After reading ynneb's post about his $600s for 12 Wisecarver bearings, i had an idea. this is it:

The text is to small to read. basically this idea uses regualr roller bearings and a very simple machined part to achieve the capability of the grossly prices wisecarver system. Anyone know why this idea hasnt been explored before? Alot of the people out here have lathes.... this would be a very easy product to make $$$ off of also.. sell it on ebay as "bishop wisecarver alternative"

1 48" rail & 2 shuttles can be built for $50 or less. probably less.

another picture:

One last iamge - this one only uses 1 bearing, and looks most like the wisecarver. either a good pressfit, or somesort of ocking rings would be required with this design. probably both. Then. im no machinist. Any ideas why this isnt done? Why are wisecarvers so expensive?

Hey Vac, funny you should post about this. Tonight I was showing a friend the bearings and he said, why didnt I just bolt two bearings together with a washer seperating them. Now I feel sick.

I dont know how the bearings would wear with the force on the side pushing them apart though.

Yes I did think of your idea too, but dont have a lathe to make the wheels. I could have almost bought a lathe at those costs though, and I would have got to keep the lathe. You see this is why the forum is so good, others can learn from others mistakes.

Oh and just remember you are quoting Aussie dollars and not US dollars. US dollars would be about $500 for the same thing. Just been pedantic to make myself not feel so bad. Truthfully I am still happy I didnt pay much more for proper linear bearings though.

EDIT: Your design is better than the bearings I bought, not only because it is cheaper but because the load is spread over two bearings and not one.

well. to really not feel bad, consider this: there is no way $8 of rollerblade bearings can beat precision made linear components. They may come close for many practical applications. But you have some parts designed for what you want them for: providing movement for a production quality machine. i hope your machine build lives upto the components. they look like they need a very sturdy rail to ride on.

I am about to investigate if their is a potential product idea here. i could sell these things to hobbiests for some reasonable cost. they can make the rail from cheap steel.... hopefully...

dont worry ynneb, you get what you pay for many times - especially with high quality motion components.

Benny, did you buy those direct? From Bishop Wisecarvers online order pages, I can get #2 size wheels for $21.88 each, and 10ft lengths of track for $75 each. 12 wheels would be $262.56. And these can carry loads over 500lb, so there is no need to get the larger, more expensive ones. Just curious why you had to pay so much. Could be the Australia thing, I guess.

While vacpress design look nice and makes it feel like it would be easy there are lots of dificulties on actualy making them, the precision is on of them. Also the small problem of a late, archiving exact same dimentions on all linear bearings, hadren the steel. It is way cheaper to buy a precision machined linear guides/bearings than making it oneself (speaking for regular people).

Beny you cannot use radial bearings with axial loads, they will wear way too fast. I didnt knew that bearings are so darn complex until I read a document describing a spingle design, so many variables to consider, the axial and radial loads, speeds, lubrication, temperature.

I too have had a similar idea, and wished somebody would start offereing the parts. I don't think BWC's rail is unreasonable, it may even be a bargain.

Phil

I kind of agree with Konstantin. Sometimes, its the details that kill what seems like an otherwise good idea :)

Running the V wheels on the sharp or unmachined corners of standard flat stock is not going to make a good raceway, because there would be an initial state of high wear on both the soft wheel and on the raceway itself. So right away, we get into having to chamfer both sides of the flat bar, and keep every chamfering cut parallel. This task requires a lot of care and attention to achieve.

Then, eccentric studbolts would be required in both wheels on one side, so that the gap can be properly adjusted. While doing this is not difficult, it is not just a plain old bolt.

