Setting up a Mini Mill & Stuart 10V Machining

[Dr_GMJNParticipant @dr_gmjn]

Posted by JasonB on 16/05/2020 07:06:15:

The biggest unknown is still that bit of tool steel do you have any mild steel of known spec to try cutting? Better to eliminate that unknown before mucking about with the machine.

I’ll get some steel off EBay next week.

TBH it’s a simple job to remove the column shims and repeat the test. If it’s the same Ill just replace them.

Re. The cutter – I get exactly the same results with the brand new ARC cutter I got last week (similar spec to the ball nose), albeit that is 10mm not 12mm.

I suppose I’ll have to buy another set. Any recommendations?

 

Thanks.

 

Edited By Dr_GMJN on 16/05/2020 08:11:20

[Ron LadenParticipant @ronladen17547]

Can I suggest you go to M-machine for your steel just to be sure what you get is as ordered. Excellent service, good pricing and they carry a large selection of material. If you go to their website you can download the catalogue and you will see the various grades listed against the types of material.

The 10mm cutter I used in the video is from the ARC premium range HSS 3 flutes TIAIN coated £10.36.

Ron

[Dr_GMJNParticipant @dr_gmjn]

Posted by Ron Laden on 16/05/2020 08:54:04:

Can I suggest you go to M-machine for your steel just to be sure what you get is as ordered. Excellent service, good pricing and they carry a large selection of material. If you go to their website you can download the catalogue and you will see the various grades listed against the types of material.

The 10mm cutter I used in the video is from the ARC premium range HSS 3 flutes TIAIN coated £10.36.

Ron

Thanks Ron – I will do that.

For a test like this, on this machine, what grade and thickness of material should I get?

In other words, worst case – what should it be capable of?

I’ll get some ARC premium cutters too.

That little exercise will see my spending money for the month gone! But it’s all good fun.

[Anonymous]

Posted by Ron Laden on 16/05/2020 08:54:04:

Can I suggest you go to M-machine for your steel just to be sure what you get is as ordered

+1 for M-Machine; they're one of my suppliers. Only use Ebay if you know what you're doing and are prepared for the metal quality to be poor, which may not matter for temporary fixtures.

I've had poor finishes like those shown. It's all down to the cutting tool, material and cutting parameters, especially feed rate. What it isn't down to is the rigidity of the machine. I got my poor finishes on a Bridgeport. While that isn't the most rigid of mills, it's much bigger and heavier than a SX2!

Andrew

Postscript: Get some bright steel flat (EN32B) or, if you want a slightly increased challenge and to save money, get some black (hot rolled) flat. Thickness and width aren't critical, but may be 6 to 8mm thick and whatever width will be useful. Note that bright flat will be to size, black is usually slightly over to allow for removal of the black mill scale. Learn to get a good finish on low carbon steel before worrying about testing the mill with more difficult materials like  gauge plate or stainless steel.

Edited By Andrew Johnston on 16/05/2020 09:51:27

[Jon LawesParticipant @jonlawes51698]

This thread is a real education. Lots of pictures and suggestions for why certain results are achieved. For someone like me this is excellent reading, thanks all.

[JasonBModerator @jasonb]

As for Cutters ARC's premium have been mentioned a few times in this thread and the standard length 3 flute that Ron mentions would be a good all rounder and just for risk of being called bias this 10mm 3-flute "disposable" is another alternative., I use both but would suggest you don't go at the iron castings with these until you know if there are any hard spots under the surface, keep the Tin ones for that.

[Old SchoolParticipant @oldschool]

Martin Connelly, that Mach 3 milling wizard looks useful where can I find it.

thanks Oliver

[Dr_GMJNParticipant @dr_gmjn]

Ok guys – understood. Thanks.

[Dr_GMJNParticipant @dr_gmjn]

Posted by Jon Lawes on 16/05/2020 09:49:47:

This thread is a real education. Lots of pictures and suggestions for why certain results are achieved. For someone like me this is excellent reading, thanks all.

Thanks Jon. I think pictures are worth a lot on threads like this. For example, Jason picking up on a damaged tool, even though that wasn't the primary reason for posting it.

For me, as a beginner, it's not worth just posting the good stuff. Even though it's sometimes embarrassing to post your errors it's the quickest way of learning. Hopefully one day I will be able to help a beginner too.

I must say the help on this forum, even after only being a member for a few days is phenominal. Also I have to say that ARC Euro have been extremely helpful in calling me to go through any issues I've had with the mill. I can't think of another company I've dealt with recently that looks after its customers like that.

Cheers!

[Martin ConnellyParticipant @martinconnelly55370]

It is important to understand surface metres per minute (or surface feet per minute SFM) if you want your tools to stay sharp longer and also chip load to make sure you are cutting and not rubbing. A lot of people will say they just go by ear or feel but for a beginner it is best to not be put off by experimenting and so damaging tools and workpieces. Good habits at the beginning will pay off over time and you can adjust speeds and feeds from a known starting point.

You can search for these things online to understand them or use a calculator/spreadsheet or wizard to get a good starting value for speeds and feeds. Home made tools for things like spot facing (as in the other thread) will, as Jason said, need to be run slower than the equivalent in HSS. If you halve the rpm you need to halve the feed rate to maintain chip load. If you double the rpm you need to double the feed rate to maintain chip load.

To work with feed rate without CNC you need to get a feel for how fast you need to turn the handwheels on your mill. A feed rate of 100mm/min will take 30 seconds to travel 50mm. Try timing your self winding the table 50mm and see how fast it is, Try for 50mm in 15 seconds and that is 200mm/min. A chip size (tooth load) of 0.125mm or 0.005" is a reasonable starting point as well. Anything too small will cause rubbing not cutting.

The Mach3 wizard is in the Mach3 CNC software but you do not need to have, or want to use, CNC to run the program and access the wizards.

Download Mach3

Download and run Mach3 (do not install the parallel port option, it's not needed)

Launch Mach3 Mill

Choose no device when asked (tick remember my choice)

In config select native units and pick mm if that is what you want to work in. (this is a one off selection)

Quit Mach3 to set the units and then run it to use it

In the tabs at the top select wizzards

Pick the speeds and feeds wizard

make sure you have mm selected if that's what you want because a 12 inch diameter tool will give very slow rpm

This is not the only feeds and speeds calculator but it is free and easy to use.

I've written this from memory so it may be slightly wrong!

Martin C

Added a bit to Mach3 instructions.

 

Edited By Martin Connelly on 16/05/2020 14:00:09

[JasonBModerator @jasonb]

The only thing I will add to what Martin says is you also need to know the material that you are machining and also the type of cut. most tables will give several different cutting speeds for "steel" depending on what it is from mild, through various carbon levels which get harder and then possible hardened steels too.

[Thor 🇳🇴Participant @thor]

Hi Martin,

Thanks for the Mach 3 suggestion as a feeds/speeds calculator. I tried but the wizard zeroed my input as soon as I moved to the next input field. Only by selecting Operator, Auto-Calculator was it possible to enter data in more than one input box. Still wouldn't let me enter a Chip load of say 0.2. May be you have any advice?

Thor

[Old SchoolParticipant @oldschool]

Must admit I am struggling to get it to work as well.

[Martin ConnellyParticipant @martinconnelly55370]

Press enter after you type the numbers before moving to the next input field.

Martin C

[Thor 🇳🇴Participant @thor]

Posted by Martin Connelly on 17/05/2020 12:03:14:

Press enter after you type the numbers before moving to the next input field.

Martin C

Thanks Martin, the Enter key did the trick. I'm used to use the mouse to click in the next field, and that obviously doesn't work.

Thor

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