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RE: Jett SS .40 426 motor
We have to run the carb for our rules. I was wondering if anyone is having adverse (air leak) issues with no o-ring or gasket material under the carb? I noticed there wasn't one under the venturi either - just relying on the fit?
Posted on: 5/13/2011 12:06 PM by Author "ptxman"
in the forum "Q-500 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=10517878
RE: Painting and Polishing, this will be of use to the racer guys too :)
Hmm.. I actually have an offshore sander that looks exactly like that, but its definately random orbit action. Looking at the pdf manual parts breakdown of that one you're showing, it kinda looks straight connection to mtor shaft = circular?
Posted on: 9/13/2010 4:54 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9999598
RE: Painting and Polishing, this will be of use to the racer guys too :)
[quote]ORIGINAL: LGM Graphix ...little Kangke racer I painted and polished years ago with the same Makita :) [/quote] That's kameleon or color shift or whatever you call it right? Freakin awesome. I hate to ask how much that stuff costs from what Ive seen of paint supply catalogs, but it probably comes at 'multiples of the underlying model' [:D] So... probably about to answer my own dumb question here... if round-and-round is good, and small & light is good, and inexpensive is REALLY good... I'm guessing something like these right-angle type die grinders wont work because they are too high of rpm & you can't just pinch back pressure on the reg to get it in the equivalent SFPM range like the big 6-7 inchers @ 600-3000 rpm? http://www.toolfetch.com/Category/Air_Tools/Air_Die_Grinders/CP862.htm Somebody told me there was a medium duty (lighter weight), electric, random motion sander/polisher that you could 'lock' or alter the cam or? ... anyway so it would no longer be random, it would be circular motion. Cant find it, maybe it was wishful thinking. /pt
Posted on: 9/13/2010 3:20 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9999380
RE: Painting and Polishing, this will be of use to the racer guys too :)
Awesome reply, thanks. Im going to have to read this a few times to digest it all but Im all pumped now with a new & informed plan of attack. Re the Makita, is it a round-and-round or random orbit style?Im getting the impression that random motion is preferrable for the 'sanding' part of the operation, but not necessarily so for polishing? http://www.autogeek.net/ma927po.html I guess a guy also has to factor that at optimal X rpm on a 7" dia equates to a different (must be higher?) rpm when using a 3 or 4"? I started out with that size because of the smallish surfaces but maybe a contributing factor to not seeing breakdown very fast. So 3M white waffle was used on extra cut/rubbing compound & 3M grey waffle on swirl remover? In the 3M world, do the colors correlate to foam density for these specific tasks, or doesnt really work that way & a waffle color might be different than a flat pad etc. ? Do you have a link to the turbine event?
Posted on: 9/12/2010 2:19 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9996816
RE: Painting and Polishing, this will be of use to the racer guys too :)
Hey Jeremy! You couldnt resist hanging around the piston bangers for old times sake when it comes to paint! Good timing. Thanks for posting. Can you type re-iterate your polishing products + what kind of pad + model of Makita please. I couldnt quite make out the compounds in your videos but it sounded similar to what DE on the other thread used?: - 3M Perfect in III Extra Cut Rubbing Compund 05936 - 3M Perfect in III Machine Glaze 05937 So for whatever reason, Ive been using Farecla G3 from a long time ago. I used it on my plugs & also on my molds. At the time I was more concerned that it was water based vs solvent & not wanting to introduce any kind of residue or waxes into the molds from other finishing compounds for fear of release agent incompatibility issues. But now that I think back on it, Ive never had what I'd call a mirror finish. A good shiny finish yes, a mirror no. Likely you've probably heard of Farecla being a Canuck? Am I trying to make '80 grit' do a '600 grit job' with that stuff? Or is it more operator error or the wrong polishing equipment? I see the videos posted on Farecla's site & THEY make it look nice & shiny.... But Im happy to turf it & by the big jugs of 3M if Im barking up the wrong tree. (Peter T)
Posted on: 9/11/2010 11:55 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9995834
RE: LETS TRY TO POLISH SOMETHING!
[quote] I use a hairy type wool pad for the compound and foam for glaze. [/quote] Dumb question but why is that? I would visualize the foam as more of a 'flattening operation' kind of like what a backing rubber is to sandpaper abrasive. And the fluffy looking wool more for final shine, kind of like waxing you car with a soft towel. (Its probably obvious by now why my results suck! [:D]) So Im clear, is that dynabride you use purely circular motion? or random motion like my sander?
