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The Zaxis dropping most likely won't be due to weak design problem but more probably an electrical problem, possibly a weak or under powered motor thou you'll still have the same problem if not changed.Quote:
Originally Posted by m.marino
Other than what marks pointed out then there's not much more to see or say.
Okay but then comes placement of the lead screw, as don't have the funds for a new ballscrew at present. Folks I am really aprreciative of your input it is just that I have a rather large amount of work that I have been finishing that was supposed to go to this convention for clients who are interest and some that are closed sales IF I get the product there.
Again thanks and will try to get some revised drawings up later tonight.
Michael
which one Z or Y screw? i thought you already had them??.. they will already be as long as they are :heehee:Quote:
but then comes placement of the lead screw, as don't have the funds for a new ballscrew at present.
Attachment 4547
there are ways of squeezing them in
Okay Mark and Jazz,
Here is an idea for the rails on the Y axis
Attachment 4548
The leadscrew will run down the channel between the two rail supports and the back plate will be bolted to it and the the uprights. At that point I think I will be able to move the spindle closer to centre that way.
I am going to get some sleep and get on this tomorrow. Thanks for all the input folks and will work on things to the best possible.
Michael
Okay,
Further drawing, as promised. With additional information.
Uprights of gantry are currently looking to be either 20 to 25mm (or 3/4 to1") thick. The rails are bolted down to 25 x 38mm bars that are going to be bolted to the back plate (12mm). The Z base plate is 20 (or 3/4") . I hope the way I had the jpeg done allows folks to see more of what is going on without getting a headache. This is a rough sketch done with ViaCAD 2D/3D and no I don't own any part of the company nor have vested interest in it.
Attachment 4560
Any and all opinions are please.
Michael
the preportion of flex along the Y axis looks like it will be huge compared to the X and Z
if the aspect ratio on your gantry absolutly has to be that tall id be tempted to go for a fixed gantry (heavily made) with a moving bed
I agree,
But space is an issue. I am thinking of using an old bridge builders trick and bolts some strengthening rails to the outside to help add rigidity. overall hight is 475mm will have the distances shortly between it and the rails it will run on. still working on it. design gets to be nightmarish after awhile.
Michael
You could always build tall sides for the base, to reduce the distance between the x-axis supports and the y-axis.
It would mean that when you're machining on the base, the cutter would effectively be working below the x-axis supports, but the higher rails should improve ridgidity.
Yes, that combined with a bed which you can adjust the height of is by far the most rigid way to do it. As there are effectively no gantry sides you have eliminated the flex they cause. You can make the rest of the frame as heavy, and therefore strong, as you want as it is now stationary. I changed my router to that configuration and it has made a huge difference:Quote:
Originally Posted by m_c
http://www.mycncuk.com/forums/showth...ll=1#post22767
It is interesting that you seem to have profile rails yet cannot afford ballscrews? Is that because you spend all your money on the rails!
Have this beautiful drawing sitting down on the shop computer that I swear I had transferred a copy up to the office. Well will post it tomorrow with a good bit of detail on measurments so that things can be relevant to folks when you look at it. I am now starting to get sources for materials together and final costing for the upgrade. It is coming in at an acceptable cost (lesson learned the hard never really are). If I can arrange things with folks for the cutting and milling that needs done I might just have it up and running in new form in time to make enough parts for the convention.
Also have ordered shielded cable (Thanks Jonathan and Jazz for your sources). Hope that will help with the dropping steps enough to get some cutting done while getting the rest of the parts in.
Michael
Slight interruption as the newest child arrived very early Saturday morning.
Folks,
Looking at cost and speaking to a few of you folks. I would like your opinions of this solution to the current problem with kit router I have from Marchant dice until I can get the budget back on track to build the slightly larger and more useful unit. This is just Y and Z axi' pieces and the Z is not complete as the rails will be part of an outer "box" section that will come from the rails and screw in back with the stepper mounted directly on top with a plate at top and bottom of rails going to the front where another plate will vertically connect them to give the face for the spindle mount.
Here is what I have drawn and will hopefully have more tomorrow.
Attachment 4642Attachment 4643
Thanks for all responses. I still plan to build the larger unit and will definitely be using a lot of the wonder ideas from Jonathan, Jazz, and others here.
For those who are interested Tomas is doing well and being a nice healthy baby boy.
