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Let the fun begin !!! ???
Hello to all,
i have been reading the various project builds on this site and have decided to take the plunge and build a gantry style router. i have a background in machining/ maintenance/ welding/ m/ building , autocad / inventor etc. i'm hoping to avail of the excellent experiences and know how of the various builders on this site. i will use 80 x 80 x 5 box section for the frame but i'm at a loss for overall dimensions. my cutting area will be 1240 x 1240 ( 1/2 standard sheet ) i will be m/cing wood, polycarbonate and light aluminum from time to time. i will use profile rails , ball screws, nema 23 steppers (3) , provision for a 4th axis and a 2.2 kw spindle. so as stated i would like to know the overall size (out to out) of a machine of a similar nature. i will build it in my garage and want to minimize the space used so if any body has built a similar m/c and could get me up and running with the dims. it would be a great help to get the show on the road. by the way, all my selections so far are based on the excellent advice from the various builders on this site. i will post a sketch as soon as i have dims to get the ball rollin' !!!!
cheers,
paulro
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Re: Let the fun begin !!! ???
Not that simple really. Yes I could give you an idea of dimensions but to give accurate dimensions then you'd have to build parts of machine exactly the same as I do. IE: Gantry width , bearing spacing Etc.
Best soultion is to get your Autocad and inventor hat on and get sketching then your accurate dimensions will become clear.
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Re: Let the fun begin !!! ???
thanks Jazz, i got side tracked and had to change tack for the last week or so. i'm just getting back at the inventor so i should have some dwgs in a day or so.
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Re: Let the fun begin !!! ???
hi Jazz, i'm looking for dimensions for bearing blocks for 20 mm ballscrews, could you point me in the direction? i have been reading that fixed blocks at both ends is the best option, ya? i have a frame sketched and am starting into the y axis gantry design
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Re: Let the fun begin !!! ???
Here you go this should help.
Attachment 12649
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Re: Let the fun begin !!! ???
At last i have an opportunity to get some images of the intended build posted for comment. i have read a lot of material on this forum and tried to include as much advice as possible . i haven't purchased any materials yet even though i'm itching to get started , but taking the advice given to other potential builders from Jazz, Jonathan , among others, i will build the frame first and then once i'm sure of key dims. i will take on the mechanical purchases and build. the gantry images are posted as a reference to my intended build but as always i'm open to suggestions.
the frame size should take a half a standard sheet ( 1220 x 1220 ) built from 80 x 80 box section. 5 mm wall for the top rails and 3 mm for the rest. the adjustable bed ( yellow) will be held in place by graduated 50 mm x 6 mm angle ( green) secured to the frames uprights. the stand alone box section ( blue ) is detachable to allow space for a fourth axis , eventually!!
i have a choice of extrusion for the gantry ( length 1610 mm ) either 100 x 50 , 4.18 kg/m, 120 x 40 , 4.35 kg /m or 120 x 40 , 6.8 kg /m .
the linear slides, 20 mm hiwins , ballscrews 16 mm and aluminum plate for gantry , 20 mm . i haven't any motor specs yet so i didn't finish the z axis assembly . I might use 20 mm linear slides on the z axis ( off cuts from the 2m x rails ) or just purchase 15 mm rails. i will use epoxy to create a plane for both x axis and a permanent bridge for this and the x axis motor to belt drive the twin ball screws, OR use separate motors for each x axis ballscrew. all to be decided with the advice from the experienced builders here, hopefully!!!! i'm also looking for some motor dims, nema 23 , 3nm. they seem to be the weapons of choice for what i'm about to take on , so if any one can point me in a direction for a reputable supplier that has dims i can use to finish the z axis dwgs i would appreciate it. cheers Paulro.
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Re: Let the fun begin !!! ???
Maybe you could incorporate into the fourth axis space something to allow this; http://www.mycncuk.com/threads/7688-...9686#post59686
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Re: Let the fun begin !!! ???
ya , that is a great idea. that's what's great about this site , ideas get bounced around and seeds are sown. i've been on this site for the last year getting as much info. as possible and getting cash together at the same time for a router build. can't wait to get stuck in. i'm confident of the mechanical side of the build and have some electrical experience but will need help to get me through the potential pitfalls i think i will find myself in. hopefully i can rely on the experience of the previous builders on this forum.
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Re: Let the fun begin !!! ???