Posted on: 9/11/2010 11:24 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9995789
RE: LETS TRY TO POLISH SOMETHING!
[quote]ORIGINAL: Kevin Matney Hi PTXMAN What plane is that I like it? [/quote] Sweet Vee
Posted on: 9/11/2010 11:46 AM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9994703
RE: LETS TRY TO POLISH SOMETHING!
What do you think of this one for an electric jobber? http://www.autogeek.net/porter-cable-7424xp.html Im using a 2K clear too, this one was 5-Star, reletively inexpensive. But that stuff has since gone the way of non-compliant VOC here (Alberta, Canada) so I'm about to try some RM shortly which is the new stuff. Actually the clear itself seemed to come out ok (fuse untouched). Its when I started the sanding & polishing (the wing) that it took on the wonderful matt finish. But Ive also come to realize I was pretty skinny on clearing the wing worried about weight buildup. Turns out wasnt much of anything. On my next one I gained some experience, used a light source & hose-piped it on a bit heavier (knowing I would polish). A bit better but still not like yours. Someone suggested 5-star was kind of a softer material clear but Im thinking the issue is this smaller dia polisher & rpm like you say. And maybe the Farecla (water based polishing compound). Im kind of motivated to try your recipie now. Couldnt be the operator or technique ... no way...[;)]
Posted on: 9/11/2010 12:33 AM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9994087
RE: LETS TRY TO POLISH SOMETHING!
Awesome article DE. The pictures really do the talking, nice shine! Jeez, now I dont feel so bad about my clear coat, maybe there hope after all to achieve a final finish like that. Your polishing results are waaay better than mine. Couple questions: - what specific kind of clear is that on the model? - shot in X applications of wet coats? or seperate with intersanding, or? - can you elaborate on the buffing pads themselves. Right now Im using 3" foam pads intended for polishing (car detailing they say), velcro backed, came with the polisher. But there seem to be a multitude of pads, color coded based on density or hardness I guess? I cant really see much difference which makes me suspicious of either my clear or teh compound. But what I dont have is the fluffy looking one like you show. What goes with what? - I had a pneumatic buffer (well actually it was a choked back right angle mini random sander pushed into service as a polisher) but when I started looking at the CFM spcs of palm polishers like yours, I figured my compressor might be running full time to keep up. What compressor do you have on the business end supplying air on yours? I ended up buying one of these (as they will ship to Canada). http://www.autogeek.net/griots-orbital-polisher.html Im sure its a knockoff of something but because its electric vs pneumatic & light compared to others out there, seemed like a logical choice for the money. Ive only done 1 racer with it, but Im using Farecla G3 & foam pads... After sanding (1200 I confess) the finish is dimensionally nice & flat & 'semi-shiny', but just not that high luster. Now Im having 'gloss envy'. Spill your guts. And dont tell me 'wax-on', 'wax-off' [:D]
Posted on: 9/10/2010 9:06 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9993643
RE: Pondering Props ???
[quote]ORIGINAL: It costs me $225 for a 2100W setup to turn a 9X8 prop @ 21K. 5 minute flight, Pretty Close to your example, consider 2100W/748=2.48HP weight of this powerplant is 34oz or 975grams total, could be reduced to 21oz or 600g for a 2 minute flight.... compared to say a 2+HP .40+ @ 16oz + fuel for 5 minutes??[/quote] Looks like you have it all figured out. Id be curious to hear what hardware setup that corresponds to. I see you posted the same question on RCG/Ezone. Why dont you do a search in their High Performance section under Q40, F3D, Q500... etc & check out some of the E-retrofit setups that people have been experimenting with in the various classes. Ive inserted a couple links below to help. I would say loading is very important - if the wing folds on a typical 30G turn or stalls & snaps trying to support much more additional weight due to the drive setup over & above the airframe weight, thats a bad thing. My gas equivalent comment is not to deter you from electrifying a pylon model, Im just saying its not quite as slam dunk to acheive the combined goal of IC engine speeds AND maintain the existing weight AND for $225. F3D http://christian-hanke.blogspot.com/search?updated-min=2009-01-01T00%3A00%3A00-08%3A00&updated-max=2010-01-01T00%3A00%3A00-08%3A00&max-results=10 Q40 http://www.rcgroups.com/forums/showthread.php?t=1233828&highlight=q40 http://www.rcgroups.com/forums/showthread.php?t=1111569&highlight=q40&page=2 Q500 http://www.rcgroups.com/forums/showthread.php?t=1062338&highlight=q40
Posted on: 9/2/2010 11:34 AM by Author "ptxman"
in the forum "Q-500 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9976064
RE: Pondering Props ???