Michael
Michael congratulations on the new addition well done mate
:toot::toot:It's a boy :toot::toot:
James
wait until you get shopping bags under the eye's LOL
Well,
Thomas is settling in just fine and I have been working on the model like a mad man to try to get things done and production back on line. As such you will find attached three jpegs that show the current design with leadscrews and anti-backlash nuts from DumpsterCNC. Stepper motors are not mounted nor are their mounts in the X or Y axis. Not all bolt holes have been put in yet for take apart for piece generation but getting there.
The 1st (a) is the full model minus the above and the gears and belt for Z; 2nd (b) is with table plate removed and Spindle plate of Z removed; 3rd (c) is with the close leg ofthe Gantry removed & the under plate of the Y/Z section. The extrusion you see I already own and they are simply migrating from the old machine to the new. I have not finished the holes for the Bearsing as of yet even though their models are in place, excluding the exterior bearing forthe Y axis (still debating whether to go that route or stick with just the one, leaning heavily on adding the second bearing).
Well with all that said, please constructive opinions please.
I do have to give thanks to Jonathan for a lot of input and also Jazz for some very usefull ideas.
Attachment 4736Attachment 4738Attachment 4737
Again thanks for all the knowledge and support in this I have received.
Michael
Michael but if I've read your post's right to are going to have a X-axis between 750 cm to 1500 cm on a unsupported rail
I would think you are asking for trouble??
I am no expert and have not completed a machine yet but I know how little force is required to bend ( make the ball screw arc) and your asking it to support around 25kg with out any movement
sorry but I think you will have to rethink it
James
James this is the rebuild of the current machine and if it was that long you would be completely correct. That rail is only 500mm of 20mm dia. So should support it over the 250mm of travel it has.
Thanks for the input though and the build from ground up is still in progress.
Michael
He is asking for trouble using unsupported rails. Apparently a future upgrade will be the rail and changing to ballscrews when there is more time.Quote:
Originally Posted by luke11cnc
sorry I put a extra 0 in my post even so I would buy supported rails or even bearings on a length of steel like the FA100 Machine I think that's the right machine if cost is a issue
worth a look Michael
James
Michael knowing the tolerences you want to work too then even at this length the unsupported rails will make that nigh on impossible.
With a machine this small the little extra cost for frame material and supported rails would be worth every penny.!!. . . . Dont dont it mate.!
I'd forgotten the required tolerances were very very tight ... so I couldn't agree more.Quote:
Originally Posted by JAZZCNC
You've gone for profile rails on Y/Z, which couldn't be better, then used the worst option (disregarding silly things like aluminium angle+bearings) for X which is the main support.
Just make the bed a little wider and you can fit some nice profile/supported rails underneath with the added bonus of them not getting covered in swarf.
here is the link and bearings I was talking about
https://www.finelineautomation.com/store/show/CRP101-00
when are you intending to build you CNC machine ??
James
Even these wont be good enough for what micheal needs james, they will be strong enough but not really accurate enough. These are better suited for wood routers thou do have there issues, namely crap getting on the steel surface causeing sticking etc.Quote:
Originally Posted by luke11cnc
Really what micheal needs is a milling machine or a very substanial frame router.? Given the small size think actually better would be a fixed gantry moving table design, could be made much stronger allowing for better accurecy. . . . thou Under stand he's trying to upgrade an existing machine so his restrained by what he's already got.
Personaly Micheal I think your on a very very fine line financialy between not being worth the trouble of upgrading and going straight into building exactly the machine best suited to your needs.
Honestly I feel that by the time you have invested money on profiled rails, upgrading cheap lead screws with dumpster nuts and stiffening the chassis and all the other stuff you'll have to invest into getting this machine something like near the accrecy you would like, which I also feel you will never achieve anyway with this type of design. Then you'll be much better advised to not waste time or money and go straight into building the new machine. . . . Also think time wise it wont take you much longer.!!. . . you'll spend so much time chasing and tweaking the old machine a new build could be done in about the same time.? . . .Obviously if the finances are available.
Sometimes it's just better to cutt your loses and start a fresh.!!
Ok Jazz
How much would it cost Michael to have profiled rails for the X-axis for his machine
James
James thanks for the information. For the most I am rebuilding/building this one. Cost wise, I am having to keep it as under control as I can. The rub is this is the tool that i make a good bit of my busines from. Okay, what do I make? Chromatic harmoinica parts (custom combs, mouthpieces, and such), parts for the no longer made and Hohner pitched the tooling for them in 1985, Harmonettas (Google it, they are really nice pieces of kit, and Yes I am the Mike/Michael that makes the gaskets for them), repair parts and upgrades for Bass/Chord Harmonicas. Parts for concertinas.
