New Mill – Starter Tooling

[BOB BLACKSHAW 1Participant @bobblackshaw1]

If you check out the thread on the 09/02/2016 SX2 PLUS MILL ,the link by Dennis D, the photos etc is how I done the DRO, and why there is less room for fitting at the back.

Bob

[Ron LadenParticipant @ronladen17547]

Bob,

Thanks for the link, the guy went for the front of the table so not to lose any travel. I am still going to fit the DRO at the back, using a 25 x 20mm piece of angle as a swarf cover I lose 15mm of travel but I am ok with that. The thing I dont like about fitting to the front is you lose access to the gib screws and the table locking handle.

He also went with a 500mm DRO which meant a mounting extension added to the end of the table. I have ordered a 300mm which covers the length of X travel or at least it will the way I use the mill. The spec for the table is 330mm of longitudinal travel but I try not to go further than 280mm, though if required I may stretch it to 300mm which keeps the table in full contact with the length of the gib. If you wind the table fully to one end there is an awful lot of unsupported table hanging in the breeze and on only 3/4 of the gib. To consider that with a heavy lump mounted to it plus machining forces I dont think bodes well not on a mini mill anyway.

I,m sure you know Bob that the DRO,s are not swarf or coolant proof and need protection which is easily done with a length of thin angle running the length of the scale. Its easy with the X and Y but not so the Z, with the scale column mounted and the connecting bracket to the side of the head its not possible to fit an angle to the front of the scale. I havnt to date seen any Z mounted scales with any protection but I have an idea which I,m going to try, if it works I will let you know.

Ron

[Nigel Graham 2Participant @nigelgraham2]

An excellent set of tooling there.

Referring to Paul Lousick's " I also spend …. time making jigs to hold the job. "

Whenever I make a jig, even of something a bit rough-and-ready for a simple, non-critical task on the bench-drill, I try to think " Can I also use this for XXX type of operation… " simply by , say, adding some extra mounting-holes, or making it bigger than for the immediate project so it can be modified readily. And doing so without undue extra time.

As an example, I needed an inner circle, so to speak, for the rotary table so I could round off the carriers on a Hemingway Kits boring-bar set. (My RT's T-slots end quite a way out from the middle.) While at it, I drilled and tapped quite a few more than immediately necessary of the clamping-screw holes, to cope with a range of similar tasks in future.

+++

On Ron's remarks about protecting DRO scales, the Allendale Machine-DRO set I am fitting to my Myford VMC comes with lengths of purpose-made extrusion. Fitting the Y-scale cause me much cogitating (it's all right, it's allowed) and a lot of making of brackets and semi-rigid PVC-sheet cover . The Z-scale is even worse because the machine's column is a cast frustum of a pyramid, but I have worked out a mounting arrangement on large-section aluminium angle that also protects the encoder by a sort of " wrap-around " assembly. It puts the strip facing the wall behind the machine.

The set I purchased does have a pitch-circle calculator, but all is not lost without it because tables of (x, y) constants originally developed for setting jig-borers are available, and it would not difficult to create a simple spread-sheet in, e.g., MS Excel to rattle off the actual dimensions from them, the hole-count and p-c radius. easily.

[Ron LadenParticipant @ronladen17547]

Would anyone happen to know the rubber thickness of a bicycle innertube, I am looking for some thin rubber strips and an innertube sprang to mind. Thinking about it I guess there may be various sizes, i.e a mountain bike tube been heavier than a normal road bike but I am not sure.

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by Ron Laden on 28/07/2019 14:49:04:

Would anyone happen to know the rubber thickness of a bicycle innertube…

I've got a collection of old inner tubes waiting to come in useful. Thicknesses are between .75 and 1mm.

HTH,

Rod

[Ron LadenParticipant @ronladen17547]

Thanks Rod, that is helpful.

Ron

[Ron LadenParticipant @ronladen17547]

The DRO,s arrived and I started by fitting one to the Z axis, its relatively easy to offer some protection against swarf on the X and Y but not so easy on the Z. The X and Y DRO can be fitted with a piece of angle which covers the beam and sensor head, on the Z the sensor bracket comes forward to connect to the mill head so not allowing any angle in that position. It seemed obvious that an angle cover could be fitted if slotted to allow the sensor bracket to pass through so thats what I,ve gone with. The slot along the length of the angle is 4mm wide, could have gone with 3mm but had no cutter so 4mm it is.

It wont stop all swarf but it should stop the majority and the beam is offset to the slot so any small pieces getting through should miss the beam. I have an idea for a slotted cover which would be self sealing either side of the sensor bracket as it travels along but will give this version a try first.

Edited By Ron Laden on 01/08/2019 10:57:06

[Ron LadenParticipant @ronladen17547]

For anyone with a SX2P that may be interested a couple of pics showing the installation a bit clearer.

Sorry guys, I dont know what I did with the picture sizing, if you click the image it reduces for better viewing.

Edited By Ron Laden on 01/08/2019 16:42:29

[Ron LadenParticipant @ronladen17547]

X axis DRO fitted to the rear of the table, pretty conventional, I think the majority fit them this way. Just the Y axis one to fit but I may take a bit of a different approach in fitting the one to the Y, we will see.

[Ron LadenParticipant @ronladen17547]

A couple of finishing touches to the X and Z.

Added a sleeve of heat shrink to the X sensor cable to help protect against swarf , I didnt shrink the sleeve which has left the cable quite flexible when moving with the Y front to back. I also glued a piece of plastic angle to the Z sensor to keep the cable contained and off the electric box. The box has a textured finish which is quite abrasive and I could see that wearing away the cable over time.

