Milling machine thoughts?

Thanks Rob, I will be very keen to know what you make of the DRO and how the sizes match up with the SX2.7.

I only recently got my mill and went through the same SX3/SX2.7 dilemma. I still have nagging doubts, especially as Jason recommended in this thread to go for the SX3 if funds allow. One way or another it seems you can always spend more. I hope to take some consolation from using the funds saved to add useful features, like DRO.

I do like the recent change to the SX2.7 of the speed dial, instead of buttons. My intended uses/requirements are largely crystal ball gazing. I mainly want it to make/modify what I anticipate (and now hope!) will be fairly small metal parts for repairs/improvements. More maintaining/mending than model making.

I purchased the “SX2.7 Mill Starter Set 2” with mine, so I have the 80mm vice.

My first intended project is probably at the upper end of what I expect to grip in the vice. Which is to modify the tool post of my lathe, which is currently a 90mm x 90mm x 70mm steel block with a single tool slot. The current slot is too high to take some of the tooling the (Kerry AG) lathe came with, which seems odd. There is a one inch slot but the centre height limits the tooling to 12mm.

I’m still wondering about getting a QCTP. As an aside I find it a little frustrating the when you look at QCTP specs they always describe the post as being suitable for X” swing, when the key measurement is distance from the (in my case) compound slide to centre height. Mine is 34mm, which is probably a T2 or “250 111” for Chinese imports. The specs also sometimes fail to give the vertical travel of the tool holder, required to calculate the maximum tool size for a given centre height.

Btw, thank you Jason for the videos and vice comparison photos, amongst all the other information you have provided. When you said “We have covered vice sizes on this mill in several threads” I went looking for them, but I couldn’t find them with the forum search facility, as it only searches the subject title. Is there an “advanced search” option that I’m failing to see? I found them with DuckDuckGo using: +"sx2.7" +"vice" site:www.model-engineer.co.uk/forums

The google search box on the home page is the best to use and will give similar results to DuckDuckGo.

I've not tried a new Knob equipped machine but if it's anything like my other machines with them will be nicer to use than the up/down buttons to change speeds

Hi Jason, I tried the search box with the default settings but I got "There were no exact matches for the phrase 'sx2.7 vice'".

I think part of the reason I prefer the dial (apart from being quicker) is that as a software developer I'm stuck pushing buttons most of the day!

Must be those Techie fingers hitting the wrong buttons , second hit down this list from the homepage search box

OK, I'm baffled. Are we talking about the little white box at the top of the forum home page with a "GO" button next to it? I've tried three different browsers (Firefox, Chrome and Brave) on Linux and Windows and I get "no exact matches" each time! "Forum Threads" and "Articles" are ticked. Or is "homepage search" a reference to Google's homepage? I tend to forget about that, as all my browsers are set to "blank page".

The google based one half way down the homepage

I've finally found it! I was going to the forums homepage, not the homepage for the whole site. I had never scrolled down the homepage of the site itself, so I hadn't seen that search box. It would be good if the search box at the top had a tick for "whole site", or even the one on the forum homepage.

Well the DRO arrived today, just under 2 weeks from China, it took me about 4 hours to fit it and very I'm impressed with it, need to work out a way of getting the X axis lock back in as the hole is slightly covered but shouldn't be too hard to sort out.

Im going to get the power lift and feed done hopefully this week as it is a real mission winding the head up and down.

Checked the tram today and its is out a little bit 0.02mm down on the left over 300mm, may try shimming it tomorrow (is it worth it for that amount ?)

Now have a 40mm insert shell mill, a 50mm boring head, a set of reamers, a set of taps and dies from 1.0mm to 2.5mm in addition to the 3-12mm set u already had.

Ordered a HV4 rotary table yesterday, £110 delivered, its not going to be quality and no dividing plates but should work OK (ish) that should arrive tomorrow then it's on to build the first model engine, decided to make a Potty Mill steam engine (with a few alterations) as its all bar stock and Metric, if I mess anything up its not a ruined casting.

If all goes well on that then a David Kersel hit and miss engine will be next (again bar stock)

Will sort out a build thread once I can post pictures.

Rob

That was quicker than I expected. No customs charges then?

Well done for getting it fitted so quickly. I've had no time to spend on mine recently. Glad the DRO seems up to the job. Were the 250mm, 450mm, 400mm scales the best sizes to order?

It would be great if you could post some pictures.

It sounds like your toy collection is coming on nicely! The shell mills look very effective.

Is the power feed from Arc? I don't see a power lift on their site.

The Dro was very quick, I did pay £14 for dhl 15 day delivery instead of standard shipping, tracking said it was picked up on the 24th and delivered on the 26th!!!

Didn't hear about any import tax at all so guessing there is none to pay.

