Desktop size steel welded router 3 axis

Hi folks
I would like to show my design before fabrication in case you spot something not wright.
Machine itself is tiny - working area 320x320x100. Reason for that is that I am limited with my Mill.
I will not use epoxy for any leveling, base for linear rails will be machined.
My mill with 2.5" head can do pass 450mm long along longest travel.
Both base on bed will be done from one fix - that is why frame is 360mm wide excluding base for rails and rails itself.
Profiles 50x25x2.5. I had them very cheap considering UK prices for steel.
THK 15 rails with two blocks on each rails
RM1605 ballscrew on X and Y
RM1204 on Z
Nema 23 3.1Nm stepper
Belt drive HTD 5M 15T-20T - height of profile determine that, gear 30T is greater than 50mm and sticks out from bed
Spindle - Kress 1050
Design is nearly done - only home/limit switches are mising, cable carriers and few cosmetic item - brackets etc.
Any comments welcome

Cheers
Tom

Still trying to decide if this a moving gantry or Fixed gantry machine.? In both cases I'd change a couple of things on the main frame but will wait until you clear up which it is.!

On the Z axis I'd switch the rails around and have them on the front plate with bearing on rear plate. This will give you a variable length lever depending on extension compared to the fixed length one now at any extension.

I also wouldn't use a Kress router has it will be letting a nice stiff little machine down. Either 1.5 or 2.2Kw water cooled spindle is the right tool for this machine and won't cost much more than a Kress. It will last 5 times longer with much more power and lots quiter and I mean lots.!!

Hi Jazzcnc
It is movable gantry type as can be seen from every picture. Posted two version of gantry, but will use that with vertical orientated profiles - last 4 pictures.

Reason for using blocks on spindle plate is simple - less cutting chips on rails as they are higher - means Z plate.
I am not quite sure how you can have variable length lever? Unless distance on bearing blocks can be adjusted accordingly.

I have both 2.2Kw water cooled spindle which seems to be massive for this particular design. This will be engraver - mickey mouse machine, but precise enough for my needs. I might go for 1.2KW water cooled but is hard to find, 1.5KW no problem

Thanks for reply
Tom

Quote:

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Originally Posted by Tom J

Hi Jazzcnc
It is movable gantry type as can be seen from every picture. Posted two version of gantry, but will use that with vertical orientated profiles - last 4 pictures.

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The fact it doesn't have any legs or way for the gantry to clear the bench made me wonder if it was sat on the bench and the table moved.?

Quote:

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Originally Posted by Tom J

Reason for using blocks on spindle plate is simple - less cutting chips on rails as they are higher - means Z plate.
I am not quite sure how you can have variable length lever? Unless distance on bearing blocks can be adjusted accordingly.

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Your design is like a spring board with just one fixed length. The distance from the bearing block to the end of the plate is constantly that length no matter where it is on the rails. So if say the front plates deflects for argument sake 1mm it will do so at any extension along the rails.

If you swap them around then this spring board is variable depending on how extended the rails from the bearings. So at full extension you'll have 1mm deflection but if only extend down half way then deflection halfs.!! . . . . Does that make sense.?

Quote:

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Originally Posted by Tom J

I have both 2.2Kw water cooled spindle which seems to be massive for this particular design. This will be engraver - mickey mouse machine, but precise enough for my needs. I might go for 1.2KW water cooled but is hard to find, 1.5KW no problem

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1.2 or 1.5Kw hardly much in it both miles better than Kress.

For a machine this size I'd go for the fixed gantry option.

doing miter cuts on the gantry frame is going to be a mission, unless you got a very accurate machine to cut at 45 degrees ...

agree with the rails on the plate ...

my thoughts :D

Blackrat

Mitre cuts is no problem doesn't need to be so accurate - 89-91 deg will do as I leave the gap for welding bead.
Big problem is to keep control distortion - cooling/pulling after get cold. I bought HD clamp £45 each to keep the angle.
Heat treatment is important as well - annealing (releases tension in welding joints)

Sorry, should say that, legs are missing - got adjustable stands 40mm with M8 stud on each corner, high enough so gantry can slide without touching leg surface.
All will stand on table top or designated bench with enclosure - all depends the noise from spindle (Kress or 1.2-1.5Kw water)

I will swap over blocks with rails on Z - in spite of travel of Z being 75% of distance between blocks and spindle plate overhanging length is 3 times the thickness of that plate.
Thanks for pointing that - this will help me to reduce the Z plate overall length by Z travel which is 110mm:)

I will try both spindles, only problem is that water cooled is heavier what cause the CoG move forward and is not in middle of sliding blocks on the gantry like is now with Kress.

