pursuit p mono build

[properchopper]

Mike,

I love the sliding motor mount concept - very creative and surely a "problem solver" for rear motor setups.

I needed to make motor R & R on the access-challenged JS do-able [there's NO WAY I wanted to try starting the motor bolts in this cramped compartment] without exhausting my vocabulary of obscene proverbs so I came up with this. Pop out the four capscrews from above and out it comes. Not as slick as the "sliding" idea but made motor swaps a lot more liveable. Just posting to create some thought... :

DSC02788.JPG

DSC02802.JPG

DSC02804.JPG

DSC02801.JPG


As far as accessing those PIA 3mm motor endbell-mount capscrews you've seen my quickchange nut 'n go solution at our "one motor per heat" races :


DSC06324.JPG

[TheShaughnessy]

Tony that may have been the inspiration for my idea. I had three holes in it. But then decided to go with 4, they are hidden so doesn'the matter much. Kinda figured the three holes is your "signiture"
I just got lucky with some scrap I had from work.

I might flip the motor mount around and do the studs. Not sure I could get a wrench in the recess.

[TheShaughnessy]

Made a little bit of progress. Made the mounts for the strut out of a straight edge, they are about 3" stand offs. I ended up about an 1/8th inch longer then the stinger that was on there before.

I drew a line where I plan to cut down the stringers.

Made a plate for the esc to hang on, just two bolts to remove it and gain access to the collet. Doubles as a grease sheild.

Stuck some batteries in there to see where cg was at. 9 and 3/4 is where it was at with it layed out in the pic.
9.6 is 30% so I think I should be good on layout

[srislash]

That all looks like it is coming together nicely. I think 9 3/4" is where mine is happy. A little more for pushing speed.

[TheShaughnessy]

A little more progress. I got the stringers cut down. Mount is bolted to stringers.

I'm making a tray out of the carbon fiber tape and divinycell, never tried this before so well see how it works. Light and strong is the goal.

Now that I'm using a strut I can move the trim tabs closer to the bottom of the vee. Should I move them in or leave them where they were a little further out?

[TheShaughnessy]

The battery tray seems really strong already and it still has to finish curing. It's nice and light. Looks like crap though. Clamping force was focused on one side and it shows. Didn't clean the granite well so there is a divet on one side. At least it will be hidden with batteries. Still have to cut down the tray and get it mounted.

Getting closer.

[TheShaughnessy]

I Cut down the tray, might need to make this removable to take advantage of the sliding motor mount. I should have done one that lifted straight up, but , I do like how the esc mounted to it.

Not sure if I'll use this piece. I am making another piece of just carbon cloth. 5 pieces total. Top bottom and middle are the tape and then two pieces of 1k on a 45. Well see how that one comes out. Clamped it with a vice this time. Hopefully I got the pressure more even.

Would like to just glue in the battery tray so well see if this lower profile piece will allow for that.

[srislash]

If those tabs seemed to be affective I would leave them where they were. There is a real process of prep to making your own CF. I am still having issues here and there.

[kfxguy]

Love the motor mount idea! Next time on your Glass or mirror, use mold release spray or mold release wax. I came across a heckuva deal on a case of stoner name brand mold release spray a little while back. Works well.

[CornelP]

For smaller formats of CF plate, the easiest way to get a perfect surface is to use a material that epoxy does not stick to. I use for most of the CF parts the transparent covers used for spiral binding, they are quite thick, cheap and come in large formats also. As a backing support you can still use glass, but MDF and marble/stone are quite ok also.

[TheShaughnessy]

I was talking to the guy that gave me all this cf and he suggested I stack weight instead of clamping, he said it's point pressure and stacking weight would give more even pressure. He told me bagging applies about 7 psi of pressure so just measure the surface area and do the math, then stack that much weight. The piece I did with 5 layers looks a bit better but it isn't nearly as strong, I'll check it again to see if it cured up any stiffer.

I was using release film but I haven't been taking care of it so it has wrinkles on it. The binder plastic is a good idea. Marble or glass is easier for me to come by then mdf believe it or not.

Stoner spray release? Might get that on principle

[srislash]

I was talking to the guy that gave me all this cf and he suggested I stack weight instead of clamping, he said it's point pressure and stacking weight would give more even pressure. He told me bagging applies about 7 psi of pressure so just measure the surface area and do the math, then stack that much weight. The piece I did with 5 layers looks a bit better but it isn't nearly as strong, I'll check it again to see if it cured up any stiffer.

I was using release film but I haven't been taking care of it so it has wrinkles on it. The binder plastic is a good idea. Marble or glass is easier for me to come by then mdf believe it or not.

Stoner spray release? Might get that on principle

Yes, I actually stack buckets of water set on 2X4's on the glass. It seems to give an even thickness. BTW, I have not tried this yet but was told by a FG guy, That Car Wax makes a good release agent.

[TheShaughnessy]

Release film is so easy and no polishing, just have to flatten out the wrinkles.

I've heard mother's pure carnuba wax works well but I don't
Like the idea of hand polishing.

[TheShaughnessy]

We got a cooking scale for x Mas so since some people were curious about weight I got to weighing things

Boat with out hatch. Standoffs attached. 2 lb 0.3 Oz with hatch it was 2 lb 5.7 oz

Rails motor and mount esc and mount, servo all together came to 2 lb 8.9oz

Without rudder, trim tabs, prop. Flex , strut or battery's the total weight is currently 5lb .6 oz.

The two trays ... just cloth is 21 g and 233mm long
the two sandwiched pieces are 39g and 266 mm long

Did a Lil math. The just cloth layup came out to 1108 cm3 per gram of weight. 3,768 cm3 per gram of weight.

My conclusion is that the divinycell piece is significantly stronger and also has a better volume to weight ratio.

The other piece I did ca me out looking better, it just has quite a bit of flex to it.

[TheShaughnessy]

Been a while since I've been able to play with the boats. Not much of an update but I finally glued in the rails. I've been hung up on finding m3 SS screws with a 2.5 Allen head. I've settled on some stuff but its still going g to need to be swapped out at some point.
Cruising out to parker for the boat drags and would like to take it with me so trying to wrap it up quickly now. Paint will come after it runs and I'm satisfied nothing needs to be changed