The shell mill is brilliant, I wanted the 22mm arbor but Arc were out of stock so had to get the 16mm arbor, biggest head for that is 40mm, will get a bigger 55mm one later. Got the alloy inserts and the finish it great but still need to get the steel inserts for it.

Was planning on taking pic's today but forgot, will get some tomorrow.

Power feeds are going to be home brew ones, nema 23 steppers, Z will be belt driven but the X will be direct drive, no clutches, will have a small amount of drag on the wheels for manual movement but I can live with that, controls will be arduino based on a system from a YouTuber, I emailed the guy and he sent me the code for his!

Bracket is made for the Z axis, first use of the mill in anger, god I love it, used 6mm aluminium plate cut from a bigger sheet on a bandsaw, it was so easy to square it up, drill and tap and do the slots for the stepper motor, all the holes lined up, that's a first, before the mill it was hours on the belt sander and over size holes so I stood a chance of it fitting.

I do think I'm chasing microns with the Dro, trying to get the readout exactly right !

Rotary table arrived at 9am, it was a bit rough so took it apart and cleaned it, had to do some de burning, lubed and reassembled, 0.02 backlash, no runout at all on the centre bore and maybe less than 0.005 on the table.

Used the Amazon boring bar today to cut the stepper rebate, worked a treat considering its cheap.

Few observations, the mill NEEDS a spindle lock, the pin spanner is a real pain to use and I took a few chunks out of my hand changing collet, the drill chuck arbor is very tight, to the point it is very hard to fit and remove and tapping mode occasionally won't reverse properly ((think it's a dodgy green button.

Sorry, waffled on far too long lol.

Rob

Thanks Rob! I've been so short on time since mine arrived that I haven't even been able to clean it properly yet.

I'm pleased that you're pleased with the mill. Bodes well for my own future experience. I'm looking forward to making some use of it!

I have several Arduinos not currently in use, so that route might be worth pursuing. Can you recommend a good source for the stepper motors? What was the name of the YouTube channel?

I see that this chap has made a spindle lock :-
**LINK**

I'll have to test my tapping buttons. I've not tried them yet.

Not sure which bit was waffle. It was all interesting and/or useful to me!

I used steppers online for mine when I built my cnc router, using them motors and drivers as I intend to cnc the Sieg in the future anyway, nema 23's will be fine for the X and Y but the Z will need a nema 34 when I drive the screw without the standard reduction gears.

Will start a thread for the powerfeeds, I have seen loads using wiper motors but not many stepper ones.

TOM. MAKE. HERE is the channel, different (big) mill and he used a clutch and gears think it will be fine without.

Thanks. I'll look out for the new thread.

I don't know if I'll go as far as Y & Z (or cnc) but I can see how I may start craving an X motor.

Sorry, forgot to answer about the scale sizes, the 250, 400 and 450 were perfect, could have used a 200 for the Y but the 250 is virtually the same size as the base casting.

Thanks again, that's good to know. I'll probably go down the same route.

I finally took some pictures of the Dro today

My baby Sorry pics on its side (and the mancave isnt finished inside yet!!)

Readout

X axis scale

X axis again

Y axis scale.

Z axis scale

6 Powerlift motor

7 X Powerfeed motor.

Powerfeed drive linkage

Tested the feeds out and they move with no problems, only using a cheap chinese signal generator to pulse the stepper drivers to test, when its on they do not want to move by hand, but if the power is off they move fine, only a little bit of drag.

The Powerlift has a 4:1 reduction ratio but the Powerfeed is direct 1:1

Need to tidy the mounts up and fit better (shorter) bolts, that along with the proper controls I hope to get done tomorrow.

Mod edit: rotated pics

Edited By SillyOldDuffer on 28/04/2021 21:53:40

Good to see the photos (with any rotation). Those sizes look like a good fit.

The power lift isn't what I was expecting, although I now see what you meant now about some possible drag.

I just went to go back to my AliExpress basket and the kit has gone up since I added it. It was about £176 when Olly bought his. I think you said yours was about £180 and it's now £261.47.

The powerlift bracket was for proof of concept, need to tidy it up, make covers etc, same for the powerfeed.

Yes did see it had gone up, still think its worth it, it arrives set to Chinese language and the instructions are JUST in Chinese, that was fun changing it to English, good old google translate on the phone!!

With the X DRO on the front what are you going to do about mounting the stops for the X axis feed? They usually fit the slot in the front of the table so their position can be easily adjusted

I am thinking of mounting then in front of the scale, switches piggyback on the head and a bar with sliding stops on the scale.

I did think of the scale behind the table but with the two lots of way covers it would have been a pain and I would have lost some travel.

Z stop are easier, bracket on the side of the head and switches on the column.

I have roller ended micro switches so the stops will be a ramp so they don't get smashed if something goes wrong, they will be wired NC to account for wire damage too.