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D.c
Thanks
Yes have accounted for around £450.00 worth of "finishing" as it's titled in our budget all those bits really add up I guess I am quite fortunate to have a fair amount of bits "in stock" also cutters and collets included from running a large cnc lathe previous to this but your right it's surprising how it all adds up!
Ok right I have hit the new year running so have a full months work of build time allocated between work over Feb and Mar. Now I have the dreaded tax return out the way I have the rest of this week to work on finalising the design etc whilst I am doing this I would like to try and figure out the best place to source things other than what I already know so if people in the know would not mind chiming in to let me know where they have bought the following from eg reputable suppliers:
Nema 34 & 23 steppers ?? chinese supplier?
Leadshine Drivers ?? chinese supplier wont be ordering these until the machine is mechanically together but would be good to know
2.2kw Chinese spindle ??
Steel Box section 80x40 ideally any good suppliers?
Alumimnium plate I will be getting from aluminium warehouse as this seems the best place for cut to size pieces
Ball screws and lead screws and bearing holders from Chai
Timing Pulleys from Bearing station or bearing boys
Any help with this list would be greatly appreciated, apologies if there is a thread with all this on I have just not come across it as yet
Cheers
Francis
Il help with the bits I can,
I used Aluminium Supplier | Aluminium Stock | Aluminium Warehouse for ali. I did a bit of a hunt and these lot where about as cheap as anywhere else and very convenient.
I also used and have been very pleased with chai.
One thing I will say though, is the BK bearing block for the RM16x ballscrews I bought seem to be very good. However the BF bearing housing seems rather poor. Fortunately, for my two long X ballscrews, I opted to have the screws machined at both ends, and use BK at either end. If I did it again I would also do the same for the Y ballscrew and Z Ballscrew.
timing pulleys, i used htd 15mm from Bearing Station - Adhesives, Bearings, Belts, Chains, O Rings, Oil Seals, Pulleys & Sprockets
For the steel if you want online try fhbrundle:
Rectangular Hollow Steel Sections - F H Brundle
For the aluminium either aluminium warehouse that kingcreaky already pointed out or ascmetals.
Metal Stockists: ASC Metals Lincoln Ltd. - Metal stockholders for East Midlands/North of England
It is worth phoning around a few local metal suppliers to see what is available from actual people rather than online it might work out cheaper especially if you can collect it.
For the motors I was planning on ordering from cnc4you, the price seems as good as ordering from china surprisingly... Unless anyone has found anywhere better of course.
Nema23 3.1Nm
The spindle/vfd off ebay, I think a few people have used solar.jean
Whoever you use, Id recommend getting all of your electronics from one supplier.
Although I got my steppers from cnc4you also, Zapp Automation Ltd is a site sponsor, and from what I read a member on here and a very good at providing advice and support to the products you buy from him. No slight on cnc4you but if I did it again id use zapp for the motors / electronics as I suspect this area will trip me up most when I come to assemble it. as ive used an array of suppliers I suspect this may cause me a headache when asking support questions.
Thanks for the replies so far thats a great help, to be honest they are all names that have crossed my path before but its reassuring to find people whohave good experiences using them so thank you :)
Quick question Kingcreaky regarding the machining of the leadscrews I was considering doing the same think about having both ends machined but using the fk bearing supports the only problem I have is that I cannot work out from chais drawings when assembled does the leadscrew actually make contact with the face of the bearing within the housing or does it butt up against the seal outside? or is the seal wide enough to accomodate the machined portion of the screw through it ?
I figure a drawing may help here to explain what I mean if I get a load of ?????? coming back :)
Sounds like the very same question I spent best part of a day trying to work out, then Jonathon helped me :D
this is what you are looking for (I think)
Attachment 7902
So, for me I wanted both ends machined to fit the BK style block. I wanted 1500mm of actual screw. First off, I required type A machining at both ends and I also wanted to drive the screw via a pulley so required dimension F to be slightly longer. so I order 2 of these for the X
** (1603mm Total length) I need (1500mm) of screw, so 1500mm PLUS one end machined to type A (except dimension F to be 25mm instead of 15, and the other end machined again to type A, but without any F
when they actually arrived they are more like 1606mm. (I think this is because in china they have more space for each mm :stupid: or their tape measures are backwards or something. perhaps the marks on the tape measure have to be slightly further apart to faciliate for the funny letters they use? PMSL
So am I right in thinking that where the screw ends and the machining begins is where it butts up against the bearing inside the housing?
