback on the carriage design. I may offer a larger carriage later in the spring, for all of those asking. Likely width will be 8" between bearings.

Best regards,

Ahren

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Hi, Ahren -

I'll jump in and say YAY for this interesting carriage. I'm a bit of a noob in this arena, so I'm having a wee challenge getting my head around everything that goes into the build.

I've partway down the path with Kleinbauer's Seventh Sojurn, but have come to the conclusion it'll be nowhere stiff enough for what I need to do, edging on 1" thick HDPE and PP. So now I'm giving your system a good hard look, and from my noob viewpoint I like what I see.

I'm thinking of arranging mine as a 30" by 60" table, with movable X table and a static gantry for X and Y. Using your 80/20 + Acme screw drive system, is the intent for the steel rails to be flat on the table? Or do they need to be up on another section of 80/20 in order to clear the drive screw? (I'm -REALLY- wishing Kingjamez would post some photos, hint hint.)

From my ill-informed viewpoint, it would seem like one would need 12 carraiges: 4 flat for the X table, four for the Y axis, and four for wrapping the Z axis?

TIA for light from any direction, illuminating my ignorance. (They say that ignorance is curable, stupidity is less so.)

qinsdau

MacMarty     Join Date: Feb 2006
Location: USA
Posts: 17


{Light comes on...}

AH! Now for some happy reason, my browser shows me Ahren's 8th image in post #1 and single image in post #13, and the dawn breaks. I see (post #1 image 8) that the gantry wraps completely around the cutting surface, and it is presumably the leftmost horizontal member that attaches to a table, or at least holds the framework together. Sweet. Definitely going to go this route/er...

qinsdau

Hi MacMarty,

Thanks for your interest! The system is designed to be flexible depending on your needs, so there's no one "right" way to use it. The picture you are referring to is one method of using the carriages, and really is geared towards keeping the gantry from "tipping" (if you can visualize that), which is helpful for routers with fairly tall Z-axes.

Another possibility is to lay the rails horizontally, and "wrap" the whole table, using two blocks on each side. This is also feasible, and will do a better job of preventing racking. I'll try and post a picture of this later today to give you a better idea of how it would work. Regardless, 12 carriages is probably more than you would need for a 30" x 60" -- 8 is almost certainly sufficient. We can discuss the best way to make use of them.

Ahren