[louieatienza]

Louie, I get a definite chuckle when you say that something that is designed and could work must then be made to prove it........try telling that to Michael Angelo when he drew up plans for.......a helicopter........couldn't possibly work Michael, too many moving parts and the friction against the air would set it on fire.....LOL.....Sikorsky didn't believe it for a minute.
Ian.

First of all, it was DaVinci. Second, his design, as drawn would not work. Third, I find it hilarious that you would have the gall and feeling of self importance to give yourself parity with DaVinci. Lastly, Sikorsky actually built something, not sat there and pondered if it would.l

[handlewanker]

Oh Yeah, Leo Da Vinci.....mixed up the middle aged middle agers.....LOL.......one did his thing with a paint brush, the other with a bit of charcoal......both were ahead of their time a bit.......but I don't think Leo would have stood a chance today against some of the wiz kids fresh out of college, none of his designs were ever taken seriously, especially the one with the cannons in a round turret.....the fore runner of the tank.

I wonder what Leo would have said if you told him one of his designs could not work.....apparently he was quite a fire eater and didn't take too kindly to criticism.

I bet he would not have gone out and made the thing just to prove you wrong.

The important thing with inventions is you need to establish the principle first.....the design is what makes it work.......Sikorsky took the design of Leo's and tidied it up a bit, but it obeyed the principle of a helix rotating at speed against the air creating a lifting force......a simple propeller on a stick when rotated rapidly between the palms of your hands will rise to at least 10 metres......at least the one I gave my grand children does.

The principle I invoke is that when you squeeze a ball between a rock and a hard face that moves so does the ball, so in the design I propose, the screw being the rock and the roller being the hard face.....the ball will rotate in space between them when the screw rotates, but you already know that as it happens in a similar manner in the ball screw......... and you didn't comment on the friction present in the ball screw as the balls bump against each other as they move along.
Ian.

[yulolaf]

How much friction do you think is involved by the balls touching each other in a ballnut? I say touching because there is little to no linear pressure on the balls in the track, they are not forced against one another just following each other as they roll along one in front of the other like good little soldiers. In the event that they do touch, how much surface area of the spherical ball is making contact with the other spherical balls surface? BTW it's Michelangelo not Michael Angelo you mistakenly alluded to.

[louieatienza]

How much friction do you think is involved by the balls touching each other in a ballnut? I say touching because there is little to no linear pressure on the balls in the track, they are not forced against one another just following each other as they roll along one in front of the other like good little soldiers. In the event that they do touch, how much surface area of the spherical ball is making contact with the other spherical balls surface? BTW it's Michelangelo not Michael Angelo you mistakenly alluded to.

Michael Angelo was the shred guitarist for Nitro IIRC...

[daniellyall]

children go to you quite corners

my idea I watched a youtube vid by Dan Gelbart in it he talked about how bearings are meant to be used so with my idea if I add a second bearing behind the one that would go into the grove it would last a lot longer than one bearing i will try a cheap thrust bearing that contacts on the outside of the bearing so it can transmit the load into the shaft.

for doing a jig to drill the holes so they are concentric I have drawn it up in fusion360 I can cut it on a 4th axis as its 7 degress one side -7 the other side.

all I have to do is line up the first 7 degree hole turn it 90 degrees to the next hole drill, then pull it out and stick it into the the -7 side locate with the first hole and drill its only movements on the x axis the mill will have to do so quite easy to do, the shafts for the bearings are easy to turn on the lathe I will do it so I can lock the bearings to the shafts

[louieatienza]

children go to you quite corners

my idea I watched a youtube vid by Dan Gelbart in it he talked about how bearings are meant to be used so with my idea if I add a second bearing behind the one that would go into the grove it would last a lot longer than one bearing i will try a cheap thrust bearing that contacts on the outside of the bearing so it can transmit the load into the shaft.

for doing a jig to drill the holes so they are concentric I have drawn it up in fusion360 I can cut it on a 4th axis as its 7 degress one side -7 the other side.

all I have to do is line up the first 7 degree hole turn it 90 degrees to the next hole drill, then pull it out and stick it into the the -7 side locate with the first hole and drill its only movements on the x axis the mill will have to do so quite easy to do, the shafts for the bearings are easy to turn on the lathe I will do it so I can lock the bearings to the shafts

Daniel, I think with your design both sides should be the same exact part just flipped over. Also if you needed +7 and -7 you could just spin the jig 180 degrees.

