Author Topic: Len Mason's "Mastiff" - chewed from the solid  (Read 26023 times)

Offline deltatango

  • Full Member
  • ****
  • Posts: 148
  • Melbourne, Australia
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #180 on: August 03, 2018, 10:24:25 PM »
Hi Zee,
Yes, shrinkage that was causing corners of prints to detach from the bed was the main symptom. With polycarbonate filament even quite small prints were failing. I can't keep the heater turned on once the print bed is warm or else the printer firmware interprets the unusual heating as a thermistor failure and shuts the machine down. There doesn't seem to be any need to keep it going anyway, the heat from the machine keeps the enclosure around 30C.

BTW the distributor parts were printed in ABS with a 0.3 mm bottom layer and 0.1 layers for the rest.

MJM, thanks for doing the explaining, only the other Aussies would have known what it was. Hope your having fun on the road, 9C here right now.

David

Offline zeeprogrammer

  • Full Member
  • *****
  • Posts: 6263
  • West Chester, PA, USA
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #181 on: August 04, 2018, 12:06:22 AM »
Thanks David! Very helpful.  :ThumbsUp:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline MJM460

  • Full Member
  • ****
  • Posts: 677
  • Melbourne, Australia
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #182 on: August 04, 2018, 01:35:54 PM »
Hi David,

I more or less expected that I would eventually have to explain it.

It was 28 max here today, riding bikes along the Macintyre river flood levee bank.  A very nice level path,

Only 9 deg?  That is a great reason to be on the road.

Very interesting use of the 3-D printer for that distributor case, and really looking good.

MJM460
The more I learn, the more I find that I still have to learn!

Offline deltatango

  • Full Member
  • ****
  • Posts: 148
  • Melbourne, Australia
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #183 on: August 04, 2018, 01:45:00 PM »
When I bought the kit of bits for Mastiff from Hemingway Kits I also bought kits of materials  to make four spark plugs. These are based around a simple porcelain insulating bead with steel body, electrode etc. I didn't take pictures of the machining which is all straight-forward but here are the four sets of parts before assembly with JB Weld:



A finished plug, after cleaning the insulator with silicon carbide paper and a ride in the ultrasonic cleaner looks like:




Four sealing washers will finish these off and then the wiring is all that is left to complete the ignition system. I'm also part way through making a box for the battery and coil (a commercial coil-on-plug unit from a Ford). I won't know how much use these are as spark plugs until the engine runs (or doesn't).

The squares on the background are 1 cm. Hard shadows are due to using a on-camera flash with a macro lens.

Oil pipes and fittings are next.

David

Offline deltatango

  • Full Member
  • ****
  • Posts: 148
  • Melbourne, Australia
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #184 on: August 21, 2018, 06:26:17 AM »
I've been busy making lots more little bits but not taking many pictures. Mastiff now has an oil distribution system that gives good oil pressure, gaskets everywhere that they are needed and HT leads. I've set the valve timing and the contact breaker and distributor timing, have to cross fingers these are close to correct. The inlet manifold is made and attached. All together the engine now looks like:





The fairleads for the plug leads are two more 3D printed bits.

The carburetor is the last part to make and I'll try not to rush too much and make the time to take pictures.

David

Offline Ye-Ole Steam Dude

  • Full Member
  • ****
  • Posts: 896
  • Deep East Texas on Sam Rayburn Lake
    • Ye Ole Steam Dude
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #185 on: August 21, 2018, 08:03:57 AM »
Hello David,

Absolutely beautiful engine, workmanship and design. Looking forward to a video of this beauty running.

Have a great day,
Thomas

Offline Roger B

  • Full Member
  • *****
  • Posts: 3475
  • Switzerland
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #186 on: August 21, 2018, 08:06:02 AM »
Splendid  :praise2:  :praise2: Not long until the first pops  :ThumbsUp: :wine1:
Best regards

Roger

Offline deltatango

  • Full Member
  • ****
  • Posts: 148
  • Melbourne, Australia
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #187 on: August 21, 2018, 09:30:36 AM »
Thomas and Roger,
Many thanks for the kind comments!

Just spent a couple of hours building up a transistor ignition circuit (IGBT switch) to go into the ignition box.

David

Offline gbritnell

  • Full Member
  • ****
  • Posts: 1795
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #188 on: August 21, 2018, 12:06:43 PM »
David,
With the transistorized ignition you won't need the condenser. Using one is just for a coventional point ignition. The engine looks marvelous. I'm curious as to what the original design was to cool the engine?
gbritnell
Talent unshared is talent wasted.

Offline ozzie46

  • Full Member
  • ****
  • Posts: 263
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #189 on: August 21, 2018, 12:53:09 PM »
Mason just used a tank about as large as the engine filled with water and the water circulated by convection. When installed on a boat there was a water pickup in the water to push water thru the tank also.

Ron

Offline deltatango

  • Full Member
  • ****
  • Posts: 148
  • Melbourne, Australia
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #190 on: August 21, 2018, 01:17:07 PM »
Thanks George & Ron.
I was going to run the engine with a simple Kettering ignition then decided to go the whole way, I'll remove the condenser when I start testing.

As Ron says, the designer used thermo-syphon cooling for the engine when static and writes (p130 of the Mastiff book):

"The temporary tank need be no more than a tallish coffee-type tin, having four short stubs of 5/16" dia. copper tube soldered in, to be connected with plastic tubing to the water connections on the cylinders each side."

I can't find any mention in the book of cooling in actual use (may just have missed reading it). Ron, where did you find the reference to the boat installation?

Regards, David

Offline Zephyrin

  • Full Member
  • ****
  • Posts: 308
  • near Paris, France
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #191 on: August 21, 2018, 01:39:57 PM »
Wow, amazing build and thread to follow, and a beautiful engine, impressive work !

the sparkplugs also look great, what kind of JB Weld do you have used for the assembly ?

coffee tin for the cooling water, with plastic tubing ? for this engine ? its serious ?
« Last Edit: August 21, 2018, 01:50:43 PM by Zephyrin »

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 4383
  • Barrie, Ontario Canada
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #192 on: August 21, 2018, 02:27:14 PM »
Deltango--what a beautiful engine. Lovely work indeed.---Brian

Offline michaelr

  • Full Member
  • ****
  • Posts: 102
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #193 on: August 21, 2018, 07:14:47 PM »
You have a fine looking engine nice work, the water cooling arrangement on this Mastiff may be of interest. http://modelengineeringwebsite.com/Mastiff_Plus.html

Mike.

Offline fumopuc

  • Full Member
  • ****
  • Posts: 2180
  • Munich, Germany, EU
Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #194 on: August 21, 2018, 07:37:06 PM »
Hi David, nice looking engine. Good luck that the first pops will come soon.
Kind Regards
Achim