Reveiw: Stepmores SM-3040 CNC Router/Mill

[Nixie]

Thanks again Darren,
Im gonna look through my options, it seems that Stemores is one of the better chinese manufacturers, But the potential hastle might not be worth it. Maybe a kit/second hand is also good for me so I will spend my time.

http://www.ebay.co.uk/itm/1714913169...%3AMEBIDX%3AIT

This looks intersting, and in the EU!

Chris

[DarrenGrant]

Personally I wouldn't go for the eBay link.

To me it looks like a DIY effort made from box section extruded aluminium and will wobble more than Jessica rabbit. My guess is that the project started off as a little project with a dremil or similar engraving tool and having realised that would them nowhere they have tried to improve the machine by getting the most powerful spindle they could find only to find that the machine shook itself to bits so they have given up and decided to sell it all.

You will notice that the support rails (those two outer bars running down the middle) look thin and have no support. This means when the machine moves to the centre the the rails will flex causing the Z axis to change depending on the positioning.

If you look at the pictures in post #32 you will see that machine has rails that are supported, i.e they are mounted on the solid base with an upright section supporting round bar. This is the next best thing to having square rails as it reduces the deflection of the bar as the mechanism moves to the centre.

The way I see it you have three options, buy a very cheap machine and use it to experiment with machining forget about metal and use only soft materials like plastic and wood and put up with some of the problems and limitations that you will get along the way. Then if you find it is something you want to get more involved in put the machine on eBay and buy something better when you are ready.

If you are serious about making a go of it but have not got the budget to go for a real high end machine then try and get a half decent machine that is built on a sturdy cast base. This should be enough for a reasonable amount of hobby work to an acceptable standard.

Go in at the top and buy an all iron heavy duty milling machine that will do everything including steel and take out a mortgage for it.

[Nixie]

I think you are right, perhaps milling machinist wax and doing some lost wax tests might suffice me. I think il look at some of the chinese stuff on ebay that seems to ship from the UK or Germany, aswell as contact Stepmores directly.

Thanks again, I will consider your input!

Chris

[DarrenGrant]

One thing I would add is don't be worried about importing, I was somewhat hesitant the first time I imported something but now I do it all the time sometimes whole shipping container loads that I wonder why I ever worried about it.

The shipping agents take care of everything it is just a question of how VAT is paid. If you buy something made or sold in an EU country the price you pay will have the VAT included in the purchase price. So you are paying the VAT to the seller and they are paying the government. The only difference when importing is that no VAT is charged on the purchase price and when it lands in the country the shipping agent is legally obliged to charge you VAT on the value of the item and pass that to the government. As the shipping agents don't like being unpaid tax collectors for governments they charge you for the admin.

It is a simple process, usually someone from the local branch of the shipping company in your destination country calls you to say the parcel will land today and tell you how much you need to pay. You already know approximately what this amount will be anyway as you will need to factor it in as part of the cost of making the purchase. Simply pay the VAT immediately to avoid delays causing storage charges and make sure you can take delivery as soon as the agent is able to deliver it.

Just make sure it is a door-to-door delivery service, if it isn't just factor in an estimated €100 for the final leg of the delivery for a pallet.

[Nixie]

I don't mind the importing so much, Eric of Stepmores promises to get back to me tomorrow with prices + delivery for the 3040/6040 by sea and air, so I'l see what this comes to. In fact, here in Lux i've imported from the us before and since the item didn't disclose a value, the tax guy just emailed me asking for an amount!

Last random question of the night: different milling bits of different sizes ect will be better suited to certain passes or materials ect, how do you change 'bits' to perform each step? does the machine prompt one a general roughing stage is completed?

Thanks :)



Did you

[JAZZCNC]

Not commenting on the Stepmores machines as I have no experience of them but one thing I do have is experience of other chinese made machines. To me the problem comes from the very fact they have to compete on price with other Chinese manufactures. The net result is that they are built to price and the build quality suffers badly for this and the Stepmore machine IMO won't be any differant.!

They are mass produced so the attention to detail and quality control in areas that matter is just not there. The result being you have to sort it out your self.
This is ok with electronics as they can be replaced but when it comes to structure of the machine that's quite a differant story. Often they are so poorly made or weak that it's just easier to start again.!
Now often these machines are ok for cutting woods etc and get away with it because of the low accurecy and tolerences required but when it comes to aluminium they really struggle and show there poor quality.
Yes they do a stronger Cast machine but again these things will be made to the lowest possible price and when it comes to Cast iron the quality of the cast makes all the difference and IMO the Cast products I see coming out of china range from scrap to just about acceptable.!!. . . Now if you get a bad cast then your in world of even more pain as it's not easy to repair or true up.!

So what I'm saying is I wouldn't go rushing into buying any chinese machine until you can get a Solid report from someone using the machine for exactly the use you intend.
I can tell you from cutting huge amounts of aluminium that any machine mostly doing this needs to be very well made and I'm not just taking about strength. When it comes to harder materials like Ali then it very quickly shows any weak areas of a machine so build quality and attention to detail are just as important as the design strength and it's here IME that the chinese machines fail badly every time.

Regards multisided cutting then it's not just a simple case of remove and flip over if you need accurecy. For accurate turning you will need solid and accurate fixture jigs to help ensure accurate coordinates are re-established. It can be done but needs careful thought and planning.

Regards the electronics then that smoothie thing I wouldn't touch with a barge pole for creditable routing/milling machine. Ok for 3D printer etc but for routing/milling then it's just not upto the job and will give poor performance in comparison to good digital drives and PC with motion control card.
Also I don't see any way you can view the cutting path/G-code or control things like feed or spindle speed overide etc which is essential when milling.
Often you need to tweak the cutting conditions on the fly while working and this lack of interaction is unthinkable to anyone who's used to cutting materials like aluminium etc. This Ok with 3d printers or pick-place machines where you just hit start and walk away but milling then no way would I want this inflexabilty.!

Next about spindles is the 1.5Kw is just about enough for cutting aluminium but I'd recommend you go with the larger 2.2Kw for spare over head plus the larger ER20 collet system allows larger range of tooling.

[DarrenGrant]

Last random question of the night: different milling bits of different sizes ect will be better suited to certain passes or materials ect, how do you change 'bits' to perform each step? does the machine prompt one a general roughing stage is completed?

The CAM software will have profiles for each cutting tool and generate the appropriate Gcode for each pass. The machine will return to the home position for you to change the tool.