This way folks can understand what the accuracy issues are. Right now doingsome rework after listeningto you folks and thanks. Beofre the bearings went I was getting mouthpieces, covers and combs out of the mill without a huge amount of waste (was still making profit). The kicker is that the biggest feastival for harmonicas is the end of the month and I have order from my US distro and clients. I won't take orders if I can't supply product directly (ask a serious harmonica player about Henderson harmonicas,wear earpplugs). So I move forward as able and thank the Lord funds are coming together to do a sort of rebuild (less of the original then new) That should do the job a whole lot better and keep doing it longer then I will need it to (meaning that it will pay for the next one to be built).
Once this is all done and past I will put up potho's of some of the different parts that I make.
Again folks thanks for all suggestions and hope you are doing well. Oh, one bright point the anaerobic antibotics they finally put me on to clear up a long standing post op infection are doingthe job and I am getting a lot of energy and focus back so give praise where there is reason.
Michael
Well folks,
work and payment recieved have come together to allow me to get the pieces together to buil the model I have below. Support round rails ordered (Thanks Jonathan for challenging my idea and sorry JAZZ for not contacting you first). The rails and 2 of the carriages will be coming from Jonathan. The other 4 carriages and two rails for Y axis JAZZ has helped with me getting. DumpsterCNC anti-backlash nuts ordered and in route via post. Just need to get a hold of JAZZ on cutting and where to have the metal sent to. Also need to get a hold of m_c for the modification on the pieces that are here.
JAZZ or Jonathan (Heck anyone with more experience then me) please speak up on anything you might see wrong with the design. NO, not all bolt holes have been put into the model yet. Yo uwould be surpirsed how much time doingthat and making sure that there is no conflicts and enough Metal to grab. No the motor mounts are not all present and the gear i put in the top of Z keeps vanishing.
Attachment 4740
Thanks for all the advice and will get pic's up when all the pieces go together.
Michael
It's just occurred to me that your gantry has very poor torsional stiffness. Normally that's not a problem as with two ballscrews it can't twist, however with only one nut in the middle when the cutter is near either edge of the bed the gantry can twist causing deflection. Given the tolerances you require that could cause problems. You're essentially only relying on the joint between the gantry back plate as sides, so I'd be inclined to reinforce that. The rail mount blocks will help...also don't remember what joining the bottom of the gantry sides, that will make a difference.
Well,
Thanks to a Large amount of help from JAZZ the stress and pressure have been relieved greatly. Now finishing up a redesign that I have been working on with JAZZ and hope to start working on getting all the pieces to him for cutting soon. Additional good news is that linearmotionbearings on flea- bay has FF/FK support bearings for RM1605 ballscrews. Still going with the single central ballscrew and given the level of reinforcement going into it, I doubt racking will be a problem. right now looking at seeing if removing some of the internal metal (creating a web like effect) could be done to decrease weight while keeping stiffness up where it needs to be. Outside of that busy with work and another convention this weekend North of me (Luckily only going for one day as have too much to do to afford all three days of the event).
Will post pictures once I have something worth looking at done (Have most the structure done just adding some finishing touches but want it right first).
Off to bed as up way to late and going to pay for it.
Michael
Ok Michael and Jazz your item has been posted today 10th November with a tracking number of
FWKC8972320GB
James and Luke
Thanks James and Luke. That is going to help make a very ridge Machine. Folks I have to give a very deep felt thanks to both James and Luke as they gave me the rails and all I had to do was pay them for the postage. They have helped me greatly and I thank them greatly for that help.Quote:
Originally Posted by luke11cnc
Michael
Okay,
Update on the machine design and build. Design has been finalized with Jazz and materials are coming together. Rails from Luke and James have helped greatly in the moving forward portion. After working up all the different cost of items, the direction was given to go with twin X axis ballscrews as that was actually cheaper with the resources we have to get the parts. Plate has been ordered and paid for; as have the ballscrews which should be shipping here shortly. I will post a JPG later of the finalized design and should have a full model with bolt holes and everything for folks who find it an interesting design.
Now comes the prepping the space in the shed for it foot print of 677mm by 1200 not including the X axis stepper motors which I need to buy one more of those to have a full set. I will be currently using the System 4 set up I have from DIYCNC but will be moving to a higher voltage set up once funds allow.
