Z axis front plate on the mill as we speak just in for a nessecary cup of tea!
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Z axis front plate on the mill as we speak just in for a nessecary cup of tea!
Been busy for a week or so but have managed to get some stuff done. The z axis is now done and on the gantry which is great, all moves up and down nicely I am leaving fine tuning until its all sat on the frame.
Speaking of the frame I should be expecting the steel delivery next week for the main framework and the weekend after will be a 3 day weekend of getting the frame sorted and the gantry sitting on it hopefully.
In the mean time I have been levelling out a pad in the workshop for it to sit on as I realised after closer inspection that the floor did fall away in the corner where the machine is meant to be going so I thought I would level a specific area for it to sit on which once dried out will hopefully double as a nice flat plate to set the frame up for welding on as well. I have left adequate room around the machine for maintenance once all bolted down.
Few tedious pics of the pad going down
A decent amount of progress made on the frame this weekend, inspired by the build Jonathan did recently we decided to go down the route of a similar frame but at worktop height so working height of the bed is around 850mm at max settings. All made from 60x60x5mm, took plenty of time to weld up moving around the frame tacking then putting down some good welds so as not to distort.
End result is an extremely level frame in all directions (still will be doing resin but more to level out the bow in the cross section of the steel box section which is very noticeable along its length)
Still need to finish fully welding the frame as the bed is still only tacked but then X axis drive components next!
I'm a Boilermaker, and run into this all the time. The bow is caused by the shrinkage of the steel after it's cooled from the cherry red of the weld. If it's easier for you, if you heat the opposite side to the weld by roughly the same amount of heat that's gone into the weld (you could weld opposite, then grind flush when finished), it will shrink by the same amount (i.e. straighten). I normally put a torch to the opposite side, and eyeball down it's length until it's bob on.
Always weld opposite the last weld to keep distortion to minimum, but it'll always creep in...
You should put a couple of decent tacks on one seam, then weld the opposite. Then go back & weld over the tacks.
Might save you effort and/or time...Certainly save epoxy...
Really love that gantry, presumably ally? Would love some more details on it. Which supplier did you go to for your rails?
Looking good...
The bow in this case is consistent along the entire 7.6metre lengths of the steel when they arrived (more of a sag left to right if that makes sense, very subtle but needs to be levelled. The welding process has not accentuated this at all its not in twist intact its very straight as every joint and opposite joint was well held anddidnt really move much after welding due to the short periods of welding
The tacks then weld opposite is pretty much what I did but I did about a 30mm weld on one side then went back to the other then moved to the diagonal opposite part of the frame always checking then diagonals etc and angles for squareness so end result I am extremely happy!
Thanks for the comments :)
looking very nice, you won't break your back leaning into it at that height.
So its been a bit of a while since the last post ..........
...... Anyway things have moved on a little bit and this coming weekend I am about to lay down the x rails for the final time on a bed of epoxy, weather is not treating me to nice temperatures but have a nice set up in the garage now to maintain a good heat source for a couple of days to aid with the curing.
In the mean time I have a question I am about to order the spindle for the machine, originally I was going to go with the 2.2kw WC chinese style spindle however I was wondering if there would be any benefit in going for the 3kw version? I am looking at mainly machining aluminium on this machine and wondered if the large powered unit would be any better? Is it worth the extra?
I shall be putting up some more pictures etc once I have the rails and everything on the machine after next weekend and then probably posting every 5 min asking about wiring the damn thing!
In short.. yes as the extra torque helps when operating in the lower speed range.Quote:
Originally Posted by fvfdrums
Thanks Jonathan, I thought that might be the case I was not sure how much difference it would make but really the cost at this stages makes no real difference so I think I will go down that route many thanks.
In case you weren't aware the 3kW spindles are usually 100mm diameter, rather than the more familiar 80mm diameter of the 1.5 and 2.2kW units.
yeah thanks for the heads up I had taken that into account with the mounts one of the other reasons for making the descision so I could finalise those.
3KW version now ordered so getting on boring out the mounts!
Managed to get a bunch done today which was great!
Earlier this week I had some deliveries in the form of a 3kw spindle and inverter, some west system epoxy and extra slow hardener, some more aluminium plate and a few more essentials to move this project along a bit more.
I started out today machining up a mount for the x axis drive motor which is going to be driving 2 screws with one motor so needed a good mount and also space for a good tensioning system. The parts for the tensioners only arrived this afternoon so I have not had a chance to add those yet but they will be going on the taller part of the mount that the nema 34 motor is attached to.
