Stell frame cnc 1500X1000. Adjustable table your opinion please

[Boyan Silyavski]

I agree, i don't see how it would be done without the proper hardener.
I purchased mine from http://www.dansonmarine.co.uk/ and he shipped 2 packs to Spain for 17GBP for 3-4 days.

Maybe buy locally the epoxy and purchase only the hardener, have to check with them though.

For the Hiwin 20 rails the minimum width of the epoxy should be 40mm, that leaves 10mm each side of the rails, cause epoxy rises like 5mm near the edge. I made mine something like 5mm high. Used magnets 4.5mm thick at both corners both sides, to check visually whats going on and make perfect 5mm height


About the laser cut pieces, i dont see why they would charge more for the holes. I ordered mine with holes, that's was the whole point, to save time drilling precisely. Even the 4mm holes were perfect.

[ba99297]

Clive_S and Syliavski thanks both for your answers
As for the holes Syliavski there is a limit about the holes that laser can cut in relation to the material thickness.
So at 10mm plate isnt easy to cut 4mm holes. Also the charge at laser cutting is according the time the machine cuts ( this of course is influenced by the length of cut, material thickness and material )

Vagelis

[ba99297]

Hi everybody
Today i go on with the gantry
I start by drilling the holes for the bf/bk on y axis. to do this i remove the 120X60X3mm middle tube of the gantry. I put the ballscrew on place and point the holes


Then i put the tube back to the gantry and start aligning the tubes with the steel plates. After that i start spot welding the pieces. With small weld in order not to produce muh heat



At this photo you can see the 1120mm long m8 bolts that i use to keep in place the side 10mm steel plates


After the side spot welding i had to weld the tubes at their side that atteced each other
First pass i start with spot welding every 10-12 cm. Second pass i weld between the old spot welds ( every 6cm) and so on.... In order to have better result i turn the gantry a bit


Finally i end with this result



Then i put the front steel plate on the tubes construction and temporarily i put the rails on, in oredr to see where to drill the holes in order to bolt the plate to the tubes



The only question i have is about the way i weld the tubes. Are these spot welds ( every 3-4 cm) enough or i should make a full weld

Thanks for your time
Any suggestion will be glad to hear

Vagelis

[Boyan Silyavski]

That with the long screws holding the plate is great idea, thanks for sharing the photos. I will do the same, as i don't have long clamps.

All looks very good!

I fully welded the gantry on the machine i finished and spot welded the Z. Now that you have all in place why don't you repeat the spot welding until all spot welds are very close?
If it was me, i will fully weld it, though it seems that will work both ways. Welding precisely takes a lot of time , i know. I made 5cm stitches, and took care that the temperature of the gantry not to rise above 60 degrees. Used an infrared thermometer. And had to wait a lot for the metal to cool.

You were lucky if your long plate was straight. I had to hammer down to rectify some of the laser cut stuff. Good that i have very big plastic head hammers.

[ba99297]

That with the long screws holding the plate is great idea, thanks for sharing the photos. I will do the same, as i don't have long clamps.

Now that you have all in place why don't you repeat the spot welding until all spot welds are very close?
If it was me, i will fully weld it, though it seems that will work both ways. Welding precisely takes a lot of time , i know. I made 5cm stitches, and took care that the temperature of the gantry not to rise above 60 degrees. Used an infrared thermometer.

Syliavski i think ( not sure, that is why i ask ) that i have nothing to add to the stiffness of the machine. One small spot weld is too strong . On the other hand too much heat may cause deflection and twist . Dont forget that my machine is bigger than yours ( y axis is 1160mm long) so it is more possible to have twist issues.

You were lucky if your long plate was straight. I had to hammer down to rectify some of the laser cut stuff. Good that i have very big plastic head hammers.

I think it is not but when i bolt it on the tube construction it will be as straight as the tubes. Even then i am not sure everything will be straight. May be machining or epoxy method will be applyied.
I have a small problem with the resign. The Greek supplyer of West system epoxy doesn have the 209 hardener. On the other hand the 209 hardener is not easy to be shipped as it is described as dangerous to travel . I have to look for another resign

Vagelis

[Clive S]

I have a small problem with the resign. The Greek supplyer of West system epoxy doesn have the 209 hardener. On the other hand the 209 hardener is not easy to be shipped as it is described as dangerous to travel . I have to look for another resign
Vagelis

Well check here:- http://www.ebay.co.uk/itm/West-Syste...item1e8ff2bb79 I know this is not a good place to buy it but they do ship to your country . Have you tried to buy it from the UK or perhaps tried a boat yard, also ask them why they can ship the 205 but not the 209. Wests is the best product and it gives you about a 10 hour cure. ..Clive

[ba99297]

Well check here:- http://www.ebay.co.uk/itm/West-Syste...item1e8ff2bb79 I know this is not a good place to buy it but they do ship to your country . Have you tried to buy it from the UK or perhaps tried a boat yard, also ask them why they can ship the 205 but not the 209. Wests is the best product and it gives you about a 10 hour cure. ..Clive

The Greek supplier can ship me the 105 epoxy and the 205-206 hardener but he doesn’t import the 209 hardener.
Other sites even from uk they cant ship (via air) any hardener. Find them

http://www.ecfibreglasssupplies.co.u...acks-12kg.aspx
i think they are cheap at their prices but i emailed them and they answered

"HI Unfortunately we do not stock this product abd cannot ship outside of the Uk due to hazardous content, you may be best to contact west system direct for nearest distributor. Sorry we could not assist with your enquiry . Kind rgds Martin"

As searching i saw that some datasheet measure the viscosity at cps and others at mpa.s. I don’t know what is the difference as when i google search for a converter

http://www.aqua-calc.com/convert/dyn...cond/start/165
i see that they are equal


I found a company CARBON MODS

http://www.carbonmods.co.uk/products...arter-kit.aspx

that sells its products through this site
http://www.easycomposites.co.uk/

At this site
http://www.easycomposites.co.uk/prod...ion-resin.aspx

i found an infusion epoxy resign
here is the datasheet
http://www.easycomposites.co.uk/down...sion-Resin.pdf

From a first reading it seems to have ( according the numbers of the datasheet ) smaller combined viscosity (225 mpa.s) than 105+209 hardener resign (650 cps ) , also it has pot life 80-100 minutes (slow hardener ) smaller than 105+209 (40-50 minutes) , and the price is 18.42+vat pounds.
I don’t know which product is better for our application.


but when i go to the transport details page
http://www.easycomposites.co.uk/dang...-shipping.aspx

Greece is at the red list

Thanks for your participation

[Boyan Silyavski]

Apart from stiffness there is dampening of vibrations to consider. Not fully welding may worsen things there. I have never seen commercial mill or cnc spot welded, that should be enough answer for you.

Not every one uses epoxy. I believe it helps dampening. There is German company selling something similar, it was called Moglis, I am not sure. Will search, I had the link somewhere. It's meant to be used for shimming the rails. You can do that with normal epoxy, though the proper one has high compression rating without deformation.
Shimming definitely will be cheaper. But then you will need long straight edge.