JBEC router system UNDER THE BONNET

[StoneyCNC]

Oh dear . . Oh dear . . .Oh dear what do I Say.??????

Oh boy :) Can of worms!!!

Jazz - haha - how naive of me to seek approval so early in the debate

So in short - from your message one can summarise the following

• The linear slides on our machine are "Micky mouse"
• The gantry is thin and has poof stiffness - made from chewing gum

In light of the above points - "Very nicely done thou and very professional and you seem a very straight guy" would not suggest what the above points do in that "actually the machine is poor and its not good value for money - i.e we are ripping people off"...

I fully appreciate that this is a public forum and that by posting here it is totally up to everyone to say it how they see it - to be honest that is why I'm here... And I like the pointed discussion! However heated

JBEC and us could not offer the machine platform at the prices we do were it not for the volume of work going on with the German supplier of our sub assemblies. This is the only way we can keep costs down and to offer the machines at the prices we do. If someone could produce a platform in volume, supply and support it, offer it at lower prices and atill have a business model at the end of the day then hats off to them!

Your comments JAZZ (which are welcomed and respected in light of what I've seen on this forum and your portfolio of CNC work which is impressive) would therefore imply that 30 years of experience in the automotive industry through JBEC and 20 years of experience in machine building from our German colleagues have come together to produce a micky mouse machine that - "looks professional" but really is not up to much.

It would also go against what our customers in Ireland have been saying - in particular a customer who has been machining bog oak all day every day for well over a year now. I can see can I get details on the exact machine conditions that have been in service that long? Your comments related to the machine requiring lots of TLC to keep her in check are not echoed by our growing customer base here in IRL.

We are not trying to provide a machine like a Hurco/Bridgeport/Metal milling machine that will eat any DOC in Ali Steel and stainless for breakfast lunch and dinner. I would plea here for some relativity. This is a CNC router platform up to soft metals. Your reference to 12mm diam 3-4mm DOC in Ali is well IMO not a good parameter set for a machine in this Market sector? If someone came to me with those specs - I'd tell them to go look at a bridgeport/hurco/semco etc etc - We would not support a router operating in those conditions!

Relative to the competition in this price range and performance envelope, and relative to our experience with the competition we would strongly disagree with the sentiments here... I'm here to bash competitors as everyone is entitled to compete in a growing market - but I would plea for some standardised relativity - which as per below Jonathan has kindly provided.

Also - on the cost front - The total cost of owner ship has to be considered. Locally supported with follow up help. You are not just buying a hair-dryer

And 100% if you put our system up against a metal milling machine then yes 100% the slides are not fit for purpose and the gantry is made of chewing gum! Also - anyone who is clued in and has access to fabrication facilities could indeed put together a platform with more performance for less... not accounting for the time, design and nouse to do it. Volume production, installation and follow up support to run a business are, as I'm sure you know, a different story.

If someone could build, supply and support a machine to the same quality level as use then I want to see it!

And yes again - profiled rails TKH, HIWIN etc are phenomenal pieces of hardware! And when I first saw that particular slide design concept I was also initially sceptical. However - the Germans know what they are at and I have been proved wrong!

No. If you clamp an indicator to the bed and touch it against the spindle or Z-axis and try what you suggest you'll see plenty of movement on the dial. I agree you probably wont see the deflection before pulling the machine off the table, but that's besides the point since the tolerances required for a good CNC router are well below the distances anyone can see. Can you see 0.1mm deflection?

You'd have some eye if you could see 0.1mm deflection - either that or you were a dial gauge in a former life
I have worked on some other low cost routers and a manual nudge of the axis is a quick fire way to sus out if there is any potential stiffness in there at all.

If I was buying a CNC router I'd take a dial indicator, a force meter (e.g. cheap hanging scales would do) and a piece of string with me, then use them to do, at the very least, the following tests:

This is more like it - quantitative tests.

In full agreement with you there - this is a much better and standardised method for machine analysis. But in reality how many customers who ended up buying something like the Strike CNC would do this? Or even know how to do this?

Fancy throwing some figures out there? typical machining lets say a hardwood at moderate feeds? Lets throw some Newton values out there.......

Set the dial indicator up to measure the deflection in each axis and apply a suitable force, divide the two readings to find the stiffness of each axis and compare that to typical values or other machines.

100% with you - cross platform reference as such with a standard test would educate the buyer no end.

Use the indicator to check the backlash of each axis. For any machine that uses ballscrews and is set up correctly, the backlash should be less than about 0.05mm in X and Y. If Z uses rails with low preload, the backlash should be close to zero as gravity pre-loads the axis. If it isn't then that implies the rails and ballscrew could be misaligned.

Will gather media of other axes also.

Again set the indicator parallel to each axis, and give each axis/slide/ballscrew a sharp tap. The indicator needle will oscillate and should return to zero (+-backlash). If it doesn't return to zero then something's loose or the ballscrews aren't mounted properly. If the indicator oscillates for a long time before returning, then I'd be concerned that the machine will resonate when cutting.

Again fully agree - long oscillations would indicate poor stiffness and low damping and would cause havoc at RPM's and feed within the cutting range. And being able to knock the gantry off its current displacement location would indicate an issue with the axis alignment.

With the indicator in the spindle, put a large mass on the machine bed (e.g. sit on it), and see how much the bed deflects.

haha - yes I'll find someone with heavy bones :)

Mount indicator in spindle on L-shaped bar and use it to check the spindle is in tram. This is less significant than the other points, since you should be able to correct it without too much difficulty, however it's a good sign of how carefully the machine has been built

This is also a good point - and part of the reason the machine is designed with the bed the way it is - and also why the biggest size is the size it is.

Feel free to post a video showing these tests, I expect you've already checked these things so it shouldn't be a problem?

I don't have exact figures or media on me but these are indeed tests we looked at - I shall look to get some focused media around the points raised.


Perhaps other players could look to do the same?

The questions raised here are exactly what we all need potential CNC customers to be considering and asking - and in general this doesn't happen. Hence I guess how Strike could make sales. It is hard as I was once a noob to CNC myself and I didn't ask these questions when I bought my machine...

Thanks for the feedback guys - all welcomed!