-
20-02-2020 #21
Just a (genuine) question - have you considered belt-drive on the X as well as Y?, for me workshop space is a critical issue and being able to rotate the motors 180 degrees into the frame of the router would be a design goal if only to reduce the depth of the machine as it sits on the bench. If that's not an issue for you then ignore.
-
20-02-2020 #22
I have a mesa PCI card I don't use at the moment but there is a rare problem with MESA PCI cards when installed in some machines will not boot.
I traced this to a PSU issue, I swapped 3 motherboards into that case before I realised it was the PSU that wasn't letting it boot. The Mesa people told me it happens in 1 in 100 machines.
As soon as I swapped the PSU it booted fine but I had to move the machine so I bought a standalone controller and put it on a catering table with wheels.http://www.mycncuk.com/threads/10880...60cm-work-area My first CNC build WIP 120cm*80cm
If you didn't buy it from China the company you bought it from did ;)
-
20-02-2020 #23
Hi Doddy, I considered this earlier but as the gantry is going to extend back on the X axis, beyond the cutting bed size anyway, then the motors don't add to the footprint, and slightly simpler to connect direct. It's on a workbench which is 120cm square, so gives me about 20cm for the motors/wiring etc!
-
20-02-2020 #24
Thanks Andy - feels like the design is almost there now, drawing in CAD certainly makes things easier to tweak/measure and figure out what should work.
Yes good shout on the gantry - I've reduced the width slightly (50mm approx) so it can be cut from a smaller piece of aluminium.
Just waiting to hear from Fred @ BST , so thinking about how I'll actually machine the pieces now.
Have you found printing 1:1 and sticking to the piece worked well? Also what contact adhesive did you use there?
I've bought some centre drills / counterbores to test out . Also thinking to get a metal cutting blade for the large wood bandsaw to cut the angle. That or a blade in mitre saw but feels a bandsaw would cope more..
-
21-02-2020 #25
Yeah it was a low-tech solution that worked quite well. Can get messy though, recommend some cellulose thinners and a rag on standby to wipe the other edges of the piece you're spraying, and obviously do it on a waste surface like cardboard. I got the wife to cut the printed bits out - shes a little bit more artsy and careful with a pair of scissors. It was then mainly a case of alignment as you put it on, trying to get a straight edge aligned with the edge of the metal. We found spraying half then putting on roughly worked well as you had a couple of seconds to adjust the paper slightly. Then fold over and spray the other half, and then flatten out.
Used Evostick Impact spray, but I'm sure any contact adhesive would do the job. This one is a bit costly, I probably nicked it from the in-laws....
https://www.amazon.co.uk/Impact-Mult.../dp/B0095RFILA
Helped a lot with the marking out. I used one of those push down centre punches, but others have used optical ones which look really good.
When you're finished drilling on them, get some lighter fluid to help remove the paper and contact adhesive. That was a nasty job... Then shine with scotch-brite.
I love the counterbores I got. Great little tools. Centre drills didn't really work for me, I just ended up starting everything with a 2.5mm.
I used a crappy old table top wood band saw, and it worked okay. Just get a decent blade. I remember learning that you want approximately three teeth in contact, and I was cutting 10mm and 20mm Ali, so I went with approx 5mm pitch blade. Slow but steady, lots of cutting fluid.
However, I only used that for un-important edges. I got Aluminium warehouse to do the main cutting to size and just cut pieces in two where they had to be ordered as one piece due to minimum piece sizes. Where I had to cut a piece that mattered, I'd use Aluminium warehouse's edge as the mating side. That way all the mating surfaces have square(er) edges - the bandsaw cut edges needed a fair bit of sanding afterwards!Last edited by AndyUK; 21-02-2020 at 12:14 AM.
-
28-02-2020 #26
So the build has officially started - I should probably convert this to a Build log if that's possible!
So the profile was joined using the self tapping M12 core screws, where the head slots into the 10mm profile slots and a hole is drilled though the profile to allow the T50 key to be inserted and tightened. This worked OK but I managed to almost break my wrist using a cordless drill and even a (cheap) impact driver struggled! Got there in the end and re-enforced with brackets.
I don't have any precision measuring tools at this point, but using the digital angle measure is 90.0 degrees on all angles and to 1mm across all dimensions.
