Look at this! It will help a lot! Do it on both side

 

here you go,

http://help.autodesk.com/view/INVHSM/2016/ENU/?guid=GUID-96D3549D-81DF-4534-BF5F-47DC8F1CFAF6

so to anser your question there is a free cam that does that

 

Ask and you shall receive ... or, as the teenager deep in me would say : way cool !

Now I need to take a much closer look at these options. The Internet is wonderful, eh ?

 

Indeed!

 

Well i think rest machining is in the simplified hsm. Thinking back I'm pretty sure it is. One of those things you will have to try and see, and not a total loss if it doesn't as guarantee it's going become one of your favourite tools regardless.

 

Found another free autodesk program, looks fantastic.

 

Interesting ... could quickly (?) cut the snap-on layers - a good use of the C-Beam machine, especially if on a budget, than use plaster soaked strips, stretch fiberglass for a hard shell or even papier maché to finish the model's skin. Would make for a light weight core with a skin appropriate to the purpose of the model. Stretch plastic wrap before final skin layer(s) saving on raw material ... those huge rolls of plastic wrap still would last nearly a life time. Great for kids to get into this CNC movement of ours, eh ? Could even replace the router/spindle by a (sharp) knife to cut cardboard, etc.

 

Yeah, even use it to make the positives masters to make molds in the same way.

Cool how you can distort the panels, make some of the ultra modern CNC furniture just from the shape.

 

That is pretty cool! I'm thinking molds for an airplane fuselage...or the three foot shark my son has been asking me to cut for him. Could cut the pieces out of 1/4" fan fold foam.

 

I'm in the process of doing a fuse, I'm using engineering wax to make the master. Brilliant stuff, expensive if you buy but not too bad if you make it, just melt aload of wax and throw a loads of ldpe plastic bags in it, need to increase the volume by 1/4-1/3 with the bags. Do it outside tho as you have to take the wax to its flash point to melt the bags, then just cover the pot to put the flames out soon as they start. You will need to stir and take back to flash point a few times, once the wax ignites without heat as soon as you uncover you know it's done. cover n let cool.

To anyone that fancies trying it that is.

Best thing about engineering wax is you can collect the shavings, re melt and use again

 

You should post a video of that process, just out of curiosity, I'd like to see that.

 

Afraid the process has finished now, got 40kg of the stuff so doubt I will be doing it again soon. But it's pretty simple, get yourself some bricks lay aload down to make a bed on some stone ideally or dirt, put a few more on top around the outside leaving a hole for your blow lamp. Put a big kitchen pot on the bricks, chuck your wax pellets in, soon as it's all melted put 1 bag in. Keep heating till the bag melts. Feed all the rest of the bags in and heat to flash point, cover stir reheat cover until you move the cover and it lights without heat.

Only fill your pot half full, or if it's a big pot start with just a few kg in there, otherwise you'll never get enough heat in it unless you have a big blow lamp

 

I've made it before on a hotplate. I'll look in my notes for the ratio I was running. I used cheap plastic painters drop cloths and a slab of paraffin wax. I don't think I was anywhere near the flash point of the wax. Cool stuff though. Machined very nicely, pretty hard and self releasing for composites and most casting materials.

 

Funny enough similar to what I used, also used a 200micron sheet. Though I wouldn't say there was any difference in melting time. Problem with this stuff is the melting point of the ldpe which seems is an unpure plastic so though it does start to melt at lower temperatures, the other stuff in there ... Melts at the same temperature as the wax's flash point, also found that its then where the wax is boiling and bubbling, you get a better infusion.

I have various blocks of it here which will all get melted into one at some point, all have the same ldpe wax ratio but some of which didn't quite get up to their flash point. The ones that did you can run your nails accross and you barely mark it, the other although most likely will machine and are harder than normal, you can make shavings with your nails.

You also find a more uniform colour/appearance in the ones that have boiled.

If you do have a go at it please consider this is dangerous stuff, you talking as high as 300celcius in places. If you spill it on you will become a human candle and that wax will most likely replace your skin and fuse to your tissue. Serious hospital time so make sure your pan and heating arrangement won't wobble, do it outside in open area and wear gloves, overalls and goggles.

That idiot on YouTube doing it in his kitchen, needs his head checked.

 

You know where to get a load of LDPE ? All those water bottle caps, many shampoo and detergent plastic bottles, ... Just look for the /2\ recycling symbol. It should also have "LDPE" just underneath that symbol, where room allows.

I've been collecting some for a few weeks know as I saw a post or YouTube where they were melting the stuff in an oven (not the one used to cook your meals !) They cut and wash the collected LDPE, throw in a ... glass pan ... and slowly melt into a thick sheet. The mixed colors giving the slab a certain charm. Then mill/route to make the odd objects and works of art like coasters, etc.

The most unfortunate part is LDPE is often use for containers of pretty bad chemicals, bleach being the safest. So you won't be able to make food safe stuff unless you separate the LDPE recovered from water bottles and such from the other sources.

To mix in the wax, you probably need to get hold of a good shredder (one that does CD/DVD) to make small pieces in no time ...

Especially the flashing with the flames and all ... Hmm, any bad fumes/smoke from all that burning plastic ?

 

Reading the few latter posts, one would have to chopped the recycled LDPE pretty fine to melt into the wax The YouTube I saw was not adding wax, just melted the stuff into a slab without reaching the flash point.

 

Yeah, it will melt down into a slab at a lower temperature. That's the impure stuff in it melting which will just fuse all of the parts that don't melt that low together, hence you get the mix of colours.