Cutting area is looking to be 850mm (X) by 355mm(Y) by 150 to 175(Z) Depending on bed height. Bed at first will be MDF two piece configuration (Thanks for the idea Jazz) and I might change over to HDPE or Acrylic (as currently the price of a piece of Ali' that big is scary let alone getting the slots milled into it).
Outside of that it is a bit of prep and waiting time for me as Jazz who is helping with this project is getting the materials to him and moving forward as able. I have a lot of work as well as getting instrument finished for clients and models and G-code for projects done.
Also reading up on VaiCAD (Looking at getting the handbook printed for ease of use) and reading up in the user manual of Mach3 as finally getting to properly read and start understanding all it can do which is huge.
So watch this spot as JPG of model soon and updates of progress as they come along.
Michael
PS sorry for the ramble.
Well,
I said that i was going to get a jpeg of the model up.:whistling:
Well here is something a bit more useful as things are now moving forward. This is the base.. I will be adding more as I or Jazz have them to put up.
Attachment 4889Attachment 4890
On top of the 80 x 40 on edge profile is going index plates for the rails and on the ends will be the stepper mount plates on one end and a buffer plate on the other that will also lock the ends tighter together.
Watch this thread for more as things develop. A very big thanks to Jazz in this and as well as a thank you to Luke and James.
Michael
A few more pic's as things progress.
Attachment 4977
Attachment 4978
Attachment 4979
Will attach an image of what the finished gantry router is going to look like minus bolts as have not taken the time to put all th bolt holes in yet nor put bolts where they belong.
A Big thanks to Jazz for sending these pic's as he is progressing with the build. Should be getting the ballscrews arriving soon and also finally saved up enough to get the extra stepper motor and a few other items that needs covered.
Michael
As promised a jpeg of the model working from:
Attachment 4980
Will see how close the finished item is as things always go through changes.
Michael
well that's coming along nicely Michael thank you for the update on images and drawing
what is the dimension of the cutting bed ?? just out of interest
Looks like Jazz has his work cut out for him
James and Luke
James & Luke,Quote:
Originally Posted by luke11cnc
The overall dimensions of the bed are 1100 mm on X and 500 mm on Y. The cutting area that we are getting out of the set up is 860 mm on X and 355/360 mm on Y. Z will be 175 mm depth of plunge minus what ever table thickness is mounted above the support base. I hope that clarifies it a bit. If not, please say so and will try to do a better job.
Michael
Well the ballscrews and blocks arrived today, minor problem that a quick e-mail fixed and the parts that where not the right length will be getting replaced and the right ones air shipped to me. So that is all good in the end there. Need to ship these down to Jazz and also buy some grease nipples to fit in to well on the ballscrew nuts so that one it keeps out FOD from that area and allows more effective greasing of the ball bearings inside. BK/BF/FK/FF parts all arrived in excellent condition.
Michael
Well more is happening and still waiting for the replacement ballscrews but it is only a week so not really worried.:whistling: Here are a few update pic's that Jazz has sent to me, showing some of the progress and how nice it is starting to come together.
Attachment 5039
Attachment 5040
Hope you folks enjoy and will post some more photo's as able.
I really have to say thanks again to Jazz for the work he is doing it is looking great and coming together very well.:toot:
Michael
hello, i was just wondering how you connect the ali profile together? i cant work it out from the photos. im building something similar to this design and need to mount the pieces the best i can
Cheers
Probably best if I answer this question.!Quote:
Originally Posted by dstivens
There are numerous ways but Micheals frame is bolted together using a combination of Profile manufactures specific fasteners, T-nuts etc and ordinery bolts which go into drilled and tapped holes in the profile.
I've attached some pics may help show better.
Well folks here are some more pic's and thing are progressing well. Just waiting on th replacement ball screws to arrive and Jazz has a bit more cutting drilling and tapping to do. Other then that I am getting the shop ready for the machine, getting g-code ready and need to get the micro switches for the home/limit switches and looking into energy chain and the pattern on the forum to decide whether to buy or build it and how I am going to be mounting this onto the machine.
Now the real reason you are looking at this post is to see the new pic's so here they are:
Attachment 5057Attachment 5058Attachment 5059
The ball screw in the pictures is one of Jazz's as the Y and Z axis screws are still in route due to the problem mentioned earlier in this log. Really happy to se it this far.:toot:
Jazz is doing wonderful work and really helping get this done. I have got a bunch of g-code waiting and working on more as need to get production back up as soon as the mill is in place and had the set up, test runs and final tweaking done.
Michael