Log in

Remember Me?

Register Help

alan2525 · 09-03-2007

Does anyone have experience of machining Bakelite?

I've aquired some lengths of 3/8" Bakelite and wondered how well the stuff machines. The only info I can find online suggests carbide tipped tools, no lubricant and
for milling, a high speed and coarse feed should be used, and if possible, remove all the material in a single cut as light finishing cuts produce a torn appearance.

kevingambrell · 09-03-2007

Hi Alan
Dont need or want carbide, HSS or stelite with a negative rake and no coolant. It stinks as you cut it and dont breath in the dust.
Milling much the same you can doa finish cut but put the RPM up and the feed way down. I used to machine parts for aircraft from the stuff.

Kevin

**wonwinglo** · 09-03-2007

Alan,be careful Paxolin and Bakelite dust is carsogenic.

alan2525 · 09-03-2007

Is this from the use of formaldehyde in the resin?

I'm still on the lookout for a synthetic material which would lend itself to machining small detailed model components, machines without plastiscizing and gives a good finish, taking paint well and thats reasonably durable for small wheels and other parts.

**wonwinglo** · 10-03-2007

Probably is Alan ? all I know is that we had a storeman who insisted on grinding paxolin blocks in a confined space,he suffered for his actions,I have never used the material since,I just wish that I could suggest an alternative product for you to use ?
Many people do not understand the dangers of these materials.

inkaboat · 10-03-2007

Hi, I'm new here but I've had some machine shop experience in the distant past. Kevin is quite right about neg rake and HSS tooling, but I hope that he won't mind if I add that you can virtually discard your carbide tools for model engineering unless they are of the correct grade and quality for the job, and your machine is fast enough and rigid enough to impart the required finish. I finish grind my HSS tools with a smooth diamond file, hone them when appropriate, and you will be amazed at the results. Mind you, my ancient EMCO MaximatV10 helps. I have owned two Chinese lathes but stumped up the money for something decent!
Great site and I look forward to contributing where I can.
John Barrett

alan2525 · 16-05-2007

I was reading some threads elsewhere and stumbled upon "chemiwood"

It's a polyuretahne modelling board used for rapid prototyping and model making. It's dimensionally stable and inert. Dense uniform composition and flatness. Machines better than timbers with no material break out. Can be milled and turned, sands quickly by machine or hand.

It's a mixture of resins, fillers and plastics.

It also goes by the names model board or model lab board.

Does anyone have any experience of using this stuff? It sounds pretty expensive and isn't supplied in smaller quantities for modellers, seems to be in 4ft x 1ft sheets in a variety of grades and densities.

Sounds ideal for machining small model components.

I've found this supplier:

http://www.alchemie.com/model_board.htm

Not really sure which grade would suffice though, gets a little technical with details about it's flexural strength?? and Coefficients of Thermal Expansion...

new to trains · 18-05-2007

i have used it, for years, mostly in the manufacture of rapid prototyping/ product modelmaking - chemiwood- its a ciba geigy product, it is excellent to use, machines very very well, paints nicely- bonds easily and generally is spot on !- its virtually 100% dimensionally stable, basically unaffected by moisture/ heat variations...............

it has no grain so the finish is superb, -its a fleshy/ pinky colour and comes in sheet / slabs, can me worked with machines and also easily by hand...it does take the edge of cutters/ blades fairly quickly.

as far as grades of product goes then its a new one on me, when i used it it was all one grade- so i was not aware there are different types, ( we just went to the stores and got another slab out and used what we needed )

its turns and mills beatifully, flycutting is a dream and the only downsides are the price and the dust, one kills your wallet the other kills you.... the dust is ultra fine due to the fact it has no grain, machine it at higher speeds and as a general rule treat is as if it were a metal, it is failry tough stuff however it will snap if heavily impacted, - but its ideal for manufacture of parts you wish to mould, its often used in CNC procedures and for fabrication of components.

we were turned onto it an uni on the modelmaking course i did, we used to be able to buy it through the uni shop but most students used to contact local modelmaking businesses in the are and go and buy their offcuts for alot less than the going rate ! - but i suppose it depends on the quantity you need....

i think amber composites retail this stuff too..........

good luck

alan2525 · 18-05-2007

Thanks for the extra info, I think i'll probably just buy a big sheet of the stuff and have enough to keep me going for ages.

I got a bit fed up with trying to get hold of old offcuts from local businesses after one place just pointed me towards the skip and I cut my hand up badly trying to slavage some sheets of Arcylic from a local signmakers. It was all 8ft sheets that where more holes than anything else.

Someplaces are more helpfull than others when it comes to being helpfull!

**radish1us** · 05-01-2008

Why buy that snot "chemiwood", when you can get the creamiest product of all time, ACRYLIC.

Yep, this stuff is the bees knees for machining, you can turn it, mill it, drill it, grind it, file it, sand it, buzz plane it, band-saw it, use a hack saw on it, whatever way you want to work it, you can.
You can even bend it or form it with heat, yeh, it even melts and then reforms as a solid.
NO DUST either, just a bit of a pleasant smell, been using it for 15 yrs. and no ill affects, haven't seen any bad reports about it at all.
Stable, hard, take a coat of paint, yep, you can even polish it, so it looks like glass. Makes marvelous looking spot lights, you can even fit a globe in the back of the lens and it looks like a miniature real one.
I have personally made a number of wheel rims ( 30 ) for a 1/16th scale model truck, these rims were for the low loader and dolly tyres to fit, plus spare tyres as well. Measurements were about 25mm O/D X 24mm I/D x 15mm wide, that's right 0.5mm walls on the wheel rims and you could not crush them with your finger and thumb wrapped around them.
You can use this stuff to make anything your heart so desires, once it's painted who knows what it's made from.
Check out this site and go have a look at the first album, ALL the clearish bits are acrylic, could have made all the other bits from acrylic as well, only I had the polystyrene handy so I used that. You can see the low-loader wheels as well in the next album.

http://community.webshots.com/user/radish1us

Go get some and try it, you'll be grabbing for it quite often when you have to make something out of the ordinary.
Think of working with aluminium, that's how this stuff feels like, only it's a bit easier to work.
Same rules apply to Acrylic as to working with polystyrene with machinery, easy RPMS and quick feed to keep the tip cool, hot tip equals gunk up, stop work and clear, then away you go again.

regards radish

snot "chemiwood"--- a CNC machining centre at work had that crap on the table making vacuum moulds, that snot dust got all thru the workshop and 3 yrs. later we're still cleaning it up.