-
El Beast - Initial design phase, comments and critique welcomed!
Hello chaps,
I'm designing myself what I consider (or at least hope!) to be my ideal man cave based machine, the plan is to buy the components and materials over the next couple of months and then start machining parts for it.
I need to do a fair amount of work in aluminium, carbon fibre, FR4, and plastics so that is what the machine is being built around. If it can look nice with some fancy anodising then that's a bonus! I currently have an X6-2200L which I have upgraded with various bits and bobs, a pokeys57cnc ethernet controller (I fancied using mach4 so needed to upgrade), leadshine closed loop easy servo nema 23's, and some glass scales for calibrating.
While it generally does a pretty good job after some tweaking, there are a few design flaws though that niggle me, the bearing arrangement for ball screws is utter crap and the screws themselves have pretty mediocre accuracy. The Y-axis is also lacking in rigidity imo and there are a few other things that could stand to be improved such as the ability to tram the spindle.
Therefore, I had a choice - either I spend some fairly decent money and time upgrading and fixing these issues, or I just go the whole hog and build a new machine that addresses all these issues while also giving me a larger work area and the fun of building a new machine for myself, then transfer my electronics across. I am choosing the latter option :)
Current machine and table... you can see me sizing up the enclosure I want to build in the second pic:
http://i.imgur.com/p7YAlLB.jpg
http://i.imgur.com/vdiRoQa.jpg
I am working under some specific constraints - it needs to fit on my CNC table as I spent too much time building it to change it now lol. I am also trying to fit it inside an enclosure so every mm counts in overall footprint - it cannot grow too much over the existing machine so the increased work area needs to come from small increases in overall size and just using the space a bit more efficiently.
This is the overall design I've come up with after a few iterations (beefed the gantry arms up from 20 to 25mm, re-designed Z-axis to use 4 carriages etc):
http://i.imgur.com/oXFql8m.png
http://i.imgur.com/wMIyavq.png
Y-Axis:
- Primarily constructed from 45x90mm heavy profile, 45x45 profile, 20mm precision ground solid plate for tool plate, and 20mm plate for corner pieces.
- Dual motor to make up for massively increased weight and also to play with automatic squaring.
- Motion components: HGR20 x 4, HGH20CA x 8, FK12 x 2, FF12 x 2, MBA12-C x 2, TBI 1605 Ground C5 ball screw and nut x 2
- Total span 1000mm, Travel 750mm.
- Permanent water tray to contain chips/coolant and also for cutting CF fully submerged. Constructed from 12mm black Acetyl, 5mm Acrylic side windows and finished with a levelled platform for a 10mm Aluminium tool plate. G1/4 drain point at front.
http://i.imgur.com/nZd4H7R.png
http://i.imgur.com/i6okCIf.png
X-Axis:
- Primarily constructed from 40x160 Heavy ITM profile, 25mm precision ground solid plate for gantry arms.
- Motion components: HGR20 x 2, HGH20CA x 2, FK12 x 1, FF12 x 1, MBA12-C x 1, TBI 1605 Ground C5 Ball Screw and nut x 1
- Total Span 550mm, Travel 395mm.
It has been suggested that perhaps moving from 40x160 heavy profile to 40x200 heavy profile would yield a more rigid machine. I think I can probably do that within current constraints without losing gantry clearance... thoughts on the benefits of re-designing around the larger 200mm profile?
http://i.imgur.com/2O1qacb.png
http://i.imgur.com/cO8uHdD.png
http://i.imgur.com/jsln5T6.png
continued in next post due to pic limit...
-
Re: El Beast - Initial design phase, comments and critique welcomed!
....Z-Axis:
- Primarily constructed from 20mm and 15mm precision ground plate. 80mm single block machined spindle mount from RoverCNC.
- Motion components: HGR20 x 2, HGH20CA x 4, custom bearing blocks, FK12, TBI 1604 Ground C5 Ball Screw and nut x 1
- Tram adjustable +/- 0.5 degree using an eccentric bushing system.
