welding steel base or just getting aluminium extrusion

**Desertboy** · 29-12-2017

http://www.chinasavvy.com/tolerances...tnessroughness

**EddyCurrent** · 29-12-2017

What about this idea; https://www.cnccookbook.com/wp-conte...atheAttach.jpg
or put it at the end in a smiliar manner.

**reefy86** · 29-12-2017

Thanks eddy :)

**Boyan Silyavski** · 30-12-2017

Just responded you to the PM, but now i see here where you are going with that. There is absolutely NO NEED for the spindle to extend below the table bed in order to achieve good 4rth axis

Meaning that the centerline of the round object could be level on with your bed. And the Z gantry clearance will be your object max radius. Add 10cm for the bit and chuck. There should be your spindle in upmost position. i recommend boxing the spindle like on mine machine and making tha gantry a bit wider in vertical. So more or less a normal machine without too much mods except for strong Z. thats it

**cropwell** · 30-12-2017

I recall a build by KingCreaky that had a removeable bed that allowed a 4th axis to bolt in (can't find the thread though).

**reefy86** · 31-12-2017

been over thinking again lol but that's the fun of reading tons of posts on this forum and coming up with new idea's (stolen idea's). just out of interest whats the price difference between good stepper motors and servo motors now? because of my high z axis i need to make the gantry very beefy but after reading some more for 3d work the z front plate needs to be light so i will update soon on an updated version and see what you think.

**Boyan Silyavski** · 31-12-2017

What i think for sure is this:
Do not buy anything more until you have definitely finished your drawing and have it all clear 100%. That includes rails, screws, motors, board, etc. It will be just throwing money in the bin. And yes, we have done it all.

One more thing to note: Everyone here thinks he is a top machine designer. Nothing wrong with that. And in reality here we could see most of the best build ever worldwide. But what i learned from experience is that even if you overthink your machine, you always mess something, even small. Once you make the machine though, use the machine 1 year 8h per day, maybe make another one later, revise a couple of times the design customising it for clients, then this machine becomes better and better.
What i am saying is: assume you will make errors, if someone has made a nice working machine and you like the design, ask, listen and copy shamesly. Do not over think and over invent. look for good working designs, easy to make at home.

**reefy86** · 31-12-2017

Thanks boyan, i have not ordered anything apart from the steel for the frame and while spending the whole of january welding it together i will wait until that is completed before confirming other parts to order. i have seen loads of build logs on here from people who have rushed in and bought the parts before asking and i will not be making that mistake. i am not expecting this machine to turn out how it looks in cad software or in my head but what i am expecting is knowledge from trial and error. that is the way i always like to learn because if you can fix an error then thats a new skill you get to keep :)

**Desertboy** · 31-12-2017

Morning, unsure what you decided for drivers but if going the Leadshine AM882 route I'd order them now took about a month for mine to arrive from Hong Kong.

You can buy EU equivalent Leadshine EM806's but they're twice the price and the specifications seem identical both made by leadshine. AM882's you will not find available from UK seller if you do link me to him please lol so i can buy another 4. The only difference I can see between the EM806 and AM882 is they have different dip switch settings relating to auto motor setup but both support autotuning making this an non issue.

Don't buy 2nd hand like I did didn't save enough money to pay for the non working one I got I ended up buying a new one for £60 delivered, quick tip reduce the chances of important tax by making 4 separate orders to 2 different address's.

Personally I'd order the Hiwin's and ballscrew in at same time and from personal experience this time I would make the Hiwin's 20cm longer than the ballscrews. I'd want the Hiwin's and ballscrews before I started to make the frame after all the frame has to fit the Hiwin's and ballscrews not the other way round. You can't practically cut ballscrews down I rang a company in Leicester that specialise in ballscrew repairs to see how much to end machine a ballscrew was. It was about twice the price of buying the ballscrew from China with BK/BF fittings for the machining only.

If I had to order the Hiwin rail in UK I would use cncforyou which sells original carriages but a clone rail but I would just order from China/HK as my experiences so far have been mostly positive.

**m_c** · 31-12-2017

Originally Posted by Desertboy

Morning, unsure what you decided for drivers but if going the Leadshine AM882 route I'd order them now took about a month for mine to arrive from Hong Kong.

You can buy EU equivalent Leadshine EM806's but they're twice the price and the specifications seem identical both made by leadshine. AM882's you will not find available from UK seller if you do link me to him please lol so i can buy another 4. The only difference I can see between the EM806 and AM882 is they have different dip switch settings relating to auto motor setup but both support autotuning making this an non issue.

I would only ever buy Leadshine drives from a reputable source, as there are a lot of counterfeit drives about.

Personally, I've often wondered why the AM series got discontinued so quickly, but I suspect it was to do with forgeries. IIRC Leadshine superseded to the EM series in well under 2 years, but by that point you could pick up the AM drives cheap in lots of places. So either there was some major internal redesign, or they needed to get a step ahead of forgeries. I suspect the latter, and the AM firmware was easy to retrieve (the Chinese are renowned for their ability to extract such things, using methods you wouldn't think were possible), and the EM not so, which is why it's not yet been copied.
Most older digital drives are copies of Leadshine, which in turn were re-designed copies of Geckos, so you can't say Leadshine are just a victim in the whole counterfeit drive area, but they at least build reliable drives, and didn't deny for years they had an inherent design flaw which meant they could randomly blow up during power up (it's a shame JohnS isn't around anymore, as it's what ultimately forced him to use Chinese drives, and he liked a good rant on the subject).