Quote:

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Originally Posted by Dragonfly

For a machine this size I'd go for the fixed gantry option.

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This will reduce already short travel of 320mm to 220mm. Was considering that as is much simpler build

Quote:

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Originally Posted by Blackrat

doing miter cuts on the gantry frame is going to be a mission, unless you got a very accurate machine to cut at 45 degrees ...

agree with the rails on the plate ...

my thoughts :D

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Here is how I did welding before I got those HD clamps - previous design - travel 900x400x150http://www.mycncuk.com/attachment.ph...id=16112&stc=1http://www.mycncuk.com/attachment.ph...id=16113&stc=1http://www.mycncuk.com/attachment.ph...id=16114&stc=1http://www.mycncuk.com/attachment.ph...id=16115&stc=1http://www.mycncuk.com/attachment.ph...id=16116&stc=1

Quote:

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Originally Posted by Tom J

I will try both spindles, only problem is that water cooled is heavier what cause the CoG move forward and is not in middle of sliding blocks on the gantry like is now with Kress.

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The slight change in CoG Won't make a Jot of difference to how the machine cuts but the WC spindle will make a big difference because it's far more ridged than the kress.!

Coming along nice looking forward to seeing it working. ..:applause:

Decided to use 1.5kw water cooled one after compared noise level with Kress - thanks Jazzcnc.
Here is the base frame - profile 50x25x2
http://www.mycncuk.com/attachment.ph...id=16223&stc=1
http://www.mycncuk.com/attachment.ph...id=16221&stc=1http://www.mycncuk.com/attachment.ph...id=16222&stc=1

looking good

thats quite a thin section ... 2mm , are you going to fill it ?

Its actually 2.5mm thick, still thin, table itself is rigid enough. Gantry will have 50x5 to joint both legs, so should be no flex. In addition I use 5mm base for mounting all gantry blocks THK15. Will upload some photos after welding. Gantry is complicated as has to be adjusted to match the distance between rails on the bad. I will machine/plane X bases before welding them to top part (X mounting profiles). After all will be final machine to keep straight angle between table and Y plane and between base for blocks and Y plane - will do pictures as is confusing enough:)

Attachment 16357Attachment 16358Attachment 16351Attachment 16352Attachment 16353

Base frame - surface planing (2.5" milling head - 63,5mm)
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Looking very nice Tom thanks for sharing, keep up the good work!

.Me

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Drilling and taping M3 holes for 15mm rails

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Drilling holes - M3x16mm socket bolts. They tall enough to use entire thread depth and goes inside 25mm wide profile. There will be only 4mm hole left outside to insert the allen key:)

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Errors are inevitable - forgot to cut the slot for the belt - grrr.
Had to grind and mill 20mm slot - wasted my precious time.

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Base for legs: 2mm profile (2.5 before planing) 5mm plate plus m8 nut, so total of 15mm thread depth for vibro-damping stands.

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Frame almost done.
Y motor bracket need to be welded in place
Detecting plate for Home and Limit - this will have slots, so can be adjusted accordingly - should be done before was welded - now need to buy angle drill. I should finish design to last bolt first before starting fabrication - always do the same mistake - just not patient enough.

Had to shortened the RM1605 ballscrew by 14mm.
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My tip for turning exact diameter is to leave 0.1mm and use sand paper on the end to get nice fit to bearings.

Looking good Tom keep it up can't wait to see it Rattle n Roll. .:onthego:

Planing base for ballscrew - base is 60x5 mild still (as we know is far from flat, unlike cold rolled - bright steel)
As always got some distortion after welding.

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Updated design - new colour, few minor changes in Z plate
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Welding the gantry - was waiting for another precision angle from Amazon - Happy with the result 0.5 mm off i checked against one side - spot on from other side. When all will be welded together (base for rails, ribs, etc) than will machine the base to have straight angle. I will leave the rails on the block, as this will be reference surface to the angle plate when fix to the mill - confusing now, but will show the picture soon.
Meantime - how I achieved accuracy before welding - spot how I use the straight angles (Gantry legs, than against table and Base for X axle) All surfaces has been planed each time I weld something - this was my error, should weld everything first than machine to avoid distortion.
Attachment 16603Attachment 16604Attachment 16605

Tom I spotted 2x Fixed Prox switches on the Gantry. Do it other way around and use just one traveling switch with Fixed Targets, less switches less wiring same result.

Looking Good. . . :thumsup:

Jazz, other side is reserved for cable carrier, so switch(es) has to be near the motor. Did you noticed that bed frame has slightly more room opposite the motor (just enough for radius/bend of my cable carrier
Attachment 16619
I always was using two sensors - Limit and Home with Mach3 - connected similar to that:
Attachment 16620
can you explain how to use one switch (NC)? Wiring diagram would be ideal:)
I know how to daisychained together - but this is limit side, how to wire them to use Home?
Each black signal wire to input X,Y and Z?

Quote:

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Originally Posted by Tom J

can you explain how to use one switch (NC)? Wiring diagram would be ideal:)
I know how to daisychained together - but this is limit side, how to wire them to use Home?
Each black signal wire to input X,Y and Z?

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Ok well maybe we are at odd's here.? It looked like 2 switches for Limits and I was meaning just have one switch that traveled.

But call it option #1 if your wanting to Share one Switch for Limits and Home then you can do that but with NC switches each Axis will need a Input. So 3x switches and 3 x Inputs.
Option #2 You can use NO switches then you can have all Limits and Homes on 1 input and wire them in parallel. So 3 x switches and 1x input.

What you lose with the later is the Safety of NC switch but you have more inputs to play with if limited.

Other option #3 uses 2 inputs and 2 types of switch. NC wired in series for limits on one input. NO wired in parallel for Homes on other input.
This gives Safest option because Limits can be set to be monitored while Homing.

#1 Shared Home and Limit on 1 Input with NC Switch is easy. Just wire each Axis switch to a Input. Then in Mach3 ports&pins Inputs set the limits and home input for that Axis to same Pin number. Set Both to go Active Low. Then go into General config and Turnoff(uncheck) HomeSW safety and thats it.
Now when Mach homes it ignores Limits.

#2 Setup for NO is just the same but All Axis share same pin number for Limits and Home. Then set to go Active High. Rest is just the same.

#3 Should be obvious really.!! Limits in Input 1 set active Low. Homes in Input 2 set Active High. Then turn ON Home SW Safety.

Can do a diagram if you let me know which you prefer.

Ok. Jazz
I know what you mean by using one sensor:
Attachment 16622
So far I use 2 sensors, one is limit +, other is Home and limit- all in one, connected like that:
Attachment 16621
I think this is your option#3 " uses 2 inputs and 2 types of switch. NC wired in series for limits on one input. NO wired in parallel for Homes on other input"
I was wonder how you get away with having only one sensor, must use soft limits in Mach for safety. I've seen 3 sensors solution: limit+ limit- and home in one axis, but I think is not needed.
Correct me pls. if we I am wrong.

Quote:

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Originally Posted by Tom J

I think this is your option#3 " uses 2 inputs and 2 types of switch. NC wired in series for limits on one input. NO wired in parallel for Homes on other input"

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Well kind of but your way is a bit mixed up because the (+) Limit is NC but the (-) limit along with Home are NO so doesn't have the safety on the (-) limit side if wire breaks.!

If you used all limits with NC wired in series on one input and homes with NO wired in parallel then you'll be safer.

Quote:

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Originally Posted by Tom J

I was wonder how you get away with having only one sensor, must use soft limits in Mach for safety. I've seen 3 sensors solution: limit+ limit- and home in one axis, but I think is not needed.
Correct me pls. if we I am wrong.

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No Softlimits are optional and not required you still have Limit switch safety.
Maybe what your not realising is that Mach only Watches Limit Inputs when working and ONLY watches Home Inputs When Homing and Ignores Limits while doing so. It also by default Moves one axis at a time so only looking for one Input to change state. If all set to same Pin # then any will do for mach.

This is why you can share one input for ALL axis homes & limits provided they use NO switches. Mach doesn't know or care which Switch triggered it just responds to the trip.
So if cutting it see's this trip and knows it's a Limit so E-stops.
If it's homing then it knows the Axis it's moving and when see's Home Input change state it sets the Home position for that Axis. Then moves onto next Axis and does the same. It doesn't care which switch tripped so in practice you can actually set say the X axis Home by triggering the Z or Y axis switch.!

The ONLY time it won't work is if you have changed the HOMING sequence so 2 or more Axis home at same time. In this case you need separate Home inputs for each axis.

Quote:

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Originally Posted by JAZZCNC

This is why you can share one input for ALL axis homes & limits provided they use NO switches. Mach doesn't know or care which Switch triggered it just responds to the trip.