- Total Span 320mm, Travel 165mm
http://i.imgur.com/siZJTNZ.png
http://i.imgur.com/FyYSlCW.png
http://i.imgur.com/wJKc67f.png
http://i.imgur.com/Yyb0XQD.png
Would be keen to know any thoughts or suggestions you guys may have.
Cheers
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Looks very nice but if you want a stiff machine use a raised X axis design instead of long gantry sides.
Also on the Z axis you've gone for the tuning fork layout. Look at the layouts where the carriages are fixed on the Y axis and the rails are on the Z plate.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Awsome cadwork and really nice looking machine!
As routercnc mentioned the Z rails should be on the moving plate..
Also! If you want to increase travel of x axis you could have the y rails over and under the gantry instead of on the front. That would buy you around 25mm in x travel!
Saw that you use pokeys57cnc, how does it work for you? I'm in love with the idea of that product but others on the forum have had problems with it...
Regards
Madman
-
Re: El Beast - Initial design phase, comments and critique welcomed!
routercnc - by raised X axis are you talking about something like this?
http://i.imgur.com/GHffn17.jpg
Nr1 - Cheers. Thing with that suggestion is that the ball screw and mount is actually taking up more depth than the rails and carriages, so would need to do something totally different with the ballscrew arrangement.
I've been very happy with the pokeys57CNC - setup was easy, the mach4 plugin is great and support has been quick to answer my occasional stupid question.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Right lads,
So I've done a quick re-design of the entire Z-axis based on your feedback, re-using the existing motion components (which is handy, don't need to change my quote).
Travel is still 165mm, but I've actually managed to reduce the overall dimensions by 9mm in depth and 11mm in height with this re-design.
Before I spend too much time fleshing out the details any thoughts?
Z-Axis carriage - using 20mm plate as the back piece, 16mm plate to space out the carriages (plus 16mm top and bottom):
http://i.imgur.com/WNtL1Dv.png
Central travel position with Rails/Face plate (20mm) and tramming plate (15mm):
http://i.imgur.com/oS0qdYr.png
Bottom travel:
http://i.imgur.com/2PMycg9.png
Top Travel:
http://i.imgur.com/9KAArbc.png
View of rails at bottom position:
http://i.imgur.com/khykuu8.png
-
Re: El Beast - Initial design phase, comments and critique welcomed!
I can't see how you are going to bolt the Y rail blocks to the Z axis?
-
Re: El Beast - Initial design phase, comments and critique welcomed!
sorry to me the Y-rail is the long axis on the router bed which I'm guessing you don't mean, which blocks are we talking about?
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Quote:
Originally Posted by
Zeeflyboy
sorry to me the Y-rail is the long axis on the router bed which I'm guessing you don't mean, which blocks are we talking about?
Ok then the X rail ( the bearing blocks will need to be bolted to the Z plate) Can you get at the bolts to fix them. It is quite often a problem that they obstruct one another.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Ah do you mean how will I attach this Z-axis back plate to the X-Axis slider block?
The screw holes will be behind the 16mm Z-carriage riser blocks, so basically it would be a case of fitting the Back half of the Z-axis with motor, ball screw etc installed to the X-Axis slider block, then fitting the Z-carriage spacer block (with carriages pre-installed) to the Z-axis back plate. I will probably use 6mm DIN dowels on most mating surfaces to make alignment easier.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Quote:
Originally Posted by
Zeeflyboy
I think your design is better than this one, in this one the Y rails are not optimally placed, would be better on the side or under the table.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
I can see where the advantage is, in that the gantry arms can be a fair chunk shorter and thus give more rigidity for a given thickness.
The disadvantages are that it's a potentially a more complicated mounting assembly (especially when ball screws are considered as well), would need extra work to add shielding for the rails and would end up eating into my X-Axis bed area (although actual work area would probably be able to be kept the same with a little careful work, there would be less room for overall material size and clamping.
So the question is whether I go on the basis that 25mm thick plate will be sufficient for the gantry arms at their current length, or whether I want to take those above mentioned compromises in order to gain a little extra rigidity.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Bit more time refining the new Z-Axis design.
