[Project 5] Low Profile Table Clamps

Yes Jason we could be sent to the naughty corner but interesting you found similar results. In my case I wondered if it is my mill being a small 500 watt machine, 175 - 200 rpm with say a 0.5mm cut puts me into stall territory. If I double the speed to 350 rpm I don't have a problem, machine is happy, finish is good which I think comes from the machine getting more into its power band.

Lee, why don't you try 600rpm for the 0.3mm cut and 300rpm for the 0.75mm as Jason shows in his video, if the tool is something like good you should get similar results, worth a try.

Ron

They were both 0.3mm DOC, Don't think I'd go match above 0.5 on the SX2.7 for that width of steel. But as I say run then fast and shallow and you can do two cuts in the same time as one deep one at slow speed.

Having spent the first 11-12yrs of mill ownership using a variable speed machine with no Tacho I go but what sounds right and gives a good finish and seldom calculate a speed. I only fitted a Tacho to the X3 so I could transfer the speeds over to the SX2.7 as that is so much quieter you don't think it is turning! - No gerbox which brings us back to where the noise is as the interupted cut just loads and unloads the gear train, the higher momentum also helps reduce this.

Sorry my mistake I should have realised, I thought you were copying Lee,s cuts.

I did some playing around last night.

Reground the tool (excessive clearances).

Results (remember, you have to click on the video to see more than the preview):

0.3mm DOC - 180RPM - 36mm/min

0.3mm DOC - 280RPM - 36mm/min

0.3mm DOC - 280RPM - 20mm/min

0.3mm DOC - 600RPM - 40mm/min

Best surface finish, by far, was the 600RPM cut, but it was very noisy.

It sounded like the machine was taking a beating.

Hi

Fly cutter with the tool stuck out flailing a large radius on a small width workpiece NBG on a gear drive train.

Keep the diameter of the cutting circle just a fraction wider than the job when flycutting to minimize the torque load on a chattering gear chain. Belt drive is infinitely smoother running on intermittent cutting

Three toolbits mounted on 52 mm cutting head will cut faster with one bit starting the cut and the previous one exits.

Setting up is a breeze take out the clamp bolt and fix the setup jig in its place to get all the tips equal by installing the toolbits to sit on the jig and do up the clamp screws.

Sharpen dull HSS tips with an oilstone for longer life and almost mirror finish.

I do not currently have any plans to make new fly cutters.

In fact, I'm only using (playing really) this one until the new carbide inserts for my face mill arrive.

Not sure I can get any less stick-out than I already have. Maybe 5mm, but I've seen SO a lot further than mine.

Incidentally I have noticed a small flat spot on the base of my cutter. I think my grind needs to be improved.

Well done Lee, good that you have got a better finish. I am not used to the sound of your machine of course but the 600 rpm cut didn't sound that bad to me, sounded better than the slow cuts I thought.

Ron

Recording on the mobile phone doesn't seem to pick-up the banging sound, which is a shame.

Jason,

When cutting a shoulder, did you say it was better to come in from the side?

I have Harold's 'Milling A Complete Course' and he seems to suggest chewing away 2mm coming top down.

I would indeed come in from the side so that you get to use more of the flutes otherwise you are just wearing the end of the cutter. That's for a HSS or carbide 2, 3 or 4 flute cutter, the facemills seem to work better the other way round on my machines.

Edited By JasonB on 26/05/2020 13:06:26

Mmmm... Pretty!

I think fly cutting with HSS bits at RPM that result in a higher than recommended surface metres per minute are benefiting from air cooling over most of the revolution. Just to show that slower RPM with correct feed works here is an example. This is a piece of scrap hot rolled steel about 25mm across. RPM=166, DOC=0.1mm, feed=18mm/min.

Martin C

Edited By Martin Connelly on 26/05/2020 20:26:56

Lee, the low profile clamps mentioned earlier are here. They are priced for industry not home use but will give ideas on how to make your own.

WDS parts

Martin C

Thanks Martin. For the video and the link.

Sneaky nap-time session:

Other side milled:

Not sure how I'm going to do the vertical cuts yet.

Bandsaw !

Never mind ​​​​​​

Finished for the day: