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

[JAZZCNC]

. I started out wanting a welding trolley and what I have finished with is a welding go cart well al-right nearly finished.

Grass has nearly stopped growing so rip out the engine and throw it on the trolley and you'll have the CNC machine finished in no time. . . Lol

[cropwell]

Hi rob,
If you need larger bolts in places you can't reach back of then there's other quick and dirty ways like drilling larger hole and inserting a nut weld in place and grind flat.

Or use riv-nuts if you can't be arsed to fart about with welding

[JAZZCNC]

Or use riv-nuts if you can't be arsed to fart about with welding

Cum-on I'm a Yorkshire Man have you seen price of them buggers.!! . . . . . Can get 100 nuts for price 10 of them.!!

[grain_r]

Hey Jazz

Thanks for the kind message.I think its getting there but i don't always get the same results every time at the moment. but I absolutely love welding now it still amazes me. I want to be confident enough to weld some of the chassis on the car and not need to ask a friend it they might like a ride in it first (Just in-case ). I think because I'm teaching myself there is probably a lot of bad habits going to be there.

I did think if riv-nuts originally but it seems that if any vibration occurs then these would start to wonder about a little. I really love the idea of welding the nuts in. I'm a worrier and I have used the sander to take the zinc coating off but it says somewhere the gasses are pretty bad for you. I'm not sure if there are specific welding quality nuts around or anything ? or just hold my breath and grow a pair.

[JAZZCNC]

or just hold my breath and grow a pair.

None of the gases given off are exactly good for you so if welding for long time or anything you know isn't sweet smelling then wear a mask.! I wear mask all the time when welding.

[cropwell]

Zinc fumes can give you flu like symptoms, which can take 3 weeks to go. It is probably best to wear a good quality respirator and work in a well ventilated area. Zinc inclusion in the weld won't really happen as the zinc will burn off, but for the sake of your health it is better to sand it off, while wearing a mask as the dust is just as poisonous. A lot of heavy metals are cumulative poisons as the body can't get rid of them. Fortunately zinc can be dealt with by the body.

Have fun welding !

Thes might be what you want http://www.ebay.co.uk/itm/like/16144...s=true&ff13=80

https://en.wikipedia.org/wiki/Weld_nut

[JAZZCNC]

Zinc fumes can give you flu like symptoms, which can take 3 weeks to go.

Just got your self a new forum title.!! . . . Doc Crop. .

[grain_r]

Hey Cropwell

Thank you very much for the explanation and I will certainly wear a mask in future and I'm getting those bolts on order to make me worry less.

[grain_r]

Well I thought I would keep my progress on here. Unfortunately It's not quick but going the right way.

I have made the frame sides and tacked the end screw plates on. Everything has been sanded down with a disc sander to give the best possible accuracy and then I have used my trusty Digital Vernier calliper although I have also made the screw holes larger diameter for a little fettling movment of about 1/2 mm Just in case.



The next step is to start drilling my holes for the Threads. I have chosen M5 allen screws and I have ordered a cobalt 4.2mm drill for the threads.
I just need to experiment getting the hole exactly centred for the thread holes to be as accurate as possible.

[Neale]

The next step is to start drilling my holes for the Threads. I have chosen M5 allen screws and I have ordered a cobalt 4.2mm drill for the threads.
I just need to experiment getting the hole exactly centred for the thread holes to be as accurate as possible.

Couple of tricks that you might not have come across. One is to start the hole using a clearance drill that nicely fits the hole in the mating part. Just drill lightly to give a centre mark then switch to the tapping size drill which, with a bit of luck, will follow the first mark. That doesn't guarantee that the hole is square to the work, though. I use a small steel block (turned from an odd scrap of steel) with a projection on one end that fits the clearance hole, and a hole up the centre that takes the tapping size drill. That helps a lot when you are using a hand-held drill in awkward places. Don't know if you have the facilities to make something like this (very easy lathe job) or perhaps know someone who can help? I find that I can go through in one pass with the 4.2mm drill, hand-held, but anything much bigger than that can do with a smaller pilot hole first (much easier going through steel) and then open up with the correct drill.

One other tip, if you're not doing it already - get the right taps! For through holes in steel, use a spiral-point tap. For blind holes, use a spiral-flute tap. Avoid using conventional hand taps (straight flutes) if you can. They are hard work and you find yourself going in a half-turn, then backing off to release the chips, then every so often bringing it right out to clear the flutes. The spiral-form taps are designed to push the swarf in front or bring it up the flutes, and you can tap in one pass without backing off all the time. They're cheap enough from China (I recently bought a couple each of M4/M5/M6 plus one M8, and the whole lot, including postage, was just over a tenner). Well worth while.