What milling machine?

[rebekah andersonParticipant @rebekahanderson95322]

Well i've elected to keep this one as I'm not sure where to go with a replacement.

stripped it and rebuilt it. Working a lot better now. Just need to get a replacement Z axis ball screw.

[John Stevenson 1Participant @johnstevenson1]

Whats wrong with the screw ?

[rebekah andersonParticipant @rebekahanderson95322]

Came apart, tried to but it together but the bearing keep forcing them selves out.

[John Stevenson 1Participant @johnstevenson1]

In which case it probably just needs loading properly, until you have had a few fly apaprt thay can be daunting

[rebekah andersonParticipant @rebekahanderson95322]

Tried so many times to reload it but just epic fail. Lol

[magpieParticipant @magpie]

I read somewhere that in any recirculating ball device there are two sizes of ball. One size is very slightly smaller than the other and they should be inserted alternatly. the reason for this is because alternat balls have to rotate in opposite directions and this causes too much friction on the bearing walls. I don't know if this is true, but it does seem to make sense. If this is the case you may need to spend a while with a mic, and two small trays to get the thing working again. Cheers Derek.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by magpie on 03/06/2013 08:45:50:

… you may need to spend a while with a mic, and two small trays …

.

Alternatively … sandwich a few balls between two flat plates … if there are two sizes, the small ones drop out [onto the towel that you remembered to put on the tray]

MichaelG.

[magpieParticipant @magpie]

Nice one Michael. If there is an easy way and a hard way to do something, you can bet i will find the hard way. Cheers Derek.

[Carl Wilson 4Participant @carlwilson4]

Hello Rebekah,

Speaking as someone who has done the cheap chinese machine tool bit, I would buy the biggest most capable machine you can afford that fits into your space requirements. In my experience it doesn't matter what you think you'll be doing with it, you'll always need a slightly bigger/slightly more powerful one than you think. So, buy the best and cry once.

There are some decent Taiwan made machines out there, they are sturdy enough and not too pricey. Chester do some decent ones. A really good book that gives excellent advice and good all round general information is "The Milling Machine" by Harold Hall. It is part of the "Workshop Practice" series. It tells you all about rotary tables, clamping, and all the myriad of other milling machine related topics you'll want to know about.

Avoid anything made in the US. Worse than Chinese…threads tapped directly into aluminium anyone? No thanks.

I would also recommend another book by Harold Hall, "Milling: A Complete Course", also Workshop Practice series. Again a lot of very useful, practical information, hints and tips.

Hope this helps. Even if you've now bought your machine I would still recommend the books.

Carl.

[Anonymous]

Posted by Carl Wilson 4 on 20/07/2013 09:42:58:

Avoid anything made in the US. Worse than Chinese…threads tapped directly into aluminium anyone? No thanks.

Wot? We shouldn't be tapping into aluminium? Why not?

Andrew

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Andrew Johnston on 20/07/2013 11:58:39:Wot? We shouldn't be tapping into aluminium? Why not?

Depends which gorilla has done the screws up! I had to Helicoil all the threads for sump bolts on my Austin 7 crankcase.

Russell.

[Paul LousickParticipant @paullousick59116]

I have a Sied SX3 and it has been a great machine to use but the controller for the DC motor has just failed. Going to cost over $500 to have it replaced (the supplier does not do repairs to motor controllers). Unless you want a CNC mill would reccommend a machine with a standard motor and belts and pulleys to change the speed. Much more reliable and cheaper to repair.

PS. Anyone know where I can get the old controller repaired ?

Paul.

[Carl Wilson 4Participant @carlwilson4]

Tapping directly into Aluminium…dodgy at best. As an aircraft man I like to see it helicoiled. I suppose It is ok, per se…but on something precision like a milling machine it is definitely a bit cheap and nasty. Even on a cheap and nasty milling machine.

[Another JohnSParticipant @anotherjohns]

PS. Anyone know where I can get the old controller repaired ?

Paul; I would find the SX3 Yahoo group, and ask there. (yes, there is a group called "SIEG-SX3-C6B&quot

Another JohnS, currently stuck in a hotel, not in my workshop…

[rebekah andersonParticipant @rebekahanderson95322]

What about arc euro trade?

[Ian S CParticipant @iansc]

Studs on the in and exhaust manifold/ cylinder joint on the Continental aero engineswere tapped into the plain aluminium cylinder head, the exhaust studs usually got Heli coiled on over haul, although if they were not too bad, they got tapped out .012" oversize. Ian S C

[Jeff DaymanParticipant @jeffdayman43397]

"Tapping directly into Aluminium…dodgy at best. As an aircraft man I like to see it helicoiled. I suppose It is ok, per se…but on something precision like a milling machine it is definitely a bit cheap and nasty."

The whole idea of Taig and Sherline mills IS cheap and nasty – so hobbyists can get machining at a low price. Lots of good work has been done on them by people who do not have space or cash for a bigger ex-industrial machine. No argument about the cheapness- they are built with no extras and alum on alum slides. If they put in steel gibs and helicoils on every thread they would cost about double what they do, likely.

As to threads directly in alum, most cars, motorcycles, small engines, implements, appliances and electrical equipment have the majority of threads directly into aluminum with few problems. In other words, the vast majority of the millions and millions of machines in common use around the world – have threads directly in aluminum or zinc alloy. No doubt helicoils would improve things but usually they are not a must. On items that are frequently removed for service, helicoils are usually fitted.

When assembling fasteners directly into aluminum, a smear of copper based antiseize compound will greatly assist removal in future. The nickel or zinc antiseize compounds should not be used on aluminum threads though.

I am glad to hear helicoils are the rule rather than the exception on aircraft, but on most other common machinery this is not the case, and if it were truly "dodgy" as you say, this would not be so.

JD

[Carl Wilson 4Participant @carlwilson4]

Fair enough point. I suffer from having had things instilled in me using a method known as pain assisted learning. I can't help it I'm afraid.

[rebekah andersonParticipant @rebekahanderson95322]

I am familiar with the PAL technique lol

[Carl Wilson 4Participant @carlwilson4]

Yes I would imagine you are. It is a British military thing.

[V8EngParticipant @v8eng]

Ah PAL reminds me of my schooldays, it tended to be an instant process involving a rule across the knuckles or the board rubber being lobbed at you!

[Ian S CParticipant @iansc]

With aircraft use you have to get the right helicoil in the hole, one ultra light crashed because stainless helicoils were fitted in the spark plug holes on over haul. The plugs burned ou because of the reduced heat conductivity over the origional aluminium alloy cylinder heads. Ian S C

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