Attempt no1, Home made two foot slip rolls

[Richiew]

Minor progress report. Been pottering a bit in the garage over the weekend and then concentrated a bit more this evening.

Firstly, the original 12mm frames I messed up. Thought it was a shame to waste all that time and effort spent milling. I decided to treat them as one frame welded together and maybe make another later on to match. I chopped out the drilling mistakes and then centre drilled, tapped m10 and milled some 25mm round bar to fit. Needs welding together at another time.

Onto the two 20mm plates for the inch and a half cds tube. Ignore the two holes on the right hand side. That was a mistake from last week using 34mm centres that I'm no longer using and due to the work not being held flat in the drill vice, the top drilled hole went in at an angle so the holes would be at differing heights.

I've learned from last time and put the top hole and the vertical slot 5mm closer to the left hand edge. I have also flattened the angled slot by 5 degrees.

I've got the big 6" Abwoood milling vice out. It is a pain the rear end to set up work accurately for drilling. I have to move the work in the jaws to set the y axis and slide the bolts/vice in the T slots to adjust my x axis.

The good thing about it is it will hold the work in the jaws fully so I don't have to weld a tab to the work and clamp off that. This keeps the work flat so no drills going in at silly angles. The vice is much sturdier and holds the work better. I have parallels under the workpiece. I used a spirit level to make sure the work was flat (This time).
Look how clean the drill table was before I started.

Spirit level. (Used on the work piece to check it is flat. It is doing nothing sat on the milling vice here.)

I picked the wrong drill up and those two big holes are 1 and 1/16" rather than 1" but this doesn't matter.

Just about done.

Ready for milling, cutting shaping etc. 16mm hole top left. Angled slot holes are 1". Vertical slot holes are 1 and1/16". The plates are 40mm thick in total. I had to wear gloves to pick this out of the vice when finished due to the heat. I don't know what went wrong with the vertical slot. I thought I had set my drill holes an inch apart but there's still a fair old gap to remove.

This was a lot of work and discomfort when working on the floor.
Tomorrow evening I shall be mostly sweeping up.

 

[selectedgrub]

A pleasure to see someone not just laser cutting @#$% and actually doing it the forgotten ways.
Very good sir, thanks for sharing and watching with interest.

 

[Richiew]

Cheers. It was a lot more work this evening than I expected. A hell of a lot of material removed. If only my work load could be edited like Youtube videos where all the hard work, chew on and effort is skipped over.

I soooo want a plasma CNC.....

 

[Richiew]

Still at it this evening. Cutting slots on the bandsaw.

Had to finish the cuts off with the hacksaw which wasn't as bad as expected.

I marked out the rest of the frame.

I didn't fancy death by a thousand tiny passes on the milling machine so I figured a bit of old school sawing wouldn't do any harm to reduce the sticky out bits.

For @selectedgrub 's continued viewing pleasure.

I now have arms and shoulders like a professional wrestler.

Full disclosure. The reverse side isn't as good. A lot of wonky sawing going on. I was more concerned about not cutting outside the lines so the remaining extra material isn't an issue. Better safe than sorry, especially when you cant really see what's going on at the back

Tubes roughly plonked on top and everything looks ok so far. Milling, filing and die grinding to shape tomorrow.

 

[selectedgrub]

Thank you.

 

[slim_boy_fat]

@Richiew You're my new hero

 

[RichardM]

Full disclosure. The reverse side isn't as good. A lot of wonky sawing going on. I was more concerned about not cutting outside the lines so the remaining extra material isn't an issue. Better safe than sorry, especially when you cant really see what's going on at the back

I have hardened jaws in my vice. If I want something relatively straight I clamp it up in the vice so I can run the saw down the side of the jaw to keep it straight.

 

[Richiew]

Great Idea Richard. I'll bear that in mind in future. Perhaps I could have got the workpiece sat lower in the vice to use the jaws as a guide.

I found the curve was throwing the blade in toward the centre. I honestly can saw better than the pictures show. At the time I just wanted to get the most material removed for the least effort without sawing where I didn't want to.

