The Shop > Tools
The Sajo mill is here
Trion:
Last time I was working with the mill, I checked for play in vertical direction on both the head and the table, could not find any in the head and the play in the table required quite a bit of force to be set in motion, which I don't believe could have been caused by a 0,5mm cut. The tram is still very far out, but as said, I have difficulties adjusting it better as of now, but I think I may have come up with a solution which should let me adjust it properly. **
But when I was beginning to part of the piece into suiting T-slot width with my 8mm carbide roughing endmill, the head started making some very bad squeaking sounds, as if a bearing was running dry or with some chips in it. So I decided to disassemble the head to search for the error. Luckily I had made the gear fit into a tight sliding fit, so the spindle didn't need much persuation before it came out :)
Having everything on the table, I was not able to find the error. But upon assembly, I had the mill running and tightened the main and upper bearings until they were making a nice sound. To loose and it would sound like crunching, too tight and they would squeal, so I aimed at the middle which has been good till now.
The battery on the camera went flat, but I continued and milled the T-slot shape. Now I just need to cut the t-slot bar into suting lengths to become t-slut nuts. So last week I bought a chinese 12x9 band saw. Will do a write up on that when I begin to improve it :dremel:
** To tram the head when the table is so rough, I want to mount a plate in the vise, make a cut in the X direction and then mount the tramming tool on the cut surface without moving the Y-axis at all, so I'll be measuring in the lowest spot of the cut. Adjust the tram util there is no deviation, then mount an end mill and make a cut in the Y-direction and then adjust the tram after that. After a few iterations i better have it pretty close :scratch:
Trion:
I have made a bit of progress this weekend too :)
Bought a cheap emergency stop button and fitted it to the mill
Threaded a few of the T-slot nuts to M16
Got sick of drilling on the mill, changing collets for each drill size, so I began to use the old drill press. This one also needs some improvement, one day when I have much time to spare ::)
I tapped a total of 4 t-slot nuts to M16 threads. Will mount them on a later occasion.
Next I thought I'd try making a conventional type HSS fly cutter, so I found a piece of steel that had a ugly hole in it.
Being so eager to try sawing at an angle, i gave no thought about later machining and prepared the saw for the cut
Working just fine :)
And the finished piece. I'm quite pleased, considering the blade is very worn
What I was not so pleased about, was my lack of thinking. This odd shaped part became very inconvenient to mount in my lathes chuck, as I wanted to drill a mounting hole through the rear surface of it :bang:
So I turned it a bit on the length, just for some shinyness ::)
While I was working at the lathe, I had got the saw working on its next task: new vise jaws :D
There is no problem in making them in mild steel, right?
Trion:
The making of the fly cutter continues :)
I mounted the workpiece in the vise, just aligned by eye measurement
Drilled a hole roughly at centre. My larger drills have MT2 taper, so I had to use the biggest end mill my collet chuck would allow (20mm)
Next I found a suiting piece of bar stock, cut it to length and mounted in the lathe
Turned the OD to 19,97mm and faced of the end.
This part is intended to sit the other way around, but lacking proper tooling to measure bores, I used this with some brass foil of 0,025mm
I used this to roughly estimate the ID of the bore to 20,03mm
Next i turned the opposite end of the shaft to 20,10mm, making a 0,07mm press fit
As I don't have a shop press, I decided to use som heat to ease the assembly process
After heating the part for about 10 minutes I bashed the shaft into the hole. But again, I was lacking of planning. I used both a plastic and a steel hammer, but the steel hammer destroyet the upper part of my nicely turned mounting surface :bang:
I ground the excess metal of on the bench grinder. Then I milled a flat on the part
Drilled to 6mm, as deep as the drill would go
In order to accept this thingy. I do not know what they are called in english, the norwegian translation is something like "tension pin". Anyways, this is 6,5mm while the hole is 6, making for a nice tight fit
To hit such pins in place, special punches with an extending centre knob are used. I tried making my own, but it obviously wasn't hard enough. It took a lot of hammering to get it in place, but now it should secure the fly cutter quite safely to the mounting shaft
With that being done, I felt secure enough to mount it in the lathe. There I turned down the OD until I had removed the rusty hole from the starting jet (when the part was initially water cut)
Back on the mill, ready to mill the flat surface. Again roughly aligned by eye measurement ::)
This was a good opportunity to test out my new carbide end mills. Here's the 20mm one taking a 10mm deep cut :beer:
To make the centre cut I used a 16mm end mill. Initially I am going to use a 12mm HSS blank, but I like the ability to change, plus some room for shimming etc.
I suddenly became aware of what time it was, and it was approaching Top Gear time, fast. So I hurried on and tapped 3 holes to M8, mounted a few set screws with copper paste on the threads, roughly ground the tool bit, and got going :)
Not overly beautiful, but very functional and sized proportional to the mill. I'm happy
Taking its first cut. Tram is obviously way out.
Need to shim the tool bit to centre position, grind it a bit nicer and tram the head properly. But it works :beer:
Trion:
Here's my go at tramming the head.
On the newly cut surface I put on my 0,001mm (0,00004") indicator and played around until I had almost no movement at all
Then I put in a piece in the Y-direction and fly cut this. Afterwards I got out the tramming tool and trammed it until I was satisfied.
Then I sharpened the tool bit before I got going on a proper sized lump of steel. Somehow, the tram isn't perfect yet as you can see on the cutting marks (tool is moving from left to right)
At one end I got overlapping marks which should indicate that things are spot on
But on the other end it seemed to be a different story. :scratch:
My conclusion is that something in the Z direction is moving. The Y-axis was locked during the cut.
cidrontmg:
Weird. The tramming must be very near to spot on, or the fly cutter wouldn´t be leaving the desired marks at the right half. Have you tried running it another time back and forth without increasing the Z feed? If there´s chip dragging (and there might be, you´re doing it dry), give the cutter tip a wipe with a fine stone (without removing the cutter...) and try running it again, two passes with no Z feed. And see if it changes in appearance. Chances are it will. It will be smoother anyway!
:wave:
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