Diy tube notcher help

[NathanPrince]

Hi guys doing a fair few little tube jobs lately and had a bunch of scrap around to make my life easier and decided I'd knock up a little notching rig. I sell car parts so dug through my box and found a nice sized wheel bearing to use as a shaft guide but it seems my tube I was gonna weld up for the shaft is just slightly too big.

Would anyone be able to turn me a piece of steel rod down to the correct size and put the thread for the hole saw on one end and the part for the drill chuck on the other end? I'll pay for materials and time and send you the measurements of my bearing.

 

[Richard.]

Send me a drawing with all the details it sounds like something I would be happy to have a go at.

 

[NathanPrince]

Do you just need the bore of the bearing and length of the shaft etc?

 

[Richard.]

I need everything in order to make you the part.
Bar length total.
All OD’s
Chuck part length
Thread length
Thread size.
I’ll turn it to the drawing you supply. It can be a hand drawn sketch but the dimensions need to all be there.

 

[NathanPrince]

Okay I'll draw something up and send it over, thanks

 

[Richard.]

Hole saws use a few different threads depending on the size of the hole saw your using so let me know the right thread size for your saws. Also I noticed on your pic there is no pilot drill for getting the hole saw to start in the right place nice and stable. This is usually the bar is bored out and the drill fits inside with a flat on it for a grub screw to nip against. Is this something your wanting?

 

[NathanPrince]

That's the bit I'm struggling with is the thread size for the saws, unsure which ones to use and what threads they use, I've been notching with a grinder up until making this. The pilot drill bit does sound good though and should make the start of the cut a lot easier.

 

[Richard.]

Also I’m sure a car wheel bearing is not the right tool. Yes the arbor will be spinning but you will have in and out motion going on which needs to be free motion so it can’t be an interrupted fit. And making it with clearance to do this will mean a degree of play in the arbor. I’d look at a liner bearing set up personally allowing for rotational and retractable movement of the arbor to be done on the bearings with no play and a better more stable cut.

 

[NathanPrince]

May have to have a rethink then was just gonna use what I had to hand. Ill see what I can find on the liner bearings. Thanks

 

[wyn]

I upgraded my notcher with needle roller bearings which seem to work fine. it's probably cut nearly 1000 notches since then.
When i bought the notcher it had an adapter to use the larger thread cutters.

 

[NathanPrince]

Would something like this work and take the abuse?

https://www.ebay.co.uk/itm/112974295300?redirect=mobile

 

[wyn]

You might find that the linear bearings won't be very good with the rotation of the shaft.

 

[NathanPrince]

What needle roller bearings did you go with on yours? Do you have any pictures of your notcher at all? Interesting to see how many different ways there are of doing it

 

[WorkshopChris]

Might be worth looking at Oilite Bearings then you will be ok for rotation and linear motion.

 

[graffian]

I think 5/8th UNF is right for a 1-5/8 holesaw.
I will check tomorrow.

 

[wyn]

I'm pretty sure,as graffian says, 5/8" unf for the larger holesaws and 1/2" unf for the smaller ones.

I think the one i bought had a 16mm shaft and i used a 16mm diameter neddle roller, 16mm long at each end instead of the bushes it came with.

This is a pic of another one with needle rollers, oil seals and a grease nipple.

I think i made the shaft on this one 20mm as it's always used with a 25mm cutter.

 

[NathanPrince]

Is that all? I assumed the shaft would be thicker than that. Maybe I could get away with a smaller diameter shaft than I had planned then

So if I just get 2 needle bearings and put one at each end that would be fine?

 

[slim_boy_fat]

Excuse my ignorance, but are these then driven by a drill attached to the end?

 

[anto44]

Excuse my ignorance, but are these then driven by a drill attached to the end?

Yeah just a drill on the end. The slower speed the better

 

[hotponyshoes]

The one I have got does not have a pilot drill and works just fine.

Half of the cuts are made on the end of a bit of tube anyway so the pilot won't even have anything to go into.

When cutting on angles I think the pilot drill would slip. The core saw digs in fine without it.