Scrap Heap Challenge

[wilfy]

While i agree that you are saying your machine works well as it is in mdf and does the job that you want it to do, I'm sure there is more reason behind everyone's arguments to use metal than just do it as that's the only way, fact is mdf bends a lot. Now the only downside I can see to this flex is that your pieces will run out by a certain amount, this is quite obviously within your tolerances so great for you. I think you may get even more play from your 8 x 4 machine but again if your happy with it then super.

I originally planned to use mdf for my machine but I wouldn't want to make it and it to have play in it, so I've decided on steel box section as I see this as the next step up from mdf/ply

[TrickyCNC]

While i agree that you are saying your machine works well as it is in mdf and does the job that you want it to do, I'm sure there is more reason behind everyone's arguments to use metal than just do it as that's the only way, fact is mdf bends a lot. Now the only downside I can see to this flex is that your pieces will run out by a certain amount, this is quite obviously within your tolerances so great for you. I think you may get even more play from your 8 x 4 machine but again if your happy with it then super.

I originally planned to use mdf for my machine but I wouldn't want to make it and it to have play in it, so I've decided on steel box section as I see this as the next step up from mdf/ply

Sheep :) you know , one bleats, and the others follow.

there are plenty of other sources of info and forums on the net, with many many working, and accurate, CNC machines made from wood or wood products. Quite a few cutting ally well too.

oh and - the fact is , steel bends a lot too ;) in fact, a lot more than you would imagine !

most of the ally builds on here, you will see them being beefed up /boxed / braced ..., and talk of too much flex and twist etc. etc. "oh , you need bigger/thicker sections/thicknes" ... and so on.

same goes for MDF. It can be made to not bend.

One of the longest standing moderators on the CNCZONE (Ger21 - he's on here too) has decided to build his new 8x4 machine from .... err ... oh yes ... MDF ! He knows his stuff .

There is nothing wrong with steel or Ally. Just don't dismiss MDF . or birch ply . or phenolic ply ..... bamboo ply !

Rich

[wilfy]

calling me a sheep is a little immature,i happen to be able to make my own mind up about things and have read lots of forum posts given here, with lots of very technical workings out, things people didn't have to do as it shouldn't make any difference to their own life other than the happiness of helping others... its not like the advice here is going to make people money.

as i saw jazz post in another thread which you are also commenting.. in fact it's my thread.. a sheet of 25mm MDF which i have just bought recently cost me something like 26 quid i think and as jazz had said you could buy enough 50mm box section for £26 to build the same size machine.. i have a welder, yes i bought it to help with my cnc machine but over the past few years it's something i've felt i could have done with and i have no problem buying a tool to tap threads where needed.

so comparing the raw cost of the materials there is no way a 25mm sheet of mdf will produce the same stiff machine that steel box section machine will, thats not me following like a sheep.. thats me not being stupid and realising the difference between steel and bendy mdf.


for the record i have complemented you on this machine and i think it's great that you have made it work the way you want it to.. i just dont think it's as accurate as it could be, but thankfully the work you do obviously doesnt need this level of accuracy