As mentioned the airframe configuration plays a huge roll. But if you want to muck around with permutations of different motors, packs, prop sizes, calculators like these are pretty handy. They are propbably more orientated towards more slippery F5 type models, so the speeds & duration may not quite be accurate to bigger more scale-like racing models. But gives you kind of a relative frame of reference. http://www.castlecreations.com/support/flight_calculator.html Its always interesting to plug in a typical Q500 or Q40 or F3D prop & rpm values, then back-calculate what kind of motor/pack is required to be equivalent. It usually ends up being a pretty heavy (and big$$) lipo brick by comparison. From a power density perspective, a couple ounces of methanol still packs a punch, despite the slime & noise!
Posted on: 9/2/2010 12:13 AM by Author "ptxman"
in the forum "Q-500 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9975387
RE: Sempra Jett Q500
[quote]ORIGINAL: iamtom The hope is to fly this event at the NATS 2011. [/quote] Tom, I tried to find the 426 proposal on your ama link but must be looking in the wrong spot. You mean a new class called 426 is being proposed & its essentially the Sempra specs engine & course wise? And this would be a seperate event at Nats-2011? Or its intended to replace 428 by 2011? /pt
Posted on: 9/1/2010 7:54 PM by Author "ptxman"
in the forum "Q-500 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9974835
RE: Sempra Jett Q500
And does 'short course' mean the 2.0 mile/10 lap... what AMA regs call Q500-sport?
Posted on: 8/31/2010 4:18 PM by Author "ptxman"
in the forum "Q-500 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9972203
Sempra Jett Q500
Hi guys. Im a Canuck so pardon the question. The topic of a newish Sempra Q500 class running a fixed engine Jett on a short course came up in discussion. Is there a link to the published rules anywhere? Specifically Id like to see how the engine setup is defined (sport jett model X, muffler with/without internal pipe, prop type... yada-yada). And the course layout distance, aiframe limitations.. anything else of interest. We've been running a similar Q500 fixed engine class for quite a while in the western provinces (Nelson SS on pipe-removed muffler) & were trying to gauge the times & correlate engines. Thx/Peter
Posted on: 8/31/2010 2:58 PM by Author "ptxman"
in the forum "Q-500 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9972038
RE: Lets try to paint a Q40
Hi Dave. Sorry to see the crash heap. Those were nice looking birds. Been there done that too. Re your painting process... >lightly sanded the white with some 600 grit wet and then painted the orange base coat. I use Base coat / Clear coat for all of the colors as you can tape off your next color 10 minutes after you finish spraying a color. This makes the whole project go pretty fast. What base coat system were your colors? Im guessing it was different mnfctr than the white? Is that a solvent based, ambient cure, or is there a catalyst/hardener component that they are ready to tape in 10 minutes? >First pic is of the clear I use, It is a cheap urethane that is water thin and dries very fast.... Then here it is all cleared, next is to polish it a little Can you elaborate on the clear process. Same harbour freight el cheapo mini hvlp gun? Was it a couple wet coats & thats it, or staged coats with inter-sanding? Then what is your polishing wizardry, light sand with XX grit + the foam pad & compound treatment like car guys do? Have you found any toughness issues with the clear like on the wing saddle rubbing or removing the race stickers with lighter fluid etc? (Im using something similar I think, 5-star extreme. The jury is still out, its very thin, I like that, but seems to need progressive coat buildup to get any kin dof shine. Doesnt seem as bulltproof as the good old high iso paint I used to use, but maybe thats just my learning curve) /pt
Posted on: 6/23/2010 1:25 AM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9821173
RE: Sweet V, landing block repair
Looking at your pic again... do you drop the pre-linked assembly in like shown in the pic & screw the pushrods into the quicklink threads? Reason I ask is, Ive had those metal-to-metal threads wear out & develp slop on me without some sort of retaining goop. I went with the hard plastic links with steel pin (forgot the brand name, black ones). But they of course need to be pre-installed on the pushrod end & then 'hooked up' to the nylon tabby's through the porthole. Kind of a pain, but doable. /pt
Posted on: 6/22/2010 10:41 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9820851
RE: Sweet V, landing block repair
[quote] BTW I use the nylon tabs and Sullivan gold links on the V tail, I do not trust ball links anywhere but helicopters and throttle linkage. [/quote] You're smart, I learned my lesson the $$ way.