I have managed to get some heat into the workshop so on sunday I am going to get the epoxy resin poured. Any tips? I have read most of the builds using this and I am sure if I follow those steps everything will work out fine! (heres hoping)
Finally I did not order enough aluminium for the spindle mount so mocked 2 plates up out of polycarbonate I had lying around and fitted that on to make sure I could get at everything for adjusting etc. So far so good all looking great, just need to spend saturday on the X axis mounting blocks and the timing pulleys and should be about there ready to pour the epoxy.
One last thing do people recommend drilling the x axis rail mounting holes before or after pouring the epoxy?
Do it after the pour it drills easy and doesn't cause any problems.Quote:
Originally Posted by fvfdrums
One word of warning with the epoxy and this cold weather.? I've just done a pour using 206 hardener which is faster curing and in a thermasticly heated workshop and after being left 5 days I still got a little sinkage after fastening rails. Nothing major but still enough to need a slight shim to avoid putting bind on the bearings.
Using the 209 I wouldn't touch yours for at least 10days. If you have any spare epoxy pour a little into something to simulate the width and depth your doing and then wait until it's gone hard so snaps when trying to bend. If it bends and doesn't break it's not ready. The surface will feel hard to touch but it won't be cured all way thru.
Cheers Dean! very helpful as ever :)
The plan is to pour it on sunday and then leave it for probably near on 3 weeks as I will be away with work so cannot do anything on it anyway so figured this would be the best option. I am planning on making a sort of tent around the machine and using a 3kw oil radiator style heater on a thermostat to try and keep the temp up. I prefer these to the fan type as at least they are sealed and there is no exposed heating element. This way i am happy to leave it on for extended periods and not worry too much.
I will pour a couple of samples of any remaining material as tests as well so thanks for that. I will look out for the "Snap" test once I am back.
Any suggestions on where is a good place to have a made to order length timing belt? I have yet to find one
I cut my bridge off when the epoxy had been on for 10 days and used that (it was on parcel tape on the bridge so just slipped off no porblems) to do a snap test...made sure this time as I had proper bendy epoxy last time....Quote:
Originally Posted by JAZZCNC
I get mine from a local supplier to my business in Goole called Yorkshire engineering services give them a ring they will sort you out I'm sure. 01405720085Quote:
Originally Posted by fvfdrums
Another good weekends work out of the way...
So a slight change of plan, after heeding the warnings of laying out resin in the cold and the temp around here steadily dropping it was decided that we would attempt to see how level we could make the machine using various measuring methods and after an hour or so of painstakingly shimming and adjusting the base the top was where we wanted it to be.
A few cups of tea and staring later the straight edge I ordered arrived and from this we could see using feeler gauges there was a pretty consistent shallow curve from one end of the steel to the other mainly due to the welding around the middle of the machine as this was within 0.05mm at the same point on either side of the machine.
As the difference was not all that large we decided to embark on shims and the possibility of using epoxy putty if needed. All I can say is dont be put off by having to shim rails! Initially I did not even think I would be able to get it near close what we needed however a couple of hours of filing high spots and then measuring using a feeler and inserting the correct piece of shim steel and we had the rails matching the straight edge.
The gantry moves smoothly from one end of the machine to the other no tight spots and I just need to get hold of a DTi in order to do some final checks however all in all I am very happy with the results.
Fitting the x axis screws however was a PITA....
The first one went on fine, no binding alignment was great everything slid in place.
The second one is really bent :( I thought it was a bit bent when it came from Chai - i registered a complaint but heard nothing back after 2 emails. However with one end bolted down and the ball screw holding it steady one rotation of the thread results in the loose bearing mount the other end moving up and down about 2-3mm dependant on what part of the thread you are on.
Does anyone know anywhere I might be able to get this straightened? I have no access to a hydraulic press or anything precision enough to make this good? any suggestions?
This aside its all on and screwed in place and a few turns of ballscrews here and there results in a pleasing movement across the machine. The only other issue is there seems to be a large amount of end float coming from the bk bearings I have either end so I am going to disassemble them and see if they need shimming in the middle!
All in all a successful weekend :)
This was Chai's response to my bent screw;Quote:
Originally Posted by fvfdrums
Before shipping, we tested the ballscrews VERY SERIOUSLY as the following standard:
The ballscrew assembly (Ballnut and Spindle assembled) Precision rolled, class 7 accuracy; JIS (0.050/300mm) (0.002"/12")
Ballnut: Single ballnut with zero backlash (<0.015mm) (0.0006")
Please refer to the link:
http://www.roton.com/screw_shaft.aspx
YOU can addust it if necessary.
