BuildingAfloat

[BikerAfloat]

Hi All,

I apologise if my thanks to Wilfy caused any offence, it was not my intention and this is one of the traps I was hoping to avoid falling into.

I have never liked text conversations, they are so easily misconstrued unless your writing is 100% all of the time. This fact has stopped me from posting forums intil now, where my need for advice outweighed my reluctance to join in.

I have not once doubted anyones ability or good intentions and unless I have inadvertantly missed someone, thanked you all for your input as it has been given.

As my Mental Health stands focusing on this project is a challenge in itself, putting my ideas forward for assement was a massive step for me. Severe depression stinks, please trust me when I say I am battling my irrational needs for avoiding people and my rational needs for moving this project forward. If I am overly defensive it is a function of where my head is at!

I hope it is clear from my background, I am (just about) capable of realising this machine is far from ideal and that I have chosen this path for very good reasons. As you know my 2nd post included mature design drawings for this machine. These are a result of many many hours research, hard work, careful thought and very seriously considered compromises in performance vs cost.

Can we please leave it as a "given" I accept that "more money = a better finished product" and keep the advice to that which will allow me to make this project come to fruition.

Sorry Jazz, but I am not "Blinded by my desire to build cheap". The budget is a cold hard reality.

With regard to the build log link Wilfy sent us. I was thinking that maybe I was going to be forced to abandon starting with a router by seeing something exciting like a video of one exploding, or maybe something slightly less dramatic but equally final!

Given the guys facilities and his obvious abilities and ambitions, I do not understand him starting with a Hose pipe & Jubilee Clip build at all! It came as no surprise to see him making upgrades with the finished tool and while I did not keep an eye on the time frame of this post, very soon afterwards abandoning the project. I can only assume he had a significant change in circumstance, as "one minute" he is explaining about his lack of funds and the next a big shipment of shiney things appear! The expense he has incurred from his router experience alone would pay a big chunk of my total budget!

Ok, Next post.... The Spindle

Cheers,
Geoff.

[JAZZCNC]

Sorry Jazz, but I am not "Blinded by my desire to build cheap". The budget is a cold hard reality.

Then the cold hard reality is that you can't afford to build this machine yet.! . . . For only a few dollars more the overall savings and performance will be considerable.!

Anyway I'll say no more other than to wish you well.!

Edit: PS: Personally You didn't offend me and don't take my comment wishing well has meaning I won't advise or offer help.!! Most certainly will and happy to do so.

[mocha]

A very interesting build log. Shed loads of work and the scary amount of 7-10 thousand euros went into getting to the current position!

Interesting too that the first design was 16th December 2009 and the mark 2 design 16th January 2010! (That cost him 1500 euros)

The hardest part of my build has been the waiting until I can afford to do it.

[BikerAfloat]

Then the cold hard reality is that you can't afford to build this machine yet.!

I know I can't, but I can't afford to not do it even more!

[audioandy]

Geoff

Pm sent

[wilfy]

Guys just to note, the main reason I linked that post was to prove 2 things, the first thing was to state the obvious that starting out with a router will only lead to water cooled spindle. The second thing is more subtle, look at how much money the guy wasted, if he had been a member of this forum and listened to the advice of guys here, he would have saved a lot of money

[Jonathan]

The second thing is more subtle, look at how much money the guy wasted, if he had been a member of this forum and listened to the advice of guys here, he would have saved a lot of money

I'm sure he's going to waste more yet. Prime example is the ballscrews he used. Only 5mm pitch over than length, plus he's used expensive ones not cheap ones from china so no excuse.

[Ricardoco]

I'm sure he's going to waste more yet. Prime example is the ballscrews he used. Only 5mm pitch over than length, plus he's used expensive ones not cheap ones from china so no excuse.

Hey Jonathan, the 5mm pitch over that length, is ithat likely to cause him problems, I only ask because im building a similar size steel machine at the moment
.

Rick

[Jonathan]

Hey Jonathan, the 5mm pitch over that length, is ithat likely to cause him problems, I only ask because im building a similar size steel machine

Not sure what length he's actually used, read about 5 pages and got bored, so I'll just comment in general...
As a rough guide any axis about 1m will benefit from using greater than 5mm pitch and over about 1.5m rotating nuts become more economical. The reason is by going to 10mm pitch the RPM of the screw is halved for a given feedrate, so if the limiting factor is the critical speed (speed at which the screw starts whipping) using a 10mm pitch screw will get twice the feedrate of if you had used 5mm of the same diameter.

He's been forced to used driven nuts no doubt due to the critical speed being too low over that length, however he's starting with the wrong ballscrew and has made the shafts on the mounts far larger than necessary which will add a huge amount of inertia to the system so I'm not surprised they've not made much difference.

The other problem is using 5mm pitch has forced him to use 25mm screws, which is a massive disadvantage since their inertia is 2.44 times greater than for instance using 20mm diameter. This will greatly reduce the possible acceleration.

I believe you're X-axis is 8'? If so with sufficiently powerful motors (Nema 34 ideally with mains drivers) you could use RM2510 ballscrews and get up to about 5m/min which is nothing special, but adequate. Alternatively RM2020, which is significantly more expensive, which will get up to about 8m/min and you would probably still need Nema 34 motors but may get away with cheaper drivers. Either of these configurations would excel with a driven nut and 3Nm Nema 24 motors.

[BikerAfloat]

Hi All,

I'm after drawings for both the 1.5 & 2.2 kW Chinese spindles if someone has them, could you post them for me please?

Cheers,

Geoff.