 

[Richiew]

Few pics, a lot of effort. Not too much to see. There's much more material to remove due to the thicker plates so I expect it will take a few evenings to finish the plates.

This is both sides of the plate after hand filing. You'd have to compare them to the pics from my previous post. I fancied another workout and filed the points down using this bad boy. I can put plenty of weight behind the file and I've found it isn't hard to shift a fair bit of metal fairly easily.

Became tired and bored and got marginally further with a die grinder. Results below. The powerfile belts seem to snap very easily and weren't much use.

Off to the mill next. The vice on the mill is much smaller than the Abwood on the drill so I need a tab to clamp to.

Tacked up reasonably square. There seems to be a slight gap at the far end of the tab/square showing in the photo that I didn't notice at the time. Maybe it is the way I posed the photo?

The second weld always seems to go in nicer than the first. I wont show the first. 125amps 3.2mm 6013. Think it is a Fincord. The anti-stick function on the SWP Stealth earned its money tonight. I like that feature.
The weld splatter got chiselled off so it didn't interfere with any "precision" alignment.

Onto the mill. The slot I'm working on is only 16mm wide plus clearance when completed and it's probably only 14mm-ish after the conservatively placed bandsaw cuts so I cant use any large and long mills. This 10mm mill wont reach full depth.

The other two slots are much wider and I can use a 19mm roughing mill which has a touch over 40mm in cutting length so I should be able to true up the slot sides full depth taking tiny cuts.

Notice the square white sticker on the collet holder. Over the weekend I used a tacho on the mill to clock the running speeds for the various belt pulley positions at 40, 50 and 60hz on the VFD. I now know exactly the speed that the mill is running at. I found a good idiots guide to milling on the mad modder forum where I recognised a few user names from here. My milling is getting a bit more efficient because of this and I am getting more familiar with the machine which is the point of this project.

These two pics show the step I was left with.

I filed away the step with no bother. At a much quicker rate than I was milling to be honest. The slot needs widening out a bit more to get the bushes out through the gap. There's still about half a mm to go. They do push out through the original drilled hole in the other direction so nothing is stuck.

 

[Richiew]

Quick question for people. I don't want to waste any more money buying unsuitable material for the umpteenth time.

I am having a bit of trouble working out or just visualising the spur gears required.

The tubes I am using are 38.1mm diameter in diameter. I am thinking that a pair of 3 modulus 15 tooth gears would be suitable. I think I could also use a pair of 12 tooth 4 modulus spur gears. Dimensions attached in the tables below. In both cases the core diameter of the gear is less than than the diameter of the tube so I could get the tubes to close up to zero gap if needed without the gears binding or jamming. The outer dimensions are greater but they mesh together and the diameters overlap so they dont prevent the tubes closing up tight? Would this be correct and what would you choose? As you can tell I'm not an engineer.

I have finished the horizontal slot tonight. I think I have finished milling the vertical slot too but it will need tidying up a little with a file. Only the diagonal slot remains to be milled. I had plenty of time on the mill tonight which is was one of the aims of the project. I really rate this roughing mill. I have used it a few times now and it doesn't have a scratch on it. Still looks like new. Really impressive and it makes nice chips too. None of those horrible sharp painful slivers of metal that get everywhere when side cutting. Really happy with the milling vice too. I've found it to be very versatile. It's just a cheap one from RDG.

 

[Richiew]

I'm not a massive fan of hole saws to be honest. I understand the take less effort as they remove less material. They always appear to display tremendous runout until they settle into a groove somewhere close to where I wanted the hole. I can sharpen twist drills for free. Blunt holesaws are only fit for the bin. Might be worth an experiment in future though.

 

[Hopefuldave]

About the gears...