As Konstantin said, machining your own V wheel flange is conceivable, it is still expensive and troublesome to do properly. Hardening and then subsequent hard-turning of the wheel would be required. The tolerance for error on the wheel is zero runout. The tolerance for lateral displacement of the V in the wheel flange is also zero, or this will cause tilting of the truck. Just try actually defining the position of a V groove in a cylindrical surface sometime. Its one thing on paper, but a whole different thing on the lathe.

so evne the guys who make the little motors couldnt use this idea? boohoo. what about cnc lathe on Stainless, would that lower the price?

as for loads.. are the wisecarvers designed to take the load on their axle like that?

what about how wisecarvers are used on the shopbot? no special rail there...

is hardening absolutely needed? can some other combonation of materials be used.. like delrin bearing flanges? or copper? or something? annodized aluminum?

The B-W rollers I listed the price above are rated over 500lbs. for both axial and radial loads. And the rail is hardened.

I just looked at the shopbot site but couldn't really find any info there.

Stainless is not inherently hard at all. So it is not a "natural" choice for a rail, either. :(

Anodized aluminum is only hard for .0002" depth, and this is easily scratched because there is nothing hard underneath, backing up the anodized surface.

Using an easily available piece of C1018 cold drawn square stock still makes the best choice for a quick track for a V groove wheel. Its not hard, but its not expensive, and it is accurate, if you are selective about the piece you purchase, to try to make sure it is straight. The larger the cross section, the more likely it will arrive in a straight condition. However, this requires a bit more imagination to devise support blocks for holding square stock in the "diamond configuration". If it is a small machine, likely the bar can simply be mounted and held by a axial bolthole drilled down each end of the rail.

http://www.hepco.co.uk/hep02d_v.htm ;)

--Sven

How about CRS Angle iron ? or any hard metal sold as "90 deg.angle" placed with "pointy" side up?


^^^^^^^^^^^

Why use a "V" shape, why not go with a "U" shape?

This thread is DIY CNC Wood Routers, what keeps bothering me is I would tend to think that most people in this thread ar hobbiests. And if they are hobbiests, I guess I wonder if there is really enough router usage to worry too much about wear life. Sure if a router is going to be run a regualar work week, then bearings and rails shouldn't be scrimped on. But I imagine a machine that might run hundreds of hours a year instead of thousands, would be just fine on CRS bearings turned as above for light structual duty.

pminmo- yes. thats what i was thinking. im sure Rolleblae bearings dont have the same ability to take side loads as they do axial loads? i think i typed that right... still...

no bother - i have a nice chunk of brass that i am going to turn into 4 berings flanges and give it a shot. i will buy 2 .75x.75" square tubes and run the V groove on their sharp edge. either than, or angle iron if its got a sharp enough edge. if this works, im sure some company could churn them out on a cnc lathe.... any cnc lathers here should be interested?

how many operations and tools should such a thing take on a cnc lathe? manually, i am imagining drilling, reaming, boring, and then turning the V groove. 2 to 4 tooolchanges??

Vac I dare say that while you will probably get by with the diy bearings for yourself I would imagine that B/W would probably frown on the manufacture and sale of said bearings because in all probability the v-groove thingy is what is probably patented.

Everyone will not be as excited as we are about open source goodies!:(

Mike

the V-groove thingy is so damn basic.. its a pulley. if thats patented. shoot me. :)

They'll probably do more than just shoot you. ?:D

im sure Rolleblade bearings dont have the same ability to take side loads as they do axial loads?

I think you meant radial? I think I saw someone mention that standard bearings (rollerblade and similar) can handle about half the axial (side) load as there rated radial load.

Or V-Rollers on round stock.

Chris

I think you meant radial? I think I saw someone mention that standard bearings (rollerblade and similar) can handle about half the axial (side) load as there rated radial load.

ger21- oh. very usefull information. i wonder if the DIY V rail would work better if 1 roller was on a cam with a very strong spring pulling it to the rail. sorta complicates the thing....

cbcn- hmm. what would be easier to machine?

Look here: Majosoft (http://members.lycos.nl/majopi/index.html)
Under 'Engraving' 'Selfmade Parts' 'Leading 2'

Chris

Originally posted by vacpress
cbcn- hmm. what would be easier to machine?

