Wood Router

[Buba b]

Hi all
Ive just started a router build to see how much cash i can waste in the process . So I'm a CNC machinist by trade and converted my BF25 some time ago to CNC with Zap SY60STH88-3008B steppers and Gecko G540. I make airguns for fun and now want a router to make gun stocks from my 3D designs.
So Ive designed a router to fit the only space left in my garage , this is as big as i can fit ! , which has a cutting area of 830x530x90mm.

The base of the router is made out of 45x90mm extrusion with Y axis being 45x45mm bolted to the back of 20mm tool plate. Ive already machined the 20mm alloy tool plate for the sides of the gantry and the back plate for the Y axis which is wasted away to remove weight.
I'm fitting 20mm Linear guides to all axis which are being bashed and dropped to precision in the post on there way from China. The ballscrews are 1605 which have been sitting around for to long so will be put to use. The ballscrews will be fitted with Angular contact bearings on the driving end and a free floating bearing at the other.

The plan is to order the 60BYGH401-03 steppers from CNC4you which IL then fit to my mill and swap the Zap steppers over to the router which then have to be wired up with LONG cables ( about 20m needed ) to the PC on the other side of the garage. This is so i can run it from my PC , Mach 3 and G540 to keep the price down.


So this is where i need abit of help as i have little experience of machining wood. I'm running X and Y axis (maybe Z ) with pulleys and belts as i need to keep the machine within the foot print. Ive got to keep the 1605 screws and wonder which pulley setup would give me best performance for 3D milling , so i would appreciate some ideas






So some pretty pics ...as we all like them ... don't we ! and IL be back with some pics one Ive fixed the £7000 kitchen the F*** wit builder we employed completely cocked up on as the GF has to be sorted first ....... damit .
L8r

[JAZZCNC]

So this is where i need abit of help as i have little experience of machining wood. I'm running X and Y axis (maybe Z ) with pulleys and belts as i need to keep the machine within the foot print. Ive got to keep the 1605 screws and wonder which pulley setup would give me best performance for 3D milling , so i would appreciate some ideas

Well I run 2005 using 1:2 on X & Y direct drive 1204 on Z axis and I'm happy with it in all cutting conditions.
I run 3Nm 34's with 76V on 80V 203v's maxing out around 11M/min but I don't run it at these speeds, I keep it to 7M/min for stabilty against missed steps etc plus it allows me to have higher Accelleration which you need for 3Dwork and deliberatly do it for this reason.
You have 23's on smaller dia screws so should get higher speeds.? . . BUT . . personally I think you'll be slightly restricted by the G540 and it's 50V max, which realisticly means 45-6V.!
To get best from the 3Nm 3008B they work much better at 65-70V and seen has it's mainly wood use then speed helps here.
Yes you can gear it for speed but higher the ratio less the torque and that gantry will be heavy needing good amount of torque to control the high inertia from Accelleration and De-accellerations required for 3D machining so bigger drives would certainly help and be worth the extra outlay IMO.

Ratio 1:2 is where I would start. I would definately use belts on Z axis even if you don't use a ratio, it's more flexable and helps eliminate resonance.

Edit: If you run Mach3 then here's what I do regards tuning and belt drive.?
I setup different tuning profiles for different types of work, IE 3D work I tune the motors for lower velocity but higher Accelleration then save it has 3D which I then load when doing that kind of job.
I basicly have 8 profiles.!! 4 set for 1:2 ratio 4 identical 1:1 Ratios. These tuning profiles are basicly Aluminium, Wood, 3D and 1 imperial setp same has aluminium for when using imperial G-code.
Initially it takes a bit of time setting up but wounce done thats it and it's very quick switching from one type of work to another with optimum tuning setup.

[jcb121]

Make sure the gantry doesn't hit the Y Axsi motor :)

if you fitted the motor the other way you'd get an extra few cm's of cutting area :)

[JAZZCNC]

Just spotted something with Z axis.?

I you take the motor off the front plate and position it on the Y axis then connect to Z screw with belts you get far better Accelleration from the Z axis. You also don't need long screw and you get the other bennafits of belts I mentioned earlier.

My setup used the way you have it drawn but I now build all machines using the system described above and can tell 100% it's a much better setup.

Edit: Like these pics. Obviously done to suit your machine with round rail, which actually makes it easier.!

[Buba b]

Trust me :) the X axis dosnt hit the motor ( always thought the longest axis was the X ? .... theres a fight waiting to happen LoL ) the belts long enough to run under the gantry.
I ve seen your Z axis Jazz and did draw it up like yours but left it as it was made out of more parts and the pulleys made the router plate hang further from the gantry. I think il have to give in and sort the belt drive on the Z axis , i did think i was heading this way , with the 1:2 ratio.