The gantry ends look quite substantial but I'm not sure how well the structure will resist twist at the centre, here's some info relating to that subject.
Machine stiffness; http://www.mycncuk.com/threads/7155-...4942#post54942
Stiffness calculator; http://www.mycncuk.com/threads/2214-...5791#post15791
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Re: Let the fun begin !!! ???
Hi Paulro,
Got your PM.
Yes the gantry will be fine for your use as a wood router and yes I've built one about same size using same design so know it works. What you doing with the ends of gantry and how you connecting to ballscrews.? Drawing with gantry mated to frame would be good to see.
Regards Y axis ballscrew mount then you'll need to brace the drop bracket more.
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Re: Let the fun begin !!! ???
I could go with a heavier extrusion if that would aid the machining of plastics and aluminum (light gauge) from time to time. i have a choice of extrusion for the gantry ( length 1610 mm ) either 100 x 50 , 4.18 kg/m, 120 x 40 , 4.35 kg /m or 120 x 40 , 6.8 kg /m. i don't know if that would make for a better or worse situation.
Attachment 12986Attachment 12987Attachment 12988Attachment 12989
the images above show the gantry attached. i have yet to spec motors so haven't any motors mounts designed. i'm currently getting through Irvings tutorial on motor specs. what a great read!! i'm hoping nema 23s 3nm will do the job , by the way if i do go with these motors should i go for the heaviest i can get? any thoughts on this and the gantry extrusion choice would be appreciated.:indecisiveness:
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Re: Let the fun begin !!! ???
by the way i'm going to use timing belts to connect to the ballscrews
Paulro:neglected:
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Re: Let the fun begin !!! ???
100x50 will be fine but if possible get the HD version.
3Nm motors will work ok with 16mm screws but with 20mm you'll need to slow things down due to extra inertia so you'll get lower rapid feeds.
You'll want 10mm pitch which will be more suited to wood and plastics. Now if you use 20mm pitch screws and gear 2:1 ratio then you will still get same feed rates as 10mm pitch with 3Nm motors but with a couple of nice advantages.?
The ratio halfs the speed 20mm pitch gives but this gives same feed and resolution as 10mm so we get same speed but with half the screw speed but at same time doubles the motor torque. Lower screw speed means less chance of whip on long screws so it's win win.!
You'll need to run the motors around 70Vdc on decent drives to get best from them.
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Re: Let the fun begin !!! ???
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Re: Let the fun begin !!! ???
i'm going to put this m/c in my garage and that has a 6 ^2 twin and earth supplying the fuse board. it has ELCB. protection and an MCB for lights and MCB for sockets which supply a freezer, washing m/c and dryer in a separate room at the back. am i exceeding the supply with a m/c spec of this size? would anyone know the amperage required for a build of this spec.?
crisis averted, i 'm told 6mm2 is good for 35 amps. should be fine, i hope!!!:smug:
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Re: Let the fun begin !!! ???
My shed is supplied by 6mm^2 armoured cable, I have a machine with 4HP motors and a powerfull dehumidifier, plus other smaller machinery. This works because there's only me in there so there are only 2 things at most operating at the same time.
I keep meaning to measure the current taken but as yet I've not found my clamp meter.
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Re: Let the fun begin !!! ???
originally i designed around 16 mm x 10 mm ballscrews for X (1440 long) and y ( 1395 long) and 16mm x 5mm for z . i know from reading your previous posts that the length is critical or rather going over a certain length will almost certainly introduce whip at high speeds. i would like at some stage to tackle a Mayan calender and so i'm curious about resolution if i go with a 20 mm pitch. I'm not sure also about the amount of clearance i should leave between ballnut and bearing blocks either end. is there a standard clearance that i should factor in ? i have left 15mm either end but i'm not sure if this is enough.
Attachment 12990Attachment 12991Attachment 12992
i could also use nema 23 4Nm motors instead of 3Nm. (courtesy of Eddycurrent ) would the same psu ,motor drivers , smooth stepper, break out board etc. do for both? just trying to get a handle on the cost of everything required is a job in inself!!!!:hypnotysed:
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Re: Let the fun begin !!! ???
At this length then go with 16mm you'll be ok, 16mm will allow slightly faster acceleration due to less inertia. Resolution with 20mm isn't a problem because the ratio effectively makes it same as 10mm and even with 1:1 ratio 20mm res you'd still have enough to cut the mayan calender.
