Joe's 1000x600x200 steel and aluminium router started

[devmonkey]

Just in the process of rigging up some dust extraction which is going well, but I also need air assist for aluminium chip removal. I have a very loud compressor I don't want to use, can anyone point me towards something quiet that has the required flow rate and pressure (apparently some people use pond air pumps??) for blasting chips out of deep pockets?

I've also seen these small plastic fans you can slide onto the cutter but I can't imagine they can blow chips out of deep narrow pockets.

[Voicecoil]

I found a little side channel blower in fleaBay for about £60 - with a little nozzle it blew chips everywhere, so much so that I had to throttle it back a bit. If you're tempted to go the same route just be aware that those things come in different flavours of pressure and volume delivery, the one I found did quite a reasonable pressure, ~280mBar IIRC.
I find the noise of the air jet far louder than that of the blower itself.

[devmonkey]

I found a little side channel blower in fleaBay for about £60 - with a little nozzle it blew chips everywhere, so much so that I had to throttle it back a bit. If you're tempted to go the same route just be aware that those things come in different flavours of pressure and volume delivery, the one I found did quite a reasonable pressure, ~280mBar IIRC.
I find the noise of the air jet far louder than that of the blower itself.

Thanks for the tip I will keep a look out for one, what power rating is yours? Could probably machine up a really small one on a brushless RC motor and mount it on the Z. Another project...

[Voicecoil]

Thanks for the tip I will keep a look out for one, what power rating is yours? Could probably machine up a really small one on a brushless RC motor and mount it on the Z. Another project...

Mine's about 500W @ 50Hz mains, will do a bit more at 60Hz.

[devmonkey]

Machine is going really well, I've made a few parts for the local flying club.

I'm now in need of a rotary axis, I have a couple of options:
1. Use the headstock and tail from an old rusty taig lathe I have with a belt drive off of a stepper or servo,
2. Convert a rotary table,
3. Buy one.

I need it quite quickly, can anyone recommend anything that is known to work, even if it is one of those chinese harmonic drives? I need something with a 100mm chuck and minimal backlash as it will be used for continuous processing not stop/lock.

I was looking at this, seems extremely cheap for a harmonic drive but they have them in europe so I could get it fast:
https://www.aliexpress.com/item/33025578546.html

Cheers, Joe

[devmonkey]

I needed an HTD5 pulley for a project, this was a bit odd as it needed to be fixed to a spinning bearing housing rather than to a shaft so I decided to make one on the machine. I used the cambam trochoidal plugin for the roughing allowing the entire part to be milled with a 3mm endmill, took a bit longer but meant no tool change. Part was cut dry with air to clear chips, worked out really well.



Trochoidal clearing is excellent, no gummy chips sticking to the endmill. This was cut from some 5000 series (not sure exact spec) scrap plate, it is quite gummy, would have been better in 6061 but I didn't have any to hand. Still the part is more than serviceable for its intended purpose which is to drive a multi-turn encoder (near zero load). Was cut at 3mm DOC, 15% stepover, 24k rpm, 3000mm/s for clearing (although the machine never gets anywhere near this on this part due to the tiny radius of the spirals).



I will probably recut it with a high speed profile to finish, the finish pass was way too slow (600mm/s) which led to rubbing and the surface finish not being perfect. This was entirely my fault for rushing the CAM and not setting the feed.

[Clive S]

Very nice. I happen to make two the other day for an encoder 28 tooth .

.

[devmonkey]

Very nice. I happen to make two the other day for an encoder 28 tooth .

.

They are nice, what are they made out of and how did you cut that thread on the inside of the hollow one?

I just made it a baby brother, this one is going on an 8mm shaft with a 2mm shaft stuck in the end to go onto the encoder gearbox.

[Clive S]

The thread was done on a Myford S7 converted to cnc with an encoder to do threading.
They are made out or 6082 I think

Didn't do a vid of the thread but had to make a male thread first. The hollow one is being fitted on the end of a spindle lathe to drive the encoder. The pin nut was off the lathe and used that for the fit 35x1.5mm



https://www.youtube.com/watch?v=MyLwFqa02Bc

https://www.youtube.com/watch?v=ZR_W3w_rews

https://www.youtube.com/watch?v=IiMME9BcBHw

[Kitwn]

'Great minds' and all that.

Yesterday I used the CamBam trochoidal pocket plugin to cut out the teeth for a ratchet made from Jarrah hardwood. Conventional shallow cuts tend to take the corners off the teeth where the grain is tangential to the wheel so being able to do a 12mm depth of cut with a 2mm diameter tool is a bonus. I still had to redraw the original ratchet design (produced in Gearotic which will also draw HTD and many other pulleys for you) with rounded teeth to avoid some chipping. This cut used a two-flute straight cutter with a speed of 1000mm/min and a stepover of 0.15 (0.3mm) and the maximum 24000 rpm. This took about 25 minutes for the 110mm diameter wheel.