Posted on: 6/22/2010 10:36 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9820838
RE: Sweet V, landing block repair
Here you go. Yes, looks like I put 1/8" hard ply doubler on the insides. I was wondering why I didn't add even more like 1/4", but I because then the tank wouldnt fit in the notch. Looks like there is a center (balsa) riblet & an outboard one & CF inner skin like I figured.
Posted on: 6/22/2010 10:27 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9820804
RE: Sweet V, landing block repair
[quote]ORIGINAL: wkevinm I assume someone has destroyed a Sweet V and knows how it is made at this area of the center section. thanks, wkevinm [/quote] Kevin? I still have the wing (shrapnel) of my Regina model that got drilled half way back to its country of origin. I can cut it open & show you the guts. I think its basic bagged shell construction with CF cloth in the center & maybe a supporting rib?. The pic should reveal. I recall adding 1/8 or 1/4 some ply doublers to the inside of the landing gear block to give it more contact area to the wing. I managed to bend my gear real bad on a gopher hole but the block held. Im not sure about pinning, if you lock it in any better it might take the whole bottom of the wing out. ps - cause of crash: the steel ball fiting unwound itself off the threaded v-tail post. I did my usual almost-never-fail treatment, clean with acetone, lots of permanennt red loktite & cinch it down. Its never let me down in the past but Im thinking maybe this stuff is past its expiry. Ive heard guys use JB weld. On my #2 Im going to the nylon tabs & quicklinks so nothing can unscrew or unpop. Because the other thing that can happen is the nylon ball part can dislodge with similar $$ result. Peter T
Posted on: 6/22/2010 9:43 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9820706
RE: wing saddle potting
[quote] I use silicone glue not sealent and wax paper.There is a difference. [/quote] Do you have a brand name for that glue? Im assuming is still viscous like caulking/spooge? You mean you use wax paper as the barrier layer on the wing & it releases properly from the glue?
Posted on: 6/19/2010 7:33 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9814138
wing saddle potting
Anyone have a good method for potting in Q40 wings with a 'somewhat flexible' material like silicone or urethane or.... Im familair with the usual 'hard' technique using epoxy based splooge. But I would prefer just like a bit of 'give' & vibration dampening. Its not a big gap, its pretty close, so the potting thickness would be quite thin in areas. Ive heard there are brands of caulking that work like outdoor paintable sealant, but I must be buying the wrong stuff. I cant get it to release clean using my usual technique of shiny packaging tape on the wing + mold release wax. I have some kickbutt mold release but silicone doesnt seem to like to cure on it. /pt
Posted on: 6/19/2010 7:09 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9814105
RE: Lets Try To Mold A Moldie!
Hi Dave, nice work! I missed the description of what paint system you were using. Can you elaborate? /pt
Posted on: 6/19/2010 6:55 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9814086
RE: Nelson Q-500
pm'd you
Posted on: 5/21/2010 2:40 PM by Author "ptxman"
in the forum "Q-500 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9749672
RE: Panzerfaust
[quote]ORIGINAL: Bootalini ... The Panzerfaust is a large 60 size pattern ship, circa mid-nineties. My good friend David Birk designed, flew, and kitted this airplane.... Jeff [/quote] Za 'Faust'! Now THERE's a blast from the past. The pic looks like the one Dave flew when you guys stayed at my place... one of those Western Canadian Pattern Champs circa 199X.... (exact year becoming fuzzy, but likely more due to exessive beer & tomfoolery than old age). Ya gotta build that one Boots, its a classic! -Peter
Posted on: 5/9/2010 12:18 PM by Author "ptxman"
in the forum "Classic RC Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9721381
RE: applying gel cote to mold
[quote] Spray it through a gel Coat Dump gun.... [/quote] Do you have firsthand experience with these? Ive often wondered.. - do these dedicated guns do anything better in terms of removing entrained air in the gel brought about by mixing (which become porosity or pinholes in the gel-coat)? In other words, the viscous gel mixture is exiting a small orfice, dropping pressure prior to getting sprayed (or 'squirted'). I was wondering if this helped break out air vs vacuum/de-aeration pots & brush-on technique. - do these guns operate on an HVLP principle & you need a compressor of sufficient CFM? - any mnfctr links?
