Strike CNC (My first CNC router)

[Jonathan]

i tested the higher torque version and found that they performed worse than the 3nm version.

Interesting, that's precisely the information I was after here:

http://www.mycncuk.com/forums/showth...ers-or-drivers

Please could you elaborate on what tests you performed?

[Gary]

I ran the SY60STH88 and the SY60STH100 on the same drivers at the same voltage and the larger motor could only get to about 60% of the speed as the 88mm long motor.
I ran them on the Leadshine M542 at 40V and the Leadshine M880 at 70V.
While the longer motor would give more torque at the lower speeds, this soon changed after hitting a few hundred RPM.
Also the specification in the link you posted looks all wrong.
Look at the inductance and the current and compare it to the 88mm long motor.
The Inductance is lower than the 88mm long motor but also the current is lower.
You would expect the inductance to be higher if the current is lower.
I suspect the inductance is actually a lot higher than is shown in the datasheet, and if this is true you need a much higher voltage driver to get a good performance from the motor.
even at 70V, the 88mm long motor performed better.


There is only so much power you can get from a motor with such a small frame, and if you want more power you have no choice but to go to a larger frame motor like a nema 34, but at the same time also use much higher voltage.

Interesting, that's precisely the information I was after here:

http://www.mycncuk.com/forums/showth...ers-or-drivers

Please could you elaborate on what tests you performed?

[luke11cnc]

To tell you the truth I think they made a mistake on the enclosure as I know that the extrusion was over £400.00 for my frame work alone


James

[Shinobiwan]

Have any of you guys tried building this vacuum hold down kit:

http://www.m-powertools.com/products...h/big-mach.htm

The price seems good compared to the alternatives and because it works off a regular hoover you don't need venturi or vacuum pump.

[Shinobiwan]

I've looked back through some old emails and can confirm the PSU is 60v. No other details on the make or model of the drivers though.

[Shinobiwan]

Weird, I thought I'd posted this earlier but must have miss-clicked.

Should problems arise. Can you tell me if its possible to swap the nema24 to a more suitable motor? And if so what would you recommend.

[Strike CNC]

£600 is very cheap for the enclosure like as been said but to be honest for 7K I'd want far more for my money than this machine offers. I'm self employed so know exactly how hard times are at the moment but to be honest at 7K there making VERY good profit.!!

Hi All Just wanted to say hi & introduce ourselves we are a CNC router Engraver & laser manufacturer based in the south west of the UK just outside Gloucester our premises are on the vantage point business park our address can be found on google maps.I thought i would post & answer a few questions some have had We have x8 CNC routers in our range from our standard models to our PRO range boasting full hiwin rails on all axis we also offer a range of upgrades for the standard models as well as a bespoke service for custom models , this particular CNC router was originally a 1200x1200 for this client he then chose to up grade to the enclosure as well as the hiwin profile rails on the 1 axis, we did recommend the hiwin rails on all axis & pointed out they are far superior on all axis as opposed to the standard supported bearings in a ideal world we would only recommend hiwin rails on all axis but this is ultimately the customers decision weather to go for the upgrade or not & we have to supply the customer with what they want that said as long as the Z axis rails are not long unsupported shaft for the Z axis is acceptable many of our competitors use unsupported rails on the X & Y which to us is not acceptable.The dual axis is run from 6A drives with a high powered PSU we use dual power supplies on our CNC routers ,by using the 6A drives on the dual axis this allows us to use higher powered PSUs that cannot be used with the standard.4.2A drives The motors are nema 23 4NM on the X & Y axis & we found these (once powered with a high voltage power supply) provide more than enough torque to move the gantry at 5mpm , we have tested many motors & drivers over the years from not only the UK suppliers but also a few of the US suppliers & found our current system the most efficient , by moving to a nema 34 motors you start to have problems with slow acceleration & deceleration due to the high inductance & high inertia not to mention the vibration due to refinance in the 34s this coupled with the even higher voltage requirement deemed them not strictly necessary, we found that our current 4NM motors (& there are a few different manufacturers of these) are some of the highest powered we have come across & we have tested a lot of motors & drives across multiple platforms before coming across our current system but of course we can add nema 34s if that's what our customer prefer. This particular machines gantry is our standard range & has heavy gauge 30x180 gantry back support, the upright gantry is heavy gauge 40 series we only use heavy gauge extrusion on all our products including all bases & mini models this gives a more rigid & robust design, the Z axis back plate as well as the front Z plate bearing our logo is solid plate.i do hear your criticism about the supports but once you see the machines in person you get to see just how rigid they are we have been told pictures do not give our machines any justice Also the cost of the enclosure was 600.00 this is VERY cheap as we use lexan polycarb (some of the highest quality in the business) this plastic will not break infact you can tie it in a knot bend it even stamp on it & it will not break the cost also includes the larger base for the CNC as the standard machine base was 1400x1400 with the enclosure the base had to be 1850x1750 so included all the materials to make the larger base so this was a very cheap upgrade for enclosure, yes you can make one cheaper out of wood if you go down the DIY route but we are a business & a wooden enclosure may not fit in with the overall look of the machine. This client payed £4460.00 for this model & we thought it was a very good price We do also sell a pro version of the model for 7K but this contains full hiwin 20 rails ,T Nut bed & a gecko control system also for 7K we have a 4 axis 8x4" CNC router with full Hiwin upgrade 8" 4th axis with tailstock the base has 80x80 legs & 80 series base , we use larger components on this model so it does weigh quit a fair bit which is testament to its rigidity it is a solid beast of a machine we are currently manufacturing x2 of the larger 4 axis 8x4 CNC routers for another client & will post pictures if any one is interested in seeing them over the next few weeks Any constructive criticism is welcomeAll the best Strike CNC