You could do either on V Blocks.

Chris

OOOOH i love that 4 axis router! so nice looking

Originally posted by ger21
They'll probably do more than just shoot you. ?:D



I think you meant radial? I think I saw someone mention that standard bearings (rollerblade and similar) can handle about half the axial (side) load as there rated radial load.

My kid has played Travel Roller hockey for 9 years. Those bearings take some major abuse, including a significant side load. There are many degress of the quality bearings, and they do last depending on mfg and abec rating. I wouldn't flinch a bit on using two ABEC 5 Roller Hockey bearings in a turned V groove housing on a good axle such as the first drawing for a hobby machine.

Phil

Yes, for the light duty you guys are talking about, I wouldn't worry about the axial thrust load on plain ball bearings. After all, your machines are of insignificant weight.

Don't forget that standard metric ball bearings are quite inexpensive and yet solidly built little units.

I used to play rollerblade hockey also. i know these things can take hundreds of pounds of abuse in any direction. making the V-groove flange now sounds very difficult, from the scepticism on the board... as for the patents issue. the "Dual-V" has 2 Vs. i have seen this bearing design alot. it must be a hundred years old.. if they havet patents. it wouldnt cover the flange in my first post.

anyone know of any accuratelt machined rails avaialble for some other use that might work good for these guys? something made for like... scraping.. or just some sort of well cut metal source?

tappered roller bearings handle both axial and radial thrust very well If you anticipate heavy loads. Cam followers or yokes could also be used in a similar fashion that vacpress has drawn. I think I would be a little worried using abec bearings where significant angular contact was invovled.
More pics please.........

more pics of what?

LOL! I think Trubleshtr means we just want more pics of whatever you are doin'
Better yet...set up a webcam so we can all look over your shoulder...
Much of my learning has been from seeing another "do it"....that is when the "teacher" didn't mind eyes peering from behind..;)

i hate those teachers who dont really want anyone to learn their techniques. you run into that all the time in design school.. luckily, the most talented teachers will almost always be the best at helping students also...

i am still thinking about this linear guide idea. i may use it on my upcomming machine ive got planned. way cheaper and less stressfull than waiting for decent ebay deals to come around..

anyone know if emachineshop would be able to make these pieces economically?

i think upto $8 per bearing would be OK

about those linear guides....
I think they could be reduced in quality to handle less loads if there were another two bearings riding directly on the surface of the rail taking the brunt of the load.....now the groved bearings would act more as only guides to reduce side slop and "jumping" as the load rides along. Does this hold any water? Since this will be for a paint machine, there would be no "build-up" of debris on the rail..and if so maybe a "cow-catcher" that cleans the bearing travel surface as it works?

bloy- i have toomany plans!

i was refering to a router table im working on. for the painter, i will just use rollerblade bearings on CRS square tube.. either .5 or .75"

for my router table, i will probably end up with ebay linear components, but if my first attempt at makin the v-groove idea on my lathe pans out...

Hey Vac, I must admit I really like the original idea of bearings attached to angle iron. I think this idea could be improved on though. If instead of angle iron, a cast aulminium holder would be better. If it was a triangular prism it would make mounting it to the fixture easier and more accurate. The load bearings would have a fixed position, but 2 more adjustable bearings would then be mounted at 4 o'clock and 8 0'clock. This would hold the bearing in place. Having the two under bearings would alow for the rail to be suported at any point.

If you designed this and spat out the G code then maybe someone here with foundry capacities could make them and sell them on here. Or You could do it yourself.

If You came up with a design and then cast it, I am sure it would be a very popular purchase item.

Maybe the design would just be a profile that could be extruded in long lengths that the individula could cut to lenth upon need.

this summer im gonna build my propane forge.. i doubt it will be profitable though - ive heard they are very expensive to run.

Vac, tell the truth....... this summer you wont get that furnace happening, you spend too much time doing wonderful drawings here.

ennn... drawings are fast & mostly for preperation. i like to make stuff too

What program are you using to do your drawings with?

solidworks 03 and photoshop sometimes and illustrator sometimes.