There's very little between the 3Nm and 4Nm motors in terms of performance so you wouldn't really see much differance. Either will work fine with what your planning to use. Just run them around 70Vdc and you'll be fine.
With bearing blocks/ballnut then all you need is to leave a enough clearance in case you over run limits. In which case the limits should stop the machine so you need enough clearence for the over run. That said your better fitting hard stops in case of over run and have the bearing blocks just past these.
To be honest I wouldn't sweat over it you can control this with adjusting limits and they take a fair old bang to damage anyway so worst you'll do is knock something out of alianment.
Let me just say if your at the point of planning in cad to this level of detail then your wasting time that could be better put to use building the machine because in reality you'll more than likely to see a better place to put them on the actual machine.!! . . . . . Time to put the pencils down and pick up the tools.
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Re: Let the fun begin !!! ???
it's time to put the overalls on o.k i should have steel middle of next week so i'll be fighting iron the following weekend. i'm just gathering the most info before i start into the build. i will be missing in action in the near future for a couple of weeks so i'd rather take time at this stage and plan it out . having said that i have enough info to get me up and running.:excitement:
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Re: Let the fun begin !!! ???
Just for the crack, keep a spreadsheet of everything you buy and the cost, maybe categorise as 'mechanical', 'electrical', 'sundries'
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Re: Let the fun begin !!! ???
it time to source linear rails, ballscrews , ball nuts , bearing blocks etc. so i'm looking for contact details for chai. i have found an email address for him but i'm getting no reply. i have looked at zapp but want to do a compare & contrast before i purchase. so if any body has his web address can they send it on?
cheers Paulro
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Re: Let the fun begin !!! ???
please check your pm inbox
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Re: Let the fun begin !!! ???
i have touched base with chai and just need to work out the 16mm ballscrew lengths. i also notice that the bearing shaft diameters for BK and BF are different and am curious to know why this is.
Attachment 13000
Attachment 12999
this is my z axis end view, it has 20 mm rails and a travel of 160 mm. i'm thinking of a z axis ballscrew length of 400+ 30 for for a timing pulley. i'm sure this is enough or should i go more?
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Re: Let the fun begin !!! ???
I may be wrong but the BK end will have AC type bearings and the BF end will have a radial bearing they use a larger bearing at the BK end. Not sure if they make the ac bearings in the same sizes as the radial.
You will need to order the F measurement on the screw to be at least 30mm I think Chai standard is 15mm. ..Clive
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Re: Let the fun begin !!! ???
Quote:
Originally Posted by
PAULRO
this is my z axis end view, it has 20 mm rails and a travel of 160 mm. i'm thinking of a z axis ballscrew length of 400+ 30 for for a timing pulley. i'm sure this is enough or should i go more?
If the backplate is 400mm same as the spindle mounting plate you will likely want the outside faces of the bearing blocks to be 400mm apart so they are flush top and bottom, this will allow the maximum travel.
So the BK bearing is 25mm thick (excluding the end cap and locknut) the BF is 20mm thick, so that gives a ball screw length of 355mm between shoulders. Then 12mm turned section on the BF end, 69mm on the BK end (E+F = 39+30). Total length = 436mm. You have to allow for the Z ball nut thickness , this will reduce the overall travel, I drew mine out using Sketchup to make sure I was getting the expected travel.
Also you might as well get the ball screw as long as possible because the price difference for a few mm is going to negligible.
I know it might slow the build but in my case I waited until the ball screws arrived before cutting metal. It was easy to size the metal to the ball screws but impossible the other way round if in error. That's one of the reasons I built the electrical panel first, waiting for the stuff from China.
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Re: Let the fun begin !!! ???
Cheers Eddy, how long was the delay from Chai ? also did you get the ballscrews machined locally or by chai and if so would you recommend it? i might get it done locally because i have access to a lathe but if it's not too costly to get it done by Chai i might go that route but then i have read that some of the screws turn up slightly bent. i have used suppliers from china in a previous life ( job) and remember some of the parts delivered with poor packaging and very little protection ( not all suppliers ). it's very helpful to have the experience of previous builders who have gone down this route, hence all the questions!!!
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Re: Let the fun begin !!! ???
