SX2P milling machine – X, Y & Z axis locks

[Ches Green UKParticipant @chesgreenuk]

[Ches Green UKParticipant @chesgreenuk]

Hello all,

I joined the forum a few weeks ago. I'm a retired Johnson Matthey Metals/Ferranti Radar design engineer.

Here is my first question

I bought an ARC SC2 lathe a few months ago and am very happy with it, and used it to help build my first model steam engine, a Stuart 10V.

I also used a Proxxon MF70 mill for the 10V but have now upgraded to an ARC SX2P mill. Which leads me to my question(s)…

Am I correct in thinking that locking any of the SX2P axes is done by

a) the locking lever on the Z axis and

b) the two M4 cap head screws on the X and Y axes?

And is the Z axis lever also 'nipped up' to prevent head drop?

Thanks ,

Ches.

Edited By Ches Green on 03/11/2021 17:18:32

[Jon LawesParticipant @jonlawes51698]

There should be a locking lever (well, a bolt with a sprung lever on it) for each axis; I've looked on the Arc website and it shows it in the pictures. I don't have quite the same model but its present on mine (SX2.7L). They can be easily snapped if you are not careful (ask how I know…) so if the machine is second hand someone may have replaced them with bolts.

https://www.arceurotrade.co.uk/Catalogue/Machines-Accessories/Milling-Machines/SIEG-SX2-PLUS-Mini-Mill/SIEG-SX2P-HiTorque-Mill

In the picture in the above link you can see the locking levers on the front and the right hand side, in the case of the front one it's directly in line with the feed handle.

[HOWARDTParticipant @howardt]

You are correct. Looking at the photo on the Arc web site it shows capscrews on the X and Y axis and quick lever on the Z, older machine that I had came with quick lever clamps on all axis but these often got n the way on X and Y. Always nip tight any non moving axis and tighten the moving axis just enough to stiffen the movement and keep them lubricated.

[Ches Green UKParticipant @chesgreenuk]

Jon, I think there may only be one locking lever (ie on the Z axis), the other two axis use socket head screws. I don't see any 'levers' on my machine's X & Y axis. There is a head Stop lever but that's to prevent the cutter meeting the machine bed.

Howard, thanks for the info.

I've not used my SX2P in anger yet…just gently milling some test pieces of mild steel to get a feel for the machine. It does have a tendancy for the milling cutter to screw into the work piece if I'm not careful…that prompted my interest in locking the axes.

Once I've done a project on the mill and located any parts that need fettling, then I'll get to work on them.

Thanks again to both of you for the quick responses,

Ches.

[JasonBModerator @jasonb]

As Howard says cap head screws for X&Y and a lever for Z. You could replace the two screws with levers, just check if they will need extending to clear the table or base casting as it save shaving to keep reaching for an allen key.

What are you using to hold your cutters, the supplied 3-jaw is really only for drilling, an ER collet would be the best all round option.

 

Edited By JasonB on 03/11/2021 18:18:37

[Ches Green UKParticipant @chesgreenuk]

Jason, Good idea on replacing with levers. I'll have a look around for something suitable. Thanks.

I've already got a set of ER32 collets from the lathe, so have bought the mill collet holder.

Ches.

Edited By Ches Green on 03/11/2021 18:23:47

[geoff walker 1Participant @geoffwalker1]

Hi Ches,

I put levers on mine, like Jason said saved messing with an Allen key especially underneath the slide.

Can't remember where I bought these but I noticed goodhanduk have 4mm levers in stock. Take care to make sure you get the right screw length.

Geoff

Edited By geoff walker 1 on 04/11/2021 07:34:14

[Ron LadenParticipant @ronladen17547]

On my SX2P I have the locking lever handle on the Z but found a lever handle on the Y can catch depending on where the table is in X. I use a ball ended T wrench for the X and Y, the ball end making it easy to locate in the caphead. Something to note is don't over tighten the capheads a light nip is all that is needed to lock the table. The small M4 capheads threaded into cast iron will strip the thread in the casting if heavy handed over time.

Yes lock the head using the lever when milling but again don't over tighten it's not needed.

Ron

[Ches Green UKParticipant @chesgreenuk]

Geoff, thanks for the pic (tells 1000 words) and a possible source of lever.

Ron, thanks for the advice. After using standard Allen keys for decades I eventually bought a set of ball-ended, handled keys a few months ago…(https://www.amazon.co.uk/gp/product/B005UNKZD4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1) … the old keys rarely get used now!

Ches

[Ches Green UKParticipant @chesgreenuk]

I've replaced the X & Y axes Capheads with Butterly Wing Screws (M4 x 25 mm from Amazon).

I haven't fully tested them out on a project but they appear to be 'good enough'.

Moderate finger force can nip them up sufficiently to take the slack out of the table and saddle. And they are reasonably easy to reach by hand – no tools required.

[geoff walker 1Participant @geoffwalker1]

Hi Ches,

Just the job mate and a few to spare.

Are you doing the gas strut mod?

If you are like me and really dislike the torsion spring swing arm assembly then it's well worth doing.

Geoff

[Ches Green UKParticipant @chesgreenuk]

Hi Geoff,

and a few to spare … and then some! I'm sure they will come in handy, one day

I did also try thumbwheel screws but the finger leverage wasn't sufficient – the wingnuts have a longer lever arm.

No plans as of yet to do the gas strut mod. Still feeling my way around the machine. I think I've read most of Ketan's posts on that subject so will hang fire unless I feel I really need it.

I'll focus on backlash first to see if any parts need improving there. But, as with my ARC SC2 lathe, the machine seems really quite competent for the price and I'll try to keep fettling to a minimum…. he says.

Shame the winter is due, but Spring will soon be upon us before we know it.

Ches

 

 

 

 

 

 

 

Edited By Ches Green on 13/11/2021 17:17:45

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