Quite an Unusual one

[Boyan Silyavski]

I am more and more inclined to make a special machine for the purpose. Anyways still contemplating it.

Nevertheless i have to start buying. So i decided to go backwards. The spindle first.

Need some help with the choice:

Now the big question is 3kw or 2.2kw spindle? I am more inclined to the 3kw. As a brand name inverter will be expensive this size, i am looking into the chinese vfds. Are they reliable enough, Dean mentioned somewhere that now they make them good. Should i know how to distinguish them or what? I see some have aluminum backs some not.

[Wobblycogs]

I recently bought a 2.2kW spindle + VFD from Chai (ebay: linearmotionbearings2008) as part of a larger order. I've not had a chance to fire it up yet but it came well packaged and all appears to be in order. The price came out to be a few pounds more than the cheapest I could find but I found a number of very bad reviews for the cheapest seller (things not turning up, etc). From what I've read the spindles are normally ok, they all claim Japanese / German bearings but it's luck if they are. The standard VFD's are also normally ok but they seem to vary in quality more although I think the quality has improved a lot in recent years, it seems they either last for ever or go pop in the first few weeks.

[Boyan Silyavski]

Guys, i have to start sooner this build as everyday i change my mind.

Now here is the deal. i have decided to make the machine with working area 1200 x 2500 and at the same time make it fast and rigid. Till now the problem was limited space and problems in moving the machine.
Now the funny part. I bought yesterday a towbar and am looking to buy a suitable platform trailer, so i will mount directly the machine on the trailer
I did not want to cut myself short just because i could note move it from home to home. So its decided.

I will definitely go with the Johnathan design of a gantry just make it suit my needs and abilities. maybe even add one more beam at one side like a standart gantry, as Dean suggested somewhere.

So here is where i need help:
When the machine was small it was clear that 1605 screw for the z and 1610 for X and Z.

Now some options for the gantry:
1. make it from 2 100x100x4 = whole gantry below 50kg

2. make it from 3 100x100x3 / 2soldered together/ - 1m=9kg, so whole gantry will be ~ 65 kg

3. make it from 3 100x100x7 = whole gantry 80-90kg

-So, the big question is how to move the gantry at 2600mm length?
-What screws, what motors?
-Servo maybe ? I know nothing about servo, can you point me to good money wise servo for the long axis?
-What drive relation 1:1 , 1:2, 1:3
-unfortunately i can not machine rotating ballnut. Could somebody help me here? any other options?


So now i am a bit confused between 2 options, make a sturdy beast 1250x1250 or make a sturdy beast 1250x2500 with your help. I mean an exemplary sturdy beast for the generations to come

[Wobblycogs]

If you are going to put this in a trailer you'll need to make sure you add some way so you can jack it up on sturdy legs. If it's resting on the trailer wheels I think the machine will probably shake itself to bits.

[Boyan Silyavski]

If you are going to put this in a trailer you'll need to make sure you add some way so you can jack it up on sturdy legs. If it's resting on the trailer wheels I think the machine will probably shake itself to bits.

I agree with you. i will take off the wheels and hard mount the trailer to the floor, and the machine will be hard mounted on the trailer. The trailer idea is to use it only when i change rented houses. Will not drive it around