I vote vacpress as the hottest 3d-model pics for 2004. those cnc gantry pics were amazing.

Originally posted by svenakela
http://www.hepco.co.uk/hep02d_v.htm ;)

--Sven

can anyone give an idea of what the cost is for these -- any web sites?

owen

http://www.bwc.com/html/dualvee.html

They have online ordering with prices.

They will be too large. Look at the specs for 75mm dia wheels: 10400N. Comparable to THK HSR20. And that's on hardened+ground rails that we cannot make ourselves.

But please look at this: http://www.skc-technik.de/bilder/antifriction_coatings.pdf
If I could pour my own machine slides in Aluminum, then use SKC 60 or SKC 62 that according to independent tests when used against CI have stick slip of 1/5 of CI against CI. And static friction is lower than moving friction. (The opposite of stick slip.) Then we could buy the THK or comparable rails only, it's the blocks that makes them expensive. Then we make our machine parts with integrated blocks for stiffness, drawn by Vacpress and poured in aluminum by diffferent people on different continents (or yourself). Look in the .PDF for a full description on how to use it.

This seems very compatible with our need for a simple procedure, and is used in industry for heavy duty machining equipment. I haven't checked the price yet, so that may be where my nose hits the grinding wheel. But it surely leave much freedom for design, as it is only 2-4mm thick. The rigidity of course have to be in the casting. It also looks perfect for refurbishing worn machine parts. The slide will have to be ground, but then the mating slide fit and friction properties will better than new.

They will be too large. Look at the specs for 75mm dia wheels: 10400N. Comparable to THK HSR20. And that's on hardened+ground rails that we cannot make ourselves.

I don't think anyone here is looking for a design to carry that much load. The #2 size is more than sufficient for what most people here need, and although the price of the wheels can add up, the track is reasonably priced; about ~$0.62 per inch vs thk style rails, at about ~$6-$8 per inch. Roughly 10x the cost for the rails alone. (I got these prices from McMaster-Carr)

i really think someone with a decent smal cnc lathe should try this idea... i bet it would work just great.. especially if you bought real BWC rail. .62/in is even cheaper than igus... with the 2 bearing design, i bet these things can take ANY loads we would put on them...

Yeah, if I had a metal lathe, I'd definately try to make the rollers, and buy the rail. At $20+ each, they add up fast.

i have a lathe, just no experience turning parts.. i havent had it long. i use it alot to make couplers and to true parts, etc. nothing much. i bout the lathe used with lots of tooling.

anyone got any specific advice on what setups to use to make a vflange style bearing like in my first images?

id image some kind of carbide facing cutter to machine the outside diameter true? then using a v-cutter carbide tool to make the V?

ive got lots of tools i dont know the names of -different lathe cutters.

Teilhardo...reading one of the posts from the first page. A V shape can be less tolerent to fit the same shape. In other words...it could roll on angle iron, strap steel, or round stock. I am going to turn down some old skatboard wheels, and see it that works. You can usually get skateboards cheap at garage sales, thrift stores, etc.

Originally posted by ESjaavik

But please look at this: http://www.skc-technik.de/bilder/antifriction_coatings.pdf


This appears to be similar to Moglice. You can make your own using epoxy, moly disulfide and teflon powder. Most any type of ground shafting will work for the rails - thomson, drill rod, hydraulic, etc. The latter two have the advantage of being easily drilled.

Doug

I am currently using UHMW with 1 1/2" cold rolled polished with 600grit wet/dry sand paper (wet) and it seems to be holding up really well. I cut the blocks on a high quality table saw and drilled them with an 1 1/2" forstner bit on my drill press. Then drilled (6) 3/8" half moon reliefs about the perimitter and use silicone spray as a lubricant. Got to say it has been working great with no signs of wear at all. 4' of cold rolled cost me $20 .00 . Originally this was just a temporary setup and I was going to replace them with some wheels that I turned out of aluminum with abec 7 bearing inserts but it has worked so well that I never had to change them. It's been over 2 years. I use my router to carve signs and craft projects for our country gift shop.

the partialy finished aluminum wheels that are finished now but no recent photo

Finished wheels.

