Thread: Beaver Knee Removal

Hi All,

I need a little guidance on my thoughts for removing the knee on my beaver milling machine. I had intended on using slings under it but have been hesitant in doing it this way as there is nothing for the slings to lock in to and if they slip then... well...
While searching around for a solution I found a bloke that has removed the knee from his beaver which is detailed here

BUILD LOG: Beavermill conversion to CNC - Page 4

this picture shows how he did it:

Attachment 192421

So armed with those detailed plans I cobbled together this:

Attachment 192422

The plan is to have 12mm plate on top of the ways and then attach 6 x 7/16 bolts through the jig to clamp everything in place

Attachment 192423

I can then use either the forklift or engine crane to remove the knee with a little less trepidation than with just a sling.

The ways stick out 18mm on each side of the knee and are 18mm thick on one side and 36 on the other. The jig is 300 mm long.

Can anyone reassure me that this is not likely to end in tears. I am hoping there is enough meat in the ways to support the weight of the knee. I plan on doing this tomorrow so hopefully I will get some prompt answers if this looks iffy.


Thanks,

Jayson

Hi Jayson,
I am a member over their and followed that build. I usually use a sling down the centre onto the cross brace to lift it, but I see yours doesn't have any opening.
Your set up looks the same as his though yours looks a little shorter along the ways. The knee shouldn't weigh all that much so I think it will be fine. But just for precaution could you put a metal strap down and under the bottom of the knee to help with taking some of the weight off the ways? I would hate to see you do any damage to the ways.

Dave

Thanks for the thought Dave.

I could use a tie down to sling under the knee to take the weight. That should work well.

Thanks for replying.

Regards,

Jayson.

Hi Jayson,
Can't say I like it all that much. But then I've always had a thing about welds supporting loads.

Could you run a sling under the table and use your jig to hold it in place?(also tying it back somehow to the point where the Z screw sits)



Stuart

No problems,
we maybe worrying about nothing, but better to be safe than sorry so you cant really over do it.
What are you doing with the mill? Just giving it a clean up or a conversion?

Dave

Thinking about it, how about running a couple of slings through the square tube and under the knee. This would act like a fail safe as well for the welds.

Dave

Thanks Stuart,

I worry about welds giving way also. I will try and tie it all together with slings/ tie downs so that there is little force acting on the welds.

Dave,

I am in the process of doing a clean up and a conversion although it will not be as in depth as the one linked to earlier. He has done a wonderful job, but a little beyond me.

Regards,

Jayson.

Hi Jayson. I don't like the way the sling has to go around a sharp corner on the RHS. I wouldn't give up on slinging underneath without a fight. I had a slightly similar situation when lifting the ram on my shaper. In that case the sling wanted to slide towards the middle. The front I could anchor but there was nothing at the back. I clamped a piece of timber across the ways, not to take any weight, but just to stop the sling from sliding. I think this is what Stuart meant. I think your rig would be more secure for that than my bit of pine. And I second the idea of looking for an anchor at the screw mount. Don't go ahead till you're comfortable.

Years ago I made a drum lifter kind of like this one. Easy to make and won't slip. Just a thought.

Phil


http://www.jbwade.com.au/images/prod...m%20Lifter.gif

Originally Posted by Jayson

Thanks Stuart,

I worry about welds giving way also. I will try and tie it all together with slings/ tie downs so that there is little force acting on the welds.

Guys, if you worry about welds holding loads, you really should learn how to weld properly and/or get a decent welder. In A36 plate, a weld done properly is as strong as the parent material. I've made spreader bars to lift 600kg of steel keel shoe from RHS with welded on tabs for shackles etc.

IMO the best rod bar none for backyard welding if you want sound welds is an E4111 or 4311 electrode. They are finicky to learn to use due to the arc length but are a fast freeze, deep penetration all position rod. The surface finish is rough and they make a ton of smoke as the flux is cellulose dosed with various chemicals. You won't find them at Bunnings, needless to say.

PDW

Hi PDW,

Originally Posted by PDW

a weld done properly is as strong as the parent material.

Sure it can be. A wonderful looking weld can also be doing next to nothing(which seems to be easier to do when welding two different thicknesses together).
Not to pick on Jaysons welding as they dont "look" to bad, but I doubt they are anything like as strong as the parent metal. Though they may very well be up to the job(I'd be guessing the table is in the 100kg ball park so my math say a single 1/4" bolt would be able to lift it), why find out if there is another way of lifting it?

Stuart

Hi Stuart,
I was going to comment on pretty much the same thing. Jayson might be a boiler maker by trade, or he might be brand new to welding, we don't know so we are going the safe route by thinking the worst.
I am more concerned with the ways on the knee and is why I suggested another strap underneath, I would not be nice if he turned up latter to say he broke one off, then again I might be over thinking it, but better to be safe than sorry.
I have learnt my lessons over the years wishing I could reverse it all and do it again after something broke, LOL

My mate the truck driver always bags me out when he sees machinery on my box trailer, saying things like I don't even have that many straps on my 44 footer etc (exaggeration), but like I say to him, at least it's not coming off and I don't have to stop every 15 minutes to tighten thing up, or worry about it coming off on a long trip. It only takes a few minutes extra, but I do worry about the guys over taking me with a single bit of thin rope holding something on theirs doing 120 + kmh down the free way.
I sent you those pictures of the piece of ply into the front of our car, another one with a single under rated strap.

Dave

Thanks for all the help guys.

I got the knee off today without any trouble what so ever.

I did make a slight modification to the rig:

Attachment 192490

I welded some 1/2 inch bright mild steel to the ends of the rhs. I did not want to damage my new tie downs (thanks Bryan).

I forgot to take a photo of the setup when I was lifting it off but followed suggestions and had a sling under the knee and through the rhs above. There was a fair chance that just the sling alone would have done it but I liked the way it ended up coming off. It seems that I also managed to get it all in the right place also as the knee lifted straight up with no swing once it was clear of the mill. Sometimes luck is on my side.

Attachment 192491

Got it home on the forklift from where it has been stored and have started to degrease it ready for filling, undercoat and paint. Hopefully will get it all finished soon.

Thanks all,

Jayson.

Great to hear Jayson and I hope you'll post some updates on your Beaver.