I think it took 18 days from payment to delivery. The machining was fine, exact dimensions, good fit to bearings, far cheaper than anywhere else. Holding the ball screws in a lathe is not as simple as a bit of round bar plus they are very hard on the outer skin.
The parts looked okay until I fitted them whereupon I noticed some bending. I decided to straighten them myself and it appears to have worked well enough, it's all in my build log.
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Re: Let the fun begin !!! ???
Quote:
Originally Posted by
EddyCurrent
i had a look at these and will go ahead but i'm not up to speed with the rest of the gear required for the electric build . i'm hoping to get into 3d carving at some stage so i would like the m/c to be able to cope with that as well. i don't know if my design needs to be changed to accommodate this requirement. i read a reply to a post recently by jazz stating that a requirement for 3d carving is fast direction changes and high acceleration and it started me thinking that maybe i need to take other requirements into consideration and as my steel will be delivered this week i could make alterations to the frame to allow for this requirement. any input would be greatly appreciated on this.
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Re: Let the fun begin !!! ???
Regarding metal work, I think you have it sorted with respect to 3D carving, i.e. adjustable height bed, 4th axis option.
Have you thought about how the 4th axis will physically attach to the frame ? and will material held in the chuck be parallel to the X plane or the Y plane ?
I'm thinking about a 4th axis myself but there's no room in my control panel for the gear, but thinking about it I feel it would be best as a stand alone unit with control wiring back to the main panel via plug & socket.
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Re: Let the fun begin !!! ???
Quote:
Originally Posted by
PAULRO
this is my z axis end view, it has 20 mm rails and a travel of 160 mm. i'm thinking of a z axis ballscrew length of 400+ 30 for for a timing pulley. i'm sure this is enough or should i go more?
Why is the rear plate so long.? you only need the rear plate long enough to fit bearings onto and give travel required. If your only wanting 160mm of movement then you would get away with shorter back plate and ballscrew.
Also one thing to take into account if your trying to get every last bit of travel out of screw is to allow for the bolt heads holding ballnut, you can easily loose 10mm depending on how tight you make it.
Regards the Z axis screw bearings then with screw being so short you don't really need one at the bottom if you want to keep cost down and it makes setting up that bit easier.
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Re: Let the fun begin !!! ???
i had intended to use 20 mm rails on the z axis but after reading the various posts of your good self I am now going to use 15mm rails and guides to suit so i think a redesign is in order.
the rear plate should be shorter alright i just left it long enough to house the motor with a body of 100mm long and a plate to hold it.
i suppose the travel of the z axis could be longer but i went with that travel because of all the discussions about the length of the lever created by the extension. i suppose it's another trade off , keeping it to a minimum while having enough scope to machine to a reasonable depth. i'll get cracking at it again tomorrow, my shutters are starting to descend !
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Re: Let the fun begin !!! ???
Quote:
Originally Posted by
PAULRO
i had intended to use 20 mm rails on the z axis but after reading the various posts of your good self I am now going to use 15mm rails and guides to suit so i think a redesign is in order.
No I wouldn't. There's very little price difference between 15 & 20 and the bearing size and overall height makes building the z axis easier regards clearence for ballscrew. With 20mm you still need to machine a recess for the ball screw but it doesn't need to be so deep. With 15mm the recess is too deep so you end up having spacer blocks and this makes achieving accurecy that much harder.
In the past I've made Z axis for people who use 25mm rails just to get around having recess or spacer blocks thou I wouldn't take that route personally.
I've got 180mm on my Z axis and I rarely use more than 100mm and often it's much less than 80mm and most of this is for tool clearence not actual cutting depth so don't go chasing length as you'll probably never use it.
The fact you will have adjustable bed means you'll find a balance between Z extension and strength for the type of work your doing. This is the beauty of the movable bed you are very flexible and can always find the best height to suit the job IF NEEDED.!!! . . . I highlight these words becasue in practice you'll rarely move the bed (Because it's a pain in the arse resurfacing) but instead find that balance I've spoken off.
In normal DIY wood working every day use your very unlikely to use tools with over 100mm cutting length so I find 100mm is more than enough on a adjustable bed machine as I can always bring the work to the cutter if needed or create clearence by lowering bed.