[daniellyall]

yep i realized i can just flip it over to do the other holes after I posted the pick what I will do is put a pin in the middle of it so I just need to locate the pin and move from there it makes it easier doing it that way, as it will be something like 25 mm X, 25 mm Y then the the other holes are just 25 mm one way then - 25 the other way.

or I could do it all on the router that way it will be a bit more accurate.

its defiantly a go but the how long it will last is the big question so I will build a rig to set it up on and just run it back and forward for a few hours the ballscrew I am using is a junker so it does not matter what but gets stuffed.

its going to take some time to get done I have other jobs that need to get done, finish the table for my wheel char, make a bottle cutter, test the router on Mach4 I have run out of old XP computers to use on it, the one on it now is dying, school holidays as well fun, fun

[handlewanker]

Hi, the good thing about this forum is that you get to bounce ideas off anyone who cares to respond, either with positive vibes or just hypothesising.

I hope to make the design I proposed, but when is another question......meanwhile the idea will fester in my mind until it gets to no 1 priority and I get out to the garage and make it.....always been that way.....too many irons etc.

I've just bought Turbocad deluxe V21 for $100 on EBAY, as I'm going to need a serious CAD program to produce files that the computer can react to........ it's another step on the way to becoming proficient CNC wise even if the learning curve is another apprenticeship all over again.

I didn't know they had heavy metal rock bands in the middle ages with Michael Angelo as the lead geetar plucker.....LOL.......heavy metal with cat gut strings....LOL.
Ian.

[daniellyall]

yer that was a bit silly the point being everything that someone came up with back then the person was class as a weirdo but most of what those blocks came up with is around in some shape or form today you still get the same thing now look what the big oil out fits do to people who come up with things that can make them lose money.

I tried Turbo cad once did not like it at all but you will need something for your machines.

that person I said about he has one of those machines you have the dowlling jig what ever its called any way he said its more accurate than a cnc machine because of its size he said if something is a 100% heaver than the heaviest thing that goes on it, it will always be very accurate as long as it started that way

[RCaffin]

I have an earlier version of TC. It seems to be quite good for architectural uses, but doing general 3D work required infinite shifting of the reference planes. Drove me mad! And not quite parametric either.
Dunno about V21.

Cheers
Roger

[daniellyall]

it took me 2 years to get my head around doing 3D work I am ok with it now. I find it that I need to find a vid or what ever that turns the light bulb on its how I learn. using planes are a pain but cant get away from them

[handlewanker]

Well I'm used to doing 2D CAD with CADKEY light, but it won't run on my desktop XP computer or Win 7, so as I don't want to work with the lap top where it does actually run, the screen being so small, I decided to go up market, learn the ropes and prepare for the big event when I get to work with CNC in the truest sense of the word.

I've already got Turbocad V16, but it's only for Win XP or Vista, and a lot of the functions just don't work with Win 7 which made the learning curve convoluted when things failed to work.

Dan, I wish you the best of both Worlds with your design.... having reservations as to the practicality of it etc, but you never can tell, making it often leads onto other ideas that get generated from a hands on approach.

I have a tendency to keep researching something even though I think it's at the ultimate design stage......think twice cut once etc......can get boring as nothing gets done, but I prefer it that way than a scrap box full of hopefuls.

Leonado in his time worked with the materials and knowledge that was current and had the ability to see further than the average.....if we have "bettered" his achievements it's only because we were riding on the backs of giants whereas he was going it alone.
Ian.

[daniellyall]

the material I am using is from the junk box`s so theirs no wast only time, the reason you think will be a problem I agree with you that's way I am using stuff from the junk box`s if running it for a few hours and if everything is ok I will add weight to it to it fall`s.

if it does fail after I get it up to 20 kg I will stop with that idea then try having the bearings straight if that fail at 20 kg that will be a end to that idea, if it fails around 50 kg + it may work ok but I will run it for hours at a time so it`s going to be a hard test.

if it does not last for hours at a time it will be a fail.

there is quite a few hours in lathe work only an hour or so on the router that's the good thing about being retired

[handlewanker]

Hi.....I like that idea, my junk box also has a variety of oddments that get re-cycled from time to time.

A 50 kg test as a push pull loading would definitely prove the ability of just a couple of bearings in the screw grooves to do the trick.

Applying the loading will be the tricky part as it has to be alternately in both directions to give the backlash properties a trial, but I expect your agile brain will think of something.

Looking at the way you want to mount the bearings and it occurred to me that you could consider mounting them on a plate instead of a block......stack a couple of plate assemblies together with spacers for the pitch and you'll increase the life expectancy of the set-up.

If you did make them as two lots of bearings, you'd also have to have another two lots for the reverse motion or else the single one would wear out first.

I don't think you want to get the bearing flanges running too tight on the bottom of the screw thread as the load is applied totally in an axial direction against the sides of the screw thread flanks, while the contact on the bottom of the screw thread is just centralises it.

I would'nt expect the bearings to have a long life as the load is axial and they are designed to be radially loaded, but they could have a useful life if carefully made and adjusted.

Finding bearings with flanges wide enough to be reground will be the hard part.
Ian.