New build in UK - Warwickshire UK
 

hi
I am located in Warwickshire UK, I love the design of this amazing machine and just have to have one.I have been reading many of the posts in the forum to get an idea of what is involved.

I have downloaded the drawings and am designing my table to take a 8' x 4' standard sheet, and hope to start building in january.

I have a fully functioning metal and wood workshop, can weld , machine and have cnc milling and cad/cam expertise, therefore am hoping i can build fairly easily.

Just wondwering if there are any other mechmates in my area, maybe to look at.

regards paul:)

Paul,

Welcome to the team !!!

Hi "pauly"
How you getting on with your build? Im from Newcastle and im thinking of building this myself. If you get stuck for laser cutting and you want a cheap option im able to cut the parts via Plasma.

Hopfully we could help eachother out finding parts.

All the best
Derek

Hi "Pauly",
I will also be starting a build but not till the summer, so a good six months to go.
I will be watching your build with interest.
Please make a list of the parts and where you got them from.

I hope to build for 8 by 4 sheets and I'm not sure if to go with belt reduction or 7.2 built in gear boxes.

Good luck.

Andrew

Southampton UK

possible motor
 

I have read many of the posts about motor selection and belt drives.
I am gravitating towards a half coil wired stepper with belt drive to pinion.
3.2:1 ratio is popular, although i think higher would be better, with that in mind is this stepper motor listed on ebay a candidate?



http://www.ebay.co.uk/itm/2708951470...84.m1423.l2649

it has 8 leads therfore can be wired half coil, stated holding is 560 oz/in torque at 5.5 amps and 3.5 mh inductance.

has any one an opinion. I appreciate there has been great discussion about motor selection, but i think there are more motors on the market now.maybe to rival the accepted choices?

pauly::confused:

The site doesn't tell us whether the inductance is bipolar series or bipolar parallel. It also doesn't tell us whether the motor pulls 5.5A wired bipolar series, or bipolar parallel (or even half-coil).

If the motor is actually rated at 3.5 mH inductance, half-coil or bipolar parallel, then a 50VDC to 60VDC power supply would work. If the current rating matches the wiring method, then a 15A power supply should be adequate. You'll need about 20,000 uF of capacitance to smooth out the ripple.

(80,000 X Amps / Voltage = 80,000 X 15 / 60 = 20,000 uF )

Be sure that the voltage rating of the capacitors is at least 1.4X greater than the actual power supply voltage.

motor question
 

thanks mike,
i have requested a full data sheet for the motor from the seller.

Your answer didnt seem to condemn the idea of using this motor.
maybe if i purchased one of them i could test it?

Pauly :rolleyes:

progress
 

hi
thought i would give an update of progress.

we have completed the base frame, made from steel beams, the laser cut parts are in the workshop awaiting welding and have ordered the racks, which are 1.5 module with 26 teeth pinnions.

attached image is of my mate pete grinding the tops of the x rails after cutting.

next week we will hopefully be making the y axis gantry frame.

I am planing to make my own rollers, the bearings are on order.

they will be made from EN8 hardened and ground.


still a little undecided on motors, will deffinitely make our own gear boxes!

more progress from warwickshire
 

Hi all

thought we would post a few more pictures.

Rails are now ground and profiled, using our English version of the grinding skate, design of which is copied from various forum members designs( many thanks to all).
Looking forward to assembling the frame and progressing some more.


Regards Paul

Isn't it risky to work on rails while the table is not builded ?
I thought the table must be done to adjust rails for parallelism, am-I wrong ? :confused:

I cannot see any reason why.
It seems to me that the rails are only as accurate as the steel they are bolted to, there is little means to truly check that they are ground straight.
If they were ground straight on a sophisticated surface grinder, then bolted to the beams they could still be distorted!

I feel that geralds design philosophy has always been to enable the construction to be achieved in a simple workshop, and therefore limiting the accuracy to an acceptable tolerance and no more.

I will be perfectly happy with a deviation of 0.25 mm, but hey i will never know, as it is impossible to guage it.

Sorry, my english is not realy good, I'm not sure to explain well enough.
I mean, the holes and bolting of your rails and your X axis are fixed now.
When you will weld your X axis on your table, many things might happens.
The distance between your two Rails must be very accurate.
I guess you will unmount your rails to weld the whole table.
A small angle while welding may displace rails more than 0.25mm.

I thought I could be safer to weld the table, adjust the rails to the good shape,
then drilling, fixing and grinding to a V profile.
Maybe you have an idea to do it in a safer way ?

sorry I have miss understood you.

Our table is of bolted construction, we have designed it with sufficient adjustment to allow us to align the rails for parrallelism.
I will post some pictures of the table as soon as we have assembled it.

paul

Ok, thanx I understand better.