Or put simpler if I ordered 1200mm of screwthread (plus the machining) with the bk attached at both ends I would have 1200mm of screw between the faces of the bk blocks?
I have just redesigned how I am mounting these as to start with I had fixed plates to hold the FK version bearings but was a little concerened that if I order this screw and find its even 3mm oversize length on the machining it wont fit so by going back to the bk style I have a bit more flexibility.
right ignore the last bit I think I have figured it out, is there a small spacer that goes in the bearing block?
Sorry, gonna have to pass on this question in the hope somebody else can reply. Until I get home and have a look atleast. I havent really inspected them. However, I think the bearing buts up against where the screw starts... no spacer.
I think I am beginning to confuse myself here! thanks for the help though.
Ok So after re drawing this gantry for what seems like forever to make it work the way I want I have nearly got it where I want it I think.
As said before this machine is heavily influenced by the red machine Jazz put up, so its all aluminium plate bolted together using ecocast plate where needed running on 20mm profile rails.
Ok can anyone recommend anywhere for the following?
Nema 34 approx 6nm and nema 23 3nm both from the same supplier? I can only find nema 23 from CNC4you
Also best place to get the dq860ma drivers?
Finally anyone had any experience with these guys?
PERFECT FOR NUMERICAL ENGRAVING/MILLING WATER-COOLED SPINDLE MOTOR 2.2KW q4 | eBay
Just noticed that they do a 34 at cnc4you but its an 8.7nm motor will this run with the above drivers ok. any alternatives for this motor more like 6nm? only thinking it might be a bit cheaper!
Hi Fvfdrums
I contacted a couple of people who had bought from happykissoul and they said they were happy with the quality and delivery though I've noticed that the price for a 2.2kw spindle + vfd on ebay has jumped massively from around £250 to nearly £650!!! :blue:anybody got any ideas why? - I'm about to restart my project :joyous:
Regards
Mike
Hi FVFDRUMS, i have been watching this build log because i,m going to build a m/c similar to yours, similar cutting area with similar size tooling(20mm linear guides and 16mm ball screws) .the lengths will be different sizes. i plan to m/c hardwood ( the occasional guitar body) can you let me know where you bought the slides, ball screws and bearing blocks to suit? also is there a download of the specs available so i can incorporate this info in to my dwg.
By the way, how is your build going?
Mike, I read another post that said the reason for the price hike is because none are available in the UK, but when back in stock the prices will be back to normal. G.
Hi PauROQuote:
Originally Posted by PAULRO
I got my parts from Chai at linearbearings2008 on eBay. Many on this forum have used him with good results. I got the following (see link) but swapped the supported round 1100mm SBR16 slides for SBR20. Chai was excellent in changing the order and I received everything intact within 10 days. 3 SBR16 sets +3 ballscrews RM1605+3BK/BF12 +3 couplers | eBay . I'm building my CNC to make guitar bodies
Regards
Mike
Well its been quite a while (9months) since I was last on this thread talking about the machine I was about to start and as per usual a whole load of "Life" has got in the way preventing this from moving forward in the way I had hoped.
Anyway to cut a long story short its got to the time of the year when for me work goes a bit quiet and means I can legitimately take some "time off " a real rare thing, so I have now planned in for work to start on the machine in the 1st or 2nd week of November.
I now have a great garage space I have converted with heating and all my machine tools so it will be much easier to produce a better quality machine in the space.
Only problem is somehow in the last 9 months the folder containing all my drawings has vanished and apparently its nothing to do with the other half :| so I need to start drawing up from scratch again which will give me an oppertunity to have a look at the design with fresh eyes. Honestly I am not sure I will change too much from before as it was based on a machine Jazz had shown me some photos of and I really liked the compact aspect of it and the moveable bed design.
So I guess its a case of watch this space over the next month and hopefully I will be back up and running with a shopping list a workable design to go with it. Thanks to everyone so far for their inputs and guiding me in the right direction.
Quick question that I was trying to get answered earlier in the year but never got a definative so I thought I would get "paint" involved.
I was wondering if the BK12 bearing units have a rubber seal in them before the 2 bearings in the houseing and if so does the machined end of the ballscrew stop at this seal or the black part at the back of the unit or doe it fit right up to the bearings inside the unit. Picture attached is it A or B or even C and I am way off!
On a separate note I am awaiting the arrival of some profile rail and bearing carraiges, managed to find a good deal in the end and they are now in the country according to Royal Mail and out for delivery so there is a chance they may turn up today which would be great.