I realised I needed the plate that slides down to be slightly slimmer than the unit as a whole, otherwise it would jam on the water/chip tray sides when in the lowered positions so tweaked that along with some more design details and seals, tramming plate etc.
http://i.imgur.com/pbNgIU2.png
http://i.imgur.com/ETE60pS.png
http://i.imgur.com/2RbdWrP.png
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Quote:
Nr1 - Cheers. Thing with that suggestion is that the ball screw and mount is actually taking up more depth than the rails and carriages, so would need to do something totally different with the ballscrew arrangement.
I've been very happy with the pokeys57CNC - setup was easy, the mach4 plugin is great and support has been quick to answer my occasional stupid question.
You are of course right about the ballscrew placement! So nevermind about that :)
I'm glad you like the pokey's, might be that Im gonna place an order.. but mach4? Is it working alright as well?
The new Zaxis is looking sweet, what material are you planning on using for the "seals" in red?
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Red silicone strip for the flat seals and not sure yet for the shaped stuff, either I'll laser cut some thicker silicone strip or 3D print in a flexible rubber.
Yeah I'm very happy with mach4 - it generally feels much more modern and clean than mach3, and it's far more responsive in terms of reacting to your manual inputs or feed hold etc.
It is probably a case of burning money somewhat if you've already got mach3, but I just wanted something a bit more future proof since I'm on a new pc running windows 10 pro. I believe that the pokeys57cnc is better supported on mach4, so that's certainly something to consider as a potential extra expense if going the pokeys route (although even the pokeys57CNC + mach4 is cheaper than the smooth stepper + BoB I had).
If getting mach4, I recommend looking at the pdmx site - even without a joint purchase its slightly cheaper to the tune of 10 bucks or so.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Looks nice. If you move all 4 z axis blocks down you will gain more travel, or move down the lower ones to increase rigidity at full extension.
What CAD programme is that?
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Quote:
Originally Posted by
Ross77
Looks nice. If you move all 4 z axis blocks down you will gain more travel, or move down the lower ones to increase rigidity at full extension.
What CAD programme is that?
Cheers,
Won't gain more travel by moving them down - it can already travel the full length of the rail so it's limited to rail length minus 2x carriage.
However it's been pointed out that moving them towards the bottom does put the "fixing" point closer to the work which would reduce the lever arm and increase rigidity. I will probably slide them down a bit and slide the tram plate up to match.
I'm using fusion 360 for everything these days, the built in cam is awesome.
-
2 Attachment(s)
Re: El Beast - Initial design phase, comments and critique welcomed!
For raised X axis I mean something like these where the gantry is mounted directly on top of the X rails, which are themselves raised well above the level of the bed. The raised X axis can then be reinforced and made as stiff as you want. Often they are steel box section, which is x3 stiff as aluminium (like-for-like sizes). This avoids having the long drop down gantry side plates which will not be as stiff.
It is very difficult to overcome offsets by beefing up/reinforcing the connecting structure. Much better not to have the offset in the first place.
Attachment 20802
or
Attachment 20803
The example you choose still had gantry sides and the X axis rails were level with the bed so no real advantage and not what I would call raised X axis design.
Z axis swapped around looks good. I'm adding a pair of tram plates to my new machine so good to see it used on yours.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Hi!
I can recommend the high (X or Y axis depending on what you call it!!) rail approach (my machine is the bottom photo) to give stiffness. My machine munches aluminium and I've even cut (I'll say tickled really) 6mm steel plate. I presume you're the same person who frequents (or possibly did as I've not been on there for a few years now) RcHeliAddict forum, I think the last time I was on there you were just testing your small FPV Quad you designed?
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Quote:
(my machine is the bottom photo)
And mine is the top one. I to was recommended to go down that route:thumsup:
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Both very nice machines! No size envy here.... :hororr:
Were the frames DIY?
Yeah that was me - it was the vortex race drone that I was designing back then.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Quote:
Originally Posted by
Zeeflyboy
Both very nice machines! No size envy here.... :hororr:
Were the frames DIY?