Also here's some info on fixing those bearings; http://www.mycncuk.com/threads/6565-...6128#post56128
If you identify the bend location you can make a fair job of straightening these screws using a vice and 3 blocks of wood. You'll be surprised how much bend the screws will tolerate before becoming a problem. Obviously any bend will have a little impact on the life of the screw/nut but IME even moderate bends won't affect machine performance to much and last years without any problems. I doubt you'd still have machine before it became a problem and when it does you'll be ready for changes and upgrades.
Regards the BK bearings then check the bearings are not in wrong way around which often happens. I strip every bearing to clean/re-grease then shim and every other one the bearings are in wrong way around.
I have had a play around with the bearing blocks, all of them had both bearings facing the same way round rather than back to back, also there was a larger amount of slop in at least 4 of them so I have ordered some alternative bearings to replace with as I was getting 0.4mm of end float once everything was tightened up.
So whilst I am waiting for bits to arrive I am trying to source some bits I was wondeing if people could let me know if they have any suggestions for the following?
e Chain? - have found a reasonable supplier on eBay for it so might just go down this route about £10-15 for a metre
Breakout board combination: Can someone tell me if I go down the PMDX or smooth stepper route what I would need. I did not order a BOB when I bought my stepper drivers as I had heard so many people knocking the cheap BOBs. So my question really is which of the two do I go for SS/PMDX and if so what do I need as well as this to connect to mach 3 (I am not talking limit switches etc I just mean between stepper driver and PC)
Finally now I have the rails levelled using shims I have a litre of WS resin and 209 hardener I dont use I would be willing to let go for a good price if people are interested please IM me :)
First I'll take the resin if you still got it.!! I'll PM you
Looking really good now well done. I wasn't happy with my 2 X-axis ballscrews so sent the worst one away to be straightened using a hydraulic press. My original post is here:
http://www.mycncuk.com/threads/7160-...bent+ballscrew
Looks like I never followed up this post but it came back really straight and ran sweetly in the bearings.
I decided not to send out the ballscrew which was only slightly bent and fitted it to the machine instead. As Jazz mentioned there were no noticeable problems.
I know your spindle mounts are only temporary perspex parts, but I assume the real parts will be much thicker (my first ones were 20mm aluminium and worked well).
Thanks it's nice to be finally getting somewhere!
It just so happens I have justified a 12 ton press this week as my van needs all it's bushes replacing and for the cost of the bushes and a press I've saved a heap on garage costs so I may well set up some v blocks and have a go at that.
Running them up and down I have noticed the bent one is considerably more noisy than the straight one
So you too like Justifying? :hysterical: I have my garage full cause of this...
Dont forget to grease the screw right now. In all tech docs is said the screw should be greased /oiled/ prior to putting to use.
Thanks Silyavski :) yep justification is key!
Whats the best kind of grease for the screws and bearings?
Hiwin Lubrication Guide, in short any grease or oil that has no solids like Mo and Graphite. That includes WD40 too. That would be any normal bearing automotive grease which says NLGI2
I used yesterday normal lithium grease that said NLGI2. I thought of making central oil system but at the end decided against it, too much hassle and extra cash to do it properly, when i could simply use the grease gun and forget about it.
Quote:
Grease lubrication
Grease lubricationFor grease lubrication, we recommend greases in accordance with DIN 51825 of consistency class NLGI 2 as specified by DIN 51818.
For normal loads, standard greases with the designation " – K1K“ are sufficient.
For higher loads (P/C < 15), high-pressure lubricating greases are required: "– KP1K“The use of greases of other consistency classes is possible subject to the approval of the lubricant supplier.
NOTE Greases with solid particles such as graphite or MOS2 must not be used.The following information on lubricants serves to provide examples and is only intended as an aid to selection.
Quote:
Oil lubrication
Lubricating oils offer the advantage of more even distribution and reach the contact surfaces moreeffectively. However, this also means that lubricating oils collect in the lower area of the product asa result of the force of gravity and thus more quickly cause soiling. For this reason, higherquantities of lubricant are required than with grease lubrication.
Oil lubrication is as a rule onlysuitable where a centralized lubrication system is used or for products equipped with a lubricationunit.Observe the lubrication system manufacturer's instructions.The following information on lubricants serves to provide examples and is only intended as an aidto selection. Other lubricants may be used after clarification of the specific application and thecentralized lubrication system used with the lubricant supplier.
Lithium 2 (grease) is what I always suggest, can get a tube for £3 here, can't remember size but it's on par with a tube of silicon sealant or decorators chalk, so quite large for the amount you'll use.Quote:
Originally Posted by fvfdrums
Oil don't last as long but grease clogs up, take your pic.