[Strike CNC]

Hi all
there must be some typos wrong the motors are nema 23 4NM
this machine has dual 20mm ball screws the motors are more than powerful to power these personally i would not move up the the 34s as there are inherent resonance issues & problems with acceleration & deceleration as well as the other problems stated in previous post that's not putting the 34s down they are good motors but not needed on this machine our competitors use only 3nm & lower in some cases our are 4NM motors powered & high voltage
RE the bed once the bed is ready for skimming the bed is 34mm thick there will be no discernible flex issues.

[Shinobiwan]

this particular CNC router was originally a 1200x1200 for this client he then chose to up grade to the enclosure as well as the hiwin profile rails on the 1 axis, we did recommend the hiwin rails on all axis & pointed out they are far superior on all axis as opposed to the standard supported bearings in a ideal world we would only recommend hiwin rails on all axis but this is ultimately the customers decision weather to go for the upgrade or not & we have to supply the customer with what they want.

I would also like to add that you did upgrade the base axis to hiwin rails at cost(£240) simply because I couldn't afford it otherwise and you wanted these rails in place as the machine size pretty much needed them. A real shame I couldn't stretch my budget a little further to get the other 2 axis done as well. Hat's off to you for doing this. I've since looked at the prices of hiwin rails and bearings blocks and they're not cheap.

that said as long as the Z axis rails are not long unsupported shaft for the Z axis is acceptable many of our competitors use unsupported rails on the X & Y which to us is not acceptable.

I think it'll be fine. I have a Bosch GCM10SD Mitre Saw that slides on about 35cm of unsupported rails. Its extremely accurate and the only thing that moves during a cut is blade deflection. With the cnc, as long as I keep to sensible speeds and materials that the machine was designed for I can't see any problems.

This particular machines gantry is our standard range & has heavy gauge 30x180 gantry back support, the upright gantry is heavy gauge 40 series we only use heavy gauge extrusion on all our products including all bases & mini models this gives a more rigid & robust design, the Z axis back plate as well as the front Z plate bearing our logo is solid plate.i do hear your criticism about the supports but once you see the machines in person you get to see just how rigid they are we have been told pictures do not give our machines any justice

Would have been great if I could have moved up to something like a couple of 80x80mm beams for the gantry and 40x200 for the uprights but as always my budget was the limiting factor. Its good to know you used the heavy gauge of extrusion rather than the light or even the eco version that have progressively more and more voids in the cross section.

Again I've got a great base and enclosure so DIY'ing a machine in the future and just bolting it down on the base is a possibility. Something like the Fine Line Automation FLA300 kit or cncrouterparts CRP4848 for example. This isn't something I'd do for at least a year or two however but the option is there if I ever felt the need for higher feedrates or harder materials.

Also the cost of the enclosure was 600.00 this is VERY cheap as we use lexan polycarb (some of the highest quality in the business) this plastic will not break infact you can tie it in a knot bend it even stamp on it & it will not break the cost also includes the larger base for the CNC as the standard machine base was 1400x1400 with the enclosure the base had to be 1850x1750 so included all the materials to make the larger base so this was a very cheap upgrade for enclosure, yes you can make one cheaper out of wood if you go down the DIY route but we are a business & a wooden enclosure may not fit in with the overall look of the machine. This client payed £4460.00 for this model & we thought it was a very good price

I can't argue with the price. You gave a few bits for free or at cost. And I'm pretty sure you lost money on the enclosure if you factor the labour. Price is always subjective but its what your happy to pay that matters and at £4.5k I'm happy. I looked around at the alternatives and the only way you can beat that is by DIY'ing and that's assuming your competent enough to pull it off to the same standard (I'm not!) and you also don't mind spending a good number of hours building (I don't have the time either).

Anyway the machine will arrive within the next few hours and I'll post some photo's.

[Shinobiwan]

I thought you guys might be interested to see what the machine will be cutting so have attached a couple of renders to show.