Aluminium Profile Type Router - Initial questions

[CNCRY]

OK so I've figured out enough of Fusion 360 to model something - not going to win any awards but at least it's clearer and I can edit the design as needed.







The blocks on top of the X carriages are set to 40mm thick currently
All rails are 1000mm , to be adjusted if needed
Aluminium profile on gantry is 120 x 40 with 90x90 on top.
The purpose of the ballscrew and ballnut running inside gantry plate is to allow an L angle (or perhaps long brush) to be fixed to the extrusion above the screw and cover the ballscrew from dust/chips
*

Issues I'm thinking of so far is the the Z axis clearance isn't huge, 125mm from top of baseboard to bottom of gantry, although probably OK for my needs.
The Z design with rail on front and top is based on the fact Z clearance would be even lower if I put rails on top/bottom of profile. I plan to add extra C shaped plates to side of Z axis to strengthen - will it be enough/OK design?
Y axis travel is limited by how far forward Z is - losing about 275mm so probably need to bring the carriages closer together and gantry plates narrower, maybe mount motor to back of gantry extrusion instead with pulley.
Any comments on those bits? thanks

Aluminium profile arriving tomorrow - only thing I've ordered so far, but will be good to get a feel for size. Also built a 1.2m square workbench for it , 25mm ply top and 50x100 wooden frame on castors, hopefully that'll be rigid enough.

Ryan

[CNCRY]

Hi All,

I've spent some more time on the design - moved the dual X motors to the back, and added a pulley based drive to the Y axis (borrowed from Andy's build log!)
Also shortened the plate fixing gantry to Y rails to give more Y cutting area. I expect I'll get 750mm out of the 1000mm total Y length.





For my Z axis, I'm planning to make this 350mm tall with 350mm rails and 265mm ballscrew.

I think I'm ready for a quote on linear components - would appreciate if someone could take a quick look and advise if there are any glaring issues?

These are sets from BST automation e.g https://www.aliexpress.com/item/3288...35f43557qd67J5
Ballscrew sets to include ballnut and mount, BK/BF supports and coupler.


2 set 1610 ballscrews X @ 965mm long
1 set 1610 ballscrew Y @ 1000mm (With Pulley Machining)
1 set 1605 Z @ 265mm (With Pulley Machining)
X rail set 2 x 1000mm rail and 4 x Hiwin 20mm Flanged Carriages
Y rail set 2 x 1000mm rail and 4 x Hiwin 20mm Carriages
Z rail set 1 x 350mm rails and 4 Hiwin 20mm Carriages

Thanks.
Ryan

[JAZZCNC]

On the model, you show BOTH ends of the ball screws using BK bearings which are the fixed end bearings, which is the best way to fasten, BUT it's not the standard way. Usually, you have a fixed end BK bearing and a floating end BF bearing, so if you want BK on both ends you will need to tell Fred at BST otherwise they will machine them to standard.

Also mention you want the "F" Dimension which is the coupler portion at 25mm otherwise they will machine it 15mm.

Tell Fred you want the best BK/BF bearings not the cheap ones.

[CNCRY]

On the model, you show BOTH ends of the ball screws using BK bearings which are the fixed end bearings, which is the best way to fasten, BUT it's not the standard way. Usually, you have a fixed end BK bearing and a floating end BF bearing, so if you want BK on both ends you will need to tell Fred at BST otherwise they will machine them to standard.

Also mention you want the "F" Dimension which is the coupler portion at 25mm otherwise they will machine it 15mm.

Tell Fred you want the best BK/BF bearings not the cheap ones.

Thanks Jazz - the BK bearings in the image were more just to guide placement and I'd just been copying the same object in fusion 360 rather then using the BF, but I do intend to do it the standard way.
OK - will request a bearing upgrade too. As mentioned in another thread, no idea if BST are shipping out at the moment, so will check on that. Just being impatient to start building something:)
Does the design overall look OK? It's heavily copied of course with a few tweaks!
I do intend to take up your kind phone offer soon - I think electronics will be a Major learning curve so have many questions!
Ryan

[AndyUK]

added a pulley based drive to the Y axis (borrowed from Andy's build log!)

I stole it from Joe, who I'm sure stole it from someone else. I'm reliably told it's called development!

Great progress Ryan, it's coming along.

Jazz's comments are spot on, and also your BK nearest the motor is back to front. Mention to Fred that your dimensions are for the screw part not total length else you'll end up short!

I'd recommend an F length of 30mm on Y and Z to give more room for those pulleys. Don't know if Jazz was saying 25 for the X couplings or the pulleys? Either way just gives more room to align that pulley.

I've noticed your gantry vertical plates are wider than the distance between carriages - the angle continues further than the carriage. Might be worth trimming that because it's essentially cosmetic in its current form and will be costing you when you order the plate.

[CNCRY]

I stole it from Joe, who I'm sure stole it from someone else. I'm reliably told it's called development!

Great progress Ryan, it's coming along.

Jazz's comments are spot on, and also your BK nearest the motor is back to front. Mention to Fred that your dimensions are for the screw part not total length else you'll end up short!

I'd recommend an F length of 30mm on Y and Z to give more room for those pulleys. Don't know if Jazz was saying 25 for the X couplings or the pulleys? Either way just gives more room to align that pulley.

I've noticed your gantry vertical plates are wider than the distance between carriages - the angle continues further than the carriage. Might be worth trimming that because it's essentially cosmetic in its current form and will be costing you when you order the plate.

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..

[AndyUK]

Have you found printing 1:1 and sticking to the piece worked well? Also what contact adhesive did you use there?

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'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..

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!

[CNCRY]

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!

[Sterob]

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.

Is the bottom section a different Series? They both should be the same...ie Series 45( 45 mm between slots )?

[JAZZCNC]

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?

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.!!

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.

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.?

Also thinking of what you mentioned Jazz - adjustability. Would slightly oversize holes be the usual way to achieve this?

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.

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?

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