If I am not mistaken it is more like B but there is a little spacer at each end of the bearing so that the ball screw does not squash the rubber seals. Be in mind that you will have a bit of free movement at the BF end as the bearing can float in it, say about 3mm. ..Clive
You're not mistaken :)Quote:
Originally Posted by Clive S
Thanks for the replies, I also had one from Chai and confirmed the same thing I am actually planning on using the bk12 on both ends so wanted to make sure where the ball screw ended in relation to the placement of the bearing blocks.
Whilst i am here, this machine will have an adjustable bed, I was wondering what peoples opinons are on a sensible distance between adjustment holes? 50mm 100mm? That is how far the bed moves up and down between one set of holes and the next
There's two reason to use angular contact bearings (bk12) on both ends of the screw. One reason is it increases the axial stiffness of the screw, since you have twice the number of bearings supporting it. The other reason is it raises the critical speed of the screw, so you can spin it faster without it whipping. For the vast majority of DIY builds, the stiffness of the screw is at least an order of magnitude greater than other parts in the axis, so you're unlikely to see a tangible gain from doing so. The critical speed however is important, but for the 1610 screw you've chosen you'll be able to get good feedrates so long as the screw is no longer than 1500mm. According to an earlier post ('1200x900 footprint area with approx 1000 x 800 cutting area'), your machine is well below this length so using two BK supports on each screw will only increase cost with no useful gain.Quote:
Originally Posted by fvfdrums
(Search on google for 'Ballscrew stiffness calculation' and 'ballscrew critical speed calculator' if you want a reference for the above.)
It depends on your Z-axis travel. Also no need to have them evenly spaced, why not have more holes nearer the place you expect to be using the bed most often and less at the limits? In the past I've gone for 60mm spaced an 50mm spaced, simply because that what the size of the box section I used. You'll probably only move the bed about once a year anyway! I'm not sure I've even moved mine that often, and the latest machine is so much stronger that it doesn't matter where you put the bed.Quote:
Originally Posted by fvfdrums
Hi
Glad to hear that you have restarted your project. So have I and I've just ordered my aluminium plate for it. I noticed that you are going to use BK12/BF12 bearings - I have 2 pairs surplus to my build as I am using FK12 and FF12 instead on the Y and X axis. If you are interested, pm me andwe can come to some arrangement.Quote:
Originally Posted by fvfdrums
I will be officially opening my build log soon!
Regards
Mike Campbell
Ok, so today started with me making a 5 mile trek with these linear bearings on my shoulders all the way across nottingham becuase the other half has the car and is away for a week and there was no one around to grab a lift from (I know I could have got a taxi but that would have been some of the cnc fund ;) ) Anyway I would not recommend it.
Having said all that when I finally got back home and inspected the package it was extremely well packaged and I would not hesitate from ordering from FA Systems from ebay again or recommending them. They were extremely easy to deal with even had a bit of negotitations with them for a better deal on price and postage and they arrived in 5 days from Korea. I got stung for a little Import duty but overall it was a great deal.
The bearings themselves hardly look used, they are well greased and run smoothly up and down the rails which also are mark free so all in all very happy indeed.
@ Mike - Thanks for the offer but I have just placed an order with Chai so I already have these parts on the way otherwise I would have been in touch. I look forward to seeing your build come together.
So due to the dimensions of the rails it has meant we have a slightly different sized machine now, its 1130 x 1060 with a cutting area of 940 x 940. The redesign of the machine is going well and even though I would have rather had the original files to work from its bee refreshing to tackle the design from the ground up and incorporate some of the great ideas people have come up with over the last year since I put the original together.
More ordering done from overseas!!
We got a great deal on the motors and drivers so now we have 1 x nema 34 and 2 x nema 23 plus 3 of the 7.8amp drivers coming in the next 5 days or so.
Also the order from Chai has been processed now and is also enroute so once everything is here and checks out I think its time to get on to Aluminium warehouse and start the gantry build!
btw: Chai was extremely patient and helpful even pointing some things out I missed and I did not feel the language was a barrier at all. Hopefully what arrives is as good as the service
Chai is a top bloke and he's saved my bacon a few times when ordering stuff because I've forgot to add BK/BF bearings and he's sent them anyway. Suppose that's because he knows I always buy them together but still good to know he's got my back.!!Quote:
Originally Posted by fvfdrums
Ha ha! exactly the same things with me, so concerend with getting the sizes right of the ballscrews that I didnt even put the BK on the order low and behold the quote came back with the relevant number of bearing housings on the list! The guys greatQuote:
Originally Posted by JAZZCNC
Another question?