Yeah that was me - it was the vortex race drone that I was designing back then.
Ahh thought it was, I remember your fpv Eurofighter too...fantastic plane.
Yes, both were welded from scratch. Mine's now vertically mounted (well 85° to be precise) on another frame I welded up...
Sent from my HUAWEI VNS-L31 using Tapatalk
-
Re: El Beast - Initial design phase, comments and critique welcomed!
I should learn to weld one day...
Cheers chaps - I'm off to scratch my head and think what I can do with the bed/frame design.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Well I've been playing around with it, and unfortunately I'm just not going to be able to get the work size I want to work in the space I need if going with the raised gantry type design, at the moment the work area is more important to me than absolute rigidity.
That said, taking on board that feedback I will be tweaking the design a little to take the 15mm mounting plates higher up (thus making the gantry arms effectively 40mm thick until they leave the bed surface) and I can also move the gantry down by about 14mm and make it line up with the bottom of the z-axis without losing any clearance... I can also switch from 20mm plate to 15mm plate for the main bed which would allow me to drop another 5mm off the gantry height. All adds up!
Given that the current machine does a pretty decent job of aluminium already, I hope that the re-designed Z-axis and the significantly beefier gantry arms (current ones are 150mm wide and 15mm thick vs the new one at 250mm wide and 25mm thick will be more than sufficient for my needs while giving the larger work area I need.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Just looking back again at your design, why the 2 rails each side of your Y axis? One rail will have more than sufficient strength for anything you can throw at it?
-
1 Attachment(s)
Re: El Beast - Initial design phase, comments and critique welcomed!
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Been re-working the gantry a touch...
Its now a 40x200mm ITM profile vs the 160mm before... in addition to that, I reasoned that given that I was having to put 20mm spacers on the carriages to bring them in line with the ballscrew block, I may as well put that material into the gantry strength instead and raise the rails themselves out by 20mm... to that end I've designed a 20mm thick plate that will be mounted to the profile, then the rails will attach to the plate... the centre will be machined out to accommodate the motor mount and ballscrew bearing block.
The back is 12mm plate, and the top and bottom covers I figure may as well be made structural, so they are now mostly comprised of 4mm plate and will be screwed into the profile top/bottom, which I figure should help a little to reduce any deflection from forces in the Y-Axis.
Should be fairly strong?
http://i.imgur.com/LLGBjXU.png
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Oh and just out of interest guys, is there anyone in the south east here (I'm horsham based, south west of gatwick) that has a machine big enough to just accurately size up and drill a 1040x520x15mm piece of plate for some beer money?
I generally order from aluminium warehouse but they always come with -0/+2mm on dimensions and it would be nice to get it sized up more accurately and the holes drilled on a CNC to save me trying to mess around with jigs and figuring out how to get the width and length accurate. It would just be a case of whizzing up to 1mm off the edges and drilling some mounting holes, no skimming required or anything.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
quick and dirty assembly with the revised designs... no finer details worked out yet like seals etc
Changes:
- I've just brought the end plates within the work envelope of my current machine so that I can do them as a single piece, narrowed the bed slightly to allow the 15mm gantry mount plates to extend up to just beneath the bed surface.
- Bed taken down to 15mm to allow same clearance with slightly shorter gantry
- Gantry profile extended from 40x160 to 40x200, plus the extra 20mm of plate for spacing out the rails, back plate bumped up to 12mm.
- Moving rail Z-axis design.
http://i.imgur.com/fNZZxj8.png
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Quote:
Originally Posted by
Zeeflyboy
quick and dirty assembly with the revised designs... no finer details worked out yet like seals etc
Changes:
- I've just brought the end plates within the work envelope of my current machine so that I can do them as a single piece, narrowed the bed slightly to allow the 15mm gantry mount plates to extend up to just beneath the bed surface.
- Bed taken down to 15mm to allow same clearance with slightly shorter gantry
- Gantry profile extended from 40x160 to 40x200, plus the extra 20mm of plate for spacing out the rails, back plate bumped up to 12mm.
