This is it posed with a completed gear. There's a missing spacer shim that goes in the back to push the teeth into the cut on the second pass, this is why it looks a bit recessed here. The teeth protrude more towards the top as well to give a progressive cut.
- Thread starter Kram
- Start date
Here's a couple of better pictures. I have installed the shim and the broach is driven up to the top tooth. We can see it is pretty much exactly where it should be.
Curiosity got the better of me so I took a few measurements.
Shim thickness 0.85mm
Slot depth 9.50mm
Tooth heights. The teeth have a bit of angle on them so it hard to get an exact height with a micrometer and I wasn't hanging about when taking measurements.
9.55
9.65
9.70
9.83
9.92
10.00
10.12
10.18
10.32
10.41
10.45
10.52
10.55
This is an average of 0.077mm cut depth per tooth so my slot depth should have been about 9.48mm to obtain the average cut with the first tooth
Close enough I reckon.
Curiosity got the better of me so I took a few measurements.
Shim thickness 0.85mm
Slot depth 9.50mm
Tooth heights. The teeth have a bit of angle on them so it hard to get an exact height with a micrometer and I wasn't hanging about when taking measurements.
9.55
9.65
9.70
9.83
9.92
10.00
10.12
10.18
10.32
10.41
10.45
10.52
10.55
This is an average of 0.077mm cut depth per tooth so my slot depth should have been about 9.48mm to obtain the average cut with the first tooth
Close enough I reckon.
This is quite a good resource. The table shows a 3mm broach takes only 295kg (650lbs) of pressure to cut.
Munkul
Jack of some trades, Master of none
- Messages
- 7,808
- Location
- Cumbria
Started roughing out my fly cutter from a bit of scrap 6" round... It didn't look like this when I started!
It had keyways and flats and holes in this end, so the interrupted cuts were a bit of a pain, having to slow down for them. Now I'm passed them and can motor on at 4mm DOC and 0.3mm/rev.
I need a 32mm shank, so plenty to go... although half wondering about making it arbor mounted rather than shanked... the slot will be a royal pain to set up for milling.
It cuts nicely, it's not hard enough to be en24 or en19, but too tough to be en8, so maybe it's en16.
It had keyways and flats and holes in this end, so the interrupted cuts were a bit of a pain, having to slow down for them. Now I'm passed them and can motor on at 4mm DOC and 0.3mm/rev.
I need a 32mm shank, so plenty to go... although half wondering about making it arbor mounted rather than shanked... the slot will be a royal pain to set up for milling.
It cuts nicely, it's not hard enough to be en24 or en19, but too tough to be en8, so maybe it's en16.
May be of interest to some, a little unconventional line boring to renew a seal location in situ. Been in the planning for nearly a year so I was relieved it did the job. Dimensionally accurate to a thou and to correct surface finish.
Fasteners are 2” for reference and the machined face is around 60” deep.
Fasteners are 2” for reference and the machined face is around 60” deep.
Brad93
Member
- Messages
- 19,102
- Location
- Essex, United Kingdom
What make boring kit did you use?
Maker
Most folk just call me; Orange Joe
- Messages
- 10,633
- Location
- Keeler crater
That's an impressive bit of kit! Can you say what the part being machined is?
It’s a mirage lb90. I don’t believe this model is available any more, but looking at the brochure online it seems to have been replaced with the lb100 which is basically the same machine according to the specs.
Got quite a bit of mirage gear, top quality stuff.
It’s a combined stop and control valve. IP steam system in a power station
My Old Landy
Engineering Mayhem
- Messages
- 3,626
- Location
- North Lincs
If they work they are good
Munkul
Jack of some trades, Master of none
- Messages
- 7,808
- Location
- Cumbria
Part 2 of the installment
I finished off the fly cutter last night.
I got this lathe tool that uses the "blunt" corners of CNMG inserts. I thought the approach and relief angles could work really well for fly cutting, and if nothing else, I could grind my own carbide edges out of used-up inserts. If the relief wasn't enough to avoid recutting chips, then I have some brazed carbide that I could grind to suit.
I put one of my random ceratip inserts that I don't know what they are for. (The box says steel, but they don't work on steel worth anything). I tried it out-of-the-box, and I also tried it after giving the edge a little tickle with a grinder.
My first couple of cuts were way too fast, it left a nasty smeared surface. I slowed the spindle right down to around 250rpm and about 30mm/min feed which worked much better.
This was a 1 thou cut (I did several at different speeds/feeds). The pictures don't do the finish justice. I couldn't clean it properly, but trust me, this is almost mirror finish. Really happy
Just need some grub screws to replace the bolts I used for testing...
and to get some more materials to try out... need to learn these things before a job comes in that has to be perfect... I'll try it on steel as well and see how rigid the setup is.
I finished off the fly cutter last night.
I got this lathe tool that uses the "blunt" corners of CNMG inserts. I thought the approach and relief angles could work really well for fly cutting, and if nothing else, I could grind my own carbide edges out of used-up inserts. If the relief wasn't enough to avoid recutting chips, then I have some brazed carbide that I could grind to suit.
I put one of my random ceratip inserts that I don't know what they are for. (The box says steel, but they don't work on steel worth anything). I tried it out-of-the-box, and I also tried it after giving the edge a little tickle with a grinder.
My first couple of cuts were way too fast, it left a nasty smeared surface. I slowed the spindle right down to around 250rpm and about 30mm/min feed which worked much better.
This was a 1 thou cut (I did several at different speeds/feeds). The pictures don't do the finish justice. I couldn't clean it properly, but trust me, this is almost mirror finish. Really happy
Just need some grub screws to replace the bolts I used for testing...
and to get some more materials to try out... need to learn these things before a job comes in that has to be perfect... I'll try it on steel as well and see how rigid the setup is.