In peoples experience what is the best size bolts for joining 20mm 6082 plate together in this case for the gantry of the machine? I am thinking of fitting dowel pins in place once the whole assembly is together to aid with reassembly should it need taking apart in the future?
Not much point using bigger than M8, so most people use that.
To aid alignment when assembling you could machine reference edges on the relevant plates, if you've got a milling machine?
I have got a mill but its not big enough for the cross pieces at 1100mm long to do that. I could maybe do reference edges on the side plates.
Thanks for the info on M8 :)
I use M8 for bolting together the Gantry your copying. M5 for fastening profiled Linear rails.
In general you'll need an assortment of M5,M6, M8.
Depending on how your fastening Steppers then you may want M4 But I tend to use M5 and tap the stepper. If your bolting thru stepper then some times depending on stepper frame M5 socket head will touch motor side, not always but does happen. I just whiz head against bench grinder rather than use M4. I try to keep different bolt sizes to minimum, fewer tools needed and less variety of bolts required.
If tapping the stepper you can use M6 without any problems but M6 is no good for bolting thru stepper has head is much too large.
Thanks JAZZ that's all really useful to know.
The nema 23 inside the gantry is bolted face on to a plate that uses a screw to adjust the tension and another to lock it off so I would imagine bolting straight through with m6 tapped frame in the motor will work well there.
As for the z that will probably be the m5 (with head modified if needs) as the design calls for it to be bolted to the mount rather than the other way round.
Hopefully I can get the gantry built over November if work allows and then have December to get the frame cut and welded up for the base.
I have not put any feet on the frame design and was thinking about sitting it on a concrete pad in the garage that I will run some levelling screws over. Does this sound like an ok base for a machine like this? I will be bolted down ideally which is why I'd rather it was as level as poss to avoid distortion to the frame
Or should I bolt it down as I weld it up?
Best if bolted down but it will be heavy anyway so won't exactly float away. Thing you need to avoid is not putting machine in twist.Quote:
Originally Posted by fvfdrums
Don't know how you plan to get X axis rails on same plane but which ever way then do it after the machine has been situated where it's going to live and fastened down.
Don't bolt it down has your building it. When building try to find level and flat surface that is not in twist to work from, don't just work from floor unless you absolutely know it's perfectly flat and not in twist. If you don't have decent surface then It's worth taking the time to build one. If the work surface is in twist then the frame will be in twist when welded up.
My original idea was to pour a temporary surface to do all the welding on and then remove this once done.
Alternatively I suppose I could make a torsion box to assemble from.
Got a text at 7am this morning to say the Motors and drivers should be here today, thats crazy they were collected in HK at 10pm on friday night and are here this morning now thats service!!
So hopefully I should be able to add a few more pics to the component pile.
I had "yet" another question, whats the smallest or should I say recommended diameter for a 5mm pitch HTD timing belt pulley running 1:1 - is there a minimum number of teeth people would recommend (other than as many as possible) being in contact with the pulley at any one time?
The reason I ask is not for the z or the y as they are simple straight connections with the pulleys in front of each other.
Its the X where I am driving the two screws with the single belt, I can get half the way round the pulley on the left hand side however on the side with the motor I am going to have to put in some idlers to make the belt contact more with the pulley so I can nearly get about 120-130 degrees around one side of the pulley would this be enough?
I thought about doing one belt connecting the two axis and then stacking another pulley on top of the right one and driving this but my concern was "if" the belt were to snap (the long one between two axis) then one side would still be driven by the drive pulley and could cause some bending if it carried on and the other stayed still. Where as if the one belt were to go they would both stop.
Suggestions?
Wouldn't go lower than 20T.
Regards the one belt connecting 2 screws then that's how my machine runs and I've not snapped a belt in 6 years use so wouldn't worry about it.!
If you want to be extra careful then use spring loaded NO limit switch with bearing on end tensioned against the belt and wire in series with E-stop so if belt breaks tension releases and causes an E-stop.
I think I have them as 24 teeth at the moment so i guess that should work.
Motors and Drivers have just arrived. Well packaged and look good so one more package to come from Chai and I can start on the Gantry. I would just rather have the parts with me to measure from before I start drilling and cutting.
How long does Chai generally take to get things machined etc once the order has been placed? I know it takes 1-2 weeks to ship.
Attachment 10477Attachment 10478Attachment 10479Attachment 10480Attachment 10481
Can't tell you that but Usually arrive between 9-12 days from placing order. Often any delays comes from UK end.!!Quote:
Originally Posted by fvfdrums
24T will work fine.