Model water pump from casting kit.

[darwenguy]

Hi all.
Not sure if this is fully relevant here, but pumps and generators always add interest to a running engine. Im sure some of you will find it interesting and i have had a few requests about machining setups so as im currently making a batch of the pumps, here is how i machine the pumps. Lots of pics to come.

This is the finished pump with a base and tank.

And a pic of the pump running with a little dc motor.

The kit comes with all the casting, fittings and drawings to make the pump.
Il start machining the alloy castings first.

First the front shell.

Chucked on the flange spigot.

And cut the joining face to size..

Next up the rear shell.

Change to external jaws and chuck and machine joining face.

 

[darwenguy]

After machining the joining faces on both front and back shells i replaced the chuck with the faceplate. I just center the casting using a tailstock center and some simple homemade clamps and m6 bolts secure the part to the face plate.

The flange is then machined and the inlet bored out to size.

Then rear shell is clamped in the same way as the front shell.

First centered then drilled 6.5mm through.

Then machine the gland face and bellhousing mating spigot.

The 10mm bore for the gland follower can then be bored. I use a 10mm milling cutter, they do tend to cut oversize! so i make the gland followers a little over size later on.

 

[darwenguy]

Next part il start is the bell housing this part includes the bearing housing.

Mounted on the lathe.

Center drilled then drilled through 8mm.

The 10mm bore can then be cut for the rear bearing. The bearing should be a light press fit in the bore.

To machine the rest of the bellhousing i use a mandrel a length of bar turned down to fit the 8mm hole through the bearing housing.

A drip of lock tite hold it onto the mandrell, make sure it leave some space for cutting the front bearing bore.

The bellhousing flange and the 12mm bearing bore can then be machined.

And check fit of the bellhousing spigot.

A little heat breaks the locktite bond.
And thats all the turning of the alloy castings finished still some milling and drilling to do on these parts.

 

[darwenguy]

The front cover was drilled next, center pop and drilled 3.2mm through.

The front shell is then used to mark the holes through to the rear shell. I use a drop of super glue to hold the two together while spot drilling through.

I use a length of scrap bar and a m6 caphead screw to help hold the setuo in the drill vice.

The holes are then drilled to depth 2.4mm and tapped m3.

 

[darwenguy]

Next part il work on the brass fittings first the pipe flanges.

Faced off then drilled and tapped m4 for mounting onto an arbour.

The arbour with short length of m4 stud to hold the part.

The part can then be turned to final outer diameter and thickness.

Then using the same arbour the part is setup with a rotary table on the mill and the bolt holes are drilled 3.2mm through.

Then back onto the lathe to drill then bore the inside diameter.

And the finished flange..

 

[darwenguy]

The gland follower is next and the turning operation is much the same as with the flange.

First face off, center drill, drill 3.2mm through then tap m4.

Then onto the arbour again.

The part and arbour are then set up on the mill again to drill the two flange holes.

The flange can then be filed to the outer profile and drilled through 6.5mm.

And the finished gland follower.

The brass fittings were then used to transfer hole centers onto the castings. All holes drill 2.4mm to depth and tapped m3.

Il update more tomorrow.
Best regards.
Luke.

 

[GreenTwin]

Very nice machining work, and great photography.
It is difficult to get a well lit photo with small parts in a lathe (for me anyway).

I like that pump kit.
.

 

[darwenguy]

Very nice machining work, and great photography.
It is difficult to get a well lit photo with small parts in a lathe (for me anyway).

I like that pump kit.
.

Thanks, yes the little shiney parts can be awkward to get a clear photo, i usually take 3 shots for every photo and choose the least blury one.
My phone camera does quite a good job to be honest.

 

[Richard Hed]

The gland follower is next and the turning operation is much the same as with the flange.
View attachment 128221
First face off, center drill, drill 3.2mm through then tap m4.
View attachment 128222
Then onto the arbour again.
View attachment 128223
View attachment 128224
The part and arbour are then set up on the mill again to drill the two flange holes.
View attachment 128225
The flange can then be filed to the outer profile and drilled through 6.5mm.
View attachment 128226
And the finished gland follower.
View attachment 128227
The brass fittings were then used to transfer hole centers onto the castings. All holes drill 2.4mm to depth and tapped m3.
View attachment 128228
View attachment 128229
Il update more tomorrow.
Best regards.
Luke.

1st, yes, it is appropriate, 2nd, where did you get the castings? I love the stuff you make, keep it up.

 

[Larry G.]

The gland follower is next and the turning operation is much the same as with the flange.

First face off, center drill, drill 3.2mm through then tap m4.
Then onto the arbour again.
The part and arbour are then set up on the mill again to drill the two flange holes.
The flange can then be filed to the outer profile and drilled through 6.5mm.
And the finished gland follower.

The brass fittings were then used to transfer hole centers onto the castings. All holes drill 2.4mm to depth and tapped m3.
View attachment 128228
View attachment 128229
Il update more tomorrow.
Best regards.
Luke.

“I love it when a plan comes together!
- Hannibal Smith, A-Team”
Well designed, well produced, well engineered, well documented.
The engineering is clever in avoiding procedures and techniques that may produce greater precision than required, and corresponding cost.
A rotary table is nice, but a pair of dividers would layout six holes equally well. Match drilling the front and rear volutes does the job sufficiently well.
Others with superior skills and equipment, such as Joe Pieczynski , www.advancedinnovationsllc.com does on his YouTube channel, currently finishing a model lathe, would do it superbly "by the numbers".
Keith Appleton often takes a different approach; www.mainsteam.co.uk, as shown on his numerous videos; .

Thank you for your efforts on behalf of the HMEM community and wishing you commercial success with your products.

Stay well,
Larry in NJ

 

[darwenguy]

1st, yes, it is appropriate, 2nd, where did you get the castings? I love the stuff you make, keep it up.

Thanks Richard
The pump is my own design, i produce it as a kit sold on my website.
www.cringlemodelengineering.co.uk

 

[darwenguy]

“I love it when a plan comes together!
- Hannibal Smith, A-Team”
Well designed, well produced, well engineered, well documented.
The engineering is clever in avoiding procedures and techniques that may produce greater precision than required, and corresponding cost.
A rotary table is nice, but a pair of dividers would layout six holes equally well. Match drilling the front and rear volutes does the job sufficiently well.
Others with superior skills and equipment, such as Joe Pieczynski , www.advancedinnovationsllc.com does on his YouTube channel, currently finishing a model lathe, would do it superbly "by the numbers".
Keith Appleton often takes a different approach; www.mainsteam.co.uk, as shown on his numerous videos; .

Thank you for your efforts on behalf of the HMEM community and wishing you commercial success with your products.

Stay well,
Larry in NJ

Cheers Larry.
I like to keep things simple, well i just use what i have available. But i do tend to just use precision were needed.
I am a fan of Joe's videos he has some very nice £quipment, i would love a nice DRO and some collets and just about everything els lol. Il admit though he does tend to over complicat things at times i drift off but obviously a perfectionist.
The PM resurch kits are superb for the cost i would love to get the full miniature machine shop set.

Best regards.
Luke.

 

[darwenguy]

Hi all.
Sorry I forgot about this thread ive been so busey, I thought i had finished it.
The pumps have long been finished now but i did take some photo's so i will continue and try to make sense of how the machining was compleated.

Drilling the bell housing mouting holes 3.2mm

Center drill, drill 3.3mm, couterbore 8mm and tap m4 for the bearing housing oil cup position.

The assembly mounted in a vice using a simular setup as the reverse side. The m6 bolt and washer secures it to the bar stock.

The bell housing holes can then be trasfered through and drilled 2.4mm to depth and tapped m3.

The same setup can then be trasfered to the mill and the base and top flange face machined flat.

Then the top flange holes can be drilled and tapped.
Some more turning next the pulley.

The pulley casting.

Chucked and machined first side.

Then re chucked on the spigot and machined to outer diameter a V groove cut and drilled through 6mm.

Then the part is mounted in the drill vice and drilled and tapped for the m3 grub screw.

Next page ......

 

[darwenguy]

Next we need the shaft.

This is a very simple turning threading operation, just take care on the 5.0mm bearing fit on the shaft.
Next part is the impeller casting.

Onto the lathe to face the rear the center drill, drill 4.2mm and tap m5.
The impeller is the screwed onto the shaft and fixed with locktite.

The bearings were pressed into the bearing housing.

And check fit of shaft and pully.

Assemble the pump and test fit the shaft/impeller, some more machining will be required on the impeller. It is best to finish the part with a little testing then removing material a little at a time untill the impeller spins freely with the front cover fitted. We are aiming for a close fit to the internal casting of the volute chamber.

 

[darwenguy]

Thats all the photos i have of the machining steps but i think it covers all the parts.
Was then just cleaning, masking up and painting the parts before final assembaly with a little sealant around the flanges.

The rubber nitrile oring is placed in before the gland follower. This simple seal works surprisingly well with no leaks and little friction. it is best to adjust the seal when the pump is running.

Thats all for now onto the next job.

Luke.