Marchant Dice router no thrust bearings?

[JAZZCNC]

It's quite smart, in that it does the job while reducing parts count and the amount of machining needed. Maybe not the ideal way to do it, but perfectly functionable.

Erm.!!. . . . I'd be more inclined to call it lazy arse bodging fueled by greed.!!

[gavztheouch]

john this machine has a working area of around 300mm by 500mm

[John S]

What size machine is this we are talking about ?

Press fit is fine provided it's pressed into something substantial, pressing a bearing into a length of licorice extrusion doesn't cut it with me.

Also stepper motors have one bearing pre loaded with a wavy washer to allow for expansion, any design that relies on this setup of deep grooved bearings and flexible thrust again isn't good design.

I can understand cutting corners to save money, many make that mistake but at these prices quoted they are not cutting corners to save money they are fleecing customers who believe all the bullshìt

[gavztheouch]

The press fit as bad as it may look does not concern me as much as the steppers holding ballscrew in place. The reason being is I can measure the shaft of the motor moving along the motors axis as the load on the ballscrew changes. Inside the motor is a spring washer, if you pickup a stepper and try pulling and pushing the shaft you will see it takes very little force to move it. Maybe your lathe has different types of steppers with thrust bearings built in, or maybe its designed to work within the range of the spring washer inside?

[JAZZCNC]

The press fit as bad as it may look does not concern me as much as the steppers holding ballscrew in place.

But it should do because it's only a matter of time before that's floating around more than screw and stepper do.!!

Think I'd be putting at least a Grub screw of 2 thru the profile has a minimum precaution.?

[John S]

An anteater is also functional but I wouldn't want to take one out on a pub crawl and bed it afterwards.

Mind you if they are serving Old Rosie scrumpy it might stand a good chance.

[martin54]

An anteater is also functional but I wouldn't want to take one out on a pub crawl and bed it afterwards.

Mind you if they are serving Old Rosie scrumpy it might stand a good chance.

Yes but it you met an anteater at the end of your pub crawl you might take the sexy young thing home to bed with you, then in the morning you have to gnaw your arm off to get away without waking it up !!!

[Web Goblin]

Looking at this it seems the machine isnt getting any better. Press fits are normally ok with certain materials but not pressing steel into aluminium especially when its not actually been machined to fit it in the first place and its supposed to be a permanent fit. The more I read this the more I'm glad I managed to send all my stuff back to them and get a refund although it was a struggle to get it.
I would go with Jazz recommendation and get a grub screw through the side of the alu to hold the nut in place. Remember you just want to dimple the casing of the nut for the grub screw to locate into and get some thread locker on it.

[martin54]

Can't see how a grub screw would help much in this case, no where to put it really, with the centre of the profile rail machined away the fit is only relying on 4 very small points of contact so you would need at least a grub screw either side but there is a big gap between the profile rail & the ballnut which would probably make the grubscrew ineffective.

[marchantdice]

Our designs have been through many years of development as our business has grown, we have automated many of our processes using our machines, to produce components for sale via eBay and worldofcnc. Any issue we would evaluate and redesign.

As the majority of our customers have business interests and therefore purchase a machine that is task related, we can adapt one of our many designs accordingly.

Press fit ballnut?
The ballnuts are not press fit….we use RSW ballnuts with an external V thread, the centre aluminium profile is bored and threaded to accept the RSW ballnut…
This range of machines are supplied to the world's leading probing manufacturers, in tests we achieve an accuracy of less than 0.010mm/300mm of the whole machine.

Later this year, all our Ballscrew driven machines will be fitted with thrust bearings this will align our product with our Class 5 preload Ballscrew driven machines and coincide with our 5 axis CNC being launched.

Finally
The floating end of a Ballscrew….
What happens if the Ballscrew spindle became warm? The spindle would need to expand along its length, hence the term floating.

If anyone would like to discuss in more detail please email [email protected] or call us 01805 628222 (phone line currently down however will be working again in the next day or so)

Many thanks
Kevin Marchant