a Steel Box Section Build with SBR20 & Ballscrews Plus a few questions

[grain_r]

Wow It all sounds like an outside job then. and if I ever don't want fingerprints there's the stuff.

[JAZZCNC]

Wow It all sounds like an outside job then. and if I ever don't want fingerprints there's the stuff.

Def outside job with mask plus eye protection. The fumes from Acid are just has bad the stuff it's self so be careful.

Oh and You wan't Sulphuric acid to get rid of Finger prints! . . I can let you have some if you like. .

[grain_r]

I hope I never upset you, If you offered me a drink i'd certainly think twice i'm trying to work out if you have a workshop or and evil genius lab.

[cropwell]

Yes Jazz - I know all this and more (chemistry at Uni), thats why I recommended the Wickes stuff. It will get the zinc off in about 15 to 20 minutes and is not as dangerous as more concentrated hydrochloric or sulphuric acid. I am not so sure about chip shop vinegar, acetic anhydride would do the job, but I certainly wouldn't want to inhale the vapours of that stuff.
I have been told that in Barnsley, the pigeons fly backwards to avoid getting the shit in their eyes. Is this true Dean ?

Happy Holiday.

Rob

[JAZZCNC]

I have been told that in Barnsley, the pigeons fly backwards to avoid getting the shit in their eyes. Is this true Dean ?

Ye along with we all wear Flat caps and have Whippits mi old Cock.!! . . . . n wi av r own X factor darn intarn called B factor n ter's latist winners..

[grain_r]

Hey all

Well I though I would pop a couple more pics on here as I'm doing bits to keep me motivated too. I'm having a tapping Issue for some reason at the moment. I have used a 4.2mm Cobalt drill bit and I have used a centre punch and then I have used the cobalt but it wanders I have then even turned the pillar drill by hand a few times and I was surprised but it did cut which I guess is because its a new drill bit and then started it and unfortunately it still wandered so I stopped it and put a little pressure on the work piece and then started the drill and that works better but still not good. I think My holes have then gone oval even when the wandering stops when in a decent start for the bit.

I'm thinking I might even get a better job done with a hand dewalt battery drill. Yes I know its a cheap drill but Would have thought it should drill holes but maybe its me.
I have even tried to use a stepped drill of 4mm and better rigidity but they are the worst with one side ok and the other only 1 thread

The Culprit



The Holes (Although it does screw in and hold when tightened but not right somewhere)



I have ordered a new tapered tap but wondering if the 3mm just isn't thick enough. Luckily On this bit I can put nuts on them but won't be able to weld them on.

Oh Well I will carry on.

[JAZZCNC]

Then You need a spot centre drill bit to start the holes.

[Colin Barron]

A very small drill bit can be used to find the centre spot made with centre punch,(spindle not moving), work should be clamped lightly but adjustable, clamp the work tight when positioned and check again to confirm it has not moved. Drill a small hole to confirm position then full size. A smaller drill bit will not move off centre as much as final size. If you still have problems use a centre finder (point) as shown here. https://www.youtube.com/watch?v=RhtBdar4iVg . I was informed as an apprentice many years ago that using the pointer method an accuracy of 1/64th inch (0.4mm) is achievable.

[Colin Barron]

How do you propose to get the main axis shafts level and parallel with each other? Commercial companies using this style of frame will have accurate jigs to hold the frame in position while they weld it. Special purpose machine makers mount rails onto a flat ground plate, which is mounted onto the frame, to ensure flatness. With the flat plate and one shaft mounted you could check parallelism using a dial indicator to locate the position of the other shaft.