Picked up a piece of alu angle this morning at B&Q so I can make a start on the Y in the morning.

Edited By Ron Laden on 03/08/2019 16:41:29

Edited By Ron Laden on 03/08/2019 16:46:19

[Ron LadenParticipant @ronladen17547]

Fitted the Y axis DRO this morning though I didnt follow the norm, I fixed the sensor head to the base casting and the beam travels with Y carriage. A couple of reasons, the fixed sensor means no cable sliding back and forth plus easy to fit the swarf guard behind the beam. Doing it this way means the beam needs to extend 40mm forward of the carriage in fact the alu angle swarf guard becomes the mount for the beam.

So all 3 axis now have a DRO, just need to make a mounting board for the displays.

[Ron LadenParticipant @ronladen17547]

Final job, mount the displays. DRO,s all done and dusted..

Edited By Ron Laden on 05/08/2019 15:06:50

[Ron LadenParticipant @ronladen17547]

What a difference DRO,s make to using the mill, may seem obvious but when you have never used them before I am surprised what a bonus it is having them, well worth fitting and at £120 from ARC for a 3 axis set, hardly expensive.

Ron

[Ron LadenParticipant @ronladen17547]

A bonus in having a full set of ER25 collets which came with the 918 lathe means I can now get myself a R8 chuck for the mill, I see that ARC do one which I,m sure will come in very handy.

[Ron LadenParticipant @ronladen17547]

I have had the DRO,s fitted to the SX2P for 3 months now and they are working well. Fitting a swarf guard (thin alu angle) is easy with the X & Y but not so on the Z as the sensor bracket comes forward to connect to the head. Previous posts above show I slotted a length of 1" x 1" x 1/16" for the bracket to fit through and give it a try, well just to say it works a treat. You can see from the picture that the beam is completely clean, some swarf does get through the slot but the slot is offset to the beam so not much reaches the beam and been vertical it must just fall off as it is always clean.

If your are about to fit a DRO to the Z on a SX2P or even have one fitted but unguarded I think it is worth adding the slotted guard.

Ron

[John HaineParticipant @johnhaine32865]

Why not just buy R8 collets, gain about 59mm of daylight and better rigidity?

[Martin ConnellyParticipant @martinconnelly55370]

R8 collets are single size, ER are parallel closing so can be used for a small range of sizes. This means that for a full range of sizes more R8 collets are required than ER collets. Having said that having both ER and R8 gives more options for tool holding. I have R8 in metric (1-18mm in 1mm steps), common imperial sizes and also Morse taper and an ER32 chuck on a 16mm shank. Normally I use the ER32 mounted in the 16mm R8 collet, this gives me two benefits.

1. On my round column mill I can use the ER chucks but if I need more headroom I can take the ER chuck out and use R8 to hold longer tooling or to work in pieces with a large range of working heights. For short tooling I can loosen the R8 and lower the ER chuck all without the need to move the head height.

2. There is no spindle lock on my machine. With the ER chuck I have the correct wrench for the ER nut and the chuck has flats for a large spanner (if you buy one make sure it has this feature if you want it, not all do). This makes it easier to change tooling than loosening and tightening the R8 drawbar.

Martin C

[JasonBModerator @jasonb]

And another reason for not using R8 Collets is that when using small cutters it becomes hard to see what you are doing and any form of clamps have to be kept well away from the spindle.

[EmgeeParticipant @emgee]

Posted by JasonB on 29/11/2019 13:06:48:

And another reason for not using R8 Collets is that when using small cutters it becomes hard to see what you are doing and any form of clamps have to be kept well away from the spindle.

That's the reason I can't understand why most users here go for ER32 chucks, they clearly don't do small work held in a chuck either on the table or on a dividing head, ER16 is suitable for much of the milling work done by smaller scale model engineers and allows working close to the chuck jaws.

I can only believe it is because they have ER32 collet chucks on a lathe so making greater use of the collets.

Emgee

[JasonBModerator @jasonb]

I suppose the reason for ER32 is that they also want to use it for workholding on the lathe and can only afford one set of collets which makes sense. Thats what I managed with for a number of years but now have ER16 for the mill too.

[Ron LadenParticipant @ronladen17547]

I have just 4 x R8 collets 6, 10, 12 and 16mm and they cover all my current tooling plus of course a drill chuck, boring head and 22mm arbor all of which are R8.

Having had a set of 15 x ER25 collets come with the second hand lathe it would be a bit daft not to have a chuck to enable me to use them on the mill.

[Ron LadenParticipant @ronladen17547]

The R8 collet chuck arrived from ARC, quality looks to be very good indeed.

I also got a ball bearing type nut for it which seems to work really well without the need for having to over tighten it.

[old martParticipant @oldmart]

The only thing wrong with that er25 collet is the lack of spanner flats on the body. I put flats on the ones I use, and made a custom spanner, carbide endmills made the flats a doddle.

[Ron LadenParticipant @ronladen17547]

I am using the C spanner on the nut and one on the spindle seems to work well enough, like I mentioned the ball bearing nut doesn't seem to need excessive tightening.

[Derek GreenhalghParticipant @derekgreenhalgh23299]

What an amazing thread, i just read it front to back in one go, not only that but the various linked threads too. So much information, not only relating to the original post but have saved links to various sellers that i did not know existed, lots of new tips and tricks too. Following the journey of Ron too, who has passed me on our learning curve, I started off not knowing much and using youtube a lot to learn.

Having people with so much knowledge and willing to share it shows the difference in progress between going alone and having you guys only a few messages away, thanks to Ron and all the participants in the thread where i have gained lots of info and a pleasent afternoons reading.

Derek

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