Issue #1 - In my haste to add an extra piece of profile to my order (to have an L shaped gantry profile) the 2 profiles have different slot spacing. As far as I can tell the main issue is joining them. If these are joined simply by using the side gantry plates and socket head bolts to hold the pieces in contact is that a terrible idea? Could it be enhanced with some strong adhesive between the pieces to compensate. Really wan't to avoid wasting money on the extrusion if I can help it.. Any ideas?
I've also placed the order with BST Automation - Thanks for the recommendations. All smooth so far, Fred seems very responsive and helpful. There are expected delays due to the coronavirus but it sounds like production is just slightly slower then usual.
Only linear motion components so far - 1610 ballscrews and 1605 for Z. 20mm Linear rails and Carriages. Flanged Type for X axis for stability as I'm using a wide plate.
For the blocks which will mount to carriages - Is Ecocast type aluminium recommended here? Quite pricey for 50mm thick block so want to be sure it's worth using this.
Also thinking of what you mentioned Jazz - adjustability. Would slightly oversize holes be the usual way to achieve this?
On electronics - I'm considering Hybrid steppers now, certainly on X due to the dual X motors and potential stalling. Any recommendations on models here?
Thanks!
-
28-02-2020 #27
-
28-02-2020 #28
-
28-02-2020 #29
It's not the best of ways but if you bolt the profiles together along there length as well as the ends it should be ok. Obviously, because the slots don't line up you won't be able to use the slots to lock together but you should be able to drill and tap them together from underneath with a few bolts.
Don't use adhesive.!!
Cast plate isn't required but the plates must perfectly flat with parallel faces and exactly same thickness on both sides of machine. Rolled plate isn't flat or with parallel faces so unless you machine it flat and parallel then ground plate is your only choice if you want it right. Why 50mm thick.?
Try to keep the holes to correct size if possible. Only make oversize if needed.
When I say adjustability I mean don't machine plates with slots etc that lock things together unless the whole machine is built this way and on an accurate machine. Adding plates or brackets that allow adjustability is always a good idea. When making plates etc then adding slots rather than holes can help in some places but depends on machine design.
One of my methods is to use slots to allow adjustabilty then when it's all setup I'll lock it in place using tappered holes and pins.
Wouldn't use anything else. These work well and allow AC or DC with voltages upto 70Vac or 100Vdc. This means you'll get good speed and with 5.5Nm you've plenty of power.
If you go for the lower powered motors just check the drives Max voltage because a lot of them are 50Vdc Max which will limit your speed.
https://www.aliexpress.com/item/3279...44bf3421SaYv5O
-
01-03-2020 #30
I did some more thinking on 2 profiles with different spacing - as the 2 do not need to align on the face in the design, I can offset the top piece by 5mm so at least the front slot is in line, then bolt/tap the rear.
OK great - I'l either go for Ecocast or see if I can get it milled. Its 50mm thick as the block is intended to add some Z clearance for the gantry. Without it clearance is only about 100mm, so takes it upto 150mm .
Hybrid Steppers are slightly more reasonable price then I had expected Vs standard steppers. Looks like the LC60H2102 (4.5Nm) and LC60H2112 (4.8Nm) both also support 100VDC with the same LCDA86 Driver, although strangely are twice the price as the 5.5Nm from what I can see!
Would the 5.5Nm be overkill on the Z axis ?
I noticed the 5.5Nm has a 35mm shaft and keyway, which should help with pulley mounting. How does that work with direct coupling though, a keyway and standard shaft coupler?
Thanks
Thread Information
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
Similar Threads
-
600 x 400 Aluminium Profile Gantry Router
By Journeyman in forum Gantry/Router Machines & BuildingReplies: 0Last Post: 02-03-2016, 04:28 PM -
Initial workpeice tooling set-up instructions using a pendant controller type machine
By Nthkentman in forum Machine DiscussionReplies: 25Last Post: 30-08-2014, 08:33 PM -
aluminium profile for cutting bed of router
By steeplejack in forum Marketplace DiscussionReplies: 3Last Post: 19-10-2013, 10:52 PM -
Some initial questions....
By andy586 in forum Gantry/Router Machines & BuildingReplies: 5Last Post: 27-01-2013, 03:00 PM
Bookmarks