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Pete O
3rd Jun 2019, 03:00 PM
I'm planning on casting a part with some raised lettering, wondering what people have used to add letters to patterns? I think somewhere around 20mm height should fit the necessary wording onto the part. I'm thinking I'll try and find some of those fridge-magnet plastic letters, keen to hear what others have used that has worked.

KBs PensNmore
4th Jun 2019, 12:11 AM
Another alternative is to contact a paternmaker to find out how they do it, or get in touch with someone with a CNC who can cut the letters out for you, they may need to be reversed to be effective,
Kryn

bts
4th Jun 2019, 01:14 AM
Back in the day aluminium letters were commonly used.
Some were glued on others were pinned in case they needed to be changed.

Tony

eskimo
4th Jun 2019, 09:47 AM
scroll/coping saw and some ply/masonite?

joez
4th Jun 2019, 10:01 AM
Sounds like a prefect job for a 3D printer, how many letters do you need?

379749

Pete O
4th Jun 2019, 10:17 AM
Sounds like a prefect job for a 3D printer, how many letters do you need?




I need 48 characters, made up of 23 different letters, numbers and symbols with several multiples.

They don't need to be reversed, the pattern is done on the positive, the sand mould in the negative. I've ditched the fridge-magnet idea, those letters tend to be way too chunky for the purpose. Original pattern-makers letters seem to be difficult to find although I'll keep looking. I don't want to spend much on this part, I may end up carving them with a printed stencil.

joez
4th Jun 2019, 10:38 AM
I need 48 characters, made up of 23 different letters, numbers and symbols with several multiples.

They don't need to be reversed, the pattern is done on the positive, the sand mould in the negative. I've ditched the fridge-magnet idea, those letters tend to be way too chunky for the purpose. Original pattern-makers letters seem to be difficult to find although I'll keep looking. I don't want to spend much on this part, I may end up carving them with a printed stencil.

ah ok, probably not worth 3D printing that much unless is for ongoing long term use, theres probably 30-40 hours of printing time.

CNC would probably be the easiest route, how thick do they need to be?

OxxAndBert
4th Jun 2019, 10:55 AM
Have you had a look at the silicon letter moulds used for cake decorating etc?
If you could find the right size/font then it should be as simple as casting some out of something like automotive filler (maybe one of the ones with fibre reinforcement in it).

Steve

Pete O
4th Jun 2019, 11:03 AM
ah ok, probably not worth 3D printing that much unless is for ongoing long term use, theres probably 30-40 hours of printing time.

CNC would probably be the easiest route, how thick do they need to be?


Yeah I figured 3D printing would be a big investment of time- my own time is ok but I can't pay for someone else's on this. Same goes with CNC routing really, it's not something I can afford to spend money to get someone to do. The letters need to be maybe 6mm thick.

Pete O
4th Jun 2019, 11:06 AM
Have you had a look at the silicon letter moulds used for cake decorating etc?
If you could find the right size/font then it should be as simple as casting some out of something like automotive filler (maybe one of the ones with fibre reinforcement in it).

Steve


That's worth a look Steve, thanks for the suggestion. One hurdle I'm finding is the fonts used in most craft-type stuff are things that would be out of place and look silly on the milling machine.

clear out
5th Jun 2019, 10:37 AM
We bought pattern letters from Barnes about 3 years ago from memory.
ive checked their cattledog and there’s no mention but it may be worth a phone call.
Kevin Barnes was the Sydney Pattern supply shop.
There was one in Melbourne but I never bought from them.
Kevins daughter has taken the business very successfully into the resin mouldings, special effects etc.
I had a quick search for US pattern suppliers as I’ve bought from Adolfs in the past.
No luck at a reasonable price and the UK seemed similar.
There are possibly still pattern shops out here sitting on a heap of this lettering.
When the Toowoomba foundry was auctioned off there was a cabinet full of it.
Ive carved the odd item from lead or Lino but that won’t work for you.
H.

Pete O
5th Jun 2019, 12:53 PM
I've made a start on carving a set of letters and numbers onto an MDF board so I can take a negative off it in soft resin and use that to cast useable pattern letters. If it doesn't work out, I'll chase up one of the suppliers mentioned. I found a set in the US for a couple of hundred bucks, but I'm trying not to spend money on this little project.

Pete O
6th Jun 2019, 09:08 PM
Finished carving stage 1 of this little project this afternoon, I printed off all the characters in 72 point 'Franklin Gothic Book' font, perfect size for what I have planned. I stuck the two sheets onto a bit of MDF board and carved them all out with plenty of draft. I have some flexible castable polyurethane that has been sitting on the shelf for several years waiting for this, tomorrow I'll fence the board and pour the castable to make a soft mould that I can cast the actual pattern letters in.
379816

Pete O
2nd Jul 2019, 03:24 PM
I've been meaning to update this thread. I've had limited success with the letter making. I made a negative mould from the carved master board by building a dam around the carved sections and pouring a mouldable 2-part rubber that I had left over from making some motor mounts a few years ago. This resulted in a couple of sheets of soft rubber with the letters, numbers and punctuation marks recessed and reversed.
380399380400

I used automotive body filler to mould the required letters in the rubber form. Because the nameplate I wanted to cast for my frankenmill was quite crowded, I had to fettle the moulded letters quite a bit, using the disc sander, files etc to shave the draft down to make the letters narrower. I've had a lot of difficulty getting the resulting pattern to release cleanly from the sand, it wants to lift the sand away between the letters where they are most crowded. I've had increasing success by working away at the pattern with a scalpel etc but it's turned out to be way more time-consuming than it's worth. I've put the nameplate aside for now and moved on to other things, I'll revisit it some time when the mood strikes.
I have another few castings though that I want to use lettering on in a much simpler way and that has been more promising. I'm burying some bore water outlets in my front lawn, I've had 5 taps on posts sticking up out of the lawn since we bought this place, I'm sick of mowing around them and been wanting to put them underground for years so have finally got around to it. They'll be in holes that are sleeved with 300mm PVC pipe, so I need covers for the holes. I've cast one thus far in aluminium, the casting was not a complete success but the lettering is more promising, it's far simpler than the nameplate and much less crowded so I left the draft as-is and spaced them further apart. Here's the pattern, and casting attempt number 1:
380403380402

So I'm calling the letter making a qualified success.

vin
24th Oct 2023, 08:08 PM
I see its a bit late, but just to help anyone out in future

I made this bell for a local shop and they wanted the business name on the bell so I hand carved the letters in a kids rubber stamp mat, you can see the finished result in the youtube


https://youtu.be/9-RUD2qJlCg