Unusual Opportunity to Evaluate
If you follow RCVR on YouTube you know I’ve been working closely with Bitgo Hobby on numerous product reviews over the last 60 days. Bitgo contacted me before the holidays about conducting reviews on Dynam equipment and as I already had significant experience with Dynam planes, I was happy to get on board looking at other offerings.
A Look Back
Before we consider what’s new, let’s review a few rather well known opportunities with Dynam aircraft up to this point:
- ESCs – Probably one of the single biggest flaws with older Dynam planes were those Detrum ESCs. They stuttered terribly. This wasn’t a one off issue (Google it) either. I experienced this on multiple planes. My fix was always the same: Replace the ESC with a different brand.
- Power – Dynam planes all get off the ground and fly; however, they tend to be a little soft in the power department. So the flight experience can be lackluster. In most of my earlier Dynam planes I either used higher voltage batteries, bigger props, more prop blades, or in the case of the Corsair and Hellcat I upgraded the motor from the stock 3720-500kv to a 3720-650kv.
- Landing Gear – The two main issues related landing gear are reliability of retracts, and landing gear geometry. Dynam retracts can be finicky at times. Sometimes cold weather is blamed, other times, design and manufacturing. Landing gear geometry on certain Dynam warbirds creates some significant ground handing demands. On a personal note, I had a Dynam P-51 that I landed successfully one time without nosing over on roll-out. I fought quite a bit with the Dynam Spitfire but finally won with several shims under the aft edge of the retract raking the gear forward.
- Hinges – Since Dynam air frames are EPO, the control surface hinges are EPO. Unfortunately, the molding process leaves only a few millimeters of material for the hinge. That material is easily separated leaving the control surface flapping in the wind. This really isn’t a Dynam issue per se. It is the result of using EPO for build material. In other words, every EPO plane that uses EPO hinges has the same potential problem.
- Lights – I never understood the thinking on lights with Dynam. They went through significant effort molding the plane to support lights and embedding the lights and wires; but, the lights were always too dim to be effective for anything other than eye candy on the bench. In fact, the lights were so dim, after my first Dynam warbird I never bothered connecting them on subsequent planes.
- ESCs – Gone are those awful yellow shrink-wrapped Detrum ESCs. In are the new Skylord ESCs. I have a feeling if I peeled back the shrink-wrap on a Skylord ESC and Skywalker ESC I would find the same product wearing different labels. I have nothing to base that on other than instinct, but I’ve flown so many Skywalker ESCs I just know them. Whether or not they are the same doesn’t matter though. The new Skylord ESCs do not share the stuttering issue with their predecessor. Amen!
- Power – Unfortunately, not much has changed here. I recently built and maidened the Dynam Grand Cruiser and C-47 Skytrain. Both planes weigh the same 1200g and both use the same 2815 1100kv brushless motors. This power to weight combination yields an unimpressive 125w/lb on both planes and honestly–they aren’t a lot of fun to fly that way. The good news is both planes can handle 4s with the stock ESCs and testing reveals plenty of headroom on the motors to handle 4s power. It may take a little tweaking for CG, and a little surgery with a hobby knife to make room in the foam for the bigger battery, but these are minor adjustments and well worth the effort. The Grand Cruiser on 4s flies very well.
- Landing Gear – In this recent run of evaluations I haven’t had the opportunity to put the landing gear to the test yet; however, I still have the F4U Corsair and P-47 Thunderbolt. Over the past 3 years I’ve replaced the gear on the Corsair one time. The P-47 gear is original. The reason for the change on the Corsair had nothing to do with the retracts. It had everything to do with the Pilot landing a bit too hard a few too many times. Cannot fault Dynam for that. Bottom line here: I have no reason to fault the landing gear for reliability yet. I have no opinion on geometry because while Dynam has put a number of v2 airframes out, I have not had the opportunity to evaluate them yet.
- Hinges – Personal experience speaking here: Fly the plane, watch the hinges. When the hinges start to separate, cut them off clean and replace with a CA hinge. I see no reason to complain about this. It is the nature of EPO. In reality, every build material has strengths and weaknesses. This one is a weakness of EPO. Let’s leave it at that and move on.
- Lights – Seem to be…likely improved? I’m not sure. What I am sure about is the lights on the Focke Wulf FW-190 are far more visible than the lights on the older Corsair. And I commented while flying the Waco that the landing lights were visible from quite a distance. On the FW-190, the belly light was very visible while flying. That said, there is room yet for further improvement. The wingtip lights on the Waco, Grand Cruiser and FW-190 could be brighter still.
It seems Dynam is paying attention to the boards and they’re taking steps in the right direction. They cured the single biggest problem by switching to Skylord ESCs. Those old Detrum ESCs really were terrible. My instincts say they’ve made improvements to the lights but I can’t say for certain. What I do know for certain is the FW-190 and Waco lights are better than any lights on prior models.
EPO hinges are what they are. The only real improvement I could see here is if Dynam did away with EPO hinges all together and switched to mechanical hinges. I have no idea what that would do to the cost/price structure of their products but it would definitely be a worthwhile change.
Landing Gear – Until I get my hands on some of the newer v2 airframes I can’t really make an informed comment regarding improvements. I can say that my Corsair and P-47 have held up well. The Mustang and Spitfire retracts worked, but those two planes loved to tip over. I hope to get some v2 planes to test and will revise this information when that happens.
I think the next single biggest area for improvement is in the motor. Dynam doesn’t need to do much here, but if they were to target about 150-175 watts per lb for planes like the Grand Cruiser and the C47 they’d have a much more desirable product.
I am fortunate enough to have owned and flown many Dynam airplanes over a span of about four years: Mustang, Spitfire, Hellcat, Corsair, Thunderbolt, FW-190, Waco, Grand Cruiser, C-47, and T-28. So I have an arguably unique perspective and wide basis for evaluation. I’m delighted that Dynam has taken some steps in the right direction and look forward to continued improvements to their product line.