Another Boll Aero 1.8

[SteveT]

Hi Guys!

Well, my first head went bad, as holes were out of measure, so after starting another, i decided to make a carrier stop, and it worked well, now i can make grooves or parting with confidence...

so. having 2 heads, i decided to try some anodize, as had trouble with reds in the past, decided to try again (blues and greens seems to be a lot easier to use).

tomorrow will try another gig for make the holes in my new head....View attachment 118773View attachment 118774

Hi Rodrigo
Great job on the anodising. What dye did you use?
I spent some 2 weeks last year experimenting with anodising with mixed results. Part of the problem was not being able to get de smut solution in the UK.
I tried commercial red dye but the colour was more orange than red and it was very expensive. RIT dye was much better and cheaper but the red fades in direct sunlight. I had test samples outside for several months. Commercial dye kept its colour, RIT red faded after a couple of months. RIT blue and black kept their colour quite well.
Keep chucking
Steve T

 

[Rodrigo Castellanos]

Hi Rodrigo
Great job on the anodising. What dye did you use?
I spent some 2 weeks last year experimenting with anodising with mixed results. Part of the problem was not being able to get de smut solution in the UK.
I tried commercial red dye but the colour was more orange than red and it was very expensive. RIT dye was much better and cheaper but the red fades in direct sunlight. I had test samples outside for several months. Commercial dye kept its colour, RIT red faded after a couple of months. RIT blue and black kept their colour quite well.
Keep chucking
Steve T

Hi Steve!

Thanks!

As any other part of the hobbies, there is a lot of trial and error, i been using cloth dyes with good results BUT, they only work fine in the Blue-Green range... Reads are a real pain to use or simple useless.... even black....
I found an Anodizing Company in USA who sells good dyes.
Anodizing Kits - Anodizing Dyes - Page 1 - Caswell Inc
i still having trouble with gold colors, even with this dye..... seems to needs to be very precise about time and amps to work... for that head, i use 300mAh for about 80 minutes.

Cheers Rodrigo

 

[Rodrigo Castellanos]

Hi Guys!

Some more work done today.... seems to be just a little, but is impressive how long it takes to make some parts!! i made my carburetor (needle missing) and start to turn my piston....
i start to lap my cylinder with diamond paste, starting with 10 microns as i don´t have coarse valve paste... seems to be ok, but once y started the piston...... seems to have a moderated taper.... maybe 0.002" or 0.003" larger at bottom.

i really don´t know if this engine will run at all, but at least, i know that my tools (lathe and Mill) are in the range for something this size..... for sure something bigger will be imposible to handle.

 

[Rodrigo Castellanos]

Hi Guys!

not much progress this week:
i try my first piston and went wrong... the inner bore was not deep enough, so when i drill the pinhole, the drill hit the top and got some flexibility... so i made a new one...
and today had a couple hours free so i decided to try my cornod

 

[dethrow55]

looking good been watching your build.

 

[Rodrigo Castellanos]

Hi guys!

Today i lap my piston and made a little more work over the crankshaft. just missing some little parts and see if all fits good!

 

[Rodrigo Castellanos]

Hi Guys!

Some more work done today!
Finished my crankshaft what i almost put on the thrash, as being made from a bolt, was a little short, but i gave it a try and made the knurled part a little more short as per plan. so i compensate in the prop drive. it worked!
I even made the contra piston, and cylinder seems to have a nice small tapper, as when install the contra piston from top, it has a nice tight fit and it gets more soft if push it thru the cylinder....
having all internal parts done, i assembled the engine to see if all is aligned.... yes! The piston is a little loose so i will heat it tomorrow and see if it grows enough....

so... Missing parts: Spinner, carb nut, compression screw-tommy bar, and anodize head and spinner.

 

[Rodrigo Castellanos]

Hi Guys!

Now we have an engine! after making 3 heads, 2 pistons, and having a lot of fun, all parts are complete... not very happy with my compression screw and my drive plate (is very small) at least, i can feel the engine! seems to have good compression, after 3 drops of oil in the exhaust and some flips, the contrapiston moves nicely and seems to have no leaks....
let´s wait until weekend and see if it runs.
Maybe is time to anodize the head and reanodize or make a new spinner.

 

[Tim Wescott]

As to dressing it up -- if it runs, it's pretty, no matter how scratched, dented, lumpy, or asymmetrical. If it doesn't run, it's a paperweight. Get it running! Then make another one with all the lessons learned from this one.

 

[Nibby2226]

Fingers crossed. Mine took a long time to start the first time - mainly because I had no experience of starting small model engines. I added a hex nut on the crank so I could turn it over with a cordless drill. Eventually, I got a "pop" and the characteristic smell of burnt fuel. A few minutes later, it burst in to life, blue smoke,oil,noise and..... A big grin, first engine built and it runs! (Note all other family members / friends will be completely unimpressed)
I found the following was good...
Back off the compression, close the needle valve then open 1.5 turns, one or two drops of fuel in the exhaust port and be careful not to flood it with fuel.
Good luck

 

[dethrow55]

nice job well done

 

[Rodrigo Castellanos]

Hi Guys!

today gave it a try..... and have partial success, starting from small breaths to short bursts.... after 2 hours of flipping, my arm was tired.
here a video of that...



after unmount the engine to clean it up, i decided to check my internal pressure blowing some air and noticed a good lead in the backplate.... will make some gaskets and see if goes better.

 

[Tim Wescott]

Woot woot! It runs! OK -- maybe it only barely runs, but this is your first engine, right?

I'm not a super-duper expert with diesels, but when you get it to the point where it runs at all -- like where you are at about 3:10 -- then it's time to stop messing with the compression and start working the needle valve to see if you can do better. If it were a glow engine (which I do have experience with) I'd say it was adjusted just a bit too lean, such that multiple flips were getting it primed after a fashion, and then it'd run out that prime.

A bad crankcase seal wouldn't help -- if the leak is just the right size it'd let the thing run but not very fast. Kinda like it's running in your video, when it's running.

 

[scottyp]

Nice work, I think Tim is on to something and your arm is going to be sore tomorrow!

 

[stackerjack]

An excellent job you've done there, keep at it, I'm sure you'll have it running soon.
Check your fuel line for air leaks. Is the connection to the spraybar leakproof? Is your fuel filter leaking?
If the fuel tubing is old, it may have become brittle and not sealing properly. Are there any bubbles in your fuel line?
Check your backplate again, and try the new gasket.
Best of luck,
Jack

 

[andrewh]

Hi, Rodrigo
Well done! This must be classed as a triumph!

I an a diesel freak enthusiast for more than 60 years, and your video is so real that I wish I could lean in to help!

As Tim Westcott says, you have the compression almost exactly right, but need to open the needle valve a little till it runs more steadily.

A triumph anyway!
I am delighted that you are using the correct hand to start your engine with!
My habit is to have the prop with a blade at about 8 o clock when it comes to compression, and flip across the bottom of the engine (finishing up well clear of the running prop)
9 x 4 tornado prop? Good choice. Generally the larger the better when you are learning the habits and settings for a new engine

 

[Nibby2226]

Mine was like this - try raising the fuel tank a bit / opening the needle valve gradually it sounds a bit lean. A leak in the crankcase won't help either as it will reduce the "pull" of fuel in to the carb...