The pitch diameter is what would be fully meshed (taking up all the clearance), so for your 38mm rollers the ones you mentioned are going to be too large and you'll have a gap between the rollers - if you imagine the gears havve infinitessimally small teeth (rollers, basically, if they relied on friction) the pitch diameter of the gear is the diameter of the roller - so this is (taking half the pitch diameter for each) the *closest* you can put the centre of the gears!
Gear teeth mesh because you have the Addendum (sticking up beyond the pitch diameter) poking into the Dedendum (the groove between teeth, going below the pitch diameter) which are both near-as-dammit one pitch - so e.g. a 3 Mod will have addendum and dedendum of about 3mm each (which is why the 10 tooth is 30mm pitch diameter, 36mm overall, see the chart).

For your rollers at 38mm diameter, you need a pitch diameter D in the chart as close to the rollers as you can get, erring on the small side - e.g. at closest fit, the 4Mod 10-tooth will have centres 40mm apart - OK if you'll never roll anything below 2mm thick, but...

As your rollers are imperial (38.1mm = 1.5"), you might get a better fit with Imperial DP gears - take the number of teeth and divide by the DP to get the pitch diameter, e.g 12 teeth, 8DP, 1.5" pitch diameter (and roller size with the gears closed up).

HTH,
Dave H. (the other one)

 

[Richiew]

Cheers Dave, that's a great help . Not really what I wanted to hear though as only the metric gears are cheap off the shelf. I did buy myself a rather crap Chinese dividing head a while ago and this could be the excuse I need to actually start using it rather than just looking at it. I can get the gear cutter for the the price of a couple of metric gears. Looks like I will go down this route. It puts me back a bit for progress but the education should be worth it.

I hope my mill is up to cutting these gears. I think I could probably do with a bit more horsepower.

 

[Hopefuldave]

Cheers Dave, that's a great help . Not really what I wanted to hear though as only the metric gears are cheap off the shelf. I did buy myself a rather crap Chinese dividing head a while ago and this could be the excuse I need to actually start using it rather than just looking at it. I can get the gear cutter for the the price of a couple of metric gears. Looks like I will go down this route. It puts me back a bit for progress but the education should be worth it.

I hope my mill is up to cutting these gears. I think I could probably do with a bit more horsepower.

You can make the gear cutter for a lot less (only needs to be a single-tooth like a flycutter, the gears are running super-slow and usually with too much clearance = don't get hung up on accuracy) if you're dead keen... And you don't have to cut full depth in a single pass, so don't *have to* have a humongous mill to cut 'em!

Dave H. (the other one)

 

[Richiew]

Cheers but I am so far out of my comfort zone already without making my own cutting tools Dave. Good job it is nearly payday.

 

[Hopefuldave]

Got a lathe? 4-jaw chuck?

Dave H. (the other one)

 

[Richiew]

Course.

 

[Hopefuldave]

Then you could make a 4-tooth gear cutter, a bit quicker than single in the cut...

 

[Richiew]

But, but.... I could press "buy it now"!

 

[Richiew]

A bit of minor progress to show. Over the weekend the slots got completed. There might be a little more work to do when I make the bearing carrier pieces that fit inside the slots. I just have to summon the courage to drill and tap the holes but I am sick of looking at these plates at the moment so thought I'd go back to the tubes as I need to make some more bungs.

I learned about half dead centres the other week on another thread on this site. I had some half centres but didn't know what they were used for. They came in handy tonight as the workpiece got turned down to a narrow diameter. I used a full live centre until access became a problem.

First one sort of done. I am thinking of drilling and pinning these into the tubes rather than welding. At least it wont be permanent if I need to revise things. What does everyone think?

I'm quite pleased with the finish using HSS. Well, its good for me anyway. Another five to go.

Stub arbor and involute cutters are on their way. I'm going to practice cutting gears on aluminium first. I want a few goes at it before or in case I blunt the cutters. I think I might struggle cutting steel gears. I've done a bit of reading and people are quoting mill speeds of around 100 rpm for cutting steel gears. The bottom end on my mill is about 375. I can lower the speed further using the VFD but there'll be no torque. I suppose I will have to cut at higher speeds and take shallow, multiple cuts . Has anyone cut steel gears using a little mill? 8dp are on the chunky side which doesn't help much either. Stupid question but if I make really wide gears out of ally might they be up to the task? I think I may end up finding this out myself.

Cheers