Marchant Dice router no thrust bearings?

[gavztheouch]

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.

In this situation you can see how thrust bearings may be of less importance, but these kits are being sold as cnc routers with the ability to cut material. Try yanking on the stepper shaft and feel the washer inside, unless I have misunderstood again this is the only part resisting axial motion.

[gavztheouch]

This is a quick mock up to mount my thrust bearings. This will fix in place the normally floating end, this means the spring in the motor will soak up the expansion of the screw and the motor side will effectively become the floating end, if it need more I can use a oldham coupler.

Il need another 4 holes that will be tapped to fix the bearing to the mount which will be made of aluminium.

[Shinobiwan]

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

I'm sorry Kevin but you will win no supporters on here for your method of construction.

I bought a copy cat of one your machines that was actually better in some cases than yours but still inadequate. In this case at least it correctly captured the ballnut but still had similar issues with the ballscrew mounting that you have engineered into your designs.

Its sloppy, cheap and has serious question marks for the long term accuracy of the machine. You're basically knocking these out as simply as humanly possible to maximise profit. It wouldn't be so bad if you were charging a suitable amount but 4 series extrusions with the most basic and barebones mechanical make up possible? Not acceptable in my opinion.

You talk about selling to businesses? Your going to cost them money in the long run because they'll have to fix or replace what you should have done right to start with.

Please go back, redesign and come with something fit for purpose and stop inflating the capabilities of your machines. They're very very lightweight machines capable of only light cuts in soft materials. And your accuracy figures mean little. Is that the accuracy of a part, if so what material? Or is it more likely the accuracy of the machine with no load ie. cutting air?

[magicniner]

Just reading through older stuff and saw this, I always thought their stuff looked particularly shonky for the price on eBay but it looks like they manage under-engineering on a scale that would put professional bodgers everywhere to shame!
Boring and threading the "Liquorice Extrusions" was the high point of the BS excuse for me!
Anyone seen any of their more recent contraptions?

[cropwell]

I had the problem of the floating acme screw and I put in a small thrust bearing from ARC Euro held against the motor mount extrusion by a collar with a grub screw to remove the end float on the screw. I did similar on the X axis, but the Z axis was a slightly different bodge as I needed to prevent it pushing upwards, so I put in a couple of thrust bearings to space it out (1 bearing and washers would have done !) and used the coupler to act as the retaining collar.


The machine is now (just) adequate for hobby use.

But I have to give a big thank you to Marchant Dice for opening my eyes to CNC. I now have the great desire to make a decent machine.
This quote from MD amused me 'in tests we achieve an accuracy of less than 0.010mm/300mm of the whole machine' I would have expected better than rather than less than, but Hey Ho maybe ?
Cheers,

Rob

BTW Nick, I have not seen any of their recent excrences - I believe their machines should be labelled 'For amusement only', they certainly make me smile
AND I like your use of the word 'contraption' - very apposite.

[magicniner]

I believe their machines should be labelled 'For amusement only'

And perhaps "A Learning and Growing Experience"? :D

[John S]

I believe their machines should be labelled 'For amusement only', they certainly make me smile
AND I like your use of the word 'contraption' - very apposite.

Now that was funny