Quote Originally Posted by JOGARA View Post
Trying to reduce the force that is pulling down the bit.

The thing I changed when it started to happen was that I went from 1mm DOC to 1.5mm DOC.
So I am changing that back (sadly the 1.5mm DOC halfs my machine time which is why I want it).

Wondering if the helix is also too much? It sounds nasty when it does it but that could be down to the machine rigidity?




I am tempted to grab a 8mm carbide drill bit and use that to get as far down as possible and use that hole as the "pre drill position"
If you are having these kind of problems now I really dread to think whats coming.

I thought your problem was the cutter being pushed back in the collet not being pulled out? Maybe i need to read back and check that out again. The ramp is fine if anything its to shallow cutters need and want to be worked, sadly you cant do this on a machine like you have. It's just not up to it.

The collet/Nut cutter slippage problem you have. Something is wrong somewhere. These ER systems, although not the best in engineering terms are perfectly adequate for their purpose. Either the collet is out, the spindle taper is out the shank on the cutter tapered. Something is wrong somewhere. It could be you and just lack of knowledge and experience I cant say for definite because i'm not there to see or check whats going on. You are using baby cutters which generate little load and there is no way you need a ball nut for what you are doing. Tightened correctly all should be fine. I cut far in excess of what you are doing by multiple times with ER systems as i have done for years with little issue if ever. It could be a combination of things going on, without someone being there who's knows their stuff its hard to quantify. Also no you should not rough up the cutter or collet or anything for that matter you will solve nothing but will cost your self new equipment when it's buggered up. Plus all this gear is hardened so only serious animalisation would have any effect to 'roughen up'

Regarding your ramp. This is the bottom line, rigidity is everything and more so trying to use helical strategy's because it strains the machine in all directing that traditional tool paths don't. Rigidity is something you do not have, I'm not surprised it sounds bad. In Engineering terms, if it sound bad, it is bad. It's bad for the machine its bad for the cutter particularly and will give premature excessive tool wear so be prepared to be buying many cutters.

You have to work within the restrictions of the machine you have. A machine like that is not capable of very much hence why you can not do very much.

I did also pm you about your RFQ but like Chaz i also had no reply after you sent models that were in a usable format. It was only after mailing you i realised this thread existed which did throw another light on the RFQ and why i had no reply most likely. After seeing this thread it's obvious by first choice you want to try to tackle this job on your own and after buying a machine. No one can blame you for that and i admire anyone that has a go. After reading this whole thread through I do kind of think you went in the wrong direction for what you want to do, the quantities particularly is going to be hard on a time vs money factor unless you have zero value of your time and you physically have the time to be spending so long on each part, plus the times scales you quoted per part are very long indeed. Without proper coolant systems and a tool changer on a machine and one that as the ability to actually cut properly, I think you are really up against it in a big way.

I did offer to give you a run through of your parts on the phone via my pm and explain how you could help yourself a lot with the designs and other details with no obligation on your part. It's pretty much impossible to design parts to be economically manufactured without having a good machine shop grounding. This is what i was offering you FOC with no obligation. I have helped and guided a lot of people on this forum over the years with no obligation on their part. But not replying to people that have spent time looking at this for you is a little off. Their time is also valuable. I'm not annoyed, but it raises peoples eyebrows. I'm just being straight with you.

Without intending to offend anyone who may have advised on this job. I can't go back and read every post to check but things i have noted.

You are using the wrong material. It's expensive by comparison and is not that hard. It cut's fine but it wont help you using tooling plate on this job plus some of it has Anodising problems that you mentioned about some are ok and designed for anodising but you need need to make sure. I don't know why you have chosen tooling plate but you choose the right material for the job not the right material for the machine. The job dictates.

The general process you are using is errrrrrr wrong and long winded. I also have suspicions more is wrong in the background that you have not posted here, especially with the cam side. I appreciate you are restricted by the machine but this again comes down to the time Vs money factor. If you saw your job on a machining center you would wonder why you have been wasting your time and you would see the scale of why you are struggling with this job. 4 tons v what hmm 20 kilos of machine? It's chalk and cheese. Kind of hmm 10 seconds to face a 5 mm cut of a, ally block 3 inches wide and 4 long if that, as a simple and crude example. The difference is, you tell the machine what to do with the part as where your machine is telling you what you can do to the part.

Sorry it's long winded but its observation of the is entire thread being as i have not posted in it so far.

I hope you can at least find a few things that are helpful and sheds a bit of light on things for you.

All the best