Found Dreaming

Wife's niece got herself engaged and they had a party about three weeks ago and I've been thinking what could I make them as a gift, after a lot of thought I came up with a heart shaped clock with their names on it. The heart was cut out of a piece of MDF on a cnc machine, its just been painted, and letters, numbers and hands are just sitting there at the moment, hopefully tomorrow I'll get to finishing the pattern off
I can get my hands on some phosphor bronze for about $5.00 KG so I may even cast it in bronze yet, failing that it'll be done a aluminium

Mike

Looks like a fun project. If it's in Bronze, it's going to be heavy.

It will still be heavy but you can trim some weight by making it hollow on the back side. Take a piece of wood just a little thinner (1/8" or so) and trace a line of the profile then cut it out about 1/4" inside of the line. Mount the clock to it carefully over the hole and use is as a matchplate and that will provide the boss in the sand to make the back hollow.

Looks like it will make for an awesome gift Mike.

yep pretty much what I was going to try Harry , I've borrowed my son in-laws router so I'll trim it up a bit...any idea how much weight is in . 212 cubic feet of bronze, or is there a formula out there somewhere

Mike

According to reade

Bronze 509 lbs cu ft

So 0.212 cu ft would be about 107.908 lbs. Might want to thin it up a bit or take out a mortgage on the abode.

Where did you get the 0.212 number from? Is that solid thickness or after adding the hollow back because just picturing it I would thing it would be much less.

OOPS try 0.017657 cubic feet or 30.512 cubic inches, I used a on line volume calculator http://mathcentral.uregina.ca/volume_calculator . I should stop trying to calculate while drinking the amber fluid

I calculated that as if it was a solid mass 10inch x 8 inch and 1/2 inch thick, I was never that strong with maths

And I calculate about About 8.8 lbs or 4 kgs but I could be wrong

Mike

Add in at least half again for bobs and you are still in the range of a small melt. Sounds much more feasible now

Might be a little bit of a pain to cut them off but I think I would place some risers on the back side. Maybe places where you need bosses for mounting clockworks or hanger gear. Just thinking that large thin area might need lots of feeding to make sure there is no tearing.

Harry wrote:Add in at least half again for bobs and you are still in the range of a small melt. Sounds much more feasible now

Might be a little bit of a pain to cut them off but I think I would place some risers on the back side. Maybe places where you need bosses for mounting clockworks or hanger gear. Just thinking that large thin area might need lots of feeding to make sure there is no tearing.

Good idea Harry, cutting them off would be a pain but I have a horizontal vertical metal band saw that should do the job, then its a simple matter of clamping it on the mill and clean it all up

Mike

Mike,
I like the idea of using CNC for your pattern-making but ...

How do you get a draft-angle on the patterns?

I've often wondered if there are tapered router (or milling) cutters available? or will I have to manually hack one from a straight cutter?

I guess that commercial pattern-makers must have something ....

Geoff