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Re: Let the fun begin !!! ???
i had used 20 mm flanged bearing blocks in the original dwg and that impacted on the clearance for the ball screwnut. I had also designed the z axis plate to be machined at 160 mm wide to try and keep the gantry length to the minimum . I should have used 20 mm square type bearing block to give more clearance and accommodate the 160mm width. ya i will stick with the z axis travel of 150mm - 160mm and adjustable bed. good call. i will have to get a supplier organized for the guides and rails. I dealt with chinese suppliers in a previous job and there were reliable so i'll drop them a line and see where it takes me. maybe i should wait until i have secured the rails and guides before I go any further with the z axis design?
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Re: Let the fun begin !!! ???
Has anybody used the linear guides and rails from Chai? i have organised the ball screws from him and thought i would use his linear gear but only on a recommendation from the previous builders here.
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Re: Let the fun begin !!! ???
[QUOTE=EddyCurrent;60688
Have you thought about how the 4th axis will physically attach to the frame ? and will material held in the chuck be parallel to the X plane or the Y plane ?
I'm thinking about a 4th axis myself but there's no room in my control panel for the gear, but thinking about it I feel it would be best as a stand alone unit with control wiring back to the main panel via plug & socket.[/QUOTE]
apologies for the delay in getting back to you Eddy, i haven't decided whether to mount a plate to the inside frame to house the chuck or sit it on the blue frame dedicated for the fourth axis. I plan on clocking it true it with a clock attached to the gantry, with regard to the separate panel i hadn't really thought of that option but now that you say it ..... i haven't sourced a panel yet . i'm hoping to pick something up in the region of 800 x 600 x 200 deep if its not too expensive. i have off cuts of 1mm galvanized sheets getting in my way and if the parts that i ordered from Chai are on a slow boat then i might toy with that idea for a panel.
by the way can you recommend any supplier for linear rails ?
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Re: Let the fun begin !!! ???
Don't be apologising to me, it's your thread. :untroubled:
Quote:
Originally Posted by
PAULRO
by the way can you recommend any supplier for linear rails ?
Well sometimes I can't be bothered to piss about looking for the cheapest, so I go for the easiest. In my case I bought my rails and bearings from cnc4you.co.uk
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Re: Let the fun begin !!! ???
Quote:
Originally Posted by
PAULRO
Has anybody used the linear guides and rails from Chai? i have organised the ball screws from him and thought i would use his linear gear but only on a recommendation from the previous builders here.
If your talking about the Profiled linear guides then yes I use them all the time and they are fine.
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Re: Let the fun begin !!! ???
steel has arrived and is cut and both sidewalls are welded.
Attachment 13138Attachment 13139
I have to string the crossbeams and tie both together.
I contacted http://www.ecfibreglasssupplies.co.uk /to purchase epoxy 105 and hardener 209 but drew a blank . apparently they don't stock 209 hardener but told me the 205 or 206 hardener are very similar but for pot time and cure time. has anybody used these hardeners? i'll probably go with the 206 because it has a longer pot life but would like some feed back before i do.
i also spoke to Chai about his linear guides and rails and the preloads are as follows
Z1: 0-0.02C or Z2: 0.02C-0.05C . i'm sure either of these will do the job but would like to know which preload is the preferred choice for wood routers.
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Re: Let the fun begin !!! ???
Paul I contacted ecf as that is where I purchased mine from they don't stock it but they can order it, but they will not deliver it out of the country. Here is a chart that will show you the difference between 206 and 209 (page 3) http://www.paynesmarine.com/document...0Adhesives.pdf as far as I can see the 206 cure time is about 9 to 12 hours and the 209 has a cure time of 12-24 hours but the 209 is recommended in hotter conditions. The idea behind the slow cure time is not how long it takes to pour it, as that is only a few minuets but the time it takes to let it level out. ..Clive
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I have done a bit of research and you can buy it in Dublin here:- Waller & Wickham
Unit 96, Baldoyle Industrial Estate, Dublin, , Republic of Ireland
353 18392330 He will be in his office around lunch time today.
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Re: Let the fun begin !!! ???
Clive Cmon he's in Ireland don't think finding a cool days is going to be a problem, . . dry day well !! . . :hysterical:
Paul I've used epoxy with equivalent cure times to 206 in past and had no problems but like clive says the conditions must be correct. Infact I've just ordered some 206 because ECF didn't have the 209 and couldn't wait or fancy being ripped off.( wanted nearly double the 206.!!) and I don't envisage any problems.