Reply with QuoteThat looks like stuff from Isel http://www.isel.com/en/ , and if so, not very cheap.
Lars
Originally Posted by Master of nun
Hello,
I saw the add the other day, and probably not a bad deal if you have the $$ but I do not fit in that category. I will have to try and scrounge and build my own. I hope someone else is more fortunate and can use the Doughty drive on sale.
Regards,
Wes
That looks like stuff from Isel http://www.isel.com/en/ , and if so, not very cheap.
Lars
Your right it looks like the same product.
The Indian place might be manufacturing for isel though and could still be had for much cheaper....it will only cost an email to find out
Hello,
I just wondered if anyone has done anything with the building of a 5th axis head since the last post here? I have to admit I have done nothing along that line myself but it sure would be great to see someone else making some progress with a 5th axis B/C head build.
Regards,
Wes
Yeh, I've done some more work on mine just this weekend gone. I'll post some pictures as soon as my gallery upgrade takes effect.
It's starting to look pretty smart now, I've trimmed it right down now to make it more compact, milled it out to contain the stepper for the 5th axis and drilled the holes to bolt the two axis's together.
I still need to work out a way of attaching my spindle.
Not I... on the tail end of a cabinetmaking/trim carpentry job right now.
However, I was thinking of a compact spindle for the head and wondered if this could be hacked to do just that...
http://www.dremel.com/en-us/Tools/Pa...id=Dremel+Trio
dremel trio. I think is a no...... I seen one guy with a dewalt diegrinder.... If it take the force of someone beating a deburr into some rusty steel. Gentle cnc programming shouldn't phase it.....
Im interested in building one...please drop me a line, maybe we can work together or gather other people in making a cheap efficient design that can work for a DIY project...
Kindest Regards,
Hector
Count me in
Hello guys,
It is good to finally see some more posts to this thread showing more interest in building a B/C head. I guess I need to get more motivated and start cutting some prototype parts for my design. I will be glad to work along with others and perhaps by sharing our ideas and findings we can accomplish the task with better results? I am limited when it comes to cash outlay, but normally have a lot of time to devote to design and working drawings or toolpaths.
Regards,
Wes
I like that doughty unit. Maybe use that design as a starting point. I'll take one at the $1k price mark pt or less. $2k is a bit out of the average hobby guys' budget.
I think my design is very similar to the Doughty unit, but it is not a copy of his at all. My design is not complete but I have most of the fabricated metal items drawn and close to ready for making the parts. I don't currently have the ability to model the parts as an assembly to check for fit and interference, so I might do a prototype to test the fit and function of the parts. So far with all the parts I have designed and made for my CNC router build I have had very good results with little or no problems with those designs. They fit as designed and have all functioned very well so far, so I don't expect to see too many problems with the B/C head design. This is a little different as there could be some clearance difficulties when the B/C head is functional and moving along its gantry. Also the spindle to be used will make a big difference in the quality of the cut so I want to incorporate a real spindle with ability to machine metal and perhaps variable speed.
Regards,
Wes
I'm glad I'm going at my project slowly. Just found out that not all cam packages work with 4/5 axis. Thinking about Madcam 4.2, since they have an educational package. I heard it works well with Rhino. Rhino also have an educational package. Probably both for less than $500. Any problems with this combo? Anyone else using something else for their 4/5 axis design?
An update on my BC head for your viewing pleasure
Basicaly I' shortened the two axis to make it more compact,40mm on the C axis and about 30mm on the B
[IMG][/IMG][IMG]
[/IMG]
You can make out here how far the stepper is recessed inside the housing(the machined square in centre), this housing is mearly a means of connecting the two turntables at right angles to eachother.
[IMG][/IMG]
Machining the slots for bolts connecting the housing to the B axis turntable
[IMG][/IMG]
A shot showing the housing upsidedown, harmonic drives and steppers bolted inside.
The square attached to B axis is two pices of 12mm plate, one will be welded to the end of the 150 x 150 x 6mm RHS of the Z column, the other bolted to previous after machining for any error in alignment from horizontal in both planes.
[IMG][/IMG]
More on this as it progresses
I hope this is of use to someone, feel free to borrow ideas,copy, improve on etc.
HereinCS, I'm hoping to use Solidcam or similar as I'm after simultainious 5 axis movement. I also use Rhino, very easy to use and will work with many other packages.
Liam
Hello Liam,
Wow, your BC head assembly is looking too sweet! I don't have the resources to build such a great BC head, but with some luck I will be able to get my belt driven design parts started soon. I basically used a fabricated sheet metal design but after looking at yours I think I could do some wooden patterns and cast them from aluminum for a stronger and better looking unit.
Keep the pictures coming as it is good to see someone making some progress, and might motivate the rest of us to get with it.