- Moving rail Z-axis design.
http://i.imgur.com/fNZZxj8.png
That's exactly what I meant on CNCZone about those end plates. Did you do the same change for the bottom end plate? The one moving the gantry? I think even that should be made of one piece, not two.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Yup same on the back - narrowed them enough to just squeeze within my current machine's work space so can do them both as single piece now.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Did sb tell you already to rid of that ridiculous Y Hiwin design? Why would you need 2 rails each side? You need one rail and 2 blocks, size 20 which have 100 times the specs higher than your machine can weight or 10x force on them.
Before rendering the design, better think how you will mount all together. Especially how will adjust and fit things and with your design especially how you will square the Y rails/ yes again the Y rails./
While side mounting is very beautiful is very hard to mount them properly in DIY design, thats why people use epoxy and mount them horizontally. Or as per your design- all MUST be Machined on mill so you fit it right.
Same as front/back mounting ball screw supports.
So the way i see it- nothing wrong with all that if you are to mill all pieces on a mill/ not your old CNC/ . If not- the result will be mediocre concerning precision
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Quote:
Originally Posted by
Boyan Silyavski
Did sb tell you already to rid of that ridiculous Y Hiwin design? Why would you need 2 rails each side? You need one rail and 2 blocks, size 20 which have 100 times the specs higher than your machine can weight or 10x force on them.
I told him that 12 days ago, the first time I saw it.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Yeah yeah, just haven't had time to work on that part yet as i've been re-designing the x-axis gantry and the z-axis first.
Boyan - plan was to mount the rail to the 45x90 and then level it to the ecocast plate bed before tightening down all the screws, which would give alignment in the Z-axis. I suppose you are suggesting that the flatness of the extrusion will leave it slightly "wavey" in the horizontal axis?
What about mounting a 20mm ecocast plate to the extrusion and then the rail to the plate, similar to what i'm ending up doing with the X-Axis?
-
Re: El Beast - Initial design phase, comments and critique welcomed!
I am speaking about how you would level the long rails that gantry moves on them / Y/- in the Z plane to be on one plane and at the same time to be flat . I am not so worried about the flatness as you say you will be using Ecocast plate.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
So the plan was to mount the ecocast bed plate, then using a shim between one of the Y-Carriages and the underside of the bed plate I could fasten the screws moving the carriage as I go, which would end up with the rails level to the ecocast bed surface.
The end pieces I have designed a pocket in the back sides to accept the 45x90 extrusions, which keeps the spacing between front and back consistent and (assuming the shop cuts the extrusions square) should keep things squared up too, and was planning on adding a couple of corner brackets to help keep the squareness of the frame acceptable.
http://i.imgur.com/EnvpC25.png
So the only thing that can cause significant issues as far as I can see is that I'm effectively relying somewhat on the flatness of the 45x90x1000mmm extrusions to provide the straightness in the horizontal plane. If the extrusions are slightly bent for example then I could get a slight curve when travelling fore/aft in the Y-axis... that would need fairly accurate shimming to get rid of.
Could be an option to get some 20mm ecocast plate to mount to the 45x90mm and then mount the rails to that perhaps?
e.g:
http://i.imgur.com/IoUA9Bh.png
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Another potential option perhaps would be to re-design around this misumi milled profile? https://us.misumi-ec.com/vona2/detai...689340/?Inch=0
Not sure of the cost or availability however.
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Seems alright. I would have done it same way. using straight edge you can make sure all is ok
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Sorry just to be clear for me - you are saying you would do the levelling the same way with the shim, or the mounting of 20mm plate to the extrusion before mounting the rail, or going with the milled extrusion?
-
Re: El Beast - Initial design phase, comments and critique welcomed!
Boyan is right
2 rails each side are nonsense. The result will be huge loads to the rail bearings due to thermal distortions, nonparallel cuts etc. General problems with gantry types is non-optimised stiffens. Torsional displacement of the gantry beam define the stiffens of whole system.
Everything is assembled from standard profiles. I-s are known, do the simple test and apply load of 100N at the end of the cutter.
Don't be surprised.
regards