.Me
So it looks like its time for some wiring!
I have spent a vast amount of time reading through the forums and over using the search facility (if there is such a thing).
Anyway I am drawing up a wiring diagram at the moment but there are a couple of things I could do with advise on.
I have decided to go with the CS Labs CSIMO -IPM as it seems to suit the machine perfectly as its running a single belt to drive both x axis screws. This also means I only need run a separate 24v DC supply for powering the unit and also the safety circuit.
So on to the safety Circuit it is....
I am confident I have the bases covered on isolating the mains supply to the drivers on fault or Estop however what is the best way to isolate the spindle? as I have been reading removing power from the inverter is not always a good thing? what are people doing to make the spindle safe in an estop senario? (chinese 3 kw spindle setup)
That then brings me on to drives, when I started the machine (many moons back) the drive and motors were ordered from china I was under the impression we were getting digital drives, having glanced over them at the time I did not really take any notice but it appears we have 3 of the DM860a drivers. Now given that this much effort has been put in I am thinking its worth switching these units out for the AM882 of the EM806 drives? Would this be a good move or a waste of time?
If a good move then I have 3 brand spanking new DM860 drives for sale if anyone is interested please PM me!
Thanks as ever for the on going support from an incredible knowledge base!
When BOB is reset it stops giving On signal to VFD ON input so the VFD stops, hence VFD low voltage On is chained on the Estop line.Quote:
Originally Posted by fvfdrums
Waste of time, these are good DSP drives. Almost the same as the AM882.Quote:
Originally Posted by fvfdrums
However if you have the simplest 3kw inverter like the diagram below, care should be taken what voltage flows there. So if you board is 5v and the inverter is 24v or vice versa. Best would be that you have an Estop button with double switch circuit or you just use an enable output on Mach3 and a relay on your BOB.
http://www.mycncuk.com/attachment.ph...id=14676&stc=1
Depends how Anal you want to get.!!! . . . Really with an emergency stop then power should be removed. Just removing the RUN signal isn't compleltely safe.
Killing power to the VFD isn't ideal but in a true emergency then it's what you want to happen. It can be done safely using timer relays to allow time for spindle to shut down safely before power is removed.
Is it really needed.? Well only you can answer this one.! . . . Me i'm happy to isolate the run signal using a relay, Which by the way the IP-M as built into the controller so can connect direct to the VFD.
Drives because you have them I'd stick with and they'll do the job ok but NO they are not good as the AM or EM which are much smoother refined drives. Just because they use a DSP doen't make them the same.!
So in a nutshell - what benefits am I likely to notice between the DM and the AM/EMs? I know they have the stall detection is that as vital if I am only running one motor for the x axis? or have I missed the point...
I think the run signal works for now. I can see this panel taking as long as the bloody machine at this rate!
Also,
just reading through the manual for the BoB it suggests if using a large contactor to switch off the power its an idea to have a diode and a noise suppression device? is this to prevent voltage spikes? and how would one go about adding these to the control panel?
In a nutshell you'd get smoother movement from the motors, esp at lower speeds. Also less motor heating as they handle current much better and the drives software seems much more refined.
These things I know for sure just from the limited experience of the DM's vs AM/EM which I've loads of experience with.
While I can't answer this 100% because my experience with DM was limited I'd take an educated guess and say you'd get slightly less speed/torque compared to EM as well.
This said I still wouldn't sell the DM if you have them as the difference in use will be minor but there is a difference. The stall detect isn't an issue at all for you so don't fret about this and you haven't missed any point.
ok so assuming that I use these DM860 drives. What do I do with the enable signal? It says in the manual normally left unconnected (enabled) if i were to use it what would I be connecting it to? Sorry a little confused on that one
Whichever controller board you decide on, it should have a connection for the enable/disable.Quote:
Originally Posted by fvfdrums
thanks for the reply, I know they have to be connected to the controller and I am settled on the CS labs CSMIO IPM board which I am sure has a facility for connection of these I am just not sure where they are meant to be connected to on this. Is it a digital in or out? .......
Give me a welder over a soldering iron any day!
Does anyone happen to know the dimensions of the CSMIO IPM board roughly? trying to source a control cabinet and know everything else size wise apart from this, it does not appear to be in the manual or on the site as far as I can see.
http://www.cs-lab.eu/en/produkt-18,2...onnectors.html
It's on the page :wink:
some times you cant see the wood for the trees - or in this case I have looked at that page so many times I just plain did not see it, now I have looked I have no idea how I missed that.
Cheers for that!