Member postings for Dave Smith the 16th

I have one of those digital ones on order, 1" travel so that should sort my problem as long as the shaft is 8mm..

Nothing i want to do is ever straightforward All this to get ABS prints to stick to the glass bed on the 3D printer..

PLA prints without any issues. Not had a failed PLA print in a very long time. Added the glass bed on the top of the table and heat it to 65 degrees and use a pritt stick just before the nozzle is at full temp. A quick wipe with it and done.

OK i set the gauge up and took a reading of 6.8mm, Unscrewed one turn and it showed 7.2mm.

0.4? Measured the thread diameter with the micrometer and its 2.42mm.

Do these tally?

Thanks.

PS, just found my M2 0.4 taps and the shaft is too small, so 2.5 appears to be right.

Cannot be certain of the thread pitch but it appears right. Need a microscope..

Edited By Dave Smith the 16th on 11/06/2016 17:41:01

Its a fairly new and cheapy gauge, Tool Zone one.

Local CFE? I contacted the Campaing for the Farmed Enviroment and they didnt know what i was talking about

CFE? College for Engineering? Do we have them these days? Wont that be dangerous for students? Electicity and moving machinery etc. Should that not be banned? My daughters school didnt have a metalwork room and the woodwork one only had hand tools.

Measure the pitch with the gauge, I will give that a try but dont hold your breath My answer maybe worse than the one i got with the digital calipers

Thanks.

Nope not connected with the seat motor, this is the shaft from a dial gauge. I 3D printed a holder to help level the printers bed but the plunger is not long enough. Silly me for not checking.

Rather than try another design thats lower yet clears the drive belts i thought about extending the plunger instead.

Checking more threads is difficult, only 3 turns to remove it. Can you rig up a projecting microscope quickly in blue peter fashion? Or would that me more stuff to order and another project onto my list?

Its 2.4mm diameter not 2.48 that i put previously.. Not sure how i got that? If i keep rotating it then a low spot will give 2.38, but the rest is 2.4 Maybe i put 2.4 and then measured again and added the 8 on?

So with the right information does that put me closer to anything?

Thanks.

Someone mentioned that free hobbing was OK for a gear that does not have to be a specific size, but when it needs to be specific then you need to cut the number of teeth into the gear to start with?

Thanks

I tried google but it just shows howto measure thread pitches which i know.

But i need to check the thread pitch on a small part that measures 2.48mm diameter. Some of you may think thats huge and easily done but I am struggling to see how you do it accurately.

I have thread gauges but at that small size it has me stumped. My gauges go low enough but its the reading of them that puzzles me.

I marked the item and gave it 2 full turns, but only had the digital caliper to check it. It closed up by 0.78, divided by 2 turns = 0.39 so probably a 0.4 pitch? Wrong way of doing it?

What do you use to accurately check that is correct?

Thanks.

Yeah i bought a bottle of 271, i put a tiny drop on 1/4 of a washer and pressed 2 together with them just overlapping approx 5mm and it took a good twist to break them apart.

Not troed silver soldering. What draws the solder into the joint? the heat or the flux?

Thanks.

Michael Cox 1, Not an 8TPI there.

The left hand set is what my manual says i need for a 2mm pitch thread. The right hand set is what the link that you gave shows i need to cut a 2mm thread.

Something not quite right there.

That gear calculator mentioned above comes out differently for my machine.

My metric machine with a 2mm leadscrew.

Picture below on my manuals figures and the figures from the calculator above.

(although i do wonder if my manual is correct, no mention of the high/low gearbox and the motor drives the spindle directly)

On my previous car i had the Jaguar flip / remote key. Got some funny looks when i got the key cut.

Handed him a Jaguar blank and a Ford key to copy. Lucky he has a brain and not a robot. I said they are the same car and he compared the keys and said no problem.

Although the MOT guy coming into the waiting room to tell me my cars not there got my heart rate up a bit. Although he looked at the paperwork to see a Mondeo booked in he just looked at the key and assumed a Jaguar.

I have some Loctite 271, is that no good?

Thanks

Edited By Dave Smith the 16th on 09/06/2016 00:01:39

Maybe its the pictures but that gear looks wrong. It should not be flush with the top of the shaftthe shaft extends very slightly and there is a hardened button the top inserted ball bearing rests on.

I can see that wearing the casing out.

I couldnt find an 8TPI tap under 12mm diameter. 0.468 i think? I put that measurement in a previous post.

As Roger says, Its the journey i want to make one, I dont even need one its just something that i thought i could knock out quite easily. But it seems to be a bit of a learning curve.

Excuse to buy a mill though

Had to get some aluminium in because i didnt have anything over 25mm. Some 2" steel to make a holder/flycutter. An arbor to take an involute cutter (if the tooth pattern matches)? If not its the flycutter ( 90degree) not angled.

3D printed a U shaped holder for the gear. This is to test the theory and possibly used as a pattern to mill one or cast one. It may even be strong enough if i use light cuts?

It cost pennies to make and approx 3 hours so not a big loss if i break it.

Thanks.

PS.. Suggestions that doesnt include buying one.

Cut the internal thread or grind the shaft?

Tight fit and threadlock, or tight fit and threadlock and a small diameter pin at the top section not the botton as in the link above?

Suggestions please

Never sure of anything but with a bit of parallax error

You can get close without the 127 gear. I have the opposite at present. I have a metric machine and need to cut an 8TPI thread.

I can get close with with a 20/66 although gearsVB6 says 40/66 ?

or a 24/80 Gearsvvb6 says 33/52? Not done the maths yet to see which ones closest.

Thread on here recently (i think) where a 66 gear was suggested instead.  Or maybe i deviated to another site?

Edited By Dave Smith the 16th on 08/06/2016 20:50:42

ARC had some in when i was looking for a machine a few weeks back. They had all been assigned to buyers though. Several options, longer beds and brushed/brushless motors with various prices.

A bit more than i wanted to pay, they may have more in now? Cheaper than the Axminster prices but i didnt compare exact specs between them. Worth a call. I had 2 visits to them and enjoyed the experience.

The shaft is only 8mm diameter and the thread depth appears to be 2mm, with a 1mm fairly square profile, slight taper outwards approx 1.5mm at the outer edge? Although i only have the calipers to hand at the moment and the jaw is a tight fit.

It will be a Ford part rather than a Jaguar one. The Jaguar was a Mondeo undeneath. Buy parts from Jaguar and they come stamped with Ford on them. Oddly though some parts are cheaper than buying from Ford?

I think grinding the thread off would be an easier solution. Just hoping to pass on a few extra ones to club members who may not have the facilities to grind the teeth off and drill and pin it.

I may try and make a boring bar, i never seem to have the right stuff to hand. 2" round stock maybe excessive to make a 6mm boring bar

Thanks

Yep thats the one but the brass ones are variable. Some come in 3 pieces and some have straight cut teeth.

The hardened shaft needs to be ground off for most of them.

Never cut a sub 12mm internal thread as yet. The tool i ordered some time back arrived looking totally different to the picture. The picture appeared to be a shaft with the carbide bit brazed directly. When it arrived the tool have a 90 degree bend then the bit brazed to that. Smalled it will thread is approx 20mm. So i never bothered trying an internal thread.

Just looking for simple options. But not buying one even though it would have been cheaper

Thanks.

Another PITA now

I got the shaft that the gear fits on and i may have mentioned i think the bar was threaded all the way and they ground off sections and took slices out of the thread to secure the plastic gear.

Thinking it maybe a good idea to thread the gear and attach it with loctite or a roll pin. I have a metric lathe and measured it at 8TPI. damn.. OK i can get it to 8.005 so that shouldn't be a problem i want it tight anyway.

But the shaft is 11.9mm (0.468". Dashed my hopes of buying a tap and cheating.

What steel do i need to make my own tap? It will be used for aluminium, but possibly brass later on.

At least the heat wont be an issue, i built a furnace to melt aluminium a while back and it may even melt steel if i try

Will a towbar bolt be hard enough? The only thing i can think off i have to hand. Otherwise i need to order something and even more delays

Thanks.

The issue is nothing matches the original gear. The equivalent would be a mod 1.314 ?? A DP20 is the closest but the figures suggest that its 1mm smaller than the gear i need to make. I made a tool which seems to fit but whether it cuts who knows

I need a straight flycutter no an angled one.. Silly me.

Plenty of grease in there normally and its in a sealed part of the motor, so not a lot of space for the grease to escape. Although i have not seen how much grease there is in one thats broken.

Its a common failing point on these cars, so i think the part was slightly under specced. Although they last well beyond the warrranty so to them they got it right. Why spend more when it fails out of warranty and you can sell them a new motor because the gears are not sold on their own.

Thanks.

Edited By Dave Smith the 16th on 04/06/2016 21:16:05

The plastic gear must have been formed on the shaft. I think the thread on the left part extended the entire length and they ground some off and then sliced some to lock the gear into place.

Searching a wreckers wont help find a solution to a weak part. Thats why i need to make a gear our of something else.

Thanks.

Edited By Dave Smith the 16th on 02/06/2016 22:35:01

Tried a load of the gear lists and nothing seems to match my gear. The closest is a 20DP gear, but the OD is 1mm smaller than the gear in the picture below.