hello, i'm considering bthe practicality of building an over sized Workbee, for a very specific purpose, which is processing, soft pine boards, to create components for oddly enough, beehives. I want to be able to place a resonsably long plank in. I dont' need to acheive 'increadble' accuracy, just good. IF i was to extend the long size axis to 3000mm ( I can purcahse the C-frame that long ), what problems am I likely to experience?
I would run a dual belted system where the bottom belt is fixed to the rail making a simple rack and pinion. Or upgrade to wider belts. At 3000 mm I can see you experiencing some belt stretch. But as you said accuracy is not a big issue so you may be fine with the standard set-up.
Deflection of the long beams. To truly do something that long you need cross members bracing the long framing which can't be done with the inside Y-axis plates on the WorkBee in place. Based on what you are doing though using the outside plates alone should be sufficient.
I follow what your saying. What about the drive along the Y-axis? Some concerns about the belts streching and impacting accuracy. Rack and pinion?
R&P would be great if it’s in the budget but based on your specified needs I would probably just go with a more substantial belt. You will need to change out the inner rollers to idler pulleys but that’s not a big issue. Look around and see what you can find in the way of 12mm belts, pulleys, and idlers.
When I read your post, before I've read the answers to it, the first thought that came to my mind was that you may not need a machine that long. You could use a machine that is only 1200mm, or so, and make the cut/s in stages by indexing the part and moving the board that you are cutting to the new position and cutting the second stage and repeating if needed. People cut material from both sides of a workpiece using indexing with great accuracy.
I had considered that but the reason to make it long is really to let the machine run largely 'unattended', and make multiple parts from the planks.. time is Valuealb.e
I believe I know what you are intending it for, and if it is for what I think, it should be fine. The bees won't care about perfection. Every year I plan on making up some homes for all the mason bees and every year I think about it too late and they have plugged every hole in my yard. This year I just started drilling random holes in scraps of wood and putting them out where the bees would find them. The mason bees in my yard preferred oak and the wheel hubs of my miter saw stand that I had outside than anything else.
Good guess, but no its not for mason bees/wasps. Its for making langstronth frames and boxes for apis mellifera. The frames are not overly complex, but i need to make thousands of them, so some automation is important!
I found some 15mm belt, pulley and idlers. I've also been able to source the C 4080 at 3000 long. I'lll probalby go 500 wide, it means i can just use an off the shelf kit. ( POWGE Transmission parts Store - Amazing prodcuts with exclusive discounts on AliExpress .. Link to an ali store selling the various bits. I need to have a look at the detailed design documentation to look at how the belts are arrangd.
I did the maths using the deflection calcultations and it coudl move enough to become problmatic. Leaving the inside plates off does seem like a viable option, and put some exttra cross members in. Theres goign to be 'some' risk in this,. but nothing risked, nothing gained. Worst case, i'll rebuild it as a shorter machine. which would still be useful, and i'd have learned something! putting the wider belts in, will need wider pulleys and idlders, i'm now wondering if i will have space to get it in.
On my custom CNC build, I do not have inside wheels and plates. What I did was tie the 1500 mm y axis to the work table like this and it is very rigid:
Thats Girac, thats helpful to know and helps me move forward. It looks like i can get a 15mm pulley and idler wheels in there as well. Time to get cad fired up so i can order the c frame pre cut.
Really no 'risk' involved with cross bracing. It's actually very simple. Modified Sketchup file attached so you can better understand how simple what you're wanting to build actually is. Note, the file only shows a 1500mm version but you'll get the idea.
Thankyou so much. thats really helpful! It helps me a lot to work out the exact parts list i need. When i built my cnc mill. ( it was a Seig SX3 conversion ) i orginally used stepper motors, that was somethign i regretted, bieng an open systme it had no way of actually knowing where it was. I replaced them with servos and iut was a decision i do not regret! Any thougths on this?
Nope. The physical build is my area of expertise. You’ll have to wait for one of the electronics experts to chime in on anything electrical.
If you are happy with servos and are comfortable installing them then stay with what you know and you wont go wrong. BTW, where are you going to get C beams 3m long from?
The electronics and controls are not somethign that scares me . I found this video which is the last video in 'Franco's build. Hes used Clearpath servos.. Which look great. but are spendy! I've used Leadshine ones ( good chinese ) in the past. The 3m cbeams are avaialble from the Ozznest poeple in teh UK, and also from bulkman3d
Hi Rick, I started to draw up my machine, and was wondering if i'd be better to put diagonal bracing between the Y Axis rails? I think it woudl be an increadibly strong frame? I've not see joiners though that are intended for connecting at 45degrees? I'll finish the picture. I'm having to fight Sketechup.. never used it. I might bite the bullet and draw everthing in FUsion. since i know it.
Diagonals are not necessary. When you screw down the spoils board at all the cross members that provides all the rigidity you will ever need. BTW, diagonals are not difficult with the Adjustable V-Slot Hinge. (They're really not that good as hinges but make great angular connectors.)
Thanks Rick, thats helpful to know. So, i've made some build decisions now.. - The y axis will be made from 3000mm C Frame. the X and Z axis will be as per a 500mm wide build. - I'm going to go with Servo motors, I was looking favourabley at the clearpath servos, but i have a few other options to consider. The Smooth Stepper folks have provided a list. Servos are consdierably more expensive than plain steppers, but they do have several advantages. COntrol will be with a ethernet smooth stepper. ( FAQ Servos ). I've used this previously for my Mill project and its been really good. It will also work well, with a possible Vision control extension project i'm thinking of. - Despite all the great drawings in Sketch uip, i'm goign to do this in fusion. Its just too hard to learn a new system. - I'm thinking of procuring my extrusions from BulkMan3d out of china. Has anyone dealt with them?? Are they ok? They will ship to me by sea freight, its going to cost a lot less than airfreight -The X and Z axis will be lead screws, the Y will be bel driven 15mm wide GT3 belt. Gettng very close to needing to order some stuff.
Decision Made, and first parts ordered. ( (This thread probably is now going to be my diary of the build. I have ordered 4 x CLearPath nema23 servos. CPM-SDSK-2316P-RLN | torque = 181 oz-in, speed = 5000 rpm. They wll get used with an ethernet smooth stepper, which i am very familar with. I had considered using the 2311 ( lower cost ), as it has higher peak torque, but only up to 200rpm. I likely wioll be running these at well under their rated powers, but thats all good. It keeps it nice and safe.
Better to make it a build report in the builds section. You can write it at your leisure and make it public when you are ready. If you put it there it will not disappear into history. Alex.
Have you considered a rubber/toothed roller drive, and running the machine similar to a Swiss lathe? Rather than having the machine so long that you may end up needing a steel substructure, you have infeed and outfeed tables with side-to-side guide rollers, boards of arbitrary length, and a fairly compact machine that consists almost entirely of an X-Z gantry next to the contra-rotating Y-axis roller drums. The overall precision can be an order of magnitude less across 90% of the total machine footprint, no belts to worry about- not long ones, anyway- and your material prep time goes to almost zero. Clearpaths are almost certainly overkill, but will be very nice to use and make processing significantly faster.
(1) If i follow what you are saying, its like an Inkjet Printer, the rollers moving wood, rather than paper? That is a really interesting idea.. Each 'part i need to make it relatively short compared to the lengths of the boards... ( the longest parts are around 500mm ). I really do like that idea. I could probably have a combination of both a short Y axis... and a feed system that can in feed he boards. *this is a very good idea*, it needs exploring! [EDIT] This is a brillant idea. And will make this project stagable. I can build the first part, then add the roller feed as a secondary project (2) Yes, i know they are overkill, the work bee can work with low cost steppers. I also know how much improvement there was with my mill project when i went to closed loop and then proper Servos. With a decent spindle, it will really speed thigns up. I'm ok with the costs. They seem to offer very very good support as well.
I did a bit more thinking about this, a roller feeder thats similar to a power feeder that gets used for feeding timber into a saw. the difference being that a power feeder needs a Lot of power as its working against a blade. A wheel like this.. ( Shop Tools and Machinery at Grizzly.com ) should do the job.. Provided my boards are reasonably consistent, ( they are 4side planed ), a manually adjustable in feed should be easy enough to setup. I'm tinking that you would run the the board in until the end of it hit an end stop, then have some automatic clamping system hold it in place so it can be cut. This also potentially solves another problem for me. If i clamp the wood correclty, at each end, it maybe vialble not to have to have a board underneath it. This would let me cut right through, without cutting into a mdf board that needs replacing. The parts would drop out the bottom.. .. after each section is cut out, could do a cut off, and the waste product could be pushed off the other end by the next piece. This is getting more interesting by the moment.