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Got it, but not quite to the end. How than having NO switch will provide safety on the limit side if wire breaks?

Quote:

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Originally Posted by Tom J

Got it, but not quite to the end. How than having NO switch will provide safety on the limit side if wire breaks?

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You can't have continuity safety with NO switches which I did say this in other post.

Summarize, if I use TB6550 or similar BOB which has only 5 inputs: 1-X, 2-Y,3-Z,4-Limit/E-stop,5-GND than 3 switches used as home/limits detect the ground signal (NC-active low). Mach knows that this axis is in home position.
How should I wire if I use the same switch as Limit? Can not wire the same switch to pin 4 (limit/E-stop)
Using pin 4 will collide with homing (all switches will be in parallel - remaining two will have NC contact therefore no homing)
Jazz, could you please send the wiring - loosing plot.

Quote:

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Originally Posted by Tom J

Summarize, if I use TB6550 or similar BOB which has only 5 inputs: 1-X, 2-Y,3-Z,4-Limit/E-stop,5-GND than 3 switches used as home/limits detect the ground signal (NC-active low). Mach knows that this axis is in home position.
How should I wire if I use the same switch as Limit? Can not wire the same switch to pin 4 (limit/E-stop)
Using pin 4 will collide with homing (all switches will be in parallel - remaining two will have NC contact therefore no homing)
Jazz, could you please send the wiring - loosing plot.

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You got me bambozzled now and Not quite sure what your asking for but here's quick diagram showing 2 options. Option #2 is probably your best option.


Attachment 16623

Hi Jazz,

Here's a question for you - If you are using one switch for home and limit does Mach ignore the limit function while homing?

That leads on to another - If you have slaved motors on an axis does mach wind both motors until a home trips and then keeps winding the untripped screw until the other trips, thus squaring the gantry and then do the backing off the home switch to complete the homing and aligning process ? In which case I presume you would need to have separate inputs for each side of the machine.

I see the point of having 2 targets and one switch, I only recently realised that Mach took into account which axis was travelling and the direction of travel when homing. It makes sense of commoning inputs.

Cheers,

Rob

Quote:

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Originally Posted by cropwell

Here's a question for you - If you are using one switch for home and limit does Mach ignore the limit function while homing?

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Yes if you turn off HomeSW Safety in General Config.

Quote:

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Originally Posted by cropwell

That leads on to another - If you have slaved motors on an axis does mach wind both motors until a home trips and then keeps winding the untripped screw until the other trips, thus squaring the gantry and then do the backing off the home switch to complete the homing and aligning process ? In which case I presume you would need to have separate inputs for each side of the machine.

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When using slaved motors Mach De-couples each motor turning back into two separate axis while homing happens which means the motors work independantly but move together in sync towards the home switches. When first switch is tripped that axis motor stops and backs off the switch while the other keeps going then does the same.
In practise provided your Gantry is square and the switches positioned correctly this appears to happen has one action. If your gantry is really out of square then you can position the switches to force it square.
When Both Motors have homed then Mach Couples the Axis again back into one slaved axis.

This does mean that the Slaved Motor needs it's own Home switch on a Separate Input.

Machining base for X -rails

Attachment 16667Attachment 16668Attachment 16669
Had to bend frame in the places to be perfectly straight - left those Irwin for overnight to see if 0.8 mm sag is dissapering
Attachment 16670

I managed to get 0.4mm off the sag, better than nothing, will use the technique like those who do not machine the profile or base. Simply will use filler gauge - industrial sheet in the middle to compensate - do not want to have tension on the bearing block while is sliding from middle towards end.
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After welding so many frames came up with solution - there is not substitute for slow welding with min heat. Mean the welding bed have to be short and fully cooled before we weld again near by.
I put all theory to the bin with current setting to metal thickness and speed wire on MIG.
I use Clarke MIG TEC230 Turbo which is capable to weld up to 7 mm on max setting (switch pos.6)
My profile is 2-2.5mm with plates 5mm and I use pos.3 - current/power and wire speed min as possible to stop splatter but fast enough to get good constant sound (not like a shooting gun)

Here is where design doesn't match reality - X drive motor bracket doesn't make the belt tight, I made all the parts in Solid Works myself - using vernier rather than dimensions data and with belt 295mm long error was like 5mm.
No big deal - 1hr+ lost for fabrication.
Attachment 16734
Here is the gantry. X motor bracket I will made longer and than will cut slots for adjustments. Lesson learnt
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