Posted on: 12/21/2009 2:39 PM by Author "ptxman"
in the forum "Composites Fabrication And Repair"
http://www.rcuniverse.com/forum/fb.asp?m=9348885
RE: Nemesis NXT
Interesting, I made a simple outline of the original NXT (blue) and a similar outline of the Trace version being constructed (red). I then normalized lengths from the firewall split line & overlayed to compare. It seems to support what I thought my eyes were telling me - the Trace vertical fin looks taller, different hinge line & P51-ish dorsal extension on the front? Im sure my outlining method isnt super accurate because of the photo angle etc. Or... maybe they are pumping out distorted jpegs to keep the modelers off balance [;)]. Cool plane though, would make a nice model.
Posted on: 12/9/2009 1:57 AM by Author "ptxman"
in the forum "Scale Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9315734
RE: plug finish?
Re plug color, Generally darker colors will better hilite reflection from indirect light & contrast more so you will be able to see any underlying waviness (the polished potatoe syndrome) as well as gloss. Dont make it black if you are for example using black tooling gel on the female mold. A different underlying plug color can help show if tooling gel might be thin like on sharper corners or the apex of a plug. Generally dark female molds are better for hand layups, but if you are pre-painting or vac bagging, its not that big a deal. Im not a paint expert but I think clears are formulated for buffing & polishing whereas pigmented paints (containing solids) maybe not as much. Just look at any show car, its always the clear you are looking at. I think clears are also less permeable so should act as a better seal for release agents. Having said that, Ive always used 2k catalysed car paints & they buff out real nice. Of course, wax mold release enhances this some more but take the paint finish as far as you possibly can, it helps with every step thereafter. /pt
Posted on: 12/8/2009 3:17 PM by Author "ptxman"
in the forum "Composites Fabrication And Repair"
http://www.rcuniverse.com/forum/fb.asp?m=9314182
RE: Q-fuel line source
Nasty boy DK! Canucks only use sphincter-pinching to make complex illustrations or long text messages or in the snow. That’s why we drink ‘your’ beer in summer & save ‘our’ beer for winter - the higher alc% keeps the S-pipe free & clear of ice plugs! Actually, I got the pinch / fuel cut-off part down pat even on the thick tubing. I drill the shutoff wire ‘U’ right adjacent to the motormount firewall ring so it shuts off flow with less servo grunting vs an outright squeeze against the firewall. But last summer I noticed the engine going lean in the air even if it was slobbering on the ground, which it never did before. I finally traced it to spongey, thin wall sport stuff when I changed the lines. Ill check out your medium grade rec, thx. Another question since you are still an Electron Sicko. On my Q40s I followed the local tradition of installing rubber grommets in the glass fuse so it doesn’t eventually cut trough the fuel lines with vibration. But ¼� od lines require big bejesus donut size grommets & 3/8� holes in the fuse. Have you ever seen/used braided sheathing material like for protecting cables? http://www.techflex.com/prod_PTN.asp http://cableorganizer.com/wire-management/
Posted on: 11/18/2009 5:06 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9263462
Q-fuel line source
Does anyone know what the manufacturer trade name is for the 'rigid' silicone fuel tubing we prefer that doesnt kink & squeeze off as much as the regular sport grade stuff? I want to order a spool. Seems to me it used to be Prather, but they are long gone. The closest equivalent I can find at the hobby shop is Dubro medium 'super blue?' or something to that effect. And even it seems a tad less rigid / wall thickness vs the pink stuff like on Jett tanks.
Posted on: 11/18/2009 2:59 PM by Author "ptxman"
in the forum "Q-40 Racing"
http://www.rcuniverse.com/forum/fb.asp?m=9263137
RE: foaming agent
[quote]ORIGINAL: jirvin Have you got cross sections of models that use propellant as a joining method? photos? I have dissected a few high end molded gliders and can see no evidence of propellant being used commercially. [/quote] I strongly suspect an 'expanding additive' is used on commercial composite racing models, specifically ones Ive purchased from Bruce. I dont have a pic handy, but one can clearly see an expanded bead (as opposed to pre-mix thicknened spooge) on both TE, LE of (glass/balsa/glass sandwich type) flying surfaces. http://www.bigbruceracing.com/prod01.htm
Posted on: 11/11/2009 3:29 PM by Author "ptxman"
in the forum "Composites Fabrication And Repair"
http://www.rcuniverse.com/forum/fb.asp?m=9246456
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