Taarks HM-46

[Taark]

Hey Guys,

Just picked up my new HM-46 mill and will be undertaking a CNC conversion on it.

Thought I would start a build thread to show my progress and get feedback from you guys.

So far this is the setup:

HM-46 Mill
DMM 400w AC Servo kit
25mm 5mm Pitch Lead Screws
Mach 3
Full Enclosure

The plan will be to use around a 2:1 belt reduction onto the screws.

Here are a few pics...

[Taark]

ok, so a few bits arrive yesterday...

The full DMM 400w AC servo kit arrive in lightening fast speed... 3.5 days from Canada to Australia, couldn't be happier...

First impressions of the kit was very good. Well packaged and everything was there. The motors were smaller than I imagined but should still work just fine!

Also picked up a bluetooth pendant. Loaded it into Mach 3 and seems to work great. A little laggy but nothing too bad...

Here are some pics:

[Taark]

Also bought this today... Just waiting to have it delivered...

400x400x200 fully sealed enclosure for all the electronics...

eBay Australia: Buy new & used fashion, electronics & home d

Taark

[kensbey]

Hey Taark,

looking good. have you spun up the ac servos yet? i bet they are smooth. What drive ratio are you planning on using? Are you going to get ballscrews or just stick with the standard leadscrews and use backlash compensation?

Kensbey

[Taark]

Already have some 25x5 ballscrews left over from the router project that got scraped so I will just use these... Will also double nut them with a preload on the 2nd nut for automatic adjustment. Havn't made a decision on the ratio yet. But will be some where around 2:1 or 3:1 or somewhere in between.

Havn't fired the servos up yet... Waiting to get the control cabinet so can I wire everything up...

How is your build coming along?

Taark

[kensbey]

Spend last weekend wiring everthing up into a cabinet Here . Got all the servos running, pretty happy with them. Microstepping on the drives works very well.

I am just finishing off models, then i will work out the exact screw lengths i need. where did you get screws from? locally or imported?

keen to see a video of that pendant in action when you get motors running.

[Taark]

Looking good mate... The race is on... Lets see who finishes first. lol

[Taark]

Some updates finally....

Have almost finished the control cabinet. Has a 17" screen with a brushed stainless front.

Let me know what you think...

Rear of screen/buttons inside cabinet






120mm Fan mounted in door






Electronics etc mounted in cabinet








Stainless steel front with buttons and Emergency stop




Breaker and on/off switch

[Taark]

Ok,

So I need a little insight to how everyone sets up their thrust bearings etc for the lead screws...

This is the design I have come up with.

This will be used with a pulley and belt to the motor, hence the 2 bearings for side load.

Let me know what you guys think and any improvements I can make.

This will have a floating opposite end.

Taark

[691175002]

Why use four bearings?

People have been doing this with AC pairs for the longest time.

[Taark]

This is why I asked the question...

I have very little knowledge when it comes to bearings....

Will have a look into AC bearings, thanks.

Taark

[SCzEngrgGroup]

The thrust bearings are completely unnecessary. The whole point of using A/C bearings is that they handle both radial and axial loads. And do NOT use bellevilles to pre-load bearings. Either the pre-load will be so high that you'll have high friction, and reduced bearing life, or so low that the bellevilles compress further under load and you have backlash. The pre-load should be provided by shimming or some other rigid means of adjustment. Also, the A/C bearings must face opposite each other.

Regards,
Ray L.