Im pretty much fixed with the G540 at the moment which drives my mill at 150imp on rapids but as you say the gantry is carrying alot more weight which has to be controled when accellerating and de-accellerating while cutting.
So the next question is would you remove more material by wasting away or would you keep the mass of the side plates ... both has benifits , but i guess a lighter ganrty is the way to go
L8r

[Jonathan]

So the next question is would you remove more material by wasting away or would you keep the mass of the side plates ... both has benifits , but i guess a lighter ganrty is the way to go
L8r

Incorrect priorities.
A heavy gantry (and machine in general) is good since you want to have as much strength as possible. Making cutouts, including the ones you have already drawn, just wastes strength and money. Rigidity is far more important than feedrate. If you're reducing the mass to improve the feedrate you're going about it the wrong way - you should select the motors and drivers to get the feedrate you require which, as Jazz said, means buying 70-80V drivers such as the M752. Bear in mind the stepper motor output torque at high speed is roughly proportional to the applied voltage, so going from 45V to 75V is a 67% gain in torque where it matters.

[JAZZCNC]

Incorrect priorities.
A heavy gantry (and machine in general) is good since you want to have as much strength as possible. Making cutouts, including the ones you have already drawn, just wastes strength and money. Rigidity is far more important than feedrate. If you're reducing the mass to improve the feedrate you're going about it the wrong way - you should select the motors and drivers to get the feedrate you require which, as Jazz said, means buying 70-80V drivers such as the M752. Bear in mind the stepper motor output torque at high speed is roughly proportional to the applied voltage, so going from 45V to 75V is a 67% gain in torque where it matters.

Yep has Jonathan knows I agree with him 100% . . .Don't cut mass for speed. I'd do without the speed before ridgity every time.! To be honest Ridgity can make up for the lack of high feed by allowing deeper DOC.

Sell The G540 get the bigger drives you won't regret it and you'll be amazed what them motors can do on 70V.!!

I'm an X Axis is long Axis believer has well and anyone who says other wise is a numbnut . .Lol

[Buba b]

So ive been looking at drive options and im thinking about going with digital drivers over the analogue , im thinking digital drivers would be best suited to run my mill and router as there using both ends of the feed rate spectrum and therefore the torque of the steppers. Having seen a video of the noise reduction of the digital over the analogue drives at slow speed i think its the way to go as im too use to the smooth operation of the Gecko G540.
I was looking at Zaps 2M880N digital drives with the 68v power supply which i was about to buy but the dam voucher code didnt work or the other option is the Kelinginc Digital stepper KL-8070D which would work out the same as Zap with the duty added. Im still trying to find some reviews of digital drives which there dosnt seam to be alot of on the net !.
The only other thing ive got to look for would be the breakout board , which at the moment i know nothing about ?.
Well the sale of the GF didnt go through but shes now in her near finshed kitchen so i can get on with this soon ...... until something else stops me !
L8r all

[Buba b]

Well the rush is on ! my job is going tits up at the speed of light with no new orders coming through the door so i could be joining all the drugged up job dodgers at the job center soon. My lying , cheating , spineless boss didnt pay out on the bounus so im taking my lead from our great goverment and its briliant fiscal policy.

So ive now put in place austerity measures to make sure the router plan balances out. (where have i heard that from !!!! )
I only need a piece of alloy for the Z axis to mount on to finish the router which just leaves the electrics , axis bearings and pulleys to finish. As a result of the austerity plan the digital drivers are out as there twice the price of the PM752,s and in comes a new round of budget tightning to drive me back into prosperity and growth. (where have i heard that from !!!! damit !)

Test fitted the router together and found im 1mm out ! with the gantry being over to one side by 1mm , it dosnt matter but its just annoying and probably the result of me rushing.l



I tracked down the PM752,s on Evilbay for £53 each at cnc-parts4u ( if i want to buy from the UK ).

I had been looking for some info on making a power supply as the £108 price tag of Zaps made me choke abit and low and behold the through the mist came a thread http://www.mycncuk.com/forums/showth...-or-sps705-psu with all the answers from the bickering twins Johnathan and Jazzcnc.
So once ive tracked down a supplier who has the transformer in stock and free post il get building.

Three Zap SY60STH86-3008BF steppers at £90

That leaves just the breakout board which ive still got to check on but a cheap as chips one for £20
Grand total of £329 or just get a cnc-parts4u kit for £364

Im going to start making a power supply and case to fit the drives , hopefully something will come along and i can get my digital drives at some point but time will tell.
L8r all

[Jonathan]

Three Zap SY60STH86-3008BF steppers at £90

That leaves just the breakout board which ive still got to check on but a cheap as chips one for £20

Three 3Nm steppers here for £82.19.

What features do you need from the breakout board? Since you're now on a tight budget, if you're not bothered about controlling the spindle and stuff from the computer you don't need a breakout board. The PM752 (or any good cheaper drivers on eBay) are already optically isolated, so the breakout board does not add any more protection for the outputs. It just makes it slightly easier to wire up. Just thought since you're happy to make the PSU you might be happy to consider making a simple breakout board...