With the wax it needs to get hotter to all mix in, if your milling it in hit a plastic bag I'd wouldn't be surprised you'd find the plastic wrap around the bit, be ripped from the wax and make a mess of it. So it's important that it all melts and mixes in.

There's no smoke whilst alight, you get parafin evaporating before the flash point that resembles steam, and a bit of black soot when you put it out like a candle. Flames will get to around 3-4" high at most. About it really, not overly dramatic.

The plastic which burns at heigher temperature doesn't seem to burn at the waxs flash point, in fact didn't even get a wif of it.

There are other ways of doing it like pressure cookers ovens, etc I'm sure. But if you have 40kg of it to do, you just want to get it to flash as quickly as possible. As you will be there for a couple of days doing it. If you start investing in tye alternative ways, you may as well just buy the stuff.

 

HDPE is /2\ - milk jugs
PETE is /1\ - water bottle
LDPE is /4\ - plastic wrap and playground slides

 

Wish I had some ideas for hdpe, got loads of 15mm thick black offcuts here, enough to make a full sheet.

So just a case of cooking in the oven, does it melt and flow?

Horrible stuff to machine tho.

 

SOLVED: X Gantry not square to Y... First time, I cut the rails with a hack saw. Not even close. Tried to use a file to square up. Square off by 1/4" Left to right. Ugh. Then, I heard you can use a miter saw with a carbide blade to cut them. Retried, was still off by 1/4". Decided I needed to square up my saw better (I had used my machinist square last time). Found a YouTube post on using a two cut method. Got horizontal and vertical to within a 0.1mm and went with it. While I had the beam off, I bolted the two rails together ( drilled and tapped). Now within 1mm left to right. Feeling accomplished.

 

Is that corner to corner?

If you have a timber store nearby that cuts mdf, I'd suggest getting a piece cut that's going to be a tight fit in your frame, drop it in. And use shims where necessary so that the frame is as square as the mdf ie if you find its tight at the - end and loose at the + end on one side. Loosen the frame brackets at the - end and add shims till its parallel. Not ideal but even the pro machines have shims.

Forgot to add, send what I call the x ie your gantry upto the loose end, undo the x profile bolts a bit and make sure a gap doesn't open up, if it does you'll either need to cut the long frame profile a bit or add shims there's as well.

 

Hi Folks,

I've learned a lot of from your conversations... thanks for that
But there are a few things I would like to ask.

I'm planning to build a 1m x 1.5m (x, y) Charging style (+dual belt) with a 1.5kW China water cooled spindle (will cutting soft/hard wood and aluminium and how knows what else in the future ).
As the spindle is quite heavy (6kg + 1kg mounting bracket + 1kg stepper) I'm not sure which Z axis should I buy from Chris.
Is the 3 wheels would be enough or should I choose the 4 wheels?

My second question would be about the steppers. Which parameter is more important? The oz or the mH?
This one have better mH with lower oz and the other have the opposite values.
What is your opinion, which one should I choose?

Thank you in advance.

Regards,
Peter

 

I cant guarantee a build of this type but i can say you would stand a better chance with a 1000x1000mm cbeam build with dual beams in a H/I configuration.

1500 is a fair distance when your hanging 6kg on it.

You will most likely find you wouldnt gain anything with a larger spindle on an ox as putting more horses into the part is only effective up to the point where rigidity is compromised, and then it becomes a problem instead of an improvement. and adding weight is detrimental to rigidity also. most effective spindle on an ox is either an 800ww or 1kw id say.

The oz/in or nm are important values when looking at torque.. resistance is also key to how efficient the motors are. lower the better. A good quality driver can burn out low efficiency motors with under rated amps. You will find the higher efficiency nema 23's are the ones upto 3.1nm.. which is plenty btw (i have two moving 250odd kg at 6m/min).. then the efficiency seems to drop off in most makes, there are a few manufacturers making plus ranges that have better efficiency, an example of an effcient 3.1nm would be 4.2 amps at 0.62 ohms parallel.

There are a few guys here looking to use cbeam for a heavier duty ox size machine that may be worth talking to. best of luck

 

Thanks Jonny for your answer.

I think I'll reconsider my statement and will build a 1m x 1m one...
If I have to cut something longer then I could do it in two batches thanks for the open ends design of the Charging style.

 

Sorry, must of been by slight tendency to be dyslexic surfacing once again ... One of those plastic wrap roll has miles upon miles of the LDPE.

Hmmm , so plastic wrap is the same stuff used to make playground slides ? The thickness does make a difference, eh ? But I diverge again ... Let's get to the regular programming.

 

Edit : Just added a resource/tutorial with three YouTube/Instructables :

How to recycle HDPE (bottles, caps, etc.) into sheets / blocks to CNC

-----

There are various opinions on the matter and I haven't tried yet, just collecting HDPE bottle caps and such and waiting for a good deal on a small oven to put in the shop as the wife (and I, btw) is not too keen on the use of the kitchen oven (possible fumes, blabla). I do have the old CD/DVD shredder on standby at work to chop up the collected HDPE ...

I've looked at severan sites, videos and such onver the 'Net, but this one seems to cover most of the issues a few have raised in various discussions on the subject (need for pressure, getting the ideal temp not to burn, liquify or whatnot, blabla) :

• http://www.instructables.com/id/How-To-Recycle-HDPE-Plastic-The-Easy-Way/

Have fun ... and be careful. What you do and how you do it is your decision and consequences, good or bad, are your responsibility.

 

https://en.wikipedia.org/wiki/Low-density_polyethylene

 

Yup and ldpe is more rigid than hdpe lol.

Hdpe has more oil it you see

 

Cool I will check it out. Thanks

 

Of course, yeah that didn't occur to me.