Regards,
Wes
I've been wanting to build a router with a b/c unit just for the coolness factor. But realistically, can some one explain what a device such as this add to a 3 axis machine?
Hello,
Perhaps is would be more graphic if you were to watch some videos of some 5th axis machines doing some machining. The added motions of the B/C head will be readily apparent after watching some videos. The software to CAM for the 5 axis is not very readily available pricewise but the CNCToolkit is a free software that will create toolpaths for 5 axis. You can find links to Rabs site on the CNC4free website along with a lot of other valuable information. Check out some of these links:
http://www.youtube.com/profile?user=.../1/MRGWd5xfaNY
http://www.cnc-toolkit.com/cnc_machines.html
http://www.cnc4free.org/
Regards,
Wes
Hey Wes, Thanks for the kind words, i hope my progress has You and others thinking about you BC heads once again.
So tell us, what resources do you have and what is your budget, the materials you would like to cut and the spindle you will be using?
Mine has cost me about AU$1700 not including the two small 300 0z-in steppers.
When you say "fabricated Sheet metal" I take it you mean Plate don't you
Casting sounds great but depending on the design if resources are limited, Machining for bearing and such may pose a problem.
You could always have someone laser cut 10mm aluminium plate and just do the drilling and assembly yourself.
Please share some sketch's
Also have in mind the gear reduction needed, I believe Doughty drives are 30:1, Mine are 50:1 only because the harmonic drives I found were this.
Taking into consideration my spindle size and possible tool length, From the centre of rotation to the tool tip could be up to 300mm. I previously calculated my resolution to be something like 0.2mm with the 50:1 reduction (worst case scenario tool length and with full steps).....something for you to think about
Come on people lets throw around some more budget/tool limited Design Ideas
Liam
Last edited by Master of nun; 07-15-2010 at 04:55 AM.
Hello guys,
Liam my design is fairly lightweight and the backplates and end plates were planned to be made of .25" aluminum probably 5052 but 6061 T6 could be used to give it a bit more strength. I normally get most of my fabricated parts laser cut at a local precision sheetmetal shop but felt these parts are all within the capacity of my first CNC router build and I may just cut them here. The rotary plates are planned to be cut from .375" aluminum and I have a cover plate planned to be made from say .050" aluminum. I posted a screen shot of my plans on the first page of this thread but I guess it is so small it may not be easy to see things and I will try and post a better shot with this reply. If there is anything that looks like it may pose a problem maybe someone here will post a reply to inform me or make suggestions to improve the design before I move forward with the parts?
I have also finished a 4th axis rotary indexer build and used a 1/250 microstepping driver and about a 8:1 ratio with a belt drive, but I have not set it up and tried any rotary jobs with it yet. I planned on doing something similar with the B/C head utilizing a belt drive at a good reduction ratio and including a good microstepping driver with it.
Maybe this idea will not be the best for the B/C head and if not I will need to change the design to use a worm and gears or something else. I guess I really should hook the 4th axis up and get it calibrated and try some things with it to get a better idea of how well it might work in other applications?
Here is a bigger shot of my original 5th axis design:
Last edited by metalworkz; 07-15-2010 at 10:53 AM.
Regards,
Wes
Looking good, Is the "aluminium alternative" drawing an alternative to the 5th axis ideas drawing OR an alternative to the 4th axis you've already built?
Some feedback:
In the 5th axis ideas drawing, it's hard to see how this will be solidly mounted to a similar 4th axis seeing that one side has a very lightweight drive cover and the 1/4" plate wouldn't take fasteners in the end.
Could you show us how the two axis would be mounted together?
I haven't had anything to do with microstepping ( I do intend to use it on mine), But i'm not sure I would rely totaly on it for resolution.
Scenario
Say you have a distance of 200mm from center of rotation to tool tip and 8:1 reduction, This gives you a circumferance of 1256mm, divided by 200 fullsteps = 6.28mm per step, divided by your ratio 8 = 0.785mm per step.
This may be adequate with micro stepping, from what I've read positioning of micro steps are no way near as accurate as the positioning of full steps.
The thing is I don't think you really need much more than 1 full rotation of your axis per second, in this scenario thats a feed rate of a whopping 1256mm per second
An 8:1 reduction will give 1 rotation per second for every 1000rpm of your stepper, you'll be able to run steppers much higher as you multiplying the torque also.
Can you add a layshaft for a second reduction stage?
keep in mind you'll be able to reduce the size of the existing 8:1 pulley.
How about two 5:1 reductions give a total of 25:1
resolution of 0.25mm before micro stepping
0.66 of a rotation per second at 1000rpm of stepper
Assuming a 400 oz in stepper, An output range of 52 ft/lbs at 0rpm and 4.6 ft/lbs at 2000rpm ( which would only happen during rapids, not cutting)
Which leads me to the question, What are the steppers your using?