TPworks,
Great looking wheel/bearing assembly. I assume you did them on a lathe, but what kind of cutter? BTW went to college with a guy from Seymour, Bob (Bud) Shippe.

Phil

I have the speedway 7x12 mini-lathe and the HF Mini-mill and I had to create a tool that pivots to cut them.

I must be extra dense tonight
"Then drilled 6 3/8" half moon reliefs about the perimitter and use silicone spray as a lubricant. "
I'm not picturing this- these are perpendicular to the axis of the cold rolled?
drilled yet "half moon"? help...

Drilled parallel to the shaft to reduce friction by reducing the bearing surface, and then spray the shaft and let dry , slicker than grease. I moved the carriage effortlessly with one finger before the screw was in place.

Hope this link works I couldn't get it to take an attachment so I tried a hyperlink.

http://a5.cpimg.com/image/E3/59/32405475-9f3d-028001E0-.jpg

Ger21
Caqn you Please give the url for Bishop Wisecarvers online site.

Thanks

http://www.bwc.com/html/index.cfm

How would this type of hole be drilled using forstner bits. Would you drill the small holes before you drilled to large? It would seem that if you drilled the smaller holes last the bit would want to walk out of position.

Originally posted by tpworks
Hope this link works I couldn't get it to take an attachment so I tried a hyperlink.

http://a5.cpimg.com/image/E3/59/32405475-9f3d-028001E0-.jpg

Small holes first.

Originally posted by ger21
http://www.bwc.com/html/index.cfm

Those Bishop Wisecarver bearings are really sweet. Just this weekend I was down at the local PetSmart and wanted to make up a few ID tags for my puppies. Of course the engraver was a cnc machine. (Very slick by the way...) However, I noticed that it was using Wisecarvers for it's X and Y axis'.

tpworks -

What is the thickness of the UHMW you used for those bearings?

well, did I have that all wrong, in the picture "they" looked like slots, so the only half round would have been (my mental image ) half round keyways ...which would have required some interesting tools...
(blush)

Hope this link works I couldn't get it to take an attachment so I tried ...

Originally posted by mvaughn
tpworks -

What is the thickness of the UHMW you used for those bearings?

mvaughn,
They are 1 1/2" deep (bearing surface) 2 1/2" wide and 3" tall.
I drilled the smaller ones after as it being an after thought, again using a forstner bit in a drill press and a cross slide vice, Isuppose an end mill might work as well.
Tom

COULD YOU SHOW US A PIC OF YOUR ROUTER?

Maybe not the prettiest thing but functional. I incorporated alot of different designs in this,JK's aluminum window channel for y and z axis. I'm working on an all metal one 72 x 48 footprint looking at about 60 x 36 cutting area.

Did you polish the cold rolled yourself? I went today and picked up 24 ft of 3/4 ground and polished cold rolled for $47.00.

yes, it took several hours, not all at once though. took a year to get it fully functional working on it when the urge struck me.

metalexpress.net sells 1045 hard chromed at very cheap prices. For inexpensive shafting it looks pretty hard to beat.

So on my next machine I want to use solid shafting but I need to be able to drill and tap end holes and/or bolt holes for supports .
What kind of steel should I use? It needs to be a compromise between hardness and machinability with normal tooling.

Chris

Chagrin,
Have any idea on the accuracy of the 1045 hard chromed?

Phil

Unfortunately they don't list any specs.

http://www.metalexpress.net/cgi-bin/index.pl?mod=catalog&ac=acDisCatList&material=Carbon%20Steel%20Cold%20Roll

i belive that cold rolled steel is generaly acurate to within 1 thou

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