TOPIC:

waterbok wrote:

stingray-63 wrote:

I would love to learn to use an unimat. My dad has the same and made a lot of pieces with it.

well give him the drawing so he has something to do (saves you two hours )

He has all options for the unimat like "gears maker" I need materials too. sure that I will do some training. That is a tool I want use.

Its great for making small bits out of aluminum or plastic.
Think Jonny and meself have showed that (well mainly Jonny)

sure . You made amazing things. My father's ford T was made for the round pieces with the unimat. canons on his boats too. He used this material for his work too. I know that I could learn a lot with him but I have not really the time. I think that I will tray with old wheeles to have something better than shrapneled rims. just to begin.

waterbok wrote:

thats quite a chunky edge on the 4mm step bit, vibration problems or is it just reflexion?
...

It's chatter caused by too much pressure at the end of a pass or two - ordinarily I'd leave the pass a bit short & set up to go in & out to tidy the edge, but it wasn't really necesary as it was all going to get turned off when I did the taper anyway.

Wow, think we figured out a solution to a big headache. Jonny, did you use the drawing for the specs. It sure came out nice.

juggnutty wrote:

Wow, think we figured out a solution to a big headache. Jonny, did you use the drawing for the specs. It sure came out nice.

Not quite... I used Lars' dimensions, the drawing wasn't correctly proportioned as I used Yellowcats photo as a starting point. I've done another drawing using my faux bodypost as a basis (and Lars' dimensions) so the proportions will be a lot better:






It's not much of a solution either - total time to make it was nearly 3 hours (most of it on the Unimat at 0.025mm per pass ) so I'm not keen to make any more at present. Additionally, the R-clip hole wandered a bit due to drilling it by hand so I really need to get a mini drill press I can keep indoors. I was looking at the Proxxon TBM220 even if it's poorly specced for the money (a tiny chuck that takes collets ?!, but that's fixable), butI was also put off by it sounding like a diesel in Youtube clips





I'm now thinking more on the lines of this cheap generic one - it buzzes like a cheap Dremel clone at peak revs, but it costs a quarter what the Proxxon does

.025 not .25 per pass? or am i off on my scales think I even did .3mm last time on alloy (thats the rough bit final cut way less)

waterbok wrote:

.025 not .25 per pass? or am i off on my scales think I even did .3mm last time on alloy (thats the rough bit final cut way less)

SL threads are 1mm pitch so 1 turn on the handwheel on the Unimat = 1mm, each has 20 graduations so 1 notch = 0.05mm ?

I've managed much deeper cuts before on alloy, certainly 4 notches (0.2mm) or even more when doing initial sizing or facing cuts close to the chuck, but in this case it's a comparitively "long" bit unsupported at one end, a heavy cut there is inviting the bed to bend & chatter. Overall I'd rather do it a bit slower (half a notch or 0.025mm) than have to do it twice. There might be a better order to do things in to allow deeper cuts, but it seemed logical to me?

Jonny wrote:

waterbok wrote:

.025 not .25 per pass? or am i off on my scales think I even did .3mm last time on alloy (thats the rough bit final cut way less)

SL threads are 1mm pitch so 1 turn on the handwheel on the Unimat = 1mm, each has 20 graduations so 1 notch = 0.05mm ?

I've managed much deeper cuts before on alloy, certainly 4 notches (0.2mm) or even more when doing initial sizing or facing cuts close to the chuck, but in this case it's a comparitively "long" bit unsupported at one end, a heavy cut there is inviting the bed to bend & chatter. Overall I'd rather do it a bit slower (half a notch or 0.025mm) than have to do it twice. There might be a better order to do things in to allow deeper cuts, but it seemed logical to me?

You already have a tail stock which you add the chuck to, How about picking up a tail stock quill to support you material ?

OK copy that, i turned a shorter alloy bit that was 20mm in diam. and 40mm long. So